If you wish to purchase Volume 2 of the Location & Design Manual, Drainage Design, contact the Office of Contracts at (614) 466-3778. To ensure proper receipt of future revisions to the manual, please visit the online Design Reference Resource at: http://www.dot.state.oh.us/drrc/. This manual is produced by the Hydraulic Section, Office of Structural Engineering. Technical questions should be directed to one of the following: Bill Krouse, P.E. Hydraulics Section Head ([email protected]) (614) 466-2398 Doug Gruver, P.E. Hydraulic Review Engineer ([email protected]) (614) 728-4585 Jeff Syar, P.E. Roadway Hydraulics Enginer ([email protected]) (614) 752-6401 Recommended changes or suggestions should be sent to: Ohio Department of Transportation Office of Structural Engineering Attn: Bill Krouse, P.E. Hydraulic Section Head 1980 West Broad Street Columbus, Ohio 43223
Transcript
If you wish to purchase Volume 2 of the Location & Design Manual, Drainage Design, contact the Office of Contracts at (614) 466-3778. To ensure proper receipt of future revisions to the manual, please visit the online Design Reference Resource at: http://www.dot.state.oh.us/drrc/. This manual is produced by the Hydraulic Section, Office of Structural Engineering. Technical questions should be directed to one of the following: Bill Krouse, P.E. Hydraulics Section Head ([email protected]) (614) 466-2398 Doug Gruver, P.E. Hydraulic Review Engineer ([email protected]) (614) 728-4585 Jeff Syar, P.E. Roadway Hydraulics Enginer ([email protected]) (614) 752-6401 Recommended changes or suggestions should be sent to: Ohio Department of Transportation Office of Structural Engineering Attn: Bill Krouse, P.E. Hydraulic Section Head 1980 West Broad Street Columbus, Ohio 43223
Table of Contents (Revised April 2004)
Preface ........................................................................................................................................................... i Ohio Counties ...............................................................................................................................................iii Concordance................................................................................................................................................ iv Glossary of Terms......................................................................................................................................... v Design Reference Documents ..................................................................................................................... ix Drainage Design Policies 1000 1001 Hydraulic Design Policy ...............................................................................................................10-1
1003 Hydrology ......................................................................................................................................10-4 1003.1 Estimation of Magnitude and Frequency of Floods on Ohio Streams ............................10-4
1004 Flood Clearance ............................................................................................................................10-4 1004.1 General ...........................................................................................................................10-4 1004.2 Design Year Frequency ..................................................................................................10-5 1004.3 Plan Designation .............................................................................................................10-5
1005 Highway Encroachments on Flood Plains .................................................................................10-5 1005.1 General ...........................................................................................................................10-5 1005.2 Type of Studies ...............................................................................................................10-5
1101.1 General ...........................................................................................................................11-1 1101.2 Procedures......................................................................................................................11-1
1102 Open Water Carriers .....................................................................................................................11-3 1102.1 General ...........................................................................................................................11-3 1102.2 Types of Carriers.............................................................................................................11-3 1102.3 Ditch Design Criteria - Design Traffic Exceeding 2000 ADT ..........................................11-5 1102.4 Ditch Design Criteria - Design Traffic of 2000 ADT or Less ...........................................11-7 1102.5 Design Aids for Ditch Flow Analysis ...............................................................................11-8
1103 Pavement Drainage.......................................................................................................................11-8 1103.1 General ...........................................................................................................................11-8 1103.2 Design Frequency...........................................................................................................11-8 1103.3 Estimating Design Discharge..........................................................................................11-9 1103.4 Capacity of Pavement Gutters ........................................................................................11-9 1103.5 Pavement Flow Charts....................................................................................................11-9 1103.6 Bypass Charts for Continuous Pavement Grades ........................................................11-10 1103.7 Grate Catch Basins and Curb Opening Inlets In Pavement Sags ................................11-10
1109 Longitudinal Sewer Location.....................................................................................................11-20 1109.1 Under Pavement ...........................................................................................................11-20 1109.2 Under Paved Shoulder..................................................................................................11-21 1109.3 Approval ........................................................................................................................11-21
1110 Reinforced Concrete Radius Pipe and Box Sections..............................................................11-21 1110.1 General .........................................................................................................................11-21
1111 Sanitary Sewers ..........................................................................................................................11-21 1111.1 General .........................................................................................................................11-21 1111.2 Manholes.......................................................................................................................11-21
1112 Notice of Intent (NOI) ..................................................................................................................11-21 1112.1 General .........................................................................................................................11-21 1112.2 Maintenance Project .....................................................................................................11-21
1113 Erosion Control at Bridge Ends ................................................................................................11-22 1113.1 General .........................................................................................................................11-22 1113.2 Corner Cone..................................................................................................................11-22
1114 Storm Water Pollution Prevention Plan (SWPPP) ...................................................................11-22 1114.1 General .........................................................................................................................11-22
1114.2 Objectives .....................................................................................................................11-22 1114.3 General Guidance.........................................................................................................11-22
1115 Post Construction Storm Water Management .........................................................................11-23 1115.1 Threshold limits .............................................................................................................11-23 1115.2 General .........................................................................................................................11-23 1115.3 Water Quality Volume (WQv).......................................................................................11-24 1115.4 Water Quality Flow (WQf) .............................................................................................11-24
1116 Structural Best Management Practices (BMPS) ......................................................................11-24 1116.1 General .........................................................................................................................11-24 1116.2 Vegetated Swales and Filter Strips (WQf) ....................................................................11-25 1116.3 Infiltration (WQv) ...........................................................................................................11-25 1116.4 Extended Detention (WQv) ...........................................................................................11-28 1116.5 Retention Basin (WQv) .................................................................................................11-29 1116.6 Constructed Wetlands (WQv) .......................................................................................11-30 1116.7 Bioretention Cell (WQv) ................................................................................................11-30 1116.8 Manufactured Systems (WQf).......................................................................................11-31 1116.9 Alternative Methods ......................................................................................................11-31
APPENDIX A – Reproducible Forms APPENDIX B – Directive 22 APPENDIX C – Sample Plan Notes APPENDIX D – Drainage Design Aids
Appendix D has been removed from the printed manual. Drainage Aids can be found at http://www.dot.state.oh.us/se/hy/Drainage%20Design%20Aids/drainageaids.htm
Preface
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Purpose This Drainage Design Manual has been prepared as a guide for the hydraulic design of highway drainage facilities. Drainage has long been recognized as one of the essential parts of the highway, and the cost involved in the adequate removal of surface and subsurface water justifies a careful and scientific hydraulic analysis.
The time required to determine by hydraulic principles such basic information as size and shape of a conduit, the need for temporary and/or permanent open channel protection, and the proper spacing of catch basins or pavement inlets constitutes a relatively small percentage of the total time required to prepare a set of highway plans. The fact that drainage facilities for most highway projects will account for approximately 25% of the total cost of the project is further justification for a detailed hydraulic analysis.
Application Adhering to recommended design procedures and controls noted in this manual should result in drainage facilities that will preclude the following:
A. Damage of private property due to flooding.
B. Undue inconvenience to the motorist during moderate to heavy rainfall.
C. Undue disturbance to the environment.
Numerous charts have been prepared and are included in the Drainage Design Aids Section of this manual to assist the Drainage Design Engineer with the hydraulic analysis. Other design charts are available in Hydraulic Engineering Circulars and Hydraulic Design Series prepared by the Federal Highway Administration. Reference is made to those charts as required.
This manual is neither a textbook nor a substitute for engineering knowledge, experience, or judgment. It is intended to provide uniform procedures for implementing drainage design decisions and assure quality and continuity in drainage of highways in Ohio. Although the manual is considered a primary source of reference by personnel involved in drainage design in Ohio, it must be recognized that the practices suggested may be inappropriate for some projects because of fiscal limitations or other justifiable reasons.
Consideration must also be given to justifiable hydraulic design standards adopted by city, county, or other local governments when designing facilities under their jurisdiction.
Preparation The Drainage Design Manual has been developed by the Hydraulic Section, Office of Structural Engineering. Errors or omissions should be reported to the Office Administrator, Office of Structural Engineering, Ohio Department of Transportation, 1980 W. Broad Street, Columbus, Ohio 43223.
The Drainage Design Manual has been developed for use in either inch-pound units or metric units. Inch-pound units and metric units are not necessarily equivalent. Metric units are shown in brackets; they are applicable to projects developed and designed in metric units.
Format and Revisions Updating the manual is intended to be a continuous process and revisions will be issued periodically.
Although pages are individually numbered within each section, new pages may be added and identified with letter suffixes after the page numbers. For example, two new pages between 10-4 and 10-5 would be numbered 10-4a and 10-4b. Figures do not have page numbers, but are numbered to coincide with the section number in the text. For example, Figure 1102-2 is the second figure listed in Section 1102. Additional figures may be added by either going to the next highest number or using a letter suffix. It should also be noted that figures are located at the end of each main section and are printed on colored paper for easy reference.
Each page has the latest date shown on the lower left hand corner. Revisions will be issued periodically by the Office of Structural Engineering. The loose-leaf format of the manual makes updating a quick and simple task. Users are encouraged to keep their copies up-to-date.
Manuals may be ordered by contacting the Ohio Department of Transportation, Office of Contracts,
1980 W. Broad Street, Columbus, Ohio 43223, (614) 466-3778, 1-800-459-3778.
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Ohio Counties
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County Code District Adams ADA 9 Allen ALL 1 Ashland ASD 3 Ashtabula ATB 4 Athens ATH 10 Auglaize AUG 7 Belmont BEL 11 Brown BRO 9 Butler BUT 8 Carroll CAR 11 Champaign CHP 7 Clark CLA 7 Clermont CLE 8 Clinton CLI 8 Columbiana COL 11 Coshocton COS 5 Crawford CRA 3 Cuyahoga CUY 12 Darke DAR 7 Defiance DEF 1 Delaware DEL 6 Erie ERI 3 Fairfield FAI 5 Fayette FAY 6 Franklin FRA 6 Fulton FUL 2 Gallia GAL 10 Geauga GEA 12 Greene GRE 8 Guernsey GUE 5 Hamilton HAM 8 Hancock HAN 1 Hardin HAR 1 Harrison HAS 11 Henry HEN 2 Highland HIG 9 Hocking HOC 10 Holmes HOL 11 Huron HUR 3 Jackson JAC 9 Jefferson JEF 11 Knox KNO 5 Lake LAK 12 Lawrence LAW 9
County Code District Licking LIC 5 Logan LOG 7 Lorain LOR 3 Lucas LUC 2 Madison MAD 6 Mahoning MAH 4 Marion MAR 6 Medina MED 3 Meigs MEG 10 Mercer MER 7 Miami MIA 7 Monroe MOE 10 Montgomery MOT 7 Morgan MRG 10 Morrow MRW 6 Muskingum MUS 5 Noble NOB 10 Ottawa OTT 2 Paulding PAU 1 Perry PER 5 Pickaway PIC 6 Pike PIK 9 Portage POR 4 Preble PRE 8 Putnam PUT 1 Richland RIC 3 Ross ROS 9 Sandusky SAN 2 Scioto SCI 9 Seneca SEN 2 Shelby SHE 7 Stark STA 4 Summit SUM 4 Trumbull TRU 4 Tuscarawas TUS 11 Union UNI 6 Van Wert VAN 1 Vinton VIN 10 Warren WAR 8 Washington WAS 10 Wayne WAY 3 Williams WIL 2 Wood WOO 2 Wyandot WAY 1
Conduits Flexible 10-1, 11-5, 11-7, 11-11, 11-19, 11-21 Rigid 10-1, 10-2, 10-7, 10-13, 11-11 Type A 10-2 Type B 10-3, 11-11 Type C 10-3, 11-11 Type D 10-3, 11-18 Type E 10-3, 10-4 Type F 10-4, 11-11, 11-20
Corner Bearing Pressure 10-8 Corrugated Metal Pipe
Aggregate Drain - A trench filled with granular material extending laterally from the pavement base or subbase layer to an outlet on the roadway foreslope with the intent of draining surface and/or ground water away from the pavement base and/or subbase.
Anti-seep Collar – Device that prevents the flow of water through the surrounding soil around a conduit that is used as an outlet for an infiltration, retention, or detention basin.
Apron - Paving at a pipe inlet or outlet, or upstream of a catch basin, constructed along the channel bottom to prevent scour.
Backwater Analysis - The determination of water surface profiles measured at specific locations upstream from a constriction causing an increased flow depth upstream.
Bankfull Discharge – The flow or stage of a stream corresponding to the highest level of active deposition. It is the discharge that, on the average, fills a main channel to the point of overflowing. For simplicity, it is generally considered to be approximately the 2 year discharge.
Camber - A slight convex curve constructed into the bottom of a pipe to overcome anticipated settlement problems.
Cast-in-place Structure - A concrete drainage structure which is placed in forms and cured at its final location. Precast beams on cast-in-place foundations are considered cast-in-place structures.
Catch Basin - A structure for intercepting flow from a gutter or ditch and discharging the water through a conduit.
Coefficient of Runoff (C) - A value, varying with the ground and ground cover, which is used in the Rational formula to determine the amount of a rainfall which is directed to streams and not absorbed into the ground.
Conduit - A closed structure such as a pipe.
Corner Bearing Pressure - The pressure generated at the corners of pipe arch structures.
Culvert - A structure which is typically designed hydraulically to take advantage of submergence at the inlet to increase hydraulic capacity. A structure used to convey surface runoff through
embankments. A structure, as distinguished from a bridge, which is usually covered with embankment and is composed of structural material around the entire perimeter, although some are supported on spread footings with the stream bed serving as the bottom of the culvert.
Cutoff Wall - A wall that extends downward from the end of a structure to below the expected scour depth, or to a scour-resistant material.
Design Discharge (Q) - The peak rate of flow for which a drainage facility is designed. Usually given in cubic feet per second(cfs) [cubic meters per second (m;/s)].
Design Service Life - The desired usable life of a pipe or structure. Certain drainage situations require a 50-year life, more stringent situations require a 75-year design life.
Design Storm - A given rainfall amount, areal distribution, and a time distribution, used to estimate runoff. The rainfall amount is either a given frequency (25-year, 50-year, etc.) or a specific large value.
Diversion Dike - An embankment to control or to deflect water away from a soil bank.
Drainage Area - The area contributing discharge to a stream at a given point.
Drop-down Entrance (Drop inlet) - A type of inlet which conveys the water from a higher elevation to a lower elevation smoothly without a free fall at the inlet.
Elliptical Pipe - Pipe which is manufactured with a span greater than rise to be utilized in shallow cover situations.
Ephemeral Stream – A stream or reach of stream that does not flow for parts of the year. As used here, the term includes intermittent streams with flow less than perennial. It is located above the water table year-round. Ground water is not a source of water supply.
Feasible – Term used to define BMP practicability. BMPS shall be: technically feasible, implemented within the procured highway right-of-way, safe for the traveling public and ODOT maintenance personnel, cost effective as compared to the benefit, and will be legal at the State, Federal, and Local levels.
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FEMA – Federal Emergency Management Agency.
Flood Fringe – The portion of the floodplain outside of the floodway.
Flood Hazard Evaluation - The act of determining if flood levels within a watercourse for a 100-year flood, or other recurrence interval floods have a significantly increased detrimental impact on upstream property.
Flood Plain – Lowland and relatively flat areas adjoining inland and coastal waters including, at a minimum, that area subject to a one percent or greater chance of flooding in any given year. This area encompasses the floodway and the floodway fringe.
Flood Plain Culverts – Relief culverts that are placed in addition to a bankfull culvert at a higher elevation across the flood plain to allow multiple outlets for floodwaters.
Forebay – Depressed area that offers pretreatment of sediment laden storm water prior to a retention, detention, or infiltration basin. Flood Plain Study - A more extensive analysis of the effects of flood levels on upstream property than the Flood Hazard Evaluation. This analysis is to be used when upstream properties appear to have been subjected to a significantly increased detrimental effect from the flood flows.
Floodway – The portion of the floodplain which is effective in carrying flow, within which this carrying capacity must be preserved and where the flood hazard is generally highest.
Friction Slope - The slope of the energy grade line.
Granular Material - A term relating to the uniform size of grains or crystals in rock, larger than sand or pea gravel.
Grate - A type of screen made from sets of bars used to allow the interception of flow, and also to cover an area for pedestrian or vehicular traffic.
Headwall - The structural appurtenance placed at the open end of a pipe to control an adjacent highway embankment and protect the pipe end from undercutting.
Headwater - That depth of water impounded upstream of a culvert due to the influence of the culvert constriction, friction, and configuration.
Highest Known Water Elevation – The highest known flood water in record.
Hydraulic Grade Line - A line coinciding with the level of flowing water in an open channel. In a closed conduit operating under pressure, a line representing the distance water would rise in a pitot tube at any point along a pipe. The hydraulic grade line is equal to the pressure head (P/γ) along the pipe.
Hydraulic Gradient - The slope of the hydraulic grade line for a storm sewer or culvert.
Idealized Channel Geometry - Physical, geometric, and hydraulic characteristics of a channel determined from empirical relationships.
Impervious Surface – Hardened pavement surface. Inlet - A structure for capturing concentrated surface flow. May be located along the roadway, in a gutter, in the highway median, or in the field.
Inlet Control - The situation where the culvert hydraulic performance is controlled by the entrance geometry only.
Intermittent Stream – A stream that is dry for part of the year, ordinarily more than 3 months.
Manhole - A structure by which one may access a closed drainage system.
MS4 Phase II Regulated Area – Area that has been designated by the Ohio EPA that requires a storm water management plan to discharge storm water.
Multiple Cell Culvert - A culvert with more than one barrel.
New Development Project – Projects that change the land use of a site from undeveloped to developed characteristics.
Normal Water Elevation – The water elevation in a stream which has not been affected by a recent heavy rain runoff. The water level which could be found in the stream most of the year. This elevation will be lower than the ordinary high water.
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Ordinary High Water – The line on the shore established by the fluctuation of water and indicated by physical characteristics such as: a clear natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, or other appropriate means that consider the characteristics of the surrounding areas. This elevation is lower than the highest known water.
Outlet Control - The situation where the culvert hydraulic performance is determined by the controlling water surface elevation at the outlet, the slope, length and roughness of the culvert barrel, as well as the entrance geometry.
Overland Flow - Water which travels over a surface and reaches a stream.
Perennial Stream – A stream that flows continuously for all or most of the year. The water table is located above the stream bed for most of the year.
pH - The reciprocal of the negative logarithm of the Hydrogen ion concentration. Neutral water has a pH value of 7. A measure of the acidity of a substance, if less than 7; alkalinity if greater than 7.
Pipe Arch - Pipe which is manufactured with a span greater than rise (semicircular crown, small-radius corners, and large radius invert) to be utilized in shallow cover situations.
Pipe Underdrain - A longitudinal subsurface drainage system composed of a perforated pipe at the bottom of a narrow trench filled with permeable material and lined with a geotextile in erodible soils, with the intent of draining surface and/or ground waters away from the pavement base and/or subbase.
Prefabricated Edge Drain - A longitudinal underdrain system utilizing a narrow trench and a vertically elongated, perforated water carrier with the intent of draining surface and/or ground water away from the pavement base and/or subbase.
Prefabricated Structure - Any drainage structure which is manufactured off site and transported to the location of intended use. It may be of various materials, including concrete, clay, metal, thermoplastics, etc. It may be of various shapes including circular, elliptical, rectangular, arched, etc.
Premium Joints - Watertight joints.
Pretreatment – Preliminary filtering of sediment laden storm water prior to secondary treatment through a structural best management practice. Rainfall Intensity (i) - The amount of rainfall occurring in a unit of time, normally given in inches per hour [millimeters per hour].
Reference Reach - A length of channel with stable geometric, physical, and hydraulic characteristics. A representation of the desired outcome of a restored channel.
Rehabilitation Project – Projects that maintain the land use of a site from existing to proposed conditions. Roughness Coefficient (n) - The measure of texture on the surface of channels and conduits. Usually represented by the “n-value” coefficient used in Manning=s open channel flow equation.
Runoff - That part of the precipitation which runs off the surface of a drainage area after all abstractions are accounted for.
Sanitary Sewer - A conduit or pipe system which carries household and/or industrial wastes. Sanitary sewers do not convey storm water.
Sediment Basin - A basin or tank in which stormwater containing settleable solids is retained, to remove by gravity or filtration a part of the suspended matter.
Sediment Dam - A dam that is designed to allow suspended sediment to settle out of flowing water in a controlled area.
Short-circuiting – The act of storm water bypassing the intended route.
Soil Bioengineering – The use of live and dead plant materials, in combination with natural and synthetic support materials, for slope stabilization, erosion reduction, and vegetative establishment.
Spring Line - The locus of the horizontal extremities of a transverse section of a conduit.
Step Backwater or Standard Step Method - An iterative use of the energy equation for determining the water surface profile of an open channel.
Storm Sewer - A conduit or pipe drainage system that conveys storm water, subsurface water,
April 2004 viii
condensate, or similar discharge, but not household or industrial wastes.
Tailwater - The depth of flow in the stream directly downstream of a drainage facility, measured from the invert at the culvert outlet. Often calculated for the discharge flowing in the natural stream without the highway constriction. Term is usually used in culvert design and is the depth measured from the downstream flow line of the culvert to the water surface.
Time of Concentration (t c) - Time required for water to flow from the most distant point on a drainage area to the measurement or collection point.
TMDL (total maximum daily load) Regulated Stream – An Impaired water body as defined by the Ohio EPA that can still meet water quality standards if the daily maximum pollutant load is regulated. Two Stage Channel – A channel that contains a cross sectional area for low and high discharges. Water of The United States - Water bodies subject to Army Corps of Engineers jurisdiction through Section 404 of the Clean Water Act. They include all interstate waters such as lakes, rivers, streams (including intermittent streams) and wetlands. Ephemeral streams are included if they have a clearly defined channel.
Design Reference Documents
April 2004 ix
��Hydraulics of Bridge Waterways (FHWA Hydraulic Design Series No. 1)
��Highway Hydrology (FHWA Hydraulic Design
Series No. 2) ��Design Charts for Open Channel Flow (FHWA
Hydraulic Design Series No. 3) ��Hydraulic Design of Highway Culverts (FHWA
Hydraulic Design Series No. 5) ��River Engineering For Highway Encroachments
(FHWA Hydraulic Series No. 6) ��Design of Stable Channels with Flexible Linings
Caltrans Storm Water Quality Handbooks, Project Planning and Design Guide, September 2002. (http://www.dot.ca.gov/hq/construc/stormwater/manuals.htm) Caltrans Storm Water Quality Handbooks, Municipal Handbook, March 1993. New York State Stormwater Management Design Manual, October 2001. http://www.dec.state.ny.us/website/dow/swmanual/swmanual.html Maryland Storm Water Design Manual, October 2000 (http://www.mde.state.md.us/Programs/WaterPrograms/SedimentandStormwater/stormwater_design/index. asp) FHWA Ultra Urban BMP webpage. (http://www.fhwa.dot.gov/environment/ultraurb/index.htm) USEPA National Pollutant Discharge webpage (http://cfpub.epa.gov/npdes/stormwater/menuofbmps/menu.cfm) Urban Runoff Quality Management, WEF Manual of Practice No. 23, 1998, published jointly by the WEF and ASCE. Rainwater and Land Development Manual, Ohio Department of Natural Resources, Draft version not yet published. Storm Water Technology Fact Sheet- Bioretention, September 1999, EPA 832-F-99-0125, http://www.epa.gov/owmitnet/mtb/biortn.pdf. Ohio Environmental Protection Agency, Authorization for Storm Water Discharges Associated With Construction Activity Under The National Pollutant Discharge Elimination System, Permit OHC000002, April 21, 2003, http://www.epa.state.oh.us/dsw/permits/CGP_renewal_final.pdf. Storm water Pollutant Removal in Roadside
Vegetated Buffer Strips, Michael Barrett, Center for Research in Water Resources, University of Austin, TX., TRB 2004.
1002 Pipe Policy .....................................................................................................................................10-1 1002.1 Introduction .....................................................................................................................10-1 1002.2 General Requirements....................................................................................................10-1
1002.2.1 Pipe Materials .................................................................................................10-1 1002.2.2 Outlet Velocity Control ....................................................................................10-1 1002.2.3 Special Shapes ...............................................................................................10-2
1002.3 Conduit Types .................................................................................................................10-2 1002.3.1 Type A Conduits .............................................................................................10-2 1002.3.2 Type B Conduits .............................................................................................10-3 1002.3.3 Type C Conduits .............................................................................................10-3 1002.3.4 Type D Conduits .............................................................................................10-3 1002.3.5 Type E Conduits .............................................................................................10-3 1002.3.6 Type F Conduits..............................................................................................10-4
1003 Hydrology ......................................................................................................................................10-4 1003.1 Estimation of Magnitude and Frequency of Floods on Ohio Streams ............................10-4
1003.1.1 General ...........................................................................................................10-4 1003.1.2 Limitations .......................................................................................................10-4
1004 Flood Clearance ............................................................................................................................10-4 1004.1 General ...........................................................................................................................10-4 1004.2 Design Year Frequency ..................................................................................................10-5 1004.3 Plan Designation .............................................................................................................10-5
1005 Highway Encroachments on Flood Plains .................................................................................10-5 1005.1 General ...........................................................................................................................10-5 1005.2 Type of Studies ...............................................................................................................10-5
1008.3.1 Height of Cover ...............................................................................................10-9 1008.4 Corrugated Steel and Aluminum Box Culverts and Corrugated Steel Long Span Culverts.....................................................................................................................................................10-9
1008.4.1 Designation and Thickness.............................................................................10-9 1008.4.2 Height of Cover ...............................................................................................10-9 1008.4.3 Foundation Reports ........................................................................................10-9
The Hydraulic Section, Office of Structural Engineering is responsible for the hydraulic and structural design standards of all prefabricated and cast-in-place structures including concrete pipe, vitrified clay pipe, corrugated metal pipe, thermoplastic pipe, box culverts, three-sided flat-topped and arch structures, etc., regardless of structure size or contributing drainage area. This includes the preparation of permissible surcharge tables for flexible and rigid pipe and coordination with Specification Committee for the material portions of the Construction and Material Specifications. The Hydraulic Section is also responsible for the structural and hydraulic adequacies of all headwalls or endwalls used in conjunction with structures. Further responsibility includes all surface drainage systems including roadway ditches and channels. The Hydraulic Section, Office of Structural Engineering, is also responsible for the determination of the type of drainage structure (i.e., prefabricated vs. cast-in-place) required to replace an existing bridge (span length greater than 10 feet [3048 mm]) 1001.2 Natural Streams
Channel designs and channel relocations of all natural streams passing through a proposed highway facility will be the responsibility of whichever Departmental Office has the responsibility for the highway structure. All other channel designs and channel relocations of natural streams shall be the responsibility of the Hydraulic Section. 1002 Pipe Policy
1002.1 Introduction
The policies herein shall govern in the determination of the size and type of pipe specified or permitted for the various items of highway drainage financed totally or in part with state or federal funds. Proposed deviations from this Pipe Policy concerning type of pipe or pipe placement by local political subdivision or agencies will be considered for all portions of the project that the political subdivision will be responsible for maintaining at its own expense. Any deviations
must be based on sound engineering judgment or experience. A policy of the local subdivision, which has been published and implemented, will be acceptable. In lieu of a published policy, prior construction with local funds will be accepted as bona fide demonstration of local practice. A written request, by the local subdivision or agency for deviation from this Pipe Policy, shall be submitted, with the necessary documentation, to the local ODOT District, who will in turn forward the request with the District’s recommendation to the Administrator of the Office of Structural Engineering. The request shall be made with the Drainage Criteria submission. 1002.2 General Requirements
1002.2.1 Pipe Materials
The type of pipe materials listed under the various conduit types in Section 603.02 of the Construction and Material Specifications shall be considered as equal within their size, structural and material durability limitations. 1002.2.2 Outlet Velocity Control
When permissible pipe alternates have different velocity characteristics, the design specified for erosion control shall satisfy the most severe velocity condition of the permissible alternates. In this case, “erosion control” refers to controls placed in the stream channel at the outlet end of the pipe such as rock channel protection, and does not refer to energy dissipators. Where the calculated culvert outlet velocity exceeds 20 feet per second [6 meters per second] or 15 feet per second [4.6 meters per second] in areas of poor soil such as fine sand or sandy silt, roughness elements (protruding concrete rings inside the pipe) may be specified at the outlet end of the alternates to reduce the velocity below the maximum allowable. The design of internal energy dissipator ring chambers is provided in report FHWA/OH-84/007 “Internal Energy Dissipators for Culverts”. This report and ring chamber details can be obtained from the Hydraulic Section, Office of Structural Engineering. Where the outlet velocity for a corrugated pipe is less than 20 feet per second [6 meters per second] while the outlet velocity for a smooth pipe requires a ring chamber, the corrugated pipe may be specified exclusively.
Drainage Design Policies
April 2004 10-2
1002.2.3 Special Shapes
Special shaped conduits (elliptical concrete, corrugated metal arch or pipe arch, or prefabricated box or three-sided structures) are generally limited for use under shallow cover installations or extremely low or restrictive headwater control otherwise requiring multiple circular conduits to satisfy allowable headwater conditions. Generally elliptical concrete and corrugated metal pipe arch of the required size to satisfy hydraulic conditions are to be shown on the plan. Special shaped conduits may be provided to conform to the cross-sectional geometry of sensitive streams identified in the environmental documentation. Where corrugated metal and structural plate pipe arches are specified or permitted, a foundation investigation shall be submitted as required by Section 1008.1.5. 1002.3 Conduit Types
1002.3.1 Type A Conduits
Type A conduits shall be designated for soil-tight, sealed-joint, open-ended cross drains under pavements and paved shoulders. The minimum size culvert (or cross drain) to be specified shall be based on the roadway type and depth of fill from the flowline to roadway surface. The minimum required round (or equivalent deformed) pipe sizes are listed in Figure 1002-1. For culverts with outlet control, under freeways or high fills (16 feet [4.8 meters]), the size shall be increased one pipe size over the required size to allow for future repair. The pipe shall only be upsized once. All hydraulically and structurally adequate pipe alternates which provide the required service life shall be shown on the plans and listed in the pertinent pay item. In the applicable size ranges, alternates should include, vitrified clay, concrete, corrugated steel and corrugated aluminum pipe. For corrugated pipe, the corrugation profile which requires the thinnest metal shall be listed. Where durability requires increased thicknesses of the corrugated steel alternate, the 1-inch [25 millimeter] corrugation profile should be specified for pipe diameters over 48 inches [1200 millimeters]. For the corrugation profile specified, all combinations of thickness and protection
providing the required service life shall be specified. Only one type of pipe may be specified where special conditions prevail such as: excessive cover for a rigid pipe; where a larger corrugated pipe would require a higher pavement grade to satisfy minimum cover requirements or require more cells than a rigid alternate; or where a metal pipe arch would be required as an alternate to a round rigid pipe. The use of a single material type shall be subject to the approval of the Hydraulic Section, Office of Structural Engineering. If the alternates to be listed in the plan are of a different size, the pipe length shall be designed for the smaller sized pipe. The length of pipe may be greater, therefore, than theoretically required if the larger sized alternate pipe is selected by the contractor. In addition to hydraulic and structural considerations, pipe material durability shall be considered in the selection of culvert materials. All Type A Conduits under State and Federal routes shall be designed to provide a minimum median service life of 50 years. At sites where the future cost to replace a pipe could be exceptionally high such as under high fills (16 feet [4.8 meters] or more from flowline to finish grade) or freeways, a design median service life of 75 years shall be used. The pH of the normal stream flow and the presence of abrasive flow conditions shall be the factors considered to determine material durability. At all sites, the pH of the normal stream flow shall be measured and a determination of the abrasive potential of the stream shall be made. The presence of granular material accompanied with a stream gradient or flow sufficient to cause movement of the granular material in the stream bed shall be the basis for the determination of an abrasive versus non-abrasive site for corrugated steel pipe. Granular material is considered to be a material larger than sand or pea gravel. A site should be considered abrasive for corrugated aluminum pipe if bed loads consist of sharp cobbles with flow sufficient to carry the bed load through the culvert. Otherwise, the site should be considered non-abrasive. If there is no normal stream flow during the culvert field review, Figures 1002-2 and 1002-3 may be used to determine pH. Future land use (such as coal mines) should be considered and the durability design adjusted to meet future needs.
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Figures 1002-4, 5 and 6 shall be used to determine the pipe materials for the design service life. These tabulations are based on the ODOT Culvert Durability Study and later reports. The equations in the referenced study can be used to determine service lives other than 50 and 75 years. The following shall govern the determination of the pH factor for the categories listed in Figures 1002-4, 1002-5 and 1002-6. 1. The instrument used to measure the pH shall
be capable of determining the pH within an accuracy of 0.1.
2. The firm or agency responsible for the
preparation of the plans shall be responsible for obtaining the pH readings.
3. A report shall be submitted, with the Drainage
Review plans, listing for all culvert sites: the pH of the stream flow, an evaluation of whether the site is abrasive or non-abrasive, and a statement that the tests were made in dry weather or low flow.
Protection greater than required for existing conditions may be specified for a culvert with potential flow conditions more corrosive than measured, if the district office is of the opinion that future use of the contributing watershed will alter such conditions. A statement of this opinion, including the reasons for the opinion, shall accompany the pH report. At culvert replacement sites, past performance of existing material should also be considered. 1002.3.2 Type B Conduits
Type B conduit shall be designated for soil-tight, sealed joint sewers under pavements, paved shoulders, and commercial or industrial drives. In areas with highly erodible soils (e.g., fine sands or silts), premium joints shall be provided. Additional protection (epoxy coating as per 706.03 for concrete pipe and polymer coating per 707.04 for asphalt paved corrugated steel pipe) shall be provided for storm sewers carrying corrosive flow.
1002.3.3 Type C Conduits
Type C conduit shall be designated for soil-tight, sealed joint sewers not under pavements, paved shoulders, or commercial or industrial drives. In areas with highly erodible soils (e.g., fine sands or silts), premium joints shall be provided. Additional protection (epoxy coating as per 706.03 for concrete pipe and polymer coating per 707.04 for asphalt paved corrugated steel pipe) shall be provided for storm sewers carrying corrosive flow. 1002.3.4 Type D Conduits
Type D conduits shall be designated for pipes under driveways and bikeways. The minimum size required is 12 inches [300millimeters]. For sizes 24 inches [600 millimeters] and larger, it will be necessary to submit calculations and specify pipe sizing required to satisfy the hydraulic controls. Such analyses shall be submitted with the Drainage Review plans. The design frequency used to analyze the hydraulic performance of the Type D conduit is the same as that used for the flow capacity of the connected ditch or channel and the headwater for that frequency shall not exceed a point 1 foot [300 millimeters] below the edge of the pavement. If potential exists for the drive pipe headwater to encroach on the adjacent roadway, the drive pipe shall be sized utilizing a design frequency as per 1004.2. Generally, the pipe alternates listed in 603.02 of the Construction and Material Specifications are applicable, except that equal size corrugated pipe will provide satisfactory alternates for sizes smaller than 24 inches [600 millimeters]. If the control is critical, a hydraulic analysis will be required to determine the proper size of pipe alternates. Drive pipes under commercial or industrial drives shall be designed for material durability as per 1002.3.1. Additional protection for residential and field drives may be specified if conditions warrant. 1002.3.5 Type E Conduits
Type E conduits shall be designated for farm drain headers inside or outside of the right-of-way lines. Headers are ordinarily provided to intercept small, closely spaced lines in a tiled field thereby precluding the need for numerous field tile outlets through the backslope of the highway ditch.
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Type E conduits may be used beyond the paved shoulder to eliminate a ditch in front of a yard where such ditch elimination can be justified. When required by hydraulic analysis, all proper sized alternates shall be specified. 1002.3.6 Type F Conduits
Type F conduits shall be designated where a butt joint or a short length jointed pipe would be undesirable as noted below: A. For the steep portion of a median outlet under
an embankment slope 4:1 or steeper, including any necessary pipe bends.
B. For the outlets of underdrains or farm drains
through the slope or connecting to a drainage structure. When used for underdrain outlets, the following pay item description shall be used: Item 603 " Conduit, Type F for Underdrain Outlets
C. For farm drains larger than 12 inches [300
millimeters] that outlet through slopes flatter than 4:1, provide a 20 foot [6 meter] length of Type F Conduit.
D. To span the trench of a lower conduit, unless
the crossing is more than 12 inches [300 millimeters] above the granular backfill of the lower conduit, provide a minimum length of 10 feet [3 meters] of Type F Conduit.
For Type F conduits in storm drainage systems, 707.05 Type C shall be specified for the steel alternate. 1003 Hydrology
1003.1 Estimation of Magnitude and Frequency of Floods on Ohio Streams
1003.1.1 General
USGS Water Resources Investigations Report 89-4126 “Techniques for Estimating Flood-Peak Discharges of Rural Unregulated Stream in Ohio” was developed cooperatively by the United States Geological Survey and the State of Ohio. This bulletin is an update of Bulletin 32 (1959), Bulletin 43 (1969), and Bulletin 45 (1977). This report provides the latest hydrologic information for determining the magnitude and frequency of floods for rural streams in Ohio. The techniques presented in Report 89-4126 shall be used to determine the design peak discharge for hydraulic
structures designated by or for ODOT. When applying this technique, the tributary with the largest contributing drainage area, not the longest reach, should be considered. USGS Water Resources Investigation Report 93-4080 “Estimation of Flood Volumes and Simulation of Flood Hydrographs for Ungaged Small Rural Streams in Ohio” shall be used to determine flood volumes and hydrographs for rural areas within the limits prescribed in the report. 1003.1.2 Limitations
The regression equations, as presented for the three geographic regions, should be used only for unregulated streams draining rural areas in excess of 6 acres [2.5 hectares]. For smaller drainage areas or larger drainage areas where no well defined natural channel exists and sheet flow prevails, the rational method (Section 1101.2.2) shall be used. USGS Open File Report 93-135 "Estimation of Peak-Frequency Relations, Flood Hydrographs, and Volume - Duration - Frequency Relations of Ungaged Small Urban Streams in Ohio” shall be used in the design of culverts, detention basins, large storm sewers, and large open channels with urban drainage areas within the limits prescribed in the report. The rational method shall be used in the design of pavement inlets, roadway ditches, and small storm sewers. For additional guidance on the proper use of USGS regression equations see Transportation Research Record 1319 Report “Information Needs for the Proper Application of Hydrologic Regional Regression Equations”. Reports 89-4126, 93-4080 and 93-135 are available in limited quantities from the Hydraulic Section, Office of Structural Engineering, 1980 W. Broad Street, Columbus, Ohio 43223. 1004 Flood Clearance
1004.1 General
Where a new highway crosses or is located in a flood plain, the highway grade shall normally be set such that the low edge of the pavement will clear the design water surface profile for existing conditions by 3 feet [1 meter], and bridges (low chord) will generally clear the water surface profile of the design year frequency flood. These
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clearances may be reduced where an economic comparison of alternatives shows that a reduction in clearance will result in significant savings, giving full consideration to future flood-related costs relative to: highway operation, maintenance, and repair; highway-aggravated flood damage to other property; and for additional or interrupted highway travel. Flood clearances may also be reduced to protect important ecological resources as identified in the environmental documentation. An economic comparison of alternatives shall be performed to determine the future flood-related costs relative to: highway operation, maintenance, and repair; highway-aggravated flood damage to other property; and for additional or interrupted highway travel. 1004.2 Design Year Frequency
* Unless otherwise approved by the Hydraulic section, Office of Structural Engineering. 1004.3 Plan Designation
The water surface elevation, velocity of flow and peak discharge for the design, and 100-year frequency storms shall be shown on the plan and profile sheets and culvert detail sheets. 1005 Highway Encroachments on Flood Plains
1005.1 General
The requirements of the Federal Code of Regulations, Volume 23, Part 650A, shall be followed for all projects. All highways that encroach on flood plains, bodies of water or streams, shall be designed to permit conveyance of the 100-year flood without causing significant damage to the highway, the stream, body of water or other property. Special consideration must be given when designing a structure located within a reach of channel that is part of a flood insurance study managed by the Federal Emergency
Management Agency (FEMA). If this condition is applicable, the proposed maximum allowable 100-year water surface elevation will generally be limited to the existing 100-year water surface elevation presented in the flood insurance study. The local FEMA floodplain coordinator must be informed of any proposed construction within the limits of a flood prone area as designated by a FEMA flood insurance study. Structures and/or channels shall be sized to satisfy the design year discharge. However, the size selected shall permit the conveyance of the 100-year flood without causing significant damage. Inundation of the highway is considered acceptable for the 100-year flood, but it is not permitted for the design-year flood. It is not necessary to lower the water surface elevation of any frequency flood below existing stages, except that the controls outlined in Section 1006.2.1 A, B and C must be satisfied. 1005.2 Type of Studies
1005.2.1 Flood Hazard Evaluation
A flood hazard evaluation is required for all water course involvements except for crossings where roadway culverts are provided to satisfy minimum size requirements. A Flood Hazard Evaluation shall entail a determination of the water surface elevation of the design year and 100-year floods by means of the procedures outlined in this section and Section 1105. Headwater pools shall be delineated on a topographic map. The valuation shall also include a discussion of the significance of any increase in the flooding limits over the existing conditions. Additional information regarding Flood Hazard Evaluations for cast-in-place or bridge structures may be obtained in the Bridge Design Manual. 1005.2.2 Detailed Flood Plain Study
If the Flood Hazard Evaluation should indicate a significant increase in the flooding of upstream property, a Detailed Flood Plain Study will be required. A Detailed Flood Plain Study should also be performed in highly urbanized areas where the potential for flooding cannot be accurately assessed without an analysis of the entire flood plain. For prefabricated structures, the Detailed Flood Plain Study, including a step-backwater analysis, will be authorized after review of the Flood Hazard Evaluation, by the Hydraulic Section, Office of Structural Engineering.
Freeways or other multi-lane facilities with limited or controlled access . . 50 YearOther Highways (2000 ADT and over) and Freeway Ramps . . . . . . . . . . . 25 YearOther Highways (under 2000 ADT) . . . . . 10 Year
Additional information regarding Detailed Flood Plain Studies for bridges or cast-in-place structures may be obtained in the Bridge Design Manual. 1005.2.3 Down Stream Impacts
For all new alignments, the down stream impact of culvert or storm sewer discharge should be evaluated when existing flow to the outlet is characterized as overland or shallow concentrated. The impact of concentration of flow at culvert or storm sewer outlets is more prominent when existing topography is generally flat. At a minimum, an application of the Manning's equation to a typical down stream cross section should be applied with the ditch design discharge from the culvert or storm sewer. If impacts are significant, steps should be taken to revise the design or employ energy dissipation methods to the maximum extent practicable. 1006 Culvert Allowable Headwater
1006.1 Design Storm
The frequency of the design storm shall be as stated in Section 1004.2. 1006.2 Controls
1006.2.1 Design Storm Controls
Headwater depth for all culverts (Type A Conduits) shall not exceed any of the following controls for the design storm: A. 2 feet [600 millimeters] below the near, low
edge of the pavement for drainage areas 1000 acres [400 hectares] or greater and 1 foot [300 millimeters] below for culverts draining less than 1000 acres [400 hectares].
B. 2 feet [600 millimeters] above the inlet crown
of the culvert or above a tailwater elevation that submerges the inlet crown in flat to rolling terrain.
C. 4 feet [1.2 meters] above the inlet crown of a
culvert in a deep ravine. D. 1 foot below the near edge of pavement for
bicycle pathways.
1006.2.2 Check Storm Controls
Headwater depth for all culverts (Type A Conduits) shall not exceed any of the following controls for the applicable check frequency storm. A. 2 feet [600 millimeters] below the lowest
ground elevation adjacent to an occupied building for a 50-year storm (it is not intended, however, to lower existing highwater elevations around buildings).
B. The designer should generally limit the
maximum 100-year headwater depth to twice the diameter or rise of the culvert.
C. A replacement structure should be sized to
prevent overtopping by the 100-year flood where such overtopping would not occur with the existing structure.
D. A replacement structure should be sized such
that flooding of upstream productive land is not increased for the 100-year flood when compared to the existing structure. Judgment shall be used in implementing this policy, considering the type of upstream property and sensitivity to the accuracy of the computed flood stages.
E. No significant increase in 100-year
headwater elevation shall occur in a FEMA designated floodway.
1006.2.3 Local Floodplain Coordinator
The local floodplain coordinator should be contacted early in the design process to determine the allowable headwater increase and or the permitting requirements. A current list of floodplain coordinators can be found at: http://www.dnr.state.oh.us/water/floodpln/communitylist.pdf.
1006.2.4 Limitations
1006.2.1 B and C; and 1006.2.2 B, C and E are arbitrary headwater controls. When 1006.2.1 B is applicable, use smooth pipe to establish the allowable headwater in meters [feet]. When 1006.2.1 C controls, use corrugated pipe to establish the headwater and thereby permit the same headwater elevation regardless of type of pipe. More heading will be considered if pipe sizes can be reduced and not cause damaging upstream flooding or excessive outlet velocity.
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1006.2.1 B and C are arbitrary controls that apply generally to small culverts. Where large structures (greater than or equal to 10 feet [3000 millimeters] in span) are involved, the structure should be sized to pass the design storm while maintaining a free water surface through the structure. The near low edge of pavement is the location where roadway overtopping will occur. This may or may not be located directly over the culvert. Where the overtopping point on the roadway is outside the watershed break, the ditch break overflow elevation should be utilized as a headwater control in lieu of 1006.2.1 A. 1007 Pipe Removal Policy
1007.1 General
The following guidelines should be used by the designer to determine whether an existing pipe that is taken out of service, regardless of type, should be abandoned or removed. A. Pipes 8 inches [200 millimeters] in diameter
or rise, or less, regardless of depth or height of fill, may be abandoned in place.
B. Pipes 10 inches [250 millimeters] through 24
inches [600 millimeters] in diameter or rise with less than 3 feet [1 meter] of final cover should be removed or filled; with more than 3 feet [1 meter] of final cover they may be abandoned in place. (The designer should use discretion in removing small pipes under existing rigid pavement or base, which is to remain in place.)
C. Pipes over 24 inches [600 millimeters] in
diameter or rise should generally be removed. (The designer should use discretion in removing any pipe with more than 10 feet [3 meters] of cover.)
D. Where it is necessary to maintain service of
small unrecorded storm drain connections to an existing storm sewer being taken out of service, but this cannot be assured without the removal of that sewer, then the storm sewer shall be removed.
1007.2 Asbestos pipe
Asbestos pipe is a regulated material. Designers should make reasonable efforts to identify existing asbestos pipes in the plans and, when
necessary, provide appropriate removal quantities. In the past, pipe containing asbestos was allowed on ODOT, LPA and utility projects under the following specifications:
Transite is a common brand name for a type of asbestos pipe. Asbestos can also be found in insulation wrapped around water pipes.
Reasonable efforts to identify asbestos pipes would include the following: A. Examination of original construction plans
and specifications. B. Contact with the owner of the pipe (e.g., utility
company or LPA). C. Inspection of the pipe for markings when the
pipe is exposed during routine maintenance operations.
Removal of asbestos pipe is specified as Item 202 Asbestos Pipe Removed in the 2002 CMS. For projects to be constructed under the 1997 CMS, use Item 202 Pipe Removed, As Per Plan and indicate that the pipe must be removed by a certified asbestos contractor. Asbestos is a hazard only when it becomes airborne. Pipes that are otherwise unaffected by ODOT work do not need to be removed simply because they contain asbestos. Not all asbestos pipe will be identified by a records search. Construction inspectors are being advised to test suspicious pipe for asbestos. If asbestos pipe is identified, the contractor will be compensated by change order.
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1008 Structural Design Criteria
1008.1 Corrugated and Spiral Rib Steel and Aluminum Pipes, and Corrugated Steel and Aluminum Pipe Arches
1008.1.1 Material Durability
The policy outlined in Section 1002 specifying types of protective coatings and/or extra metal thickness shall be followed. 1008.1.2 Designation and Thickness
The corrugation profile and required metal thickness shown in Figures 1008-1 through 1008-6 and 1008-15 through 1008-19 shall be specified. The thickness should be determined for the maximum height of cover and it shall be used for the full length of the structure. However, where a short length of conduit requiring a higher strength pipe is contiguous with a long run of pipe, then only that short length should be specified as requiring the higher strength pipe. Generally, the corrugation profile requiring the thinnest metal for a given size conduit shall be specified. When the minimum thickness shown in these figures will suffice, the thickness need not be specified. The preferred corner radius for structural plate corrugated pipe arches is 31” [775 mm]. The commercial availability of a specific sheet thickness for various pipe diameters should be verified. Use the General Notes for Figures 1008-1 through 1008-9, General Notes for Figures 1005-15 through 1008-21, and the Height of Cover Tables for this purpose. Minimum sheet thicknesses for the various corrugation profiles and pipe diameters are tabulated in the pertinent 700 Section of the Construction and Material Specifications Handbook. 1008.1.3 Cambered Flow Line
Where soil conditions at the site indicate that appreciable settlement may be expected, a cambered flow line should be provided. The amount of camber required at specific points shall be shown on the plans.
1008.1.4 Height of Cover
See General Notes for Figures 1008-1 Through 1008-9 and 1008-15 Through 1008-21 1008.1.5 Foundation Reports
An investigation of the supporting foundation material shall be conducted and the bearing capacity of the foundation material estimated. The level of detail required for the foundation investigation shall be commensurate with the importance of the structure. Such information shall be submitted for all proposed pipe arch installations and submitted in the Stage 2 review. Refer to section 1008.8 for information on foundation types. 1008.1.6 Corner Bearing Pressures
The tables of corner bearing pressures (Figures 1008-7, 1008-8, 1008-9, 1008-20 and 1008-21) are for installations with 4 feet [1.2 meters] or less cover. The minimum height of cover requirements for pipe arch shapes, from Section 1008.1.4 shall be satisfied. The corner bearing pressures listed for cover less than the minimum are for information only. 1008.2 Rigid Pipe
1008.2.1 General
Height of cover tables are shown in Figures 1008-10 through 1008-13. Information on the use of these tables can be found in the General Notes for Figures 1008-10 through 1008-14. Where soil conditions at the site indicate that appreciable settlement may be expected, a cambered flow line should be provided. The amount of camber required at specific points shall be shown on the plans. The minimum D-Load for the various diameters of reinforced concrete pipe are tabulated in Section 706.02 of the Construction and Material Specifications Handbook. 1008.2.2 Height of Cover
The maximum allowable height of cover is measured from the top of the pipe to the pavement surface. The minimum cover, from the top of the pipe to the top of the subgrade, or finish grade for pipe not under pavements, is 9 inches [225 millimeters]; however, in no installation shall
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the distance from the top of the pipe to the pavement surface be less than 15 inches [375 millimeters]. 1008.2.3 Structural Design Criteria
The following criteria are to be considered when determining pipe characteristics. A. The maximum allowable height of cover,
listed in the tables, is based on structural requirements for dead and live loads assuming an ordinary soil foundation. Where a rock or unyielding foundation is encountered in an embankment installation, additional thickness of granular bedding and/or greater strength pipe may be required. The extent of increase necessary is related to pipe size and cover.
B. Where the type of pipe is circular, reinforced
concrete pipe (706.02) and the height of cover exceeds the maximum cover listed in the Height of Cover Tables for a specific size and installation type, the pipe should still be included in the project plans. The concrete pipe alternate should be specified as 706.02 with special design.
The special design will be provided by the manufacturer after the project letting.
C. If the height of cover over a pipe exceeds 100
feet [30 meters], a special design is required to investigate foundation suitability.
D. The required pipe strength should be
determined for the maximum height of cover and it shall be used for the full length of the pipe. However, where a short length of conduit requiring a higher strength pipe is contiguous with a long run of pipe, then only that short length should be specified as requiring the higher strength pipe.
1008.3 Thermoplastic Pipe
1008.3.1 Height of Cover
The maximum allowable height of cover is measured from the top of the conduit to the pavement surface or to finished grade for pipes not under pavement. The maximum height of cover should be limited to 20 feet [6 meters]. Cover greater than 20 feet [6 meters] may be provided contingent upon the approval of the Hydraulic Section, Office of Structural Engineering.
The minimum cover, from the top of the pipe to the top of the subgrade, is 12 inches [300 millimeters]; however, in no installation shall the distance from the top of the pipe to the pavement surface, or finish grade for pipes not under pavement, be less than 18 inches [450 millimeters]. 1008.4 Corrugated Steel and Aluminum Box Culverts and Corrugated Steel Long Span Culverts.
1008.4.1 Designation and Thickness
The corrugation profile and metal thickness required shall be in accordance with the AASHTO Standard Specifications for Highway Bridges design methodologies. The Hydraulic Section, Office of Structural Engineering is responsible for the structural design of all corrugated steel and aluminum box culverts, and corrugated steel long span culverts. The skew of the structure relative to the roadway shall be given in 1° increments and typically should not exceed 15°. 1008.4.2 Height of Cover
The minimum and maximum heights of cover shall be in accordance with the AASHTO Standard Specifications for Highway Bridges design methodologies. However, in no case shall the minimum cover, measured from the trough of the corrugation profile to the pavement surface, be less than 18 inches [450 millimeters]. In addition to the above requirements, corrugated steel and aluminum box culverts shall be provided with adequate cover to ensure that the culvert rib stiffeners are located completely within the subgrade. 1008.4.3 Foundation Reports
An investigation of the supporting foundation material shall be conducted and the bearing capacity of the foundation material estimated. The level of detail required for the foundation investigation shall be commensurate with the importance of the structure. Such information shall be submitted for all proposed metal box and long span culvert installations and submitted prior to the Stage 3 review.
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1008.5 Precast Reinforced Concrete Box Culverts
1008.5.1 Designation
The allowable sizes of Precast reinforced concrete box culverts shall be as given in Figure 1008-14. Structures with a span of 12 feet [3600 mm] or less shall be designated as per CMS 706.05 and ASTM C 1433 [C 1433 M]. The pay item description shall include the height of cover (design earth cover) rounded to the highest 1 foot [300 mm]. Structures with spans 14 feet [4200 millimeters] or greater require a special design available from the Hydraulic Section, Office of Structural Engineering. 1008.5.2 Height of Cover
The maximum allowable height of cover is measured from the top of the culvert to the pavement surface. The maximum height of cover shall be as per Figure 1008-14. Greater covers may be provided contingent upon the approval of the Hydraulic Section, Office of Structural Engineering. A special design is required. 1008.5.3 Structural Design Criteria
Structures with spans 14 feet [4200 millimeters] or greater are designed with the HS25 and Alternate Military loading. A 60 psf future wearing surface is included in the dead loading for structures with spans 14’ or greater. The design loading information (ie. interstate) shall be included on the Culvert Detail Sheet or Site Plan. 1008.6 Precast Reinforced Concrete Three-Sided Flat-Topped Culverts
1008.6.1 Designation
Precast reinforced concrete three-sided, flat-topped culverts shall have a minimum clear span of 14 feet [4200 mm] and minimum opening rise of 4 feet [1200 mm]; and a maximum clear span of 34 feet [10 200 mm] and maximum opening rise of 10 feet [3000 mm]. The skew of the individual culvert units should be given in 5° increments and shall not exceed 30°.
Skew is typically limited to 30° because of the complex structural analysis required when the main reinforcement is not perpendicular to the wheel load. The skew of the structure relative to the roadway shall be given in 1° increments and typically should not exceed 30°. Structures designed to have no significant environmental impact on the affected stream may exceed this limit. The minimum deck thickness for the culvert units is 12 inches [300 mm] and the minimum leg thickness for the culvert units is 10 inches [250 mm]. The design should be based on these dimensions. 1008.6.2 Height of Cover
The maximum allowable height of cover is measured from the top of the culvert to the pavement surface. The maximum height of cover should be limited to 10 feet [3 meters]. Cover greater than 10 feet [3 meters] may be provided contingent upon the approval of the Hydraulic Section, Office of Structural Engineering. 1008.6.3 Structural Design Criteria
Flat-topped, three-sided culverts shall be designed in accordance with AASHTO Standard Specifications for Highway Bridges design methodologies. The design loading information (HS25 and Alternate Military Load) shall be included on the Culvert Detail Sheet or Site Plan. Spans greater than 12 feet [3658 mm] shall have an additional load of 60 psf to allow for future roadway resurfacing. 1008.6.4 Foundation Reports
An investigation of the supporting foundation material shall be conducted and the bearing capacity of the foundation material estimated. The level of detail required for the foundation investigation shall be commensurate with the importance of the structure. Such information shall be submitted for all proposed flat-topped, three-sided culvert installations and submitted in the Stage 2 review. Refer to section 1008.8 for information on foundation types.
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1008.7 Precast Reinforced Concrete Arch Sections
1008.7.1 Designation
Precast reinforced concrete arch sections shall have a clear span of 12, 14, 16, 20, 24, 28, 32, 36 or 42 feet [3600, 4200, 4800, 6000, 7200, 8400, 9600, 10 800, 12 600 mm] and an opening rise of 4 feet through 11 feet 6 inches [1200 mm through 3450 mm]. Other sizes may be provided contingent upon the approval of the Hydraulic Section, Office of Structural Engineering. The individual culvert units shall not be skewed. Skew is not permitted because of the complex structural analysis required when the main reinforcement is not perpendicular to the wheel load. The skew of the structure relative to the roadway shall be given in 1° increments and typically should not exceed 30°. Structures designed to have no significant environmental impact on the affected stream may exceed this limit. The deck thickness and leg thickness for the culvert units are 10 inches [250 mm]. The design should be based on these dimensions. 1008.7.2 Height of Cover
The maximum allowable height of cover is measured from the top of the culvert to the pavement surface. The maximum height of cover should be limited to 12 feet [4 meters]. Cover greater than 12 feet [4 meters] may be provided contingent upon the approval of the Hydraulic Section, Office of Structural Engineering. The minimum cover, from the top of the arch sections to the top of the pavement is 12 inches [300 millimeters]. However, in no case shall the top of the arch sections be located above the top of subgrade. 1008.7.3 Structural Design Criteria
Precast Reinforced Concrete Arch Sections shall be designed in accordance with AASHTO Standard Specifications for Highway Bridges design methodologies. The design loading information (HS25 and Alternate Military Load) shall be included on the Culvert Detail Sheet or Site Plan. Spans greater than 12 feet [3658 mm] shall have an additional
load of 60 psf to allow for future roadway resurfacing. 1008.7.4 Foundation Reports
An investigation of the supporting foundation material shall be conducted and the bearing capacity of the foundation material estimated. The level of detail required for the foundation investigation shall be commensurate with the importance of the structure. Such information shall be submitted for all precast reinforced concrete arch section culvert installations and submitted prior to the Stage 3 review. Refer to section 1008.8 for information on foundation types. 1008.8 Foundations
Arch or flat slab topped culverts are supported on either deep foundations or spread footings that are founded at a minimum of 4 feet below the flowline on competent scour resistant native soils. All of the following conditions must be met in order for spread footings to be utilized: A. The design and 100 year flood velocity
through the culvert must be less than 8 fps (2.4 m/s).
B. The 100 year flood headwater must not
overtop the roadway in the vicinity of the structure.
C. There is no previous evidence of stream
scour or degradation. D. There are no soft soils below the footing to be
undercut. In the absence of competent bearing strata, deep foundations such as piles may be utilized based upon the cost comparison justification study between alternative structure types including bridges. The excavated material along the inside of the footing shall be backfilled with Type C Rock Channel Protection for both spread footings and footings with deep foundations., to preclude scour.
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April 2004 10-12
1008.9 Waterproofing Membrane
An external waterproofing membrane shall be attached to all precast reinforced concrete box culverts, three-sided flat-topped culverts, and arch culverts. Use Item 512 Waterproofing, Type 2 along the vertical sides and Type 2 or 3 across the top of the structure. Type 3 waterproofing shall be used if pavement is to be used directly on top of the structure. Provide an overlap of a minimum of 12 inches (300mm) of the top membrane to the vertical membrane. 1009 Subsurface Pavement Drainage
1009.1 General
Subsurface pavement drainage is required on all projects. An exception may be made where the project is located in an area having a granular subgrade. The subsurface drainage design shall be submitted with the Preliminary Drainage review for approval. 1009.2 Types of Subsurface Drainage
There are three means of draining the pavement subsurface - pipe underdrains, prefabricated edge drains, and aggregate drains. Generally, pipe underdrains are used with paved shoulders and curbed pavements (Figures 1009-1 through 1009-7). Prefabricated edge drains are typically used where existing concrete pavement with paved shoulders are to remain. Aggregate drains are used with bituminous surface treated shoulders, aggregate shoulders, and for spot improvements (Figures 1009-8 and 1009-9). Additional examples of typical underdrain and edge drain placements can be found in the Sample Plan Sheets. 1009.2.1 Pipe Underdrains
Pipe underdrains are used on both sides of the pavement and are typically carried through superelevated sections. Figures 1009-1 through 1009-7 show locations for pipe underdrains with respect to several shoulder designs. Pipe underdrains generally follow the profile grade of the roadway as long as the pipe underdrain maintains a positive or zero slope. For these cases, hydrostatic pressure is sufficient to ensure the proper drainage of the subbase and subgrade.
Underdrain depth is measured from the bottom of subbase to the bottom of the underdrain trench. Shallow pipe underdrains are typically 4 or 6 inches [100 or 150 millimeters] in diameter and 18 to 30 inches [450 to 750 millimeters] deep in normal cut and fill, or fill sections. Where a dual underdrain system is provided (shoulder greater than or equal to 8 feet [2.4 meters]), the edge of shoulder underdrain is supplemental to the edge of pavement underdrain and is typically 18 inches [450 mm] deep. The 4 and 6 inch underdrains are considered equivalent in hydraulic capacity for the shallow underdrain. If a 6 inch underdrain is required, the material type must be called out in the plans as per CMS 605.02. Rock cut underdrains are used in cut sections when a rock, shale, or coal subgrade exists. The depth of the rock cut underdrain should be 6 inches [150 mm] below the cut surface of the rock (Figure 1009-10). Refer to the 2002 CMS 204.05 for undercut information. Deep pipe underdrains (50 inches [1.25 meters] below subbase) are typically 6 inches [150 millimeters] in diameter. Deep pipe underdrains are used in cut sections, or areas with a high water table, to drain the subgrade. Unclassified underdrains are those having a variable depth below profile grade within a single continuous longitudinal run. Variable depth pipe underdrains (unclassified) shall be avoided where pipe underdrains of a constant depth can be provided. Underdrains which outlet to a slope should be provided with an Item 604 Precast Reinforced Concrete Outlet and should be perpendicular to the prevailing slope grade. Underdrain outlets should be provided at a desirable interval of 500 feet [150 meters] with a maximum interval of 1000 feet [300 meters]. Underdrain outlets should be provided at a desirable interval of 300 feet [100 meters], with a maximum interval of 500 feet [150 meters], where free draining base is utilized. It is desirable to outlet underdrains at least 12 inches [300 millimeters] above the flowline of a receiving ditch; and 6 inches [150 mm] above the flowline of a receiving catch basin, manhole, or pipe. Underdrain outlets shall be type F conduit. When underdrain spans the trench of a lower conduit (utility, storm sewer, culvert, etc.) and the vertical distance between the trench and
Drainage Design Policies
April 2004 10-13
underdrain is less than or equal to 12 inches, a type F conduit should be used to span the lower trench. Use a minimum of 10 feet. A fabric filter wrap should be used when existing soils consist of a sandy or sandy-silt composition. Where necessary, the depth of the underdrains may vary slightly to accomplish this. Underdrain outlet pipe outletting into a roadway ditch or fill slope should maintain a minimum slope of 1%. Outlets should not be located at the top of high (over 20 feet [6 meters]) 2:1 fill slopes. If this cannot be accomplished by adjusting the spacing, special outlet treatments will be required. 1009.2.2 Construction Underdrains
In fine-grained soils excess water in the subgrade is the principal cause of unstable soil conditions during construction. Adequate subgrade drainage can be achieved by using temporary pipe underdrains. These underdrains are sacrificial in nature and are intended to work throughout the construction process. Construction Underdrains are usually placed in the centerline of the roadway. They may also be placed in the ditch line, if the water is coming in from a cut section at a higher elevation. The outlets for the construction underdrains are the same pipe material and backfill as construction underdrains (not Type F). The outlets should be discharged into a catch basin, manhole, pipe, or ditch. If discharging into a ditch, a precast concrete reinforced outlet is not required. 1009.2.3 Prefabricated Edge Drains
Prefabricated edge drains are located at the edge of existing concrete pavement on resurfacing projects where the existing pavement and paved shoulders are being retained. If existing paved shoulders are being replaced, a 4 inch [100 millimeter] shallow pipe underdrain at the edge of pavement shall be used in lieu of the prefabricated edge drain. 1009.2.4 Aggregate Drains
Aggregate drains should be located at 50 foot [15 meter] intervals on each side of the pavement and staggered so that each drain is 25 feet [7.5 meters] longitudinally apart from the adjacent drain on the opposite side. If used on rigid pavements, the drains shall be located at each end of each transverse joint. For superelevated
pavements, the drains should be located on the low side only, at each transverse joint in rigid pavement and at 25 foot [7.5 meter] intervals for other pavement. Figures 1009-8 and 1009-9 show aggregate drains for several treated shoulder designs.
1000 Drainage Design Policies – List of Figures
April 2004
Figure Subject 1002-1 Minimum Culvert Sizes 1002-2 Water pH Contours - Average for Counties 1002-3 Water pH Contours - Values of Individual Culverts 1002-4 Requirements for Concrete Pipe Protection General Notes for Figures 1002-5 and 1002-6 1002-5(50) Requirements for Corrugated Metal Pipe Thickness and Protection at Non-Abrasive Sites - 50-year Design Service Life 1002-5(75) Requirements for Corrugated Metal Pipe Thickness and Protection at Non-Abrasive Sites - 75-year Design Service Life 1002-6(50) Requirements for Corrugated Metal Pipe Thickness and Protection at Abrasive Sites - 50-year Design Service Life 1002-6(75) Requirements for Corrugated Metal Pipe Thickness and Protection at Abrasive Sites - 75-year Design Service Life General Notes for Figures 1008-1 through 1008-9 1008-1 Height of Cover - Corrugated Steel Pipe 1008-2 Height of Cover - Corrugated Steel Pipe Arches 1008-3 Height of Cover - Structural Plate Corrugated Steel Pipe 1008-4 Height of Cover - Structural Plate Corrugated Steel Pipe Arches (18-inch [450 mm] Corner Radius) 1008-5 Height of Cover - Structural Plate Corrugated Steel Pipe-Arches (31-inch [775 mm] Corner Radius) 1008-6 Height of Cover - Corrugated Steel Spiral Rib Pipe 1008-7 Corner Bearing Pressure - Corrugated Steel Pipe Arches 1008-8 Corner Bearing Pressure - Structural Plate Corrugated Steel Pipe Arches (18-inch [450 mm] Corner Radius) 1008-9 Corner Bearing Pressure - Structural Plate Corrugated Steel Pipe Arches (31-inch [775 mm] Corner Radius) General Notes for Figures 1008-10 through 1008-14 1008-10 Maximum Allowable Height of Cover - Reinforced Concrete Pipe with Type 2 Bedding 1008-11 Maximum Allowable Height of Cover - Reinforced Concrete Pipe with Type 3 Bedding
April 2004
Figure Subject 1008-12 Maximum Allowable Height of Cover - Reinforced Concrete Elliptical Pipe
with Type 2 Bedding 1008-13 Maximum Allowable Height of Cover - Non-Reinforced Rigid Pipe with Type 2 Bedding 1008-14 Maximum Allowable Height of Cover - Reinforced Concrete Box Culvert with Type 1 bedding General Notes for Figures 1008-15 through 1008-21 1008-15 Height of Cover - Corrugated Aluminum Pipe 1008-16 Height of Cover - Corrugated Aluminum Pipe Arches 1008-17 Height of Cover - Structural Plate Corrugated Aluminum Pipe 1008-18 Height of Cover - Structural Plate Corrugated Aluminum Pipe Arches 1008-19 Height of Cover - Corrugated Aluminum Spiral Rib Pipe 1008-20 Corner Bearing Pressure - Corrugated Aluminum Pipe Arches 1008-21 Corner Bearing Pressure - Structural Plate Corrugate Aluminum Pipe Arches 1009-1 Typical Pipe Underdrain Locations 1009-2 Typical Pipe Underdrain Locations 1009-3 Typical Pipe Underdrain Locations 1009-4 Typical Pipe Underdrain Locations 1009-5 Typical Pipe Underdrain Locations 1009-6 Typical Pipe Underdrain Locations 1009-7 Typical Pipe Underdrain Locations 1009-8 Typical Aggregate Drain Locations 1009-9 Typical Aggregate Drain Locations 1009-10 Typical Rock Cut Underdrain
General Notes – Figures 1002-5 and 1002-6
April 2004
Tables 1002-5(50) & 1002-5(75) Tables 1002-5(50) and 1002-5(75) are based on equations 6 and 8 from the ODOT Location & Design publication 82-1, “Culvert Durability Study” including: �� A 15-year service life for Bituminous Coating
with Invert Paving for culverts 54” [1350 mm] and larger.
�� A 25-year service life for Bituminous Coating
with Invert Paving for culverts 48” [1200 mm] and smaller.
�� A 35-year service life for Aluminium Coating
with pH above 5.0 �� A 50-year service life for Polymeric Coating �� All base metal must provide a minimum of 10
years of service life. Corrugated aluminium alloy pipe (707.21 and 707.22) and aluminium alloy structural plate pipe (707.23) are acceptable with the minimum thickness required to satisfy cover conditions for all non-abrasive sites with a pH between 5.0 and 9.0 A blank space in the table indicates that a gage, which satisfies the design service life, is not available. Tables 1002-6(50) & 1002-6(75) Tables 1002-6(50) and 1002-6(75) are based on equations 7 and 9 from the ODOT Location & Design publication 82-1, “Culvert Durability Study” including: �� A 15-year service life for Bituminous Coating
with Invert Paving for culverts 54” [1350 mm] and larger.
�� A 25-year service life for Bituminous Coating
with Invert Paving for culverts 48” [1200 mm] and smaller.
�� A 35-year service life for Aluminium Coating
with pH above 5.0. �� A 50-year service life for Polymeric Coating �� All base metal must provide a minimum of 10
years of service life.
Corrugated aluminium alloy pipe (707.21 and 707.22) with Concrete Field Paving and aluminium alloy structural plate pipe (707.23) with Concrete Field Paving are acceptable with the minimum thickness required to satisfy cover conditions for all abrasive sites with a pH between 5.0 and 9.0 A blank space in the table indicates that a gage, which satisfies the design service life, is not available. Abbreviations and Symbols * Concrete field paving shall be epoxy
coated per 706.03 for pH < 5.0 ** Externally coated per AASHTO M243 w/CFP With concrete field paving of invert
General Notes - Figures 1008-1 through 1008-9
April 2004
Thickness The following table shows the available commercial thicknesses for metallic coated steel and the corresponding gage number:
The maximum available sheet thickness for aluminum coated corrugated steel pipe (707.01, 707.02, 707.05, 707.07; all with aluminum coating) or polymer coated corrugated steel pipe (707.04) is 0.138 [3.51]. Minimum Cover The minimum cover is measured from the top of the pipe or pipe-arch to the top of subgrade; however, in no installation shall the distance from the top of the pipe or pipe-arch to the top of the wearing surface or finished grade be less than the figure values plus 6 inches [150 mm]. Maximum Cover The maximum height of cover is measured from the top of the pipe or pipe-arch, to the top of the wearing surface. When a dashed line is shown in any column, the pipe shown in the corresponding row shall not be specified for the thickness indicated. The maximum height of cover over any pipe is 100 feet [30 m], without a special design. Before a pipe is used under a cover exceeding 100 feet [30 m], the structural maximum allowable height of cover and the required bearing pressure should be calculated and an investigation of the bearing capacity of the foundation material performed. Parameters
The figures are based upon the following parameters: A. A standard highway loading of HS 20-44
[MS-18] for live load. B. Unit weight of embankment material = 120
pounds per cubic foot [1920 kg. per cubic meter].
C. Factor of safety for seam strength = 3.0 D. Factor of safety for buckling = 2.0 E. Horizontal soil modulus =1400 pounds per
square inch [9650 kPa] Foundation For all pipe-arch installations, the foundation material shall be investigated to determine its bearing capacity. The bearing capacity shall be a minimum of twice the corner bearing pressure. Seam Fabrication Allowable heights of cover are based upon the following types of seam fabrication: A. 707.01, 707.04, 707.05, 707.11, and 707.13
with ½" [13 mm] corrugations; pipes 12" [300 mm] dia. through 36" [900 mm] dia. with one row of rivets; 42" [1050 mm] dia. through 84" [2100 m] dia. with two rows of rivets.
B. 707.01, 707.04, 707.05, 707.11, and 707.13
with ½" [13 mm] corrugations; pipe-arches 17" X 13" [430 mm X 340 mm] through 42" X 29" [1060 mm X 740 mm] with one row of rivets; 49" X 33" [1240 mm X 840 mm] through 83"X57" [2100 mm X 1450 mm] with two rows of rivets.
C. 707.02, 707.04, 707.07, 707.11, and 707.14
with 1" [25 mm] corrugations pipes and pipe-arches; all sizes with two rows of rivets.
D. 707.03 pipes and pipe-arches; all sizes and
wall thicknesses with four bolts per foot of seam (3/4" diameter)[75 mm bolt spacing (M20 bolts)], also the 0.280" [7.11 mm] wall thickness in all sizes with six bolts per foot of seam [50 mm bolt spacing]. If six bolts per foot of seam is required, the number of bolts per foot of seam (6) [spacing of bolts] shall be specified on the plans.
Metal Thickness Inches [mm]
Gage Number
April 2004
E. 707.12 pipes; all sizes and wall thicknesses with lock seams.
F. Spot welded, helical butt welded and lock
seams are considered equal to the seam strength of riveted seams.
Abbreviations and Symbols 20+ [6+] The maximum allowable height of
cover over any pipe-arch is 20' [6 m] without a special design. The plus sign indicates the pipe-arch is structurally safe under a cover greater than 20' [6 m], but the bearing capacity of the foundation may not be adequate.
Ht. height, in feet (ft.) [meters (m)] CBP corner bearing pressure, in tons per
square foot (tsf) [kilopascals (kPa)] b/ft. bolts per foot of seam Inv. invalid. Indicates the values were invalid
for the pipe-arch. The corner bearing pressure for the pipe-arch will always exceed the given value under any allowable height of cover.
tsf [kPa] tons per square foot [kilopascals]
General Notes - Figures 1008-10 through 1008-14
April 2004
Minimum Cover Low cover situations (< 2' (0.6m) of fill) with spans > 14' (4.3m) may require >12" (305mm) thick top slabs for precast concrete box culverts. See Section 1008.2.2 Maximum Cover The maximum height of cover is measured from the top of the pipe or elliptical pipe to the top of the wearing surface. When a dashed line is shown in any column, the pipe shown in the corresponding row shall not be specified for the D-Load indicated. When an asterisk is shown in any row, the minimum strength pipe commercially available is greater than the strength shown in the corresponding column. When a blank space is shown, the pipe may be specified if a special design, verifying the structural height of cover, is provided. The maximum height of cover over any pipe is 100 feet [30 m], without a special design. Before a pipe is used under a cover exceeding 100 feet [30 m], the structural maximum allowable height of cover and the required bearing pressure should be calculated and an investigation of the bearing capacity of the foundation material performed. Abbreviations and Symbols D-LOAD The supporting strength of a pipe
loaded under three-edge-bearing test conditions expressed in pounds per linear foot per foot of inside diameter or span [Newton’s per linear meter per millimeter of inside diameter or span].
HE Horizontal elliptical reinforced concrete
pipe VE Vertical elliptical reinforced concrete pipe Precast Reinforced Concrete Box Design Loading Spans above 12' (3.6m) shall be designed as per section 1008.5.3.
1008-10
BEDDING REINFORCED CONCRETE PIPE WITH TYPE 2
MAXIMUM ALLOWABLE HEIGHT OF COVER FOR
Reference Section1008.2.1
706.02 Pipe-Minimum Test Load to Produce a 0.01-Inch Crack D-Load
Minimum Cover The minimum cover is measured from the top of the pipe or pipe arch to the top of subgrade; however, in no installation shall the distance from the top of the pipe or pipe arch to the top of the wearing surface or finished grade be less than the figure values plus 6 inches [150 mm]. Maximum Cover The maximum height of cover is measured from the top of the pipe or pipe arch to the top of the wearing surface. When a dashed line is shown in any column, the pipe shown in the corresponding row shall not be specified for the thickness indicated. The maximum height of cover over any pipe is 100 feet [30 m], without a special design. Before a pipe is used under a cover exceeding 100 feet [30 m], the structural maximum allowable height of cover and the required bearing pressure should be calculated and an investigation of the bearing capacity of the foundation material performed. Parameters The figures are based upon the following parameters: A. A standard highway loading of HS 20-44 [MS-
20] for live load. B. Unit weight of embankment material = 120
pounds per cubic foot [1920 kg. per cubic meter].
C. Factor of safety for seam strength = 3.0 D. Factor of safety for buckling = 2.0 E. Horizontal soil modulus =1400 pounds per
square inch [9650 kPa] Foundation For all pipe arch installations, the foundation material shall be investigated to determine its bearing capacity. The bearing capacity shall be a minimum of twice the corner bearing pressure. Seam Fabrication Allowable heights of cover are based upon the following types of seam fabrication: A. 707.21 pipes; 12" [300 mm] dia. through 36"
[900] dia. with one row of rivets; 42" [1050] dia. through 84" [2100 mm] with two rows of rivets.
B. 707.21 pipe arches; 17" X 13" [430 mm X 340
mm] through 42" X 29" [1060 mm X 740 mm] with one row of rivets; 49" X 33" [1240 mm X 840 mm] through 83" X 57" [2100 X 1450] with two rows of rivets.
C. 707.22 pipes and pipe arches; all sizes with
two rows of rivets. D. 707.23 pipes and pipe arches; all sizes and
wall thicknesses with four bolts per nine inches [225 mm] of seam (3/4" diameter [M20] bolts).
E. 707.24 pipes; all sizes and wall thicknesses
with lock seams. F. Spot welded, helical butt welded and lock
seams are considered equal to the seam strength of riveted seams.
Abbreviations and Symbols 20+ [6+] The maximum allowable height
of cover over any pipe-arch is 20' [6 m] without a special design. The plus sign indicates the pipe-arch is structurally safe under a cover greater than 20' [6 m], but the bearing capacity of the foundation may not be adequate.
Ht. height, in feet (ft.) [meters (m)]
Metal Thickness Inches [mm]
707.21, 707.22 & 707.24
Metal Thickness Inches [mm]
707.03
April 2004
CBP corner bearing pressure, in tons per
square foot (tsf) [kilopascals (kPa)] b/ft. bolts per foot of seam Inv. invalid. Indicates the values were invalid
for the pipe-arch. The corner bearing pressure for the pipe-arch will always exceed the given value under any allowable height of cover.
tsf [kPa] tons per square foot [kilopascals]
1008-10
BEDDING REINFORCED CONCRETE PIPE WITH TYPE 2
MAXIMUM ALLOWABLE HEIGHT OF COVER FOR
Metric UnitsReference Section
1008.2.1
706.02 Pipe-Minimum Test Load to Produce a 0.3-mm Crack D-Load
1101.1 General ...........................................................................................................................11-1 1101.2 Procedures......................................................................................................................11-1
1102 Open Water Carriers .....................................................................................................................11-3 1102.1 General ...........................................................................................................................11-3 1102.2 Types of Carriers.............................................................................................................11-3
1102.2.1 Standard Roadway (Roadside) Ditches..........................................................11-3 1102.2.2 Special Ditches ...............................................................................................11-3 1102.2.3 Median Ditches ...............................................................................................11-4 1102.2.4 Channel Relocations.......................................................................................11-4 1102.2.5 Channel Linings and Bank Stabilization .........................................................11-4
1105 Roadway Culverts .......................................................................................................................11-13 1105.1 General .........................................................................................................................11-13 1105.2 Types of Culvert Flow ...................................................................................................11-14 1105.3 Design Procedure .........................................................................................................11-14
1105.3.1 General .........................................................................................................11-14 1105.3.2 Hydraulic Analysis.........................................................................................11-14 1105.3.3 Bankfull Design .............................................................................................11-15
1105.4 Use of Nomographs ......................................................................................................11-15 1105.4.1 Outlet Control ................................................................................................11-15 1105.4.2 Inlet Control...................................................................................................11-16
1105.5 Design Criteria ..............................................................................................................11-16 1105.5.1 Design Frequency.........................................................................................11-16 1105.5.2 Maximum Allowable Headwater....................................................................11-16 1105.5.3 Method Used to Estimate Storm Discharge..................................................11-16 1105.5.4 Scale of Topographic Mapping Used to Delineate Contributing Drainage Areas.....................................................................................................................................11-16 1105.5.5 Manning’s Roughness Coefficient “n”...........................................................11-16 1105.5.6 Entrance Loss Coefficient “ke” ......................................................................11-16 1105.5.7 Minimum Cover .............................................................................................11-16 1105.5.8 Maximum Cover ............................................................................................11-16 1105.5.9 Maximum Allowable Outlet Velocity..............................................................11-16 1105.5.10 Headwall Type ............................................................................................11-16 1105.5.11 Contacts With County Engineer..................................................................11-16 1105.5.12 Minimum Pipe Size .....................................................................................11-17
1106 End Treatments ...........................................................................................................................11-18 1106.1 General .........................................................................................................................11-18
1106.1.1 Usage............................................................................................................11-19 1106.1.2 End Treatment Grading ................................................................................11-19
1109 Longitudinal Sewer Location.....................................................................................................11-20 1109.1 Under Pavement ...........................................................................................................11-20 1109.2 Under Paved Shoulder..................................................................................................11-21 1109.3 Approval ........................................................................................................................11-21
1110 Reinforced Concrete Radius Pipe and Box Sections..............................................................11-21 1110.1 General .........................................................................................................................11-21
1111 Sanitary Sewers ..........................................................................................................................11-21 1111.1 General .........................................................................................................................11-21 1111.2 Manholes.......................................................................................................................11-21
1112 Notice of Intent (NOI) ..................................................................................................................11-21 1112.1 General .........................................................................................................................11-21
1112.2 Maintenance Project .....................................................................................................11-21 1113 Erosion Control at Bridge Ends ................................................................................................11-22
1113.1 General .........................................................................................................................11-22 1113.2 Corner Cone..................................................................................................................11-22
1114 Storm Water Pollution Prevention Plan (SWPPP) ...................................................................11-22 1114.1 General .........................................................................................................................11-22 1114.2 Objectives .....................................................................................................................11-22 1114.3 General Guidance.........................................................................................................11-22
1114.3.1 Required Size of Sediment Basins ...............................................................11-23 1115 Post Construction Storm Water Management .........................................................................11-23
1115.1 Threshold limits .............................................................................................................11-23 1115.2 General .........................................................................................................................11-23 1115.3 Water Quality Volume (WQv).......................................................................................11-24 1115.4 Water Quality Flow (WQf) .............................................................................................11-24
1116 Structural Best Management Practices (BMPS) ......................................................................11-24 1116.1 General .........................................................................................................................11-24
1116.1.1 Feasibility study ............................................................................................11-25 1116.2 Vegetated Swales and Filter Strips (WQf) ....................................................................11-25
1116.6 Constructed Wetlands (WQv) .......................................................................................11-30 1116.7 Bioretention Cell (WQv) ................................................................................................11-30 1116.8 Manufactured Systems (WQf).......................................................................................11-31 1116.9 Alternative Methods ......................................................................................................11-31
1100 Drainage Design Procedures
1101 Estimating Design Discharge
1101.1 General
In order to properly design highway drainage facilities, it is essential that a reasonable estimate be made of the design and check discharges. Some of the more important factors affecting runoff are duration, intensity and frequency of rainfall; and the size, imperviousness, slope, and shape of the drainage area. Suitable topographic mapping shall be utilized to determine the contributing drainage area. For drainage areas over 100 acres [40 hectares], a 7.5 minute U.S. Geological Survey Quadrangle will ordinarily suffice. For smaller areas, or where discharges are calculated using the rational method, smaller scale maps (1”=50’ to 1”=800’) may be more appropriate. A proper evaluation should be made of the land use throughout the drainage area. Changes in land use within the drainage area which will occur in the immediate future shall be taken into account when determining design discharges. However, probable land use changes beyond this should not be assumed when determining design discharges. It is the responsibility of the local permitting/zoning agency to ensure proper land and water management techniques are utilized. These techniques will minimize the adverse affects of a change in land use. 1101.2 Procedures
1101.2.1 Statistical Methods
The statistical methods developed by the U.S. Geological Survey and published in USGS Reports 89-4126, 93-135 and 93-4080 shall be used to estimate runoff from larger drainage areas. A description and the limitations of these methods are described in Section 1003. 1101.2.2 Rational Method
The rational method is considered to be more reliable for estimating runoff from small drainage areas, usually less than 6 acres [2.5 hectares]; and for areas that contribute overland flow and shallow concentrated flow to the roadway ditch or pavement. The design discharge “Q” is obtained from the equation:
��
���
��
�
360CiAQ
CiAQ
where: Q = Discharge in cubic feet per second
[cubic meters per second]
C = Coefficient of runoff
I = Average rainfall intensity in inches per hour [mm per hour], for a given storm frequency and for a duration equal to the time of concentration.
A = Drainage area in acres [hectares]
The time of concentration is the time required for runoff to flow from the most remote point of the drainage area to the point of concentration. The point of concentration could be a culvert, catch basin or the checkpoint in a roadway ditch used to determine the need for velocity protection. Time of concentration is designated by “tc” and is the summation of the time of overland flow “to”, the time of shallow concentrated flow "ts" and the time of pipe or open channel flow “td”. Overland flow is that flow which is not carried in a discernible channel and maintains a uniform depth across the sloping surface. It is often referred to as sheet flow. The time of overland flow may be obtained from Figure 1101-1, a similar overland flow chart, or from the equation:
��
���
� ��
��
3o
3o
sLC)3.26(1.1t
sLC)1.8(1.1t
where: to = Time of overland flow in minutes
C = Coefficient of runoff
L = Distance to most remote location in
drainage area in feet [meters]
s = Overland slope (percent)
Drainage Design Procedures
11-2 April 2004
These methods should not be used to determine the time of travel for gutter, swale, or ditch flow. This equation and Figure 1101-1 assume a homogeneous drainage area. Where the overland flow area is composed of segments with varying cover and/or slopes, the summation of the time of concentration for each segment will tend to over-estimate the overland flow time, “to”. In this case it may be more appropriate to use an average runoff coefficient "C" and an average ground slope in the Overland Flow Chart. Sheet flow is assumed to occur for no more than 300 feet [90 meters] after which water tends to concentrate in rills and then gullies of increasing proportion. This type of flow is classified as shallow concentrated flow. The velocity of shallow concentrated flow can be estimated using the following relationship:
� �0.5
0.5
ksV
3.281ksV
�
�
where: V = Velocity in fps [m/s]
k = Intercept coefficient
(see Table 1101-1)
s = Overland slope (percent)
Table 1101-1 Types of Surface
Intercept Coefficient “k”
Forest with heavy ground litter 0.076 Min. tillage cultivated; woodland 0.152 Short grass pasture 0.213 Cultivated straight row 0.274 Poor grass; untilled 0.305 Grassed waterways 0.457 Unpaved area; bare soil 0.491 Paved area 0.619
Shallow concentrated flow generally empties into pipe systems, drainage ditches, or natural channels. The velocity of flow in an open channel
or pipe can be estimated using the Manning's equation. The travel time for both shallow concentrated flow and open channel or pipe flow is calculated as follows:
60VLtort ds �
where: ts = Travel time for shallow concentrated
flow in minutes
td = Travel time for open channel or pipe flow in minutes
L = Flow length in feet [meters]
V = Velocity in fps [m/s]
Where a contributing drainage area has its steepest slope and/or highest "C" value in the sub-area nearest the point of concentration, the rational method discharge for this sub-area may be greater than if the entire contributing drainage area is considered. The maximum runoff rate for a sub-area should be considered only if greater than that for the entire area. 1101.2.3 Coefficient of Runoff
The coefficient of runoff is a dimensionless decimal value that estimates the percentage of rainfall that becomes runoff. The recommended values for the coefficient of runoff for various contributing surfaces are shown in Table 1101-2. Where two values are shown, the higher value ordinarily applies to the steeper slopes. For Residential areas, lot size should also be considered in choosing the appropriate value for the coefficient of runoff. Generally, a higher value should be associated with smaller lots and a smaller value should be associated with larger lot sizes. The selected coefficient should be based upon an estimation of the typical slope, lot size, and lot development. The total width contributing flow to a given point usually consists of surfaces having a variable land cover and thereby requires a weighted coefficient of runoff “C”. The weighted coefficient is obtained by averaging the coefficients for the different types of contributing surfaces, as noted in the following example:
Drainage Design Procedures
April 2004 11-3
Table 1101-2
Types of Surface
Coefficient of Runoff “C”
Pavement & paved shoulders 0.9 Berms and slopes 4:1 or flatter 0.5 Berms and slopes steeper than 4:1 0.7 Contributing areas Residential (single family) 0.3-0.5 Residential (multi-family) 0.4-0.7 Woods 0.3 Cultivated 0.3-0.6
The average rainfall intensity “i” in inches per hour [millimeters per hour] may be obtained from the Intensity-Duration-Frequency curves shown on Figure 1101-2. Each set of curves applies to a specific geographic area, A, B, C, or D as shown on the Rainfall Intensity Zone Map, Figure 1101-3. The geographic areas were established from an analysis of rainfall records obtained from Weather Bureau stations in Ohio. Some political subdivisions may have developed curves for their specific area similar to Figure 1101-2. Such curves may be based on a much longer period of record and provide more reliable information. Any local curves proposed by the designer should be cleared with the Hydraulic Section, Office of Structural Engineering prior to incorporating that information in the drainage calculations.
1102 Open Water Carriers
1102.1 General
Open water carriers generally provide the most economical means for collecting and conveying surface water contributing to the roadway. The required capacity of a water carrier involves a determination of the velocity and depth of flow for a given discharge. These characteristics can best be obtained from charts that are based on Manning’s equation. Channel flow charts have been prepared for all the common water carrier shapes and are included in the Drainage Design Aids. A ditch computation sheet similar to that provided in the Appendix shall be used to perform or summarize ditch calculations. As a guideline, the desirable minimum roadway ditch grades should be 0.50% with a recommended absolute minimum of 0.25%. Lower grades may be used on large channels as necessary. Open water carriers should maintain a constant slope wherever possible. The proper location of a ditch outfall is quite important. Existing drainage patterns should be perpetuated insofar as practicable. Care should be taken to not capture an existing stream with the roadside ditch. If this is necessary, the designed ditch shall be in accordance to Section 1102.2.4. 1102.2 Types of Carriers
1102.2.1 Standard Roadway (Roadside) Ditches
The various roadside ditches shown in Volume I, Roadway Design, have proven to be safe and to provide adequate flow capacity. A ditch is considered to be standard when the centerline is parallel to the edge of the pavement and the flowline is a uniform distance below the edge of pavement. A modification of the above is required when the grade of the pavement is too flat to provide acceptable ditch flow, thereby creating the need for a special ditch. Channel charts, Drainage Design Aid Figures 1100-1 through 1100-10, are included for use in determining velocity and depth of flow for standard ditches having variable side slopes. 1102.2.2 Special Ditches
Special ditches other than the modified standard roadway ditch described in Section 1102.2.1 above, include the following: A. The steep ditch beyond the toe of the
embankment used to carry the flow from a cut section to the valley floor.
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11-4 April 2004
B. Toe of fill ditch which is separated from the
toe of fill by a minimum 10 foot [3 meter] wide bench, having a minimum transverse slope of ½ inch per foot [0.04] toward the ditch.
C. Deep parallel side ditches separated from the
pavement by a wide bench or earth barrier. The special ditches described in A, B and C above are ordinarily trapezoidal in shape and appropriate charts for the hydraulic analysis are included in this section of the manual or in the FHWA publication “Design Charts for Open Channel Flow”’ Hydraulic Design Series No. 3. It is required that the calculated flowline elevation be shown on each special ditch cross section. 1102.2.3 Median Ditches
The median ditches that are an integral part of all earth medians have the same shape and capacity features as the standard roadside radius ditch and the appropriate ditch chart is applicable for the hydraulic analysis. The fully depressed earth median provides adequate hydraulic capacity and the appropriate flow charts in the Drainage Design Aid Figures 1100-11, 1100-12 and 1100-13 have been developed for that shape. The rounding shown on the charts varies from 8 feet [2400 millimeters] to 4 feet [1200 millimeters], depending on the width of the median. The slight discrepancy in the rounding from that shown in Volume I, Roadway Design, is not considered to affect the accuracy of the charts. 1102.2.4 Channel Relocations
Major channel relocations should be avoided. However, if it becomes necessary to relocate a channel adhere to the following: The design year frequency used for channel relocations shall be that given in Section 1004.2. All channel relocations shall carefully be designed to preclude erosion or unreasonable changes in the environment. Whenever possible, channel relocations shall be restricted to the downstream end of proposed culverts. The relocated channel shall be of a similar cross-section. Where the existing channel exhibits a two-stage cross section morphology, it shall be replaced with like kind. The two-stage channel is comprised of two distinct areas. The first of these is a meandering bankfull width that carries the channel-forming discharge. The second area is
the flood plain width. See Figure 1102-2 for a graphical representation of the major channel features. The proposed channel should be designed such that it matches the existing channel as closely as possible in regards to existing geomorphic conditions (e.g., channel slope and length, velocity, depth of flow, cross-sectional geometry, channel sinuosity, energy dissipation, etc.). The existing channel geometry and physical characteristics should be established from reference reaches and idealized geometry. The reference reaches should be selected from stable channel reaches close to the relocated section or in locations with similar watershed and valley conditions. The relocated channel should be designed to duplicate the existing hydraulic properties for the bankfull design frequency. The flood clearance criteria given in Section 1005 should also be met. Additional information on the design of relocated channels can be found in the United States Department of Agriculture publication, “Stream Corridor Restoration: Principles, Practices and Processes”. The principals given in this publication utilize idealized channel geometry. The actual design should be refined using the channel geometry and physical characteristics of reference reaches. 1102.2.5 Channel Linings and Bank Stabilization
The use of soil bioengineering should be used to stabilize banks for relocated or impacted channels when practicable. Native plant species should be used when feasible. Bank stabilization using bioengineering is covered in the previously referenced USDA publication as well as the AASHTO Model Drainage Manual and the USDA Engineering Field Handbook, chapter 16, part 650. The design procedures and methods for determining the effectiveness of the traditional channel linings are covered in the Federal Highway Administration Hydraulic Engineering Circular No. 15 “Design of Stable Channels With Flexible Linings”.
A 10-year frequency storm shall be used to determine the depth of flow, and a 5-year frequency shall be used to determine the velocity of flow and the width of ditch lining where needed. Where a flexible ditch lining is required for calculated velocities exceeding the allowable for seed, the minimum width of the lining shall be 7.5 feet [2.25 meters]. The depth of flow shall be limited to an elevation 1 foot [300 millimeters] below the edge of pavement for the design discharge. The depth of flow in toe of slope ditches shall be further limited such that the design year discharge does not overtop the ditch bank. 1102.3.2 Ditch Protection
The velocity for the five-year frequency storm shall not exceed the values shown in Table 1102-1 for the various soil types and flexible linings. If the calculated velocity exceeds that shown in the table then use the following within the stated limitations: A. Seeding and Erosion Control with Turf
Reinforcing Mat (Supplemental Specification 836) where the ditch slope is less than 10% and maximum velocities are as follows:
Turf Reinforcing Mat
Type Maximum Velocity
fps [m/s] Type 1 6 [1.8] Type 2 9 [2.7] Type 3 12 [3.7]
B. Type B, C or D Rock Channel Protection may
be used to line the ditch if the nearest point of the lining is outside the design clear zone or located behind guardrail or barrier. The allowable shear stress (�a) will need to be greater than or equal to the actual shear stress (�ac) for the proper RCP Type. The actual shear stress is based upon the parameters of the channel slope and depth of flow for the 5-year discharge. The following equation is valid for discharges less than 50 cfs with slopes less than 10%:
Where:
D= Water surface depth ft (m) S = Channel slope ft/ft (m/m) �ac = Actual shear stress lbs/ft
2 (Pa)
Allowable Shear Stress RCP Type
�a lbs/ft2 (Pa)
B 6 (287.26) C 4 (191.51) D 2 (95.76)
C. Type B or C RCP may be utilized for lining
ditches on steep grades (slopes from 10%- 25%) that carry flow from the end of a cut section down to the valley floor. HEC-15 procedures for steep gradient channels (refer to HEC-15) shall be used with a safety factor of 1.5.
Contact the Hydraulics Section, Office of Structural Engineering for further guidance of RCP usage for 5-year discharges greater than or equal to 50 cfs.
D. Tied concrete block mat protection (601) may
be used for velocities up to 18 fps [3.0-5.5 m/sec] for channels with 3:1 or flatter side slopes and profile grade less than 5%. The matting may be used within the clearzone provided that the top of the blocks are flush with the finished grade. They should be backfilled and anchored as per the manufacturer’s specifications. Types of tied concrete block mats are shown in Table 1102-2, for various design (5 year) velocities.
Table 1102-1
ALLOWABLE DITCH VELOCITIES (feet per second)
Soil Type
Seed Lining (659)
Sod Lining (660)
Ditch Erosion Protection
(670) Sand 1.5 3.5 3.0 Firm Loam 2.0 4.0 4.0
Clay 2.5 5.0 4.0 Gravel 3.5 6.0 5.0
Weathering Shale
4.5 6.0 5.0
� ac� 62.4 D� S�
� ac� 9784 D� S�
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11-6 April 2004
Table 1102-1 (continued)
ALLOWABLE DITCH VELOCITIES (meters per second)
Soil Type
Seed Lining (659)
Sod Lining (660)
Ditch Erosion Protection
(670) Sand 0.4 1.1 1.0 Firm Loam 0.6 1.2 1.2
Clay 0.8 1.6 1.2 Gravel 1.0 1.8 1.6
Weathering Shale
1.4 1.8 1.6
Table 1102-2
CONCRETE BLOCK MAT VELOCITIES
Type
Allowable Velocity
ft/sec [m/sec]
1
10 [3.7]
2
15 [4.6]
3
18 [5.5]
E. A concrete lining should be considered only
as a last resort. 1102.3.3 Roughness
Suggested values for Manning’s Roughness Coefficient “n” for the various types of open water carriers are listed in Table 1102-3. Table 1102-3 Type of Lining
The Standard No. 4, 5, and 8 Catch Basins are suitable for the standard roadside designs covered in Volume I, Roadway Design. The tilt built into the basin top provides a self-cleaning feature when the basins are used on continuous grades and the wide bar spacing minimizes clogging possibilities, thereby resulting in an efficient design. The bases of the 4, 5 and 8 Catch Basins can be expanded to accommodate larger diameter conduits by specifying Standard Construction Drawing CB-3.4. The bar spacing can be decreased, when desirable for safety reasons, by specifying Grate “E” for the No. 4 and Grate “B” for the No. 5. The following catch basin types are generally recommended based on the size and shape of the ditch. A. Standard No. 4 for depressed medians wider
than 40 feet [12 meters]. B. Standard No. 5 for 40 foot [12 meter] radius
roadside or median ditches. (Use Grate “B” where pedestrian traffic may be expected.)
C. Standard No. 8 for 20 foot [6 meter] radius
roadside or depressed medians 40 feet [12 meters] or less in width.
D. Standard No. 2-2-A may be used in
trapezoidal toe ditches where the basin is located in a rural area. The basin should also be located outside the design clear zone or behind guardrail where the protruding feature of the basin is not objectionable. The capacity of the side inlet catch basin window, for unsubmerged conditions, may be determined by the standard weir equation:
���
��� �
�
23
23
0.55CLHQ
CLHQ
where C is a weir coefficient, generally 3.0, L is the length of opening in feet [meters], H is the distance from the bottom of the window to the surface of the design flow in feet [meters]. The catch basin grate is considered as an access point for the storm sewer and its capacity to admit flow is ignored for continuous grades.
E. Standard No. 2-2-B should be used where
minor, nonclogging flows are involved such as yard sections and the small triangular area
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April 2004 11-7
created by the guardrail treatment for a depressed median at bridge terminals. Standard No. 2-3 through No. 2-6 catch basins should be provided where a larger base is required to accommodate pipes larger than 18 inches [450 millimeters] in span or sewer junctions, or where a No. 2-2-B catch basin will not provide adequate access to the sewer.
F. In urban areas, Standard Side Ditch Inlets
should be used to drain small areas of trapped water behind curbs and/or between driveways.
1102.3.5 Calculated Catch Basin Spacing
Catch basins must be provided to intercept flow from open water carriers when the depth of flow or velocity exceeds the maximum allowable for the design storm for all highway classifications. The standard ditch catch basins, designated Catch Basin No. 4, Catch Basin No. 5, and Catch Basin No. 8, include an earth dike. The dike is approximately 12 inches [300 millimeters] above the flowline of the grate, immediately downstream from the catch basin and serves to block the flow on continuous grades and create a sump condition. When the calculated depth of flow or velocity exceeds the maximum allowable at the checkpoint in the ditch, a catch basin or ditch lining will be required. However, the capacity of the catch basin may be less than the capacity of the ditch and thereby control the catch basin spacing. Figure 1102-1 may be used to check the capacity of a catch basin grate in a sump. To use Figure 1102-1, the calculated discharge at the ditch checkpoint shall be doubled to compensate for possible partial clogging of the grate. In cut sections, the accumulated ditch flow shall be carried as far as the capacity, allowable depth, or velocity of flow will permit. The first catch basin in the roadside or median ditch will determine the need for a storm sewer system required for the remainder of the cut. Velocity control should be extended as far as inexpensive flexible ditch linings will permit. Consideration should also be given to providing positive outlets for underdrains and providing access to longitudinal sewer systems when locating ditch catch basins.
1102.3.6 Arbitrary Maximum Catch Basin Spacing
Catch basins are required at the low point of all sags and the earth dike noted in Section 1102.3.5 shall be omitted. The maximum distance between catch basins in depressed medians in fill sections shall be as shown in Table 1102-3. Where underdrains are utilized, catch basins shall be provided at a maximum spacing of 1000 feet [300 meters] (500 feet [150 meters] with free draining base) to provide a positive outlet for underdrains. Table 1102-4
Depressed Median Catch Basin Spacing (Fill Sections)
1102.4 Ditch Design Criteria - Design Traffic of 2000 ADT or Less
1102.4.1 Design Frequency
A 5-year frequency storm shall be used to determine the depth of flow, and a 2-year frequency to determine the velocity of flow and width of ditch lining, where needed. The depth of flow shall be limited to an elevation 9 inches [225 millimeters] below the edge of pavement for the design discharge. The depth of flow in toe of slope ditches shall be further limited such that the design year discharge does not overtop the ditch bank. The minimum width of lining shall be in accordance with Section 1102.3.1. 1102.4.2 Velocity Protection
Velocity protection shall be in accordance with 1002.3.2 except that a 2-year frequency event shall be used.
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11-8 April 2004
1102.4.3 Roughness
The roughness used for the hydraulic analysis shall be based on the Manning's Roughness Coefficient values shown in Table 1102-2. 1102.4.4 Catch Basin Types
Standard No. 5 Catch Basins, No. 2-2-A Catch Basin (within their safety limitations as discussed in Section 1102.3.4(D)) and No. 2-2-B Catch Basins should be considered for the lower ADT highways. Standard No. 4 Catch Basins should be used where additional capacity is required. 1102.5 Design Aids for Ditch Flow Analysis
1102.5.1 Earth Channel Charts
Standard radius roadside ditch charts have been prepared, based on the Manning’s equation, to facilitate the hydraulic analysis of ditch flow and are included in the Drainage Design Aids. Some of the more commonly used trapezoidal channel charts are also included. Other trapezoidal channel charts (with 2:1 - 2:1 side slopes and bottom widths varying from 2 feet [610 millimeters] to 20 feet [6100 millimeters]) are available in the Federal Highway Administration publication referenced in section 1102.2.2. All earth channel charts have been prepared using a Manning's Coefficient of Roughness of 0.03, which is recommended for a seed lining (Construction and Material Specifications Item 659). Qn and Vn scales have been included on all channel charts so that the channel flow may be analyzed for any value of “n” depending on the roughness of the channel or lining. 1102.5.2 Rectangular Channel Charts
Vertical side channel charts that can be used to analyze the open channel flow in box culverts are included in the Federal Highway Administration publication “Design Charts for Open Channel flow,” previously referred to. 1103 Pavement Drainage
1103.1 General
When curbs are provided at the edge of pavement or paved shoulder, (primarily in urban areas), it is necessary to determine the proper
type of pavement inlet (or catch basin) to control the spread of water and depth of flow on the pavement. Present day geometric design has resulted in relatively flat transverse and longitudinal pavement slopes. These slopes require more pavement inlets (or catch basins) and consequently result in an appreciable increase in the drainage cost. To alleviate the above, where curb is permissible, standard curb and gutter should be used adjacent to the pavement. Where standard curb and gutter cannot be provided, the outside lanes of a muli-lane pavement should maintain a transverse slope of 1/4 inch per foot [0.02]. If paved shoulders are provided, the drainage cost will be decreased appreciably due to the large volume of flow that can be carried on the pavement shoulder without exceeding the allowable depth of 1 inch [25 millimeters] below the top of curb or a maximum of 5 inches [125 millimeters]; a maximum depth of 6 inches [150 millimeters] is permissible where a barrier shape is provided adjacent to the pavement. A pavement drainage computation sheet similar to that provided in the Appendix shall be used to perform or summarize necessary computations. Additional information concerning pavement drainage can be obtained from the Federal Highway Administration Hydraulic Engineering Circular No. 22, "Urban Drainage Design Manual." 1103.2 Design Frequency
Pavement inlets (or catch basins) shall be spaced to limit the spread of flow on the traveled lane (considered to be 12 feet [3.6 meters] wide) as shown in Table 1103-1. The allowable spread may be increased slightly for streets carrying predominantly local traffic and with design speeds less than 45 mph [70 kph]. Design shall be based upon the following frequencies: Freeways . . . . . . . . . . . . . . . . . . . . . . . 10 YearsHigh volume highways (over 6000 ADT Rural or 9000 ADT Urban) . . . 5 Years
All other highways . . . . . . . . . . . . . . . . 2 Years For underpasses or other depressed roadways where ponded water can be removed only through the storm sewer system, the spread shall be checked for a 50-year storm for Freeways and high volume highways as defined above, and for a 25-year storm for other highways. The ponding will be permitted to cover all but one through lane of a multiple lane pavement. The depth of flow at
Drainage Design Procedures
April 2004 11-9
the curb shall not exceed 1 inch [25 millimeters] below the top of the curb for the design discharge regardless of the type of highway. A maximum depth of 6 inches [150 millimeters] is permissible where a barrier shape is provided adjacent to the pavement. Table 1103-1
Allowable Pavement Spread Freeways 0 feet
High Volume Highways (Over 6000 ADT rural or 9000 ADT urban)
High Speed (�45 mph) 4 feet
Low Speed (< 45mph) 2 lanes 6 feet �4 lanes 8 feet All other Highways 2 lanes 6 feet
�4 lanes 8 feet
Freeways 0 meters
High Volume Highways (Over 6000 ADT rural or 9000 ADT urban)
High Speed (�70kph) 1.2 meters
Low Speed (< 70kph) 2 lanes 2.0 meters �4 lanes 2.4 meters All other Highways 2 lanes 2.0 meters
�4 lanes 2.4 meters
1103.3 Estimating Design Discharge
Runoff contributing to curbed pavements shall be estimated by the rational method, as explained in Sections 1101.2.2, 1101.2.3 and 1101.2.4. The time of concentration “tc” shall be the actual time of concentration calculated according to Section 1101.2.2 with an absolute minimum time of 10 minutes. In urban areas, where justifiable (e.g. contributing drainage area would be difficult to determine), the “strip method” may be used to determine contributing drainage areas. The strip method assumes a contributing drainage area of 150 feet [50 meters] taken on each side of the roadway centerline. 1103.4 Capacity of Pavement Gutters
A pavement gutter has a right triangular shape, with the curb forming the vertical leg and the straight pavement slope, the gutter plate of a curb
and gutter, or a paved shoulder forming the hypotenuse. A standard curb and gutter adjacent to a straight pavement slope, or paved shoulder, forms a composite gutter section which complicates the flow analysis. In most cases, the top width of the water surface in a pavement gutter far exceeds the height of the curb. The hydraulic radius does not accurately describe the gutter cross section in this situation, thereby requiring a modification to the Manning’s equation to analyze the gutter flow. The accepted modification results in the following equation:
��
���
��
�
38
21
38
21
dsnZ0.376Q
dsnZ0.56Q
where: Q = Discharge in cubic feet per second
Z = Reciprocal of the pavement cross
n = Manning’s Coefficient of Roughness
(Table 1102-3)
s = Longitudinal pavement slope
d = Depth of flow in gutter section at curb in feet [meters]
Figure 1103-1 provides a graphical solution for the above equation and its use is comparatively simple for straight transverse pavement slopes. However, the use of the nomograph to determine depth of flow at the curb and resulting spread on the pavement for composite sections is much more involved. 1103.5 Pavement Flow Charts
Charts have been prepared for the more commonly used curbed pavement typical sections, and they are included in the Drainage Design Aids. The charts are particularly helpful for determining the flow for composite pavement sections where the spread can be read directly from the appropriate Pavement Flow Chart. To use the charts, enter with a predetermined design discharge (total flow) Qt in the gutter in cubic feet per second [cubic meters per second] and proceed vertically to intersect the longitudinal gutter slope line. At that intersection, read the
Drainage Design Procedures
11-10 April 2004
spread in feet [meters] shown on the diagonal spread lines. The spread of flow will generally control the pavement inlet or catch basin spacing, where the transverse and longitudinal slope of the pavement is relatively flat. The above is prevalent in long flat sag vertical curves, where a flanking inlet (or catch basin) should arbitrarily be provided on both sides of the low point in a pavement sag. This is particularly so for Freeways. Three inlets or catch basins in a sag can be justified only on the basis of need for other highway classifications. Usually a Standard 6 foot [1.8 meter] pavement inlet or No. 3A catch basin will be adequate, and they should be placed where the grade elevation is approximately 0.20 feet [60 millimeters] higher than at the low point. A combination grate and curb opening catch basin (Standard No. 3) should be provided at the low point. Vane grates (Grate "V") should be used for No. 3 and No. 3A catch basins, except where pedestrian or bicycle traffic precludes their use. Inlets or catch basins should arbitrarily be placed upstream of all intersections, bridges and pedestrian ramps. When justified, inlets (or catch basins) should be located a minimum of 10 feet [3 meters] off drive aprons, intersection return radii, pedestrian ramps or curb termini. 1103.6 Bypass Charts for Continuous Pavement Grades
Bypass charts are included for the standard pavement inlets and catch basins in the Drainage Design Aids. Bypass for a given structure can be read directly from the chart (At the intersection of the spread, determined in Section 1103.5, and the longitudinal gutter slope, read the bypass flow Qb on the abscissa). Experience has proven that, for greater efficiency, inlets should be sized to bypass a minimum of 10% to 15% of the design discharge. This criterion should be used to determine the type or length of inlet to be used in a given location. It is not intended to establish the required spacing. The most efficient design maintains the allowable spread on continuous grades and at the sag. The bypass for a catch basin or inlet should be added to the total flow in the adjacent downstream gutter section. 1103.6.1 Curb Opening Inlets
The flow bypassing a standard curb opening inlet, for pavement transverse slopes or combination of
slopes differing from the charts included in the Drainage Design Aids, may be obtained from Figure 1103-2. The use of curb opening inlets should be avoided where bicycle traffic is expected. 1103.6.2 Grate or Combination Grate and Curb Opening Inlet
The standard pavement catch basin in this category is considered to intercept all the flow over the grate when used on continuous grades. A portion of the flow outside of the edge of the grate will also be intercepted, the amount varying with the depth of flow “y” along the edge of the grate. The depth “y” can be determined from Figure 1103-1, and the resulting flow spilling over the edge of the grate from Figure 1103-2, using a ½ inch [13 millimeter] local depression for straight transverse pavement slopes, or no local depression for a composite gutter section. The curb opening of a combination catch basin on a continuous grade will admit some flow, particularly if there is a partial clogging of the grate; however, the additional capacity should be considered as a factor of safety only. 1103.7 Grate Catch Basins and Curb Opening Inlets In Pavement Sags
The spread determined from the pavement flow charts need not be checked any closer than 25 to 50 feet [7.5 to 15 meter] on either side of the sag, well beyond the limits of the local depression. The spread in the sag should be determined from the depth of flow at the edge of grate using Figure 1103-3 and should include the total flow (contributions from each side of the sag vertical curve) reaching the inlet or catch basin. Standard No. 3 catch basins should be used in pavement sags. The capacity of the grates to admit flow is based on the depth of ponding around the grates. The capacity of the grates shown in Figure 1103-3 is based on weir flow over the edge of the grate, up to a depth of 0.4 feet [120 millimeters]. For greater depths, the total area of grate opening is considered, with no deduction made for possible clogging. When evaluating the spread in a depressed sag for a 25-year or 50-year event, the capacity of the window shall be considered. This capacity may be obtained from Figure 1103-4. The curb opening capacity should be added to the grate capacity for submerged conditions. Where the low point of a sag vertical curve occurs in a drive, a No. 6 catch basin should be provided
Drainage Design Procedures
April 2004 11-11
at the low point with flanking No. 3A catch basins as per Section 1103.5. No. 6 catch basins may be used along curbed roadways and medians provided that the grate capacity is not exceeded. 1104 Storm Sewers
1104.1 General
Storm sewer systems are designed to collect and carry storm water runoff from the first pavement or ditch inlet, or catch basin to the predetermined outlet. (Further reference to inlets infers either inlets or catch basins). Long cut sections often result in the need for longitudinal trunk sewers to accept the flow from a series of inlets. The proper location of a sewer outlet is quite important. Existing drainage patterns should be perpetuated insofar as practicable. Careful consideration should be given to the possibility of actionable damage for the diversion of substantial volumes of flow. Long fill sections requiring median or pavement drains may best be served by transverse sewers that outlet independently at the toe of fill ditch. Storm sewer systems shall be sized to convey the current flow from areas naturally contributing to the highway or from intercepting existing storm sewers. Storm sewer systems may be oversized at the request of a local government entity to convey flow from areas beyond those considered highway responsibility or increased flows from anticipated development with the approval of the Hydraulic Section, Office of Structural Engineering. The additional cost to construct the increased sized storm sewer system will be the responsibility of the local government. The proration of project funds and local government funds will be determined from estimated construction costs. The project funding participation will be determined as a percentage of the total cost of the affected plan items. The percentage will be computed by dividing the estimated cost to construct a highway responsibility system only by the estimated cost to construct the oversized system. The affected plan items and participation percentage will be noted in the plan general summary. Type B conduit shall be specified for storm sewers under pavement, paved shoulders and commercial or industrial drives and Type C conduits for storm sewers beyond those limits. However, the type of conduit shall not be changed for a short run of conduit which would ordinarily require a change in conduit type.
As an example of the above, Type B should be used for a transverse conduit that is required to drain an earth median catch basin in an embankment section under the pavement to a point approximately 10 feet [3 meters] from the embankment slope. A concrete collar, as per Standard Construction Drawing DM-1.1, should be provided to connect the Type B and a Type F Conduit, located back of, and parallel to, the embankment slope. Type F conduit, 707.05 Type C, shall be provided for the pipe specials required to negotiate the bend at the top and bottom of the embankment. The Construction and Material Specifications stipulate the permissible pipe shapes and materials. Storm sewer designs will be based on round pipe, and the choice of the permissible material types for the conduit specified will be the contractor’s option. Extensions of existing pipes should typically be made using like kind material. The length of conduit to be paid for will be the actual number of linear feet [actual number of meters, rounded to the highest ½ meter], measured from center-to-center of appurtenant small structures. No deduction will be made for catch basins, inlets or manholes that are 6 feet [2 meters] or less across, measured in the direction of flow. 1104.2 Design Considerations
1104.2.1 Storm Sewer Depth
From a cost standpoint, it is desirable to keep a storm sewer system as shallow as possible, consistent with the following controls: A. A minimum cover of 9 inches [225
millimeters] from the top of a rigid pipe to the bottom of the pavement subbase (12 inches to 24 inches [300 millimeters to 600 millimeters] for a flexible pipe, see Section 1008).
B. A minimum cover of at least 18 inches [450
millimeters] for standard strength pipe, where permitted.
C. A sufficient depth to permit the use of precast
inlets, catch basins and manholes. Refer to the Standard Construction Drawings for this information.
D. A sufficient depth to avoid interference with
existing utilities such as sanitary sewers, the grade of which cannot be changed.
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11-12 April 2004
E. A sufficient depth to provide a positive outlet for underdrains. It is desirable to maintain the underdrain outlet 12 inches [300 millimeters] above the bottom of the outlet structure with 6 inches [150 millimeters] as a minimum.
F. Sufficient slope to provide a desirable
minimum velocity of 3 feet per second [1 meter per second], for self-cleansing. This velocity is calculated using the “just full” Manning’s Equation.
G. The crown of a smaller upstream pipe in a
longitudinal trunk sewer should match the crown of the adjacent downstream pipe.
Where proposed highway storm sewers or ditches will interfere with existing private drains carrying treated or untreated sanitary flow, the names and addresses of the affected property owners shall be submitted to the District Deputy Director. The above information shall be obtained well in advance of the Field Drainage Review so the appropriate provisions of Directive No. 22-A can be followed. 1104.2.2 Storm Sewer Access
Most standard catch basins and pavement inlets will provide sufficient access to small shallow sewers. Catch basin or pavement inlets can be used to negotiate changes in sewer sizes or minor horizontal or vertical direction changes within the size limitation of the structure, but more pronounced changes may require manholes. It may be necessary, or desirable to locate longitudinal trunk sewers away from the curb to provide for a utility strip between the curb and the sidewalk and to avoid a conflict with the underdrain system. This will require properly spaced manholes in the sewer line. Small sewers (under 36 inches [900 millimeters] in diameter) located under or near the edge of pavement, should be accessible at intervals not to exceed 300 feet [100 meters]. For sewers sized 36 to 60 inches [900 to 1500 millimeters] manholes should be spaced every 500 feet [150 meters] maximum. Manholes should be provided every 750 to 1000 feet [250 to 300 meters] maximum for larger sewers. 1104.3 Layout Procedure
1104.3.1 Plan
A print of the plan sheets involved should be used to spot catch basins and inlets that are required to drain the project and satisfy maximum allowable
depth and/or spread of flow. A strip map showing the delineated drainage area and topography is required. The map will provide the designer with a means of determining the drainage area and the weighted coefficient of runoff for the individual areas contributing flow to the required storm sewer system. 1104.3.2 Profile
A profile of the existing and proposed pavement or ground line over the proposed sewer location should be plotted. On the same profile, plot the locations of catch basins, inlets and manholes, along with a tentative storm sewer system. 1104.4 Storm Sewer Design Criteria
1104.4.1 Design Frequency
All storm sewers shall be sized to flow just full (i.e. depth of flow for maximum discharge) for a 10-year frequency storm. The size is determined by working downstream from the first sewer run. It will be acceptable to use a discharge of a more frequent occurrence if consistent with local policy (depending upon the design ADT of the roadway) or to avoid extensive replacement of an existing downstream drainage system. 1104.4.2 Hydraulic Grade Line
Starting at the storm sewer system outlet and working upstream, the elevation of the hydraulic grade line at the upper end of each sewer run should be determined using a 25-year frequency. It will be acceptable to use a discharge of a more frequent occurrence if consistent with local policy (depending upon the design ADT of the roadway) or to avoid extensive replacement of an existing downstream drainage system. Ordinarily, the hydraulic grade line will be above the top of the pipe, causing the system to operate under pressure. If, however, any run in the system does not flow full, (pipe slope steeper than the friction slope) the hydraulic grade line will follow the friction slope until it reaches the normal depth of flow in the steep run. From that point, the hydraulic grade line will coincide with the normal depth of flow until it reaches a run flatter than the friction slope for that run. The starting elevation for the hydraulic grade line determination should be the higher of either: the downstream channel water surface elevation for the 25-year event, or (dc+D)/2 at the system outlet.
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The intensity “i” in the rational equation Q=CiA [Q=CiA/360] used to determine the check discharge (25-year frequency) shall be the same for all sewer runs as that calculated for the last, or downstream run, in a continuous sewer system. The hydraulic grade line shall not exceed the following for any roadway with greater than 2000 ADT: A. 12 inches [300 millimeters] below the edge of
pavement for sections without curb. B. The elevation of a curb opening inlet or grate
elevation of a pavement catch basin. Consideration shall be given to a reduction in the design frequency and to more liberal hydraulic grade line controls for less important highways than those noted above. The check discharge, to determine the elevation of the hydraulic grade line for highways having depressed sags that must be drained by storm sewers, shall be based on a 50-year frequency. One directional lane of a multiple lane highway or one-half of a lane on a 2-lane highway should be passable when the sewer system is discharging the 50-year storm. Storm sewers for all highways shall satisfy a 50-year check to preclude flooding of buildings or extensive flooding of private property. If the hydraulic grade line exceeds the limits noted above, the controlling sewer size shall be increased. (These criteria are not intended to lower existing high water elevations) 1104.4.3 Coefficient of Runoff
The weighted coefficient of runoff shall be determined as explained in Section 1101.2.3 1104.4.4 Time of Concentration
The time shall be determined as explained in Section 1101.2.2. A minimum time of concentration of 15 minutes to the first ditch catch basin and 10 minutes to the first pavement inlet shall be used. The actual calculated time of concentration shall be used when values greater than these minimums occur.
1104.4.5 Pipe Roughness Coefficient
A Manning’s “n” of 0.015 shall be used for sewers 60 inches [1500 millimeters] in diameter and
under, and 0.013 for larger sewers. The basic “n” value for smooth pipe, concrete, vitrified clay, bituminous lined corrugated steel or thermoplastic is 0.012. The increased values are recommended for sewers to compensate for minor head losses incurred at catch basins, inlets and manholes located in a storm sewer system. 1104.4.6 Minimum Storm Sewer Pipe Size
A minimum pipe diameter of 15 inches [375 millimeters] shall be used for Freeways and Freeway ramps (Where an existing storm sewer is to remain in service, it is not necessary to replace, hydraulically adequate pipes to meet this criterion) and 12 inches [300 millimeters] for other highways. 1104.5 Hydraulic Design Procedure
With the layout suggested in Section 1104.3, start with the upper catch basin or inlet and determine the value of CA for the contributing flow (CA is the product of the weighted coefficient of runoff and the drainage area). Next, determine the time of concentration for the first area and the corresponding rainfall intensity “i” from the proper curve shown on Figure 1101-2. The design discharge “Q” to use to determine the required size of the first sewer from MH No. 1 to MH No. 2 is the product of Ca x i [0.0028CA x i]. At manhole No. 2, determine the value of CA for the additional area contributing at that point and add to the CA for MH No. 1. Compute the time of flow in the storm sewer from MH No.1 to MH No. 2 in minutes and add to the time of concentration at MH No. 1. Check the time of concentration for the area contributing to MH No. 2, and use the larger of the two as the duration for the new value of rainfall intensity for computing the design flow from MH No. 2 to MH No. 3. It is obvious that the process is quite involved, and a storm sewer computation sheet similar to that provided in the Appendix shall be used to tabulate the required information. The calculations for lateral connections to the longitudinal trunk sewer should be tabulated separately from the trunk sewer calculations. 1105 Roadway Culverts
1105.1 General
A culvert generally carries a natural stream under the highway embankment. Its horizontal and vertical alignment should approximate that of the
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natural channel and thereby minimize stream impacts and the need for channel relocations. Optimum design efficiency (i.e., best hydraulic performance and least environmental impacts) occurs when the roadway alignment is normal to the flow in the channel and is located on a relatively straight and stable section of the stream. Impacts to streams should be considered early in the design process and should be taken into consideration when determining the roadway alignments. The proposed roadway should avoid stream confluences. Culverts should not be placed on skews in excess of 45º or as further limited in Section 1008. A single-cell round pipe should be the designer’s first choice. In cases where required cover or discharge precludes a round pipe, consideration should be given to a single-cell elliptical concrete, metal pipe-arch, prefabricated box culvert or three-sided structure, in order of preferred use. For justification of multiple cell culverts, see Section 1105.6.2. When bankfull design is required, special shaped culverts, or culverts with depressed inverts shall be used. The two (2) year bankfull discharge shall be considered in the design. If the flood plain width at the proposed crossing is greater than two (2) times the bankfull width, a flood plain culvert shall be used. In wide flood plain channels, a flood plain culvert shall be used on both sides of the bankfull channel. The preceding conditions apply for all culverts except for those that meet any of the following conditions: 1. The culvert is a replacement structure.
2. The culvert does not convey a water of the United States or conveys an ephemeral stream without a clearly defined channel.
3. The culvert is 30" in diameter or rise, or less. See Section 1105.3.3 for a discussion on bankfull discharge See Section 1105.6.5 for a discussion on depressed inverts. See Section 1105.6.6 for a discussion on flood plain culverts. The proper location of the culvert is quite important. Existing drainage patterns should be perpetuated insofar as practicable. Careful consideration should be given to the possibility of actionable damage for the diversion of substantial volumes of flow.
1105.2 Types of Culvert Flow
Laboratory tests sponsored by the FHWA have established two general types of culvert flow: (1) flow with inlet control, or (2) flow with outlet control. Nomographs have been prepared for use in the determination of culvert headwater for the appropriate control. Under inlet control, the headwater “HWI” is directly related to the cross-sectional area of the culvert barrel and the inlet geometry. Under outlet control, the headwater “HWO” is further influenced by tailwater depth in the outlet channel and the slope, length and roughness of the culvert barrel. As shown in Figure 1105-1, culverts operate with a free water surface if the headwater is equal to or less than 1.2D, and with a submerged entrance if the headwater is greater than 1.2D, where D is the diameter or rise of the pipe. 1105.3 Design Procedure
1105.3.1 General
The design of a culvert involves a determination of the appropriate design and check discharges. The process begins with a delineation of the drainage area, in acres [hectares], on a suitable topographic map. The design discharge “Q” for most culvert drainage areas will be obtained by procedures described in USGS Reports 89-4126 and 93-135, applying the limitations covered in Section 1003.1.2 of this manual. The Rational method should be used to obtain the discharge from small and other unusual drainage areas as noted in Section 1101.2.2 A representative cross-section of the embankment at the proposed culvert site, along with a profile of the natural stream or ground line, will be required to determine the approximate length and slope of the culvert. 1105.3.2 Hydraulic Analysis
The hydraulic analysis of a culvert, including a determination of the headwater depth and outlet velocity for the design discharge, is simplified by the use of Pipe Flow Charts and the headwater and head nomographs noted in Section 1105.4. The charts are included with the Drainage Design Aids, beginning with Figure 1100-200.
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To preclude the need for a determination of the probable type of flow under which a culvert will operate for a given set of conditions, the headwater depths may be computed using the nomographs for both inlet and outlet control. The size of pipe is then selected by using the control giving the higher headwater limitation. The relationship of the headwater to the diameter or height of the culvert “HW/D” is read directly from the inlet control nomograph and the HWI equals that value multiplied by D. HWO is computed by the equation HWO=H+ho - SoL. The loss of head “H” is read from the flowing-full nomograph and the tailwater depth “ho”, is the greater of either the normal depth of flow in the outlet channel or the depth as flow passes through the outlet of the pipe, calculated as (dc+D)/2. D is the diameter or rise of the culvert and dc is the critical depth of flow which may be read from the critical depth curve shown on each Pipe Flow Chart. The above procedure is reasonably accurate for the majority of culvert flow conditions. For culverts operating with outlet control (see Figure 1105-1, Class 1-A and 1-B), where the calculated headwater (using the appropriate nomograph) is less than 0.75D, a backwater analysis can be justified and is recommended. A culvert analysis sheet similar to that provided in the Appendix shall be used to tabulate all the pertinent factors required to determine the controlling headwater for each culvert type being considered for a given location. The analysis sheet includes other information valuable to the reviewer and it is to be included with other supporting data for required review submissions. Hydraulic analysis of culverts may also be performed utilizing the Federal Highway Administration Hydraulic Design Series No. 5, Hydraulic Design of Highway Culverts. Computer programs such as FHWA HY-8 or ODOT’s HYDRA software package may be used. HYDRA may be downloaded from the Hydraulics website. Additional analysis methods are listed in the Appendix of Volume 3, Highway Plans. For replacement projects, an analysis of the existing structure shall be performed. If appropriate (usually depending upon whether the structure is operating with a free water surface at its entrance), it is preferable that the same analysis method be used to compare the existing and proposed structures. For bridge replacements, acceptable methods of hydraulic analyses are listed numerically in preferred order
as follows (the limitations of the method used shall be investigated prior to selecting it for use): 1. Computer Program HEC-2 (HEC-RAS) 2. Computer Program HY-7 (WSPRO) 3. Hydraulic Design Series No. 1, "Hydraulics of
Bridge Waterways", Federal Highway Administration, and computer program HY-4.
1105.3.3 Bankfull Design
The proposed culvert should convey the bankfull discharge with minimum change in the bankfull depth of flow in the adjoining channel sections as compared to the existing conditions. This check should begin with the culvert size determined from the hydraulic analysis per Section 1105.3.2 incorporating any pipe size increase per section 1002.3. Using field-obtained stream cross-sections, the depth of flow can be obtained from a standard step-backwater calculation like that used in a water-surface profile model such as HEC-RAS. The barrel size or shape may be increased if a benefit in the depth of the adjacent channel sections is realized. Until more precise data is available, the discharge used for bankfull design may reasonably be assumed to be equivalent to the 2-year recurrence interval discharge. Because the culvert geometry and barrel roughness differ from the stream channel, it is unlikely that any culvert section will be able to exactly match the hydraulic properties of the existing channel. The objective is to determine if the hydraulically sized culvert will significantly impact the adjoining stream sections and if an increase in barrel size or a change in shape can reduce impacts. 1105.4 Use of Nomographs
1105.4.1 Outlet Control
To determine the loss of head “H” for a given concrete pipe culvert with a grove-end entrance and discharge “Q”, proceed as follows: By straight line, connect culvert size with ke=0.2 (length scale) and obtain a point on the turning line. Connect the turning line point with the computed discharge “Q” and read the head loss “H”. Follow the same procedure for a corrugated metal pipe except using ke=0.9 (length scale).
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The ke value for additional shapes can be found in the Federal Highway Administration publication referenced in Section 1105.3.1. Should the roughness coefficient “n” of the proposed pipe differ from that shown on the chart, adjust the measured culvert length by the length factor given on Design Aid Figure 1100-247. For an example, see Drainage Design Aid Figure 1100-247. The Federal Highway Administration publication referenced in Section 1105.3.1 offers nomographs for culvert shapes not available in the Drainage Design Aids. Their use is recommended for special culvert shapes. 1105.4.2 Inlet Control
To determine the headwater “HW” for a given discharge “Q”, size and type of culvert, proceed as follows using appropriate Figures 1100-245, 1100-246 (Drainage Design Aids). Use Figure 1100-245 for a round corrugated metal pipe culvert and Figure 1100-246 for a round smooth-lined pipe culvert. By a straight line, connect the culvert size with the discharge “Q”, extend a diagonal line to Scale (1) and thence by horizontal line to Scale (3). Based on a groove-end entrance and a Standard HW-2.1 headwall recommended for concrete pipe culverts, the HW/D relationship is obtained by an average of the (2) and (3) Scale values. Follow the same procedure for a corrugated metal pipe with a Standard HW-2.2 headwall, where HW/D is the average values read from Scales (1) and (3). Use Scale (2) for the HW/D relationship for concrete box culverts. 1105.5 Design Criteria
1105.5.1 Design Frequency
The design frequency shall be as stated in Section 1004.2 It should be noted that a Flood Hazard Evaluation using a check discharge based on the 100-year flood frequency shall be made for all culverts as noted in Section 1005.2.1. 1105.5.2 Maximum Allowable Headwater
See Section 1006. 1105.5.3 Method Used to Estimate Storm Discharge
See Sections 1003 and 1101.
1105.5.4 Scale of Topographic Mapping Used to Delineate Contributing Drainage Areas
See Section 1101.1 1105.5.5 Manning’s Roughness Coefficient “n”
The “n” values for corrugated metal pipe are given in Figure 1105-2. The “n” value for all smooth flow pipe is 0.012. Use a weighted manning’s n for bankfull designed culverts or analyzing older culverts with sediment deposition. 1105.5.6 Entrance Loss Coefficient “ke”
See Table 1105-1 or Appendix D of Federal Highway Hydraulic Design Series No. 5, "Hydraulic Design of Roadway Culverts. 1105.5.7 Minimum Cover
See Section 1008 1105.5.8 Maximum Cover
See Section 1008 1105.5.9 Maximum Allowable Outlet Velocity
See Figure 1107-1 Table 1105-1
Type A Conduit Entrance Loss Coefficient ke
Type of Pipe Headwall Type Full One-Half None Concrete or Vitrified (thick wall) *
0.2 0.2 0.2
Corrugated Metal (thin wall)
0.25** 0.9 0.9
* groove end entrance ** with beveled entrance
1105.5.10 Headwall Type
See Section 1106.2 1105.5.11 Contacts With County Engineer
Contact shall be made with the County Engineer at the beginning of the design process to ascertain ditch cleanout grades and watersheds, and the design shall be based on that
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information. Form LD-33 (available in the Appendix) shall be used to document approval. 1105.5.12 Minimum Pipe Size
As specified in Section 1002.3.1 1105.6 Special Considerations
The following are special conditions that will be encountered in the hydraulic design of culverts that warrant clarification. 1105.6.1 Tailwater
Tailwater at a culvert outlet can greatly affect the size of culvert required at a specific site. For this reason a proper evaluation shall be made of the outlet channel so that a reasonable estimate of the tailwater can be calculated. A determination of the normal depth of flow in the outlet channel, when the culvert is discharging the design flow, normally establishes the culvert tailwater. A close examination of the downstream channel may however, reveal a temporary or permanent obstruction that will control the operation of the culvert. In some cases, the culvert will outlet near a river or other fluctuating water surface stream that could control its operation. Where that drainage area of the culvert is very much less than the receiving watercourse (i.e. 2 orders of magnitude) the effect of the receiving watercourse generally may be disregarded. Where the drainage areas of the culvert and receiving watercourse are nearly equal, concurrent flood peaks may be assumed. Where there is a significant, but not excessive, difference in the drainage area of the culvert and receiving stream, the following design procedure should be used and the culvert sized using the combination that results in the highest headwater. A. Compute the culvert headwater using the
proper design frequency for the culvert and a lesser frequency for the receiving stream water surface elevation (i.e. culvert tailwater elevation) depending upon the difference in drainage areas; say a 25-year culvert and a 10-year stream.
B. Use 10-year frequency for the culvert and 25-
year for the stream.
In some locations, a high tailwater will control the operation of a culvert to such an extent that a substantial increase in pipe size will be required for a negligible decrease in the headwater elevation. For this case, the culvert size should be based on a practical tailwater elevation (e.g. [dc+D]/2). 1105.6.2 Multiple Cell Culverts
As discussed in Section 1105.1, a single-cell culvert should be the designer’s first choice within practical limitations. Occasionally, low headwater requirements, high fills, or bankfull design will create the need for multiple cells. For these cases, it is desirable to limit the number of cells to two. Experience has proven that multiple cells well aligned with a relatively straight channel, will operate satisfactory. However, a bend in the immediate upstream channel may cause the inside cell to collect debris during normal periods of runoff and thereby substantially reduce the capacity of the culvert. 1105.6.3 Paved Drop-down Entrance
In many cases, the operation of a culvert can be improved by depressing the flowline at the entrance below the channel flowline. The drop-down will alleviate a minimum cover condition, provide for additional headwater depth, and decrease the culvert outlet velocity by reducing the culvert slope. The abrupt change in natural channel slope is effected with a short length of concrete paving. The dimensions of the slab are site specific. However, for ease of construction, a 2:1 downslope (4:1 preferred) should be used as the maximum descending slope. A 3 foot [1 meter] length of paving should be provided along the natural channel slope prior to the drop-down. A cut-off wall must be provided at the upstream end. Drop-down entrances should generally be limited to 4 feet [1200 millimeters], or one pipe diameter or rise, whichever is greater. The use of paved drop-down entrances is not recommended on stream with migratory fish, since normal passage would be obstructed. 1105.6.4 Improved Inlets for Culverts
Culverts on relatively steep slopes will ordinarily flow with inlet control. The headwater is then controlled by the entrance configuration for a given barrel size. To reduce the headwater or the culvert size, consideration should be given to an improved inlet attached to the entrance end of the
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culvert. Two general types of inlets should be considered in the following order: A. Side-taper, which is a tapered end section
from a round to an oval shape for a pipe, or a square to a rectangular shape for a prefabricated box. The length of the taper section is usually made 1.5 times the diameter or rise of the culvert.
B. Slope-taper, which is a combination of side-
taper preceded by a drop in the culvert flow line. The drop can be similar to a paved drop-down entrance, as described in Section 1105.6.3, or a more sophisticated reinforced concrete drop provided by a formed cast-in-place section with vertical sides.
The improved inlet has the advantage of admitting more flow and thereby tending to fill the culvert barrel and reduce the culvert outlet velocity. However, the improvement is only effective as long as the culvert operates under inlet control. Also, the savings in culvert cost must justify the additional cost of the improved inlet. The Federal Highway Administration has conducted extensive research and studies of improved inlets, and recommended design procedures are included in Hydraulic Engineering Circular No. 13, "Hydraulic Design of Improved Inlets for Culverts." 1105.6.5 Depressed Inverts
Depressed inverts should be provided to minimize stream impacts for bankfull design culverts. The natural channel bottom provides a substrate for passage of migratory species. Assume the depressed culvert will fill naturally, such that the channel bed in the culvert will be continuous with the adjacent channel sections. The different roughness characteristics of the culvert barrel and the deposited channel bed shall be considered in the design calculations. End treatments shall consist of Item 601 Riprap, 6” [150mm] Reinforced Concrete Slab with a cutoff wall on both inlet and outlet ends. The slab shall slope up at a 6:1 from the invert to the channel bottom and terminate with a cutoff wall that has a depth of 6” below the depression depth. See standard drawing HW-2.1 for details. The invert shall be depressed per Table 1105-2 Table 1105-2
>252” 30” [900] Modifications to the standard headwalls are not necessary for the depression depths noted above. 1105.6.6 Flood Plain Culverts
In wide flood plains the installation of a single culvert constricts the flow of water at the entrance section. The concentrated outflow from the culvert can initiate downstream channel degradation. Flood plain culverts can be used to minimize the effects of this concentrated discharge by spreading the discharge throughout the flood plain on the outlet side of the culvert. Flood plain culverts are installed on the flood plain and convey the flood plain flow through the highway embankment. They reduce both the constriction of flow at the entrance section and the hydraulic load of the main culvert. The flood plain culverts should be installed on the flood plain well beyond the channel banks at an elevation roughly equivalent to the bankfull elevation. They shall be installed when the flood plain is greater than two (2) times the bankfull width of the water crossing. On wide flood plains, a flood plain culvert should be installed on each side of the channel. The flood plain culverts shall be sized at the minimum as per Figure 1002-1 (“other” column). The line and grade of the culvert should approximate that of the natural flood plain. 1106 End Treatments
1106.1 General
Headwalls, or other approved end finishes, shall be provided at the open ends of all Type A, B and C conduits. Headwalls should also be provided for Type D conduits greater than 24 inches [600 millimeters] in diameter or rise. Generally, headwalls are not recommended for Type E and F conduits.
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In order to reduce the entrance loss in culverts, the bell end should be located upstream and the spigot end should be located downstream. Details shown in the plan should convey this to the Contractor when necessary. Figures 1106-2 and 1106-3 show typical end details for a concrete box culvert. 1106.1.1 Usage
The selection of the headwall type is based on safety and economics. Standard HW-2.1 and 2.2 half-height headwalls are recommended for round, elliptical, or pipe arch culverts where a clear zone is provided. Full height headwalls should be provided where a significant reduction in culvert length can be realized with large-span culverts (10 feet [3 meters] or greater) with foreslopes flatter than 2:1 or where right-of-way limits the culvert length. Full-height headwalls shall be provided for prefabricated box culverts and three-sided structures. The use of special end treatments may be required by Section 602.6 of Volume 1, Roadway Design. Details are available from the Hydraulic Section, Office of Structural Engineering. Justification for the use of this type of end treatment shall accompany the request for details. Miter-cut (step-bevel) end sections, when required, shall be shown on the Culvert Detail Sheet. When half-height headwalls are provided, they should be built perpendicular to the end of the conduit to eliminate the need for a skew cut. In addition to the required headwall, the upper, or exposed, half of conduits having a diameter or rise greater than or equal to 126 inches [3150 millimeters] shall be miter-cut (step-bevel) to fit the embankment slope. 1106.1.2 End Treatment Grading
The prevailing embankment slope shall be projected to the back edge of the top of the headwall to establish the required culvert length as shown in Figure 1106-1. When the roadway foreslopes are flatter than 2:1, a 2:1 slope shall be provided from the back edge of the top of the headwall to a minimum of 1 foot [300 millimeters], with 2 feet [600 millimeters] preferred, above the top of the culvert. The change in embankment slope shall be warped on each side of the conduit to fit the prevailing slope. In no case shall the distance from the pavement edge to the point where the embankment slope changes to 2:1 be less than the design clear zone width (see Section 601, Volume 1, Roadway Design) unless guardrail is provided.
Clear zone grading should only be provided at culverts when the requirements of Section 307.21 of Volume 1, Roadway Design are met. The prevailing embankment slope shall be warped on either side of a skewed culvert to assure equivalent soil loading and proper side support of the pipe. This is especially true for flexible pipes with large skews and/or large diameters. 1106.2 Headwall Types
1106.2.1 Half-Height Headwalls
If the size of the conduit exceeds that shown in the Standard Construction Drawing HW-2.1 and HW-2.2 tables, the dimensions shown in the tables may be expanded to accommodate the larger size conduits. Payment for half-height headwalls shall be on a cubic yard [cubic meter] basis for Item 602, Concrete Masonry. Masonry quantities for standard half-height headwalls may be obtained from the appropriate standard construction drawing. The quantity of concrete masonry provided in the plans shall be based on the pipe alternate requiring the largest quantity of concrete masonry. 1106.2.2 Full-Height Headwalls
The appropriate full-height headwall for round pipes shown on Standard Construction Drawing HW-1.1 may be considered at the entrance end, when the savings in the reduced size and length of the conduit will offset the additional cost of the headwall. This will most likely apply where corrugated steel pipe is specified, due to cover or size requirements, and the bevel provided for the full-height headwall will substantially reduce the entrance loss. Dimensions of full-height headwalls may be expanded to accommodate pipe sizes larger than 84 inches [2100 millimeters]. The design of full-height headwalls for box and 3-sided culverts shall be as per Sections 204.1, 204.4 and 204.9.4 of the Bridge Design Manual and the latest “AASHTO Standard Specifications for Highway Bridges.” Payment for non-standard full-height headwalls shall be on a cubic yard [cubic meter] basis for Item 511, Class C Concrete. The Class C Concrete shall be further subdivided into individual pay items for Class C Concrete for Footing, Class C Concrete for Wingwall.
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Appropriate plan notes from Section 6 of the Bridge Design Manual shall be included in the project plans. An investigation of the supporting foundation material shall be conducted and the bearing capacity of the foundation material estimated. The level of detail required for the foundation investigation shall be commensurate with the importance of the structure. Such information shall be submitted for all proposed full-height headwall installations and submitted prior to the Stage 3 review. The inlet wingwall footings of full-height headwalls shall be armored with Type B rock channel protection, with filter, to preclude scour. 1106.3 Concrete Apron
A 5 foot [1500 millimeter] length of 6 inch [150 millimeter] reinforced concrete riprap, as shown on Standard Construction Drawings HW-2.1 and HW-2.2, shall be specified beyond the outlet headwall, when the depth of the rock channel protection (if necessary), including the 6 inch [150 millimeter] granular filter, exceeds the depth of the headwall. Concrete riprap shall be provided at the inlet end of the culvert where the existing has been undercut. Concrete riprap shall be in accordance with Section 1105.6.3. Concrete riprap is not necessary at the inlet of culverts with full height headwalls that have a footing toe extending 3.5 feet [1.1 meters] or more below proposed channel grade. 1107 Rock Channel Protection
1107.1 General
Rock channel protection is used to control erosion at the outlet of culverts and storm sewers, or for lining ditches on steep grades. It is used as a scour countermeasure at the inlet wingwalls of full-height headwalls and along the footings of 3-sided structures. 1107.2 Types
There are four types of rock channel protection (RCP) that are used in various situations. The use of the proper type at culvert and storm sewer outlets can be determined from Figure 1107-1. Type A is generally used beyond the outlet of the larger conduits having outlet velocities in excess of 12 feet per second [3.5 meters per second] and
Type B and C for conduits having an aggregate filter where the protected slope is steeper than 3:1. A filter should always be specified to prevent soil piping through the rock. A fabric filter is preferred in most cases. An aggregate filter should be used when the RCP is under water. The cost of the filter is included in the unit bid price for Item 601 Rock Channel Protection with Filter. 1108 Agricultural Drainage
1108.1 Farm Drain Crossings
Where it is necessary to continue an existing farm drain crossing under the highway, the pipe shall be Type B Conduit, one commercial size larger than the existing farm drain within the right-of-way limits. Occasionally, it will be desirable to provide a farm drain crossing under a highway on new location to satisfy the future need for adequate farm drainage. It is recognized that the required length of a Type B Conduit will provide a betterment for the property owner, but it does preclude the need for a much more expensive crossing after the highway is built. Such a crossing is considered a “blind” and the cost of the installation, including suitable terminal markings at the right-of-way lines, will generally not be eligible for federal participation. 1108.2 Farm Drain Outlets
Existing farm drains that outlet through the backslope of the roadway ditch shall terminate with a minimum length of 10 feet [3 meters] of equivalent size Type F conduit. When outletting existing plastic farm drains, one size larger Type F conduit shall be used. An Animal Guard and Erosion Control Pad as shown on Standard Construction Drawing DM-1.1 shall be provided. To provide for possible sedimentation, the invert of the Type F conduit shall be a minimum of 6 inches [150 millimeters], with 12 inches [300 millimeters] being desirable, above the ditch flow line. 1109 Longitudinal Sewer Location
1109.1 Under Pavement
Longitudinal sewers will not be permitted under the pavement of a limited or controlled access facility. Also, the length of transverse sewers
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under pavements shall be held to a minimum, with no manholes allowed in the pavement. For other facilities, storm sewers should be located outside the limits of the pavement. However, in locations where this would create conflicts with existing utilities (e.g. waterlines, sanitary sewers, gas lines, etc.) the storm sewer may be located under the pavement. Care should be taken to avoid placing manholes in vehicle wheel-paths or within an intersection. The center of the curb lane is the preferred manhole location. Where an out-to-out clearance of 5 feet [1500 millimeters] cannot be provided between parallel storm and sanitary sewers, premium joints shall be provided on the storm sewer. 1109.2 Under Paved Shoulder
The above shall also apply to paved shoulder areas, unless it is determined that the cost of any other possible location is prohibitive. 1109.3 Approval
Exceptions to the above shall be submitted in the early stages of the design to the Hydraulic Section, Office of Structural Engineering for review and approval. 1110 Reinforced Concrete Radius Pipe and Box Sections
1110.1 General
To comply with the capabilities of manufacturers to provide satisfactory and economical radius pipe or box sections, a minimum radius of 100 feet [30 meters] shall be specified. The method of manufacturing the radius pipe or box sections will be an option of the producer, subject to inspection and approval by the Ohio Department of Transportation, Office of Materials Management. As an alternate to radius pipe, pipe specials may be specified to negotiate the specified radius, provided they do not reduce the hydraulic performance established by the initial design. The bends shall be located so that they shall closely follow the alignment of the radius pipe.
1111 Sanitary Sewers
1111.1 General
Any sanitary sewer, whether new or relocated, shall be constructed using resilient and flexible gasket joints, in accordance with Construction and Material Specification 706.11 for circular concrete pipe or 706.12 for clay pipe. Permissible thermoplastic pipes shall also be specified. Permits to discharge treated sanitary flow from abutting property into highway drainage systems shall be in accordance with Directive No. 22-A. 1111.2 Manholes
All new manholes for sanitary sewer lines shall be built in accordance with the Standard Construction Drawings. Precast manholes shall have joints in accordance with 706.11 of the Construction and Material Specifications. 1112 Notice of Intent (NOI)
1112.1 General
A NOI will be submitted by ODOT for all plans, which include Project Earth Disturbing Activities. Maintenance Projects, as defined by Section 1112.2, do not require a NOI. The Total Earth Disturbing Activity acreage should be estimated, which includes the Project Earth Disturbing Activity acreage (area within the work limits) and the Contractor Earth Disturbing Activity acreage such as: field offices, batch plants, and borrow/waste pits. The location and size of the Contractor Activities can be estimated using the NOI Acreage Calculation Form (Figure 1112-1). The calculated acreage’s shall be used for the Project Site Plan as required by Location and Design, Volume 3, section 1308. 1112.2 Maintenance Project
A Maintenance Project is one in which all of the Project Earth Disturbing Activities are routine operations that do not change the line, grade, or the hydraulic capacity of the facility and are limited to Earth Disturbance acreage less than 5 acres. If the project requires any temporary erosion control items it is not considered a maintenance project. Permanent erosion control items shall be included in the plans if required.
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Contact the Hydraulics Office for an approved list of activities. 1113 Erosion Control at Bridge Ends
1113.1 General
For the purpose of reducing problems of erosion in the vicinity of bridge ends, details as shown on Standard Construction Drawing DM-4.1 shall be followed. At locations where the design flow exceeds 0.75 cubic feet per second [0.021 cubic meters per second], catch basins should generally be provided. 1113.2 Corner Cone
Item 670 Slope Erosion Protection shall be placed on all bridge approach embankment corner cones, beginning at the edge of the crushed aggregate or concrete slope protection. 1114 Storm Water Pollution Prevention Plan (SWPPP)
1114.1 General
A Storm Water Pollution Prevention Plan (SWPPP) is required for all projects that disturb more than one (total) acre. The plan should be developed as per Supplemental Specifications 832 and 833. The Contractor shall develop this plan after the contract is awarded and prior to any construction activity. The plan will be kept on-site for review at any time during construction. 1114.2 Objectives
The objective of the (SWPPP) is to reduce the impacts of construction runoff to the watershed. This is achieved by using perimeter and internal project controls to intercept sediment laden flows (temporary sediment and erosion controls). Point discharges leaving the site should be filtered through as many filtering controls as practicable. 1114.3 General Guidance
Temporary sediment and erosion control Items are specified in accordance with Supplemental Specification 832. Details are available in Standard Construction Drawings DM-4.2, DM-4.3 and DM-4.4.
The size of the entire drainage area contributing flow to a roadside ditch and the ratio of disturbed to undisturbed area are used to determine the desired erosion control methods. In many cases, the major portion of the contributing area will be beyond the project right-of-way limits. For these cases it will be necessary to divert the off-project flow before it reaches the area disturbed by project construction. Flow from the area disturbed by construction shall be treated prior to combining it with off-project drainage. For specific information on individual erosion control items, the Contractor should consult Supplemental Specification 832. General guidance for project usage is as follows: A. Ditch checks should be spaced so that no
check is within the backwater of a downstream check. A ditch check should be provided at a maximum spacing of 500 feet [150 Meters] in addition to significant changes in ditch grade.
B. Where greater than two-thirds of the
contributing drainage area is disturbed by construction, sediment basins are more effective and should generally be specified. Where less than two-thirds of the total contributing drainage area is disturbed by construction, a temporary ditch, dike and/or slope drain should be provided to divert flow from undisturbed areas away from the new ditch to reduce sediment basin size, or necessitate ditch checks only for the remainder of the flow. If more appropriate for the specific site (e.g. fill areas in lieu of cut areas) the roadway or toe of slope ditch should be stabilized immediately upon construction and a bale dike or perimeter filter fabric fence should be place at the bottom of the disturbed slope as per Standard Construction Drawings DM-4.3 and DM-4.4. Sediment dams may be used to prevent ditch erosion until the permanent stabilization has been established. The specific size and location of these controls shall be shown on the plans.
C. Sediment dams or a series of sediment
basins may be specified. It is desirable to locate temporary controls within the permanent right-of-way. Dams and basins shall be designed in accordance with Standard Construction Drawings DM-4.3 and DM-4.4. For areas where less than one-half of the contributing drainage area is disturbed by construction, a temporary ditch, dike
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and/or slope drains or ditch stabilization and bale dikes should be provided. For areas where less than one-third of the contributing drainage area is disturbed by construction a temporary ditch, dike and/or slope drains or ditch stabilization and bale dikes should be provided. The specific size and location of these controls shall be shown on the plans. Sediment basins, ditch checks, etc. should be clearly shown in the roadway ditch prior to the receiving or crossing watercourse. These items should not be shown within the receiving or crossing watercourse.
D. When the contributing drainage area is
excessive, the off-project drainage shall be diverted, or the following method shall be specified. The channel carrying the flow shall be stabilized immediately by a permanent or temporary lining and perimeter filter fabric fence shall be placed between the disturbed project area and the stabilized ditch. Sediment dams should be provided to prevent channel erosion until permanent channel stabilization has been established.
E. Where project drainage is not intercepted by
a project ditch, perimeter filter fabric fence shall be placed at the construction limits. The specific size and location of these controls shall be shown on the plans. The fence shall be placed just beyond the toe of slope of all sheet flow areas adjacent to live streams or other environmentally sensitive areas identified in the environmental documents regardless of the amount of grading involved.
F. Filter fabric fence (Inlet Protection) should be
placed around all catch basins and manholes (existing and proposed).
G. Perimeter Filter Fabric Fence or sediment basins shall be used to isolate the project from any adjacent live streams.
H. For highly erodible soil areas identified in the
environmental documents, any area cleared shall be brought to grade immediately and permanent erosion control measures called for on the plans shall be applied.
1114.3.1 Required Size of Sediment Basins
Sediment basins or dams shall provide a storage volume of 67 cubic yards per acre [130 cubic meters per hectare] of total contributing drainage area (disturbed and non-disturbed), which is 0.5 inches [13 millimeters] of runoff or approximately a two-year frequency. The volume should be increased where discharge from the basin empties onto an environmentally sensitive area
as identified in the environmental documents. Should the failure of a sediment dam pose a significant danger to downstream property, the spillway should be checked to assure safe passage of a 50-year frequency storm. In many cases, larger drainage areas will produce very large sediment basin requirements. Consideration should be given to divert flow prior to reaching the construction site in these cases. 1115 Post Construction Storm Water Management
1115.1 Threshold limits
Post construction storm water management controls shall be used for all projects that meet any one of the following threshold limits:
�� Impervious surface (total cross section) width is 60 feet or greater.
�� ADT is greater than 30,000 and roadway
is classified as rural. �� More than 80 percent of the drained area
is discharged through a closed storm sewer system.
�� Project is located within an ODOT MS4,
Phase II regulated area.
�� Storm water outfall is into a TMDL regulated stream where highway runoff has been identified as a regulated pollutant source.
For projects not meeting the above criteria, measures shall be taken to provide maximum vegetation and retention time through the use of ditches and swales. Current research has indicated that typical roadway design using vegetated slopes and ditches will provide the appropriate storm water treatment for these projects. 1115.2 General
The following requirements pertain to projects that meet or exceed limits as stated in section 1115.1: Projects that range from 1 to 5 acres shall use measures to control the pollutants in the storm water discharge (ie: quality). Specific detention times are not required for projects within this range. Typical roadway design that uses
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vegetated side slopes and ditches fulfill this requirement. In highly urbanized areas, consideration may be given to installing sumps in catch basins or using manufactured systems. Projects that disturb 5 or more acres must provide measures to treat the quality and quantity of storm water (if feasible). These measures are accomplished by providing treatment for the water quality volume, water quality flow, or a combination of both. Specific detention times or velocities are required to be met to fulfill the quantity aspect of the requirements. Rehabilitation projects that disturb 5 acres or more shall be designed to either ensure a 20 % net reduction of impervious area (asphalt or concrete), or provide treatment for 20 % of the total water quality volume from the combined existing and proposed area draining to each outfall. Exceptions to this requirement may be granted if it can be shown that the existing runoff hydrograph matches the proposed runoff hydrograph through a hydrologic study. Exceptions shall be submitted to the Office of Structural Engineering, Hydraulics Section. Placement and protection of Structural Best Management Practices shall be in accordance with Location and Design, Volume I. Every effort should be made to separate off site drainage from the roadway drainage when possible. This will reduce the acreage amount to be treated by the post construction storm water management systems. 1115.3 Water Quality Volume (WQv)
The water quality volume captures the “maximized” water quantity which then protects receiving bodies for water quality and quantity. The volume is increased by 20% to allow for sediment deposition and ineffective storage (reflected by the “1.2” in the equation). Further increase of the volume does not provide significant pollution removal efficiency. The following equation shall be used to calculate the water quality volume:
WQv=(1.2*P*Cq*A)/12 Where,
P = Precipitation (0.75 inches)
A = Acres (contributing drainage area)
WQv = Water Quality Volume (acre-ft)
Cq=0.858i3-0.78i2+0.774i+0.04 Where,
i=Impervious Ratio ( percent total imperviousness divided by 100) (decimal)
1115.4 Water Quality Flow (WQf)
The water quality flow (WQf) is the discharge that is produced by an approximate precipitation of 0.50 inches. It is calculated by using the intensity of a 2-year, 180 minute duration storm from the intensity-duration-frequency curves given in figure 1101-2. This is the primary design criteria used for filtration treatments such as vegetated swales and filter strips. 1116 Structural Best Management Practices (BMPS)
1116.1 General
Appropriate structural BMPS shall be used to treat the water quality volume, the water quality flow, or a combination of both. The BMPS selected shall be: technically feasible, implemented within the highway right-of-way, and safe for the travelling public and ODOT maintenance personnel. All Structural BMPS shall be maintained by the Department and shall be considered drainage structures necessary for positive drainage. Routine maintenance may be necessary to ensure proper drainage. Post construction storm water management controls are sensitive to sediment laden water, therefore they should be constructed after the primary construction is completed. The BMPS shall not compromise any Federal, State, or Local laws and must have a reasonable cost as compared to their benefit. Any BMPS that are too large to fit within the procured right-of-way are considered infeasible. Purchasing additional right-of-way is generally not fiscally responsible unless the land is undeveloped. Volumes smaller than the calculated WQv may be used with the approval of the Hydraulic Section, Office of Structural Engineering. Example BMP designs have been provided in figures 1116-5 through 1116-12.
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1116.1.1 Feasibility study
A BMP feasibility study shall be provided for all projects that have restrictions or limitations on BMP usage. The study should summarize the BMPS that were chosen (or omitted) and indicate the reasoning behind their selection. The justification should be submitted to the Hydraulic Section, Office of Structural Engineering for review and coordination with the OEPA. 1116.2 Vegetated Swales and Filter Strips (WQf)
Vegetated swales and filter strips treat storm water via the interaction of vegetation with suspended solids in the storm water. Due to this interaction, the allowable flow depth is limited to the height of the vegetation, usually 6 inches. Vegetated swales can be further defined as dry and wet swales. Dry swales perform filtration only while wet swales perform filtering and provide some storage capability. The storage capacity is defined by the use of rock check dams or weirs along the swale. Vegetated Swales and Filters are primarily used for pretreatment of other structural BMPS, but may be used exclusively for smaller drainage areas which produce a WQv less than 0.1 Acre-ft. The following criteria applies to swales and filters: A. Design using the Water Quality Flow as per
section 1115.3. B. Provide a preferred slope of less than 2%
with the maximum being 5%. C. When the slope is greater than 2%, provide
check dams or weirs with a maximum height of 4 inches to reduce the effective slope to 2%.
D. Limit the maximum (water quality flow)
velocity to 1.0 ft/sec. E. The underlying soils must be suitable for
healthy vegetation. F. The ground water table must be below the
flow line of the (dry) swale or strip. 1116.2.1 Dry or Wet Vegetated Swales
Swales are trapezoidal channels with bottom widths that usually range from 2 to 25 feet and have side slopes no steeper than 3:1. The preferred minimum length is 100 feet (if feasible). Adequate care should be taken to dissipate the
energy and spread the flow across the bottom of the grass swale. 1116.2.2 Vegetated Filter Strip
A Filter Strip is a wide, gently sloping area that is void of gullies, ditches, or concentrated flow. The water flow is characterized as overland flow throughout the grass. The maximum recommended length is limited to 300 feet. 1116.3 Infiltration (WQv)
Infiltration techniques treat storm water through the interaction of a filtering substrate, usually soil, sand, or gravel, and the captured storm water. This technique discharges the treated storm water into the ground water rather than into surface waters. Infiltration methods require an extensive investigation of the existing soils and geology to ensure success. The investigation should begin with a preliminary soil evaluation of the project site early in the design process. Insitu testing is not anticipated during the preliminary evaluation process. Available soil and geology data found in the Soil and Water Conservation maps, United States Geological Survey (USGS), adjacent projects, or educated estimations from a geotechnical engineer should be used. Material property tables for infiltration, permeability, and porosity have been provided for the preliminary evaluation. If the preliminary evaluation yields favorable results a more detailed evaluation should be performed. The detailed evaluation will require a geotechnical investigation of the underlying soils and geology. Soil borings should be performed to a maximum depth of 20 feet (or refusal) with samples taken every 5 feet for laboratory testing. The number and location of soil borings should correspond with the approximate size (as determined in the preliminary evaluation) of the infiltration BMPS and should be recommended by the geotechnical engineer. If the detailed evaluation yields favorable results, the ground water depth must be verified. The geotechnical engineer shall provide the seasonal high ground water depth. In some cases, observation wells may be installed and static water levels may be observed over a dry and wet season for verification. The infiltration and permeability rate of the soil shall be tested in the detailed soil evaluation at the discretion of the geotechnical engineer. In some cases, insitu testing at the proposed location of the infiltration BMPS may be required.
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There are two primary methods of infiltration: Infiltration Basin and Infiltration Trench. The following criteria applies to both infiltration methods and must be met to be considered a feasible alternative: A. Design using the WQv as per Section 1115.2. B. The appropriate soil type must be present:
1. Infiltration must be greater than 0.50 in/hr and no greater than 2.4 in/hr.
2. Soils must have less than 30% clay or
40% of clay and silt combined.
C. These methods should not be used where construction is still in progress. Infiltration BMPs clog easily with sediment created from construction activity.
D. The bottom of the basin or trench must be at
least 4 feet above the seasonal high water table and any impervious or rock layer.
E. They are not suitable on fill soil, compacted
soil, or steep slopes (greater than 4:1). Consideration should be given to the long term impacts upon hillside stability if applicable.
F. Pretreatment shall be used to remove large
debris, trash and suspended sediment to extend the service life. Examples of this may be the use of vegetated swales or filters strips, trash racks, forebays, or gravel packs (see figure 1116-13).
G. Observation wells may be required to monitor
ground water quality in course soils. Table 1116-1
Infiltration Rate (k) NRCS Soil Type (from soil maps)
HSG Classification
Rate (k)
(in/hr) Sand A 8.0
Loamy Sand A 2.0 Sandy Loam B 1.0
Loam B 0.5 Silt Loam C 0.25
Sandy Clay Loam C 0.15 Clay Loam & Silty
Clay Loam D < 0.09
Clays D < 0.05
From Urban Runoff Quality Management WEF Manual of Practice No. 23, 1998, published jointly by the WEF and ASCE, chapter five 1116.3.1 Infiltration Basin
An infiltration basin is an open surface pond that uses infiltration into the ground as the release mechanism. It is generally designed to store the WQv with a calculated minimum invert area. Depending on the soil permeability, it may be used to treat from 5 to 50 acres. Lower permeable soils may require a pipe underdrain as an additional outlet. Complete drainage of the WQv should occur between 24-48 hours. Consider the following when designing an infiltration basin:
A. An infiltration basin is not considered feasible until the WQv is at least 0.1 Acre-ft.
B. Use an energy dissipater at the inlet.
C. Allow for 1’ (min) freeboard above the
WQv. D. Use side slopes of 4:1 (max).
E. Use a length to width ratio of 3:1 F. Provide bypass or overflow for larger
storm events.
G. Vegetate the sides and bottom using hearty plants that can withstand prolonged inundation.
H. Provide vehicle access to the basin for
periodic maintenance.
I. Locate basin at least 1,000 feet from any municipal water supply well and at least 100 feet from any private well, septic tank, or drain field.
J. Do not locate basin where infiltrating
ground water may adversely impact slope stability.
K. Ensure the invert of any underdrain in the
basin is below the frost line (2.5 feet). The invert area of the infiltration basin can be calculated by the following equation:
A=(WQv * S.F. * 12)/(k * t)
Where,
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April 2004 11-27
A= area of invert of the basin (Acres) WQv= Water Quality Volume (Acre-ft) S.F.= Safety Factor of 1.5 k= Infiltration Rate (in/hr)
t= Drawdown time (hours), usually 48 hours
The required depth of the infiltration basin can be calculated by the following equation:
D= WQv/A
Where, A= area of invert of the basin (Acres) WQv= Water Quality Volume (Acre-ft) D= Required depth of the basin 1116.3.2 Infiltration Trench
An infiltration trench is an excavated trench that has been lined and backfilled with a porous gravel backfill (no. 2 aggregate) A filtering mechanism (grass or no. 57 aggregate) is placed across the top of the trench to provide a pretreatment of the storm water. The storm water is filtered through the pretreatment layer and is stored within the pore volume of the backfill material. It is allowed to percolate through the sides and bottom of the trench. The ideal drain time of the WQv is 24 hours. Consider the following when designing an Infiltration trench: A. The minimum acceptable permeability of the
surrounding soil is =6.5*10^-5 ft/sec (see table 1116-2).
B. Generally, long and deep infiltration trenches
are most efficient (3 feet bottom width and 3-6 feet deep).
C. The geometric shape of the trench is a
trapezoid with sides at a 1:1 (H:V) slope due to constructability. The top width is calculated as:
Top Width = Bottom Width + (2 * Depth)
D. Pretreatment shall be used to ensure
longevity of the infiltration trench.
E. Observation wells (one or more) should be provided to facilitate ground water inspection.
F. Locate infiltration trench at least 1,000 feet
from any municipal water supply well and at least 100 feet from any private well, septic tank, or field tile drains.
G. Ensure the bottom of the trench is below the
frost line (2.5 feet) The length of the trench depends upon the depth and the bottom width. The required length is calculated by assuming a depth and bottom width. The length is calculated based upon the inflow (WQv) and the outflow (ground water recharge). The following equation calculates the required length:
Where,
WQv= Water quality volume (see section 1115.2) (Acre-feet) T= Drain time through the sides of the trench, usually 24 hours (hours) K= permeability of the surrounding soil (ft/sec) (table 1116-2) D= Trench depth (ft) b= Bottom width of the trench (ft)
Table 1116-2
Permeability of Soil (K)
From Urban Runoff Quality Management WEF Manual of Practice No. 23, 1998, published jointly by the WEF and ASCE, chapter five
Rate (K) (ft/sec)
Gravel 3.3x10-3 to 3.3x10-1 Sand 3.3x10-5 to 3.3x10-2 Silt 3.3x10-9 to 3.3x10-5
Clay (saturated) < 3.3x10-9 Till 3.3x10-10 to 3.3x10-6
L t �L tL t 43560 WQv�
3600 K� T� b 2 D( )� 0.4 D2 b D�( )
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1116.4 Extended Detention (WQv)
Extended Detention is a method that captures storm water during rain events and slowly releases the captured volume over a period of time. The WQv is used to size the detention basin and the optimum release time is 48 hours. Detention can be either above or below ground. Above ground systems are the preferred choice and should be used when feasible. However, when project site parameters dictate, a below ground system may be the optimum choice. 1116.4.1 Above Ground Extended Detention
Above ground extended detention is a dry pond that detains storm water for quality and quality. Consider the following when designing an above ground detention basin: A. A detention basin is not considered feasible
until the WQv is at least 0.1 Acre-ft.
B. Allow for 1 foot of freeboard above the WQv. C. Provide a micropool when feasible (see figure
1116-14)
D. Use side slopes of 4:1 (max).
E. Provide bypass or overflow for larger events (25 year storm).
F. Vegetate the sides and bottom using hearty
salt tolerant plants that can withstand prolonged inundation.
G. Provide vehicle access to the basin for
periodic maintenance. H. Provide a two-stage channel design through
the basin when feasible. I. Do not locate on uncompacted fill or steep
slopes (2:1 or more) or where infiltrating ground water could adversely impact slope stability.
J. Provide an anti-seep collar around the outlet
pipe. K. Provide a trash rack or gravel pack protection
at the outlet structure. L. Place channel protection (RCP or Concrete
Mat) at the entrance of the basin to minimize erosion and sediment resuspension.
M. Provide a forebay that is approximately 7-10% of the total design volume when feasible. Otherwise, provide pretreatment of storm water.
1116.4.1.1 Extended Detention Basin Outlet Structure An outlet structure should be provided that allows the structure to be fully drained in 48 hours. The outlet requires a flow control structure such as a perforated riser pipe to restrict the discharge in order to obtain the 48 hour discharge time. Details of a perforated riser pipe outlet structure can be found on standard drawing WQ1.1. The perforated riser pipe is recommended for smaller basins. It uses a catch basin as an outlet structure with a perforated riser pipe on the inlet side and culvert on the outlet side. The perforated riser pipe is used for flow control. A gravel envelope should surround the perforated riser pipe along the inlet side of the catch basin to prevent blockage of the orifice holes in the pipe. A weir should be provided to allow for larger storms to bypass the structure without damage to the detention basin or surrounding area. The 25 year design storm shall be able to safely pass through the weir control without damage to the basin or outlet control structure. The equation for a single orifice is:
Where, A = Area of orifice (ft2)
H = Head on orifice as measured to the centerline of the orifice (ft)
C = Orifice coefficient
Orifice Coefficient Guideance C Description
0.66 Use for thin materials where the thickness is equal to or less than the orifice diameter.
0.80 Use when the material is thicker than the orifice diameter.
From CALTRANS, Storm Water Quality Handbooks, Project Planning and Design Guide, September 2002. A stage-discharge curve will be required to calculate the discharge time of the WQv. The discharge time should correspond to the required minimum of 48 hours. Figures 1116-1 through
Q � A C� 64.4H�
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1116-4 have been provided to show the relationship between head and discharge given the common perforation sizes and openings per row in a perforated riser pipe (unsubmerged orifice flow). Generally, it is easier to model the outlet structure and discharge time using software such as Pond Pak or HydroCad to develop the stage-discharge relationship.
1116.4.1.2 Anti-Seep Collar Design An anti-seep collar shall be installed on conduits through earth fills. The following criteria applies to anti-seep collars:
A. Spacing between adjacent collars shall be between 5-14 times the vertical projection of each collar.
B. Place all collars within the saturation
zone.
C. All anti-seep collars and their connections shall be watertight.
D. Minimum thickness shall be 6 inches.
The assumed normal saturation zone (phreatic line) shall be determined by projecting a line at a slope of 4:1 from the point where the normal water depth (riser grate) touches the upstream slope of the embankment to a point where this line intersects the invert of the culvert. The area below this projected line is assumed to be within the saturated zone. To determine the dimensions of the collar refer to figure 1116-11. The length of the saturated zone (Ls) must first be determined (using the equation in the figure). The nomograph should then be used to determine the number and size of collars. 1116.4.2 Below Ground Extended Detention
Below ground detention consists of detention tanks, vaults, conduits, or a series of conduits. They range from an oversized storm sewer to a junction chamber specifically used for storm water detention. Due to the cost associated with below ground detention (construction and maintenance), this method should only be used in the ultra-urban environment and be considered as a last resort. Consider the following when designing below ground detention: A. A detention basin is not considered feasible
until the WQv is at least 0.1 Acre-ft.
B. Provide bypass or overflow for larger events (25 year storm).
C. Provide access to the basin for periodic
maintenance. D. If practical, provide pretreatment of the storm
water. 1116.5 Retention Basin (WQv)
A retention basin is a “wet” pond that has a minimum water surface elevation between storms that is defined as the permanent pool. Above the permanent pool is a detention pool that provides storage for 75% of the WQv and discharges within 24 hours. The full storage water depth is typically between 3-6 feet and the volume is less than 15 Ac-ft. The permanent pool is sized to provide storage for 75% of the WQv. A retention basin is ideal for large tributaries, but it may require a large amount of space. Consider the following when designing a retention basin: A. A retention basin is not considered feasible
until the WQv is at least 0.1 Acre-ft.
B. Use RCP or concrete matting at the inlet of the basin to provide energy dissipation and erosion control.
C. Allow for 1 foot freeboard above the WQv.
D. Use side slopes of 4:1 (max).
E. Provide bypass or overflow for larger events (25 year storm).
F. Vegetate the sides using hearty plants that
can withstand prolonged inundation and are salt tolerant.
G. Use a length to width ratio of at least 3:1 to
prevent short-circuiting. H. When practicable, provide a forebay (7-10%
of the total retention volume) to extend the service life of the BMP.
I. Provide an anti-seep collar around the outlet
pipe (see section 1116-4.1.2). J. Provide a trash rack or gravel pack protection
at the outlet structure. K. The underlying soils should be compacted to
prevent infiltration of the permanent pool or an impervious liner should be used.
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L. Provide vehicle access to the basin for
periodic maintenance. M. Consideration should be given to the potential
problems with mosquitoes. N. Retention basin must be greater than 10,000
feet from a municipal airport runway. 1116.5.1 Retention Basin Outlet Structure
A retention basin outlet structure is designed similar to the outlet structure for a detention basin. The primary difference is that 75% of the WQv should be discharged out of the basin within 24 hours. The outlet structures are of a similar type, except the openings will be set at a high enough elevation to maintain 0.75% of the WQv in the permanent pool (see figure 1116-13). 1116.6 Constructed Wetlands (WQv)
Constructed wetlands treat storm water through bio-retention. They are depressed, heavily planted areas that are designed to maintain a dry weather flow depth ranging between 0.5 to 2 feet. The surface area required for a wetland is usually quite large due to the limited allowable depth. The area is usually on the magnitude of 1% of the entire drainage area. They are designed in a similar manner as a retention basin. The wetland is sized to provide storage for the WQv for a time frame of at least 24 hours (above the permanent pool) while providing a bypass or overflow for larger design and flood discharges. The water depth should be maintained by an outlet structure capable of providing the required water depth with the provision of a one foot freeboard. Consider the following when designing a wetland: A. A constructed wetland is not considered
feasible until the WQv is at least 0.1 Acre-ft. B. Do not place on a steep or unstable slope or
at a location, which could induce short-term or long-term instability.
C. Wetlands must be greater than 10,000 feet
form a municipal airport runway. D. Baseflow must be present to maintain the
constant water depth (such as ground water). E. Consideration should be given to the potential
problems with mosquitoes.
F. Provide a forebay that is usually 7-10% of the total required volume at a depth between 3-6 feet to settle out sediments.
G. Provide side slopes of 4:1 (max). H. Provide access for maintenance to the
forebay and the outlet structure. I. Plants should be used that are hearty salt
tolerant and favor a wetland environment. J. Provide an impervious liner or compacted or
clay bottom to prevent infiltration of the storm water.
K. Provide a length to width ratio of 3:1 (min) to
Bioretention Cells consist of a depressed low-lying area that treats storm water through evapotranspiration and filtering through a planting soil. As the storm water passes through the soil it is filtered. An underlying perforated storm sewer or underdrain captures the treated storm water and carries it to an outlet. Extensive vegetation assists in the filtration of the storm water prior to filtering through the soil. Vegetation should consist of trees, shrubs, and grasses that are native to the area. The existing soil must be removed and replaced when constructing a bioretention cell. The bioretention planting soil should consist of a mixture of sand, topsoil, and compost. The soil shall be a uniform mix, free of stones, stumps, roots or other similar objects larger than two (2) inches. The bioretention planting soil shall consist of the following:
�� pH range: 5.2 – 7.0 �� 4 parts sand �� 2 parts topsoil �� 2 parts compost
A bioretention cell is sized to store the WQv prior to filtration (pretreatment areas or ditches can be used to store a portion of the WQv). Total filtration should occur within 40 hours. Use the following equation to determine the minimum surface area of the bioretention invert:
Drainage Design Procedures
April 2004 11-31
Where,
WQv= Water quality volume (see section 1115.2) (Acre-feet) T= Drain time of the cell, usually 40 hours (hours) K= permeability of the planting soil (3.3 x 10^-5 ft/sec) minimum A= Top surface area of the trench (Ac) D= Depth of the planting soil (4.0 feet minimum) (ft) h=Maximum depth of water above the cell mulching layer for the WQv (1 foot max)
Consider the following when designing a bioretention BMP: A. The soil must not be compacted by a
mechanical means when placed. B. Provide a maximum of 30 feet width between
underdrain laterals. C. Native plants should be used that are hearty
salt tolerant and favor a wetland environment (if feasible).
D. Provide bypass or overflow for larger events
(25 year storm). A riser pipe or catch basin is typically used in conjunction with an overflow weir if needed. Use an anti-seep collar if needed.
E. If possible, provide pretreatment of the storm
water via a vegetated swale or filter strip. F. Ensure the water table or bedrock is below
the invert of the bioretention area. G. Use side slopes of 4:1 (max). H. Provide a length to width ratio of 2:1 (min). I. Use a minimum depth of 4 feet of planting
soil. Provide at least 4 inches of depth deeper than the largest root ball.
J. Provide an organic or mulching layer at the
top of the planting soil.
K. Provide a maximum depth of 1 foot to the
riser pipe or catch basin outlet from the mulching layer for storage of the WQv.
1116.8 Manufactured Systems (WQf)
Manufactured systems consist of underground structures (cylindrical or rectangular) that treat the WQf by removing particulate matter through settlement. They are placed within a storm sewer system (on-line or off-line) and have access holes for routine maintenance procedures. Discharges exceeding the WQf are passed through the system without treatment. Routine maintenance is extremely important to ensure the effectiveness of this BMP. The BMP should be monitored (monthly) for the first 12 months after installation to determine a maintenance schedule for the specific application. Implementation of this BMP will require approval from the Office of Structural Engineering, Hydraulics Section. Usage of this BMP is primarily limited to an ultra-urban situation where traditional BMP are not feasible. These devices may be used for new development projects ranging from 1-5 acres of earth disturbance or for redevelopment projects with unlimited earth disturbance. 1116.9 Alternative Methods
Alternative methods of storm water treatment may be used provided the Hydraulics Section, Office of Structural Engineering approves them. It must be demonstrated that the alternative BMPs are equivalent in effectiveness to those listed above.
A � WQv D�
3600 K� T� h D( )�
1100 Drainage Design Procedures – List of Figures
Figure Subject 1101-1 Overland Flow Chart General Notes for Figures 1101-2 and 1101-3 1101-2 Rainfall Intensity-Frequency-Duration Curves 1101-3 Rainfall Intensity Zone Map 1102-1 Capacity of Grate Catch Basin in a Sump 1102-2 Channel Features 1103-1 Nomograph for Flow in Triangular Channels 1103-2 Capacity of Curb Opening Inlets on Continuous Grade 1103-3 Capacity of Standard Catch Basin Grates in Pavement Sags - Flow Through Grate
Opening 1103-4 Capacity of Inlets and Standard Catch Basins in Pavement Sags - Flow Through Curb Opening 1105-1 Classification of Flow in Culverts 1105-2 Corrugated Metal Pipe Sizes and "n" Values for Type A Conduits 1105-3 Example Bankfull Discharge Culvert Design 1106-1 End Treatment Grading Detail 1106-2 Box Culvert Outlet Detail 1106-3 Box Culvert Inlet Detail 1107-1 Rock Channel Protection at Culvert Storm Sewer Outlets 1112-1 Notice of Intent (NOI) Acreage Calculation Form 1115-1 Sample Water Quality Volume Calculation 1116-1 ¼ Inch Orifice Perforations 1116-2 ½ Inch Orifice Perforations 1116-3 ¾ Inch Orifice Perforations 1116-4 1 Inch Orifice Perforations 1116-5 Vegetated Swale Example 1116-6 Vegetated Strip Example 1116-7 Infiltration Basin Example 1116-8 Infiltration Trench Example
1116-9 Extended Detention Basin Example 1116-10 Retention Basin Example 1116-11 Anti-Seep Collar Design 1116-12 Bioretention Cell Example 1116-13 Deleted (see standard drawing WQ1.1) 1116-14 Conceptual Layout for Detention Basin for Water Quality 1116-15 Water Quality Cq 1116-16 BMP Selection
General Notes - Figures 1101-2 through 1101-3
The Rainfall Intensity-Duration-Frequency curves are based upon data obtained from United States Weather Service Technical Paper No. 40 Rainfall Frequency Atlas of The United States. Federal Highway Administration Hydraulic Engineering Circular No. 12 Appendix A offers a methodology for converting I-D-F data points to an equation of the general form:
cb)(tai�
�
Where: i = rainfall intensity (inches/hour) t = time of concentration (minutes) a = constant b = constant c = constant Using the above referenced methodology the curves in Figure 1101-2 can be expressed using the above general equation utilizing the constants shown below.
Intensity Zone (Figure 1101-3)
Frequency (Years)
Constant "a" Constant "b" Constant "c"
A
2 5 10 25 50 100
44.150 150.271 70.474 96.280 51.622 85.930
8.900 18.400 10.200 11.100 5.100 8.000
0.853 1.062 0.874 0.899 0.747 0.834
B
2 5 10 25 50 100
140.596 81.276 275.649 294.909 117.148 293.888
25.099 18.800 29.499 28.099 16.700 26.699
1.015 0.855 1.070 1.044 0.849 1.000
C
2 5 10 25 50 100
64.387 184.940 83.828 58.733 79.945 196.039
14.300 21.699 12.500 7.400 9.300 16.300
0.896 1.075 0.887 0.771 0.818 0.978
D
2 5 10 25 50 100
85.568 118.822 112.172 198.920 206.025 355.551
16.500 18.700 16.800 19.300 19.600 23.199
0.950 0.969 0.923 1.004 0.990 1.076
Revised April, 2003
1112-1NOTICE OF INTENT (NOI) ACREAGE CALCULATION FORM
Reference Section1112
grading, cut and fill areas, anticipated contractor-used areas within State right of way, etc.Project Earth Disturbing Activities. Enter the area of disturbed earth for the project activities. Include shoulder
equipment and materials.Field Office. These sizes were determined with regard to size of the trailer, parking, and some stock area for
project.might be used by the Contractor. This is not needed for existing plants, it is only for plants set up for the specificinvestigate the location of the project relative to existing plants, facilities, etc. to estimate whether a batch plantBatch Plant. It is assumed that a typical batch plant would occupy 2 acres of ground. The designer should
previous projects, etc. Consideration should be given for grindings, as well.acre. The designer may choose a different value based on knowledge of the project area, bedrock elevations, Off-Project Waste / Borrow. The specified estimation is based on approximately 10 feet of depth or fill over 1
for coverage up to 4.9 acres minimum.be submitted for the NOI. All projects with Project Earth Disturbing Activity greater than zero will be submittedNOI Earth Disturbing Activities (enter total acreage from line l or 4.9 acres, whichever is greater). This value is to
condition and have less than 5 acres of earth disturbing activities (see section 1112.2).Maintenance activity consists of projects that do not change the line, grade, or hydraulic capacity of the existing
Area (acres)aProject Earth Disturbing Activities bIf line a = 0 or the project is a Maintenance Project, an NOI is not required. STOPcIf line a > 0, an NOI is required, continue to line ddField Officee Enter 0.125 for Type A; 0.25 for Type B; or 1.00 for Type CfBatch Plant Yes = 2.0; No = 0gOff-Project Waste / Borrow Pith Add 1.0 acre per 15,000 CY of waste or borrowiMiscellaneous Other Off-Project Areasj Off-Project staging areas, stock yards, etc.
kSubtotalContractor Earth Disturbing Activities (add lines e, f, h and j)
lTOTALTotal Earth Disturbing Activities (add line a to line k)
(10ft. x 43560 s.f. / 27 = 16,133 c.y. ~ say 15,000 c.y.)
0
0.02
0.04
0.06
0.080.
1
0.12
01
23
45
Hea
d - f
t
Discharge - cfs
# Of Openings
812162024
1/4 - INCH ORIFICE PERFORATIONSC=0.66
1116-1REFERENCE SECTION
1116.4.1.1
0
0.050.1
0.150.2
0.250.3
0.350.4
0.45
01
23
45
Hea
d - f
t
Discharge - cfs1/2 - INCH ORIFICE PERFORATIONS
C=0.66
1116-2REFERENCE SECTION
1116.4.1.1
812162024# Of Openings
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
01
23
45
Hea
d - f
t
Discharge - cfs3/4 - INCH ORIFICE PERFORATIONS
C=0.66
1116-3REFERENCE SECTION
1116.4.1.1
9121418# Of Openings
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
01
23
45
Hea
d - f
t
Discharge - cfs1 - INCH ORIFICE PERFORATIONS
C=0.66
1116-4REFERENCE SECTION
1116.4.1.1
81012
# Of Openings
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Impervious ratio
Cq
WATER QUALITY Cq1116-15
REFERENCE SECTION1115.3
START
Consider thefeasibility
restrictions of theproject
Yes
No
Yes
No
Consider usingVegetated Swales
or Strips, anInfiltration Trech,Bioretention, or a
ManufacturedSystem
Consider usingInfiltration,
Bioretention,Detention,
Retention Basins,or Constructed
Wetlands
Consider usingVegetated Swales
or Strips, anInfiltration
Trench,Manufactured
System, or UnderGround
Detention
Prescriptive PostConstructionStorm WaterControls not
required.However, use
open ditchdrainage whenpractical and
maximize the useof vegetation.
Calculate theWQv
Is theCalculatedWQv > or
equal to 0.1Ac-ft?
Is thereadequate R/W
for the requiredWQv storage?
YesNo
Is the Project in anODOT Regulated MS4
Area?No
Is the project are-development
project?Yes
No
Multiply theCalculated
WQv by 0.20.Use this valuefor the BMPSelection.
Is ADT > 30,000and classified as
rural?
Is 80 % of thedrained area
discharged in astorm sewer?
NoIs the Outfall into a
TMDL RegulatedStream ?
No
1116-16REFERENCE SECTION
1116
BMP SELECTION
Is the impervioussurface width > 60
feet?
No
Yes
Appendix A – Reproducible Forms
Form Subject
LD-30 Treated Sanitary Flow Agreement Form
LD-33 County Engineer Approval Form
LD-34 Storm Sewer Computation Sheet
LD-35 Ohio Drainage Design Criteria Form
LD-40 Gutter Spread and Inlet Capacity Computation Sheet
LD-41 Ditch Computation Sheet
LD-42 Culvert Computation Sheet
Form LD-35Revised January 2003
GENERAL PROJECT INFORMATION
County Route Section
(Attach Typical Section)
AFFECTED ROADWAYS: Route Average Daily Traffic
INTERSTATE OR OTHER L/A FACILITIES
ARTERIALS AND COLLECTORS
LOCALS
CLEAR ZONE
Units used in design: Metric English(Check appropriate box)
PIPE POLICY:
The Pipe Policy of _____________________ will be used for this project. (See Section 1002 for additionalinformation)
If a policy other than ODOT’s is being used, the following material types are permitted:____________________________________________________________________________________________
____________________________________________________________________________________________(Please attach a copy of the written pipe policy. In lieu of a written policy, documentation of locally fundedconstruction practices may be provided)
_____________________________________________________________________________________4. ALLOWABLE VELOCITIES FOR 1102.3.2 (table 1102-1):
Soil Type
a. Seed lining __________ f.p.s [m/s].
b. Sod, jute, or other temporary linings __________ f.p.s [m/s].
c. Turf reinforcing mats __________ f.p.s [m/s].
d. Tied Concrete Block Matting f.p.s [m/s].
e. Rock channel protection __________ f.p.s [m/s].
5. MANNING’S “n” USED FOR 1102.3.2 (table 1102-2):
a. Seed lining __________
b. Sod, jute, or other temporary linings __________
c. Turf reinforcing mats __________
d. Tied Concrete Block Matting
e. Rock channel protection __________
6. DITCH CONFIGURATION 1102.2:
a. ____________________ for roadway, with __________ inch [mm] minimum depth
b. ____________________ for toe of embankment, with __________ inch [mm] minimum depth
7. TYPE OF DITCH CATCH BASIN 1102.3.4:a.
Section C. Roadway Ditches - Continued
8. MINIMUM LONGITUDINAL SLOPE OF DITCHES IN CUT SECTIONS 1102.1:
a. __________ desirable minimum
b. __________ absolute minimum
9. METHOD USED TO LOCATE EXISTING FARM TILE CROSSED BY HIGHWAYS?
a.
b.
c.
d.
10. MINIMUM WIDTH OF DITCH LININGS 1102.3.1 :
a. Sod __________ ft [m].
b. Temporary linings __________ ft [m].
c. Turf reinforcing mats __________ ft [m].
11. DESIGN FREQUENCY DEPTH SHALL NOT EXCEED 1102.3.1:
a.
b.
Section D. Median Ditches1. DITCH CONFIGURATIONS 1102.3:
a. Depressed ____________________
b. Type of barrier ____________________
2. WIDTH BETWEEN PAVEMENT EDGES _______________ ft.
3. ALLOWABLE VELOCITIES FOR 1102.3.2 (table 1102-1):
Soil Type
a. Seed lining __________ f.p.s [m/s].
b. Sod, jute, or other temporary linings __________ f.p.s [m/s].
c. Turf reinforcing mats __________ f.p.s [m/s].
d. Tied Concrete Block Matting f.p.s [m/s].
4. METHOD USED TO ESTIMATE DESIGN DISCHARGE (Q) 1101.2:a.
b.
5. CATCH BASIN SPACING WILL BE DETERMINED BY HYDRAULIC ANALYSIS USING 1102.3.4:
a. __________ year frequency and “n” = __________ for velocity
b. __________ year frequency and “n” = __________ for depth
c. Controls:i. Design frequency depth shall not exceed:
(1)
(2)
d. Catch basin spacing, depressed median, fill section:
Median Width 84' [25 m] 60' [18 m] 40' [12m]
i. Desirable maximum __________________________________________________
ii. Absolute maximum __________________________________________________
6. TYPE OF MEDIAN CATCH BASIN OR INLET 1102.3.4:a.
Section D. Median Ditches - Continued
7. MINIMUM LONGITUDINAL SLOPE OF DEPRESSED EARTH MEDIAN:
8. OTHER PERTINENT DESIGN INFORMATION:
Section E. Drainage for Curbed Pavements
1. CONTROLS FOR THE DETERMINATION OF INLET OR CATCH BASIN SPACING 1103:
a. Design storm frequency __________ year
b. METHOD USED TO DETERMINE TIME TO FIRST CATCH BASIN OR PAVEMENTINLET:
i.
ii.
c. Maximum spread of flow into traveled lane __________ ft [m]. (table 1103-1)
Outside lane width greater than 12 feet ft [m].
Total allowable spread on pavement ft [m].
d. Maximum depth of flow at curb __________ in [mm].
e. Manning’s “n” for:
i. Reinforced concrete pavement __________
ii. Asphaltic concrete pavement __________
iii. Paved shoulders __________
2. TYPE OF INLET OR CATCH BASIN PROPOSED FOR 1103:
a. Continuous grades _______________________________________________________________
b. Sags __________________________________________________________________________
3. INLET LIP OF CURB OPENING INLET WILL BE DEPRESSED __________ INCHES BELOWNORMAL GUTTER.
A local depression of __________ inches will be used to determine spacing of combination grate and curbopening catch basins.
4. OTHER PERTINENT DESIGN INFORMATION:
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
Supersedes Directive No. D-102dated March 26, 1962
TO: DEPUTY DIRECTORS, STAFF MEMBERS, AND DIVISION ENGINEERS
SUBJECT: PERMITS TO DISCHARGE TREATED SANITARY FLOW INTO STATEHIGHWAY
DRAINAGE SYSTEMS.
PART I - GENERAL
A. PURPOSE
1. To control, through the issuance of permits, the acceptance, when justified, of treatedsanitary flow into State Highway drainage systems.
2. To define conditions under which a permit may be issued and set up procedures forapplying, granting, and revoking a permit.
3. To coordinate the activities of all Highway Bureaus involved in this field and with theState and local Health Departments.
B. POLICY
1. To permit treated sanitary flow to enter the Highway drainage systems if conditionsrequire an outlet for the private sewage treatment facilities and the effluent meets therequirements noted hereinafter.
2. No permit shall be issued under these procedures unless it is established, at the expenseof the applicant, and by a Registered Professional Engineer or other qualified person asdetermined by the Health Department having jurisdiction, that the soil will not permitleaching as shown by percolation tests prescribed by the State Department of Health,and that there is no practical place to discharge the treated sanitary flow except to theHighway drainage system.
3. No permit shall be issued unless it has been established that the discharge from theprivate drain will not exceed the hydraulic capacity of the Highway drainage system, willnot cause a menace to health, will not adversely affect the maintenance of the Highway,and will not damage the Highway drainage system.
4. The permit, when issued, shall remain in force only if construction conforms to theapproved plan and only as long as the treatment facility continues to produce an effluentreasonably free of odor, color and suspended solids as determined by the HealthDepartment having jurisdiction. The approved permit for a new or existing user shallstipulate this requirement as a condition to continuing the permit in effect.
5. Written permission to discharge treated sanitary flow into the Highway drainage systemshall specifically provide for cancellation in the event the effluent at any time is notreasonably free of odor, color and suspended solids, or if other means of disposalbecome available such as a sanitary sewer extension.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
C. SCOPE
1. Treated sanitary flow means the effluent from a properly constructed and maintainedsand sewage filter or aerobic digestion treatment plant, the designs of which have beenapproved and accepted by the Local Health Department and the Ohio Department ofHealth.
2. Untreated sanitary flow is defined as the flow from all plumbing fixtures including floordrains, kitchen sinks and drains from livestock lots ad barns. Untreated sanitary flowsshall not be discharged into the Highway drainage system except as provided for inSection C-4-b.
3. This directive will apply to the discharge of treated sanitary flows into the drainagesystems on all rural State highways.
4. The following shall apply to the discharge of sanitary flows into the drainage systems onState highways within municipal corporations:
a. If the municipality enters into an agreement with the State by passing suitablelegislation in which the municipality agree to issue permits to property owners only ifthe property owners have complied with the requirements of this directive, dischargeof treated sanitary flows will be accepted.
b. If the municipality enters into an agreement with the State by passing suitablelegislation in which the municipality agrees to issue permits and to assume totalresponsibility for permitting the discharge of untreated or improperly treated sanitaryflows into the State Highway drainage system and to save the State harmless fromlegal action that might develop because of such discharge, then discharge ofuntreated or improperly treated sanitary flows may be accepted, if extenuatingcircumstances exist which would justify such action.
c. If the municipality enters into an agreement with the State by passing suitablelegislation in which the municipality agrees that no sanitary flow shall be permitted tobe discharged into State Highway drainage systems or if the enabling legislation issilent with respect to sanitary flow, then sanitary flow shall not be permitted to enterthe Highway project.
5. No permit shall be issued under these procedures to discharge treated sanitary flows intodrainage systems on Interstate highways unless such denial of access would causeextreme hardship to the applicant or result in excessive cost in acquisition of property.Substitute measures should be considered such as location of the drainage ditch in achannel easement adjacent to the limited access line, or construction of a suitable outfallsewer beyond the limited access line.
6. If, for any reason, the Health Department having jurisdiction fails to cooperate with theDepartment of Highways in implementing the requirements of this directive, no permitshall be issued to allow discharge of sanitary flow into the drainage system of theHighway, whether rural or within a municipality. For the purpose of this directive, failureto cooperate shall be considered to exist if any one of the following can be established:
a. The office of local Health Commissioner has jurisdiction and is vacant or inactive.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
b. The Health Department having jurisdiction refuses to act.
c. The Health Department having jurisdiction refuses to follow the procedures set forthin this Directive.
d. The Health Department having jurisdiction approves an effluent when it is obviousthat it is not reasonably free from odor, color or suspended solids.
PART II
INSTALLATIONS SERVING ONE, TWO OR THREE FAMILY RESIDENCES, ANDCOMMERCIAL, INDUSTRIAL OR PUBLIC BUILDINGS FROM WHICH THE ESTIMATEDDAILY SANITARY FLOW DOES NOT EXCEED 1500 GALLONS.
(RESPONSIBILITY OF LOCAL HEALTH DEPARTMENTS).
D. PROCEDURE. FOR A NEW USER (RESPONSIBILITY OF BUREAU OF MAINTENANCE)
1. APPLICATION
a. Application for Permit (Form M&R 505 Rev.) shall be prepared in quadruplicate,completed and signed by the owner. Three copies of the application will beaccompanied by a plan drawn on tracing cloth or tracing paper, or standard plans ofthe Ohio Department of Health, capable of being reproduced, and showing theproposed sewage treatment facility. These papers will be submitted to the Highwayfield division. The applicant will retain one copy of the application for his files. Theproperty owner should be advised that copies of the appropriate Ohio Department ofHealth publication entitled “Plans for Installing Sewage Disposal for the ModernHome”, are available and may be obtained at his County Health Department.
b. Plans for proposed sewage treatment facilities shall:
(1) Show the location and profile of the sewers and sewage treatment facility;
(2) Be accurate, to scale and complete in detail and design data;
(3) Provide for an inspection well, located approximately one foot inside the right-of-way line as shown on the attached inspection well drawing. In instances wherethe treated sanitary flow will be discharged into an open Highway ditch, catchbasin or manhole, the inspection well may be omitted but must be built atapplicant’s expense if and when the open ditch is enclosed later.
(4) Contain a statement, by a Registered Professional Engineer or other qualifiedperson as determined by the local Health Commissioner and retained by theowner, that the soil will not permit leaching as shown by percolation testsprescribed by the Ohio Department of Health and that there is no practical placeto discharge the treated sanitary flow except to the Highway drainage system.
2. REVIEW
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
a. The Highway field division shall review the submission and when it has beendetermined that the plan ad application satisfies the policy stated in Sec. B, andmeets the requirements of Sec. D-1 above, two copies of the application and oneprint of the plan reproduced by the Highway field division will be forwarded to thelocal Health Commissioner for action. If private access to a limited access Highwayhas been extinguished or denied and Federal funds have participated in the cost ofbuilding the project then one copy each of plan and application shall be forwarded tothe Bureau of Public Roads for concurrent review. The tracing of the plan and onecopy of the application will be retained in the Highway field division.
b. The local Health Commissioner shall review the plan to determine that leachingwould be ineffective, that no outlet other than the Highway drainage system ispractical for discharging the treated sanitary flow and that the plan indicates a type oftreatment facility which will produce an effluent reasonably free of odor, color andsuspended solids.
3. APPROVAL BY HEALTH COMMISSIONER
a. If the application and plan are approved, the local Health Commissioner will soindicate, date and return the approved application and plan to the HighwayDepartment field division, and retain one copy of the application for his file.
4. DISAPPROVAL BY HEALTH COMMISSIONER
a. If the local Health Commissioner finds that the conditions noted in paragraph D-2-bhave not been met, he will mark the plan disapproved with the date and reasons forhis action, and return the plan and application to the Highway field division.
b. The Highway field division will then notify the applicant of the disapproval. If theapplicant decides to proceed with a new application for permit he shall submit arevised plan and application to the Highway field division which will be processedthrough all required steps as set forth in Sec. D.
5. PERMIT
a. Permits for new users will be issued on Form M & R 509 (Rev.) In six (6) copies anddistributed as follows:
(1) Two copies with two prints and the original reproducible of the approved plan tothe applicant with instructions hat applicant is responsible for notifying the localHealth Commissioner and the Highway Maintenance Superintendent prior tobackfilling any trench or other part of the treatment facility. The applicant mustbe advised that failure to comply with this order will result in revoking the permit.
(2) One copy with one print of the approved plan for the Highway field division files.
(3) One copy with one print of the approved plan to the County MaintenanceSuperintendent or other specifically designated individual who shall see thatconstruction inside Highway right-of-way is in accordance with the approved planand permit.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
(4) One copy with one print of the approved plan to the Engineer of Maintenance,State Highway Department, Columbus, Ohio.
(5) One copy with one print of the approved plan to the local Health Commissioner.
E. PROCEDURE FOR AN EXISTING USER. (RESPONSIBILITY OF BUREAU OF LOCATION& DESIGN)
1. NOTIFICATION
a. When the construction or reconstruction of a highway on new or existing location willrequire removal of any part of a private drain carrying sanitary flow within the scopeof this directive as defined in Sec. C, the owner shall be notified by registered letter,
signed by the Division Engineer or by the Design and Planning Engineer, that hemust obtain written approval of his sewage treatment facility from the local HealthCommissioner if he expects to continue to use the Highway drainage system as anoutlet for private drainage. This letter shall be sent before preliminary right-of-waynegotiations begin.
b. The above letter shall advise that copies of the appropriate Ohio Department ofHealth publication entitled, “Plan for Installing Sewage Disposal for the ModernHome”, are available and may be obtained at his local Health Department. Threecopies of the Standard Agreement form L & D 950 shall be included with theregistered letter with instructions for distributing the forms.
c. A letter, signed by the Division Engineer or by the Design and Planning Engineer,requesting cooperation shall be sent to the local Health Commissioner. The lettershall list the names and addresses of all property owners who have received aregistered letter as noted in Sec. E-1-a above, and one copy of the preliminaryHighway right-of-way plan shall be attached.
d. The property owner shall be given a reasonable time, usually sixty (60) days, toprepare a layout or plan showing location and size of his sewage treatment facilityand the location of the outlet to the Highway drainage system.
(1) The sewage treatment plant layout with dimensions may be shown on the spacedesignated Layout Plan on the Standard Agreement form, on an OhioDepartment of Health standard plan, or on a separate plan. The property ownershall furnish the local Health Commissioner with two completed agreement formsand one plan, if separate, within the time limit stipulated in Sec. E-1-d above. Ifthe instructions furnished the property owner, relative to the required plans for hissewage treatment facility are not clear, he should contact his local HealthCommissioner for advice in preparing on acceptable layout or plan.
(2) The property owner shall arrange at his cost, to have a sample of the effluenttaken by the local Health Commissioner or a qualified public employee forexamination.
2. APPROVAL OF EXISTING SEWAGE TREATMENT FACILITIES BY HEALTHCOMMISSIONER
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
a. If the local Health Commissioner finds that the existing sewage treatment facility isadequate and finds by his examination that it produces an effluent reasonably free ofodor, color, and suspended solids he shall indicate his approval and date of approvalon one copy of the Agreement form furnished him by the property owner, and forwardit to the Highway field division.
b. Upon receipt of the approved Agreement form, the Highway field division will issuethe official permit on form M & R 509 (Rev.) In accordance with Sec. D-5.
c. In all cases where permits are issued for an existing user on inspection well shall beprovided by the State approximately one foot inside the right-of-way line as shown onthe attached inspection well drawing. In unusual instances where the treatedsanitary flow will be discharged into an open Highway ditch, catch basin or manhole,the inspection well may be omitted but must be built at applicant’s expense if andwhen the open ditch is enclosed later.
3. DISAPPROVAL OF EXISTING SEWAGE TREATMENT FACILITIES BY HEALTHCOMMISSIONER.
a. If the property owner’s sewage treatment facility does not meet with Department ofHealth requirements for the modern home, the local Health Commissioner shalladvise the Highway field division of his disapproval and he shall then advise theproperty owner that his existing sewage treatment facility does not meet StateDepartment of Health recommendations and that he should build a tile disposal field,not requiring an outlet, unless it can be established as in Sec. B-2 that because ofthe type of soil or other reasons, leaching requirements cannot be met, in which casethe property owner shall build a new system meeting Ohio Department of Healthrequirements for “Sewage Disposal for the Modern Home” or improve his existingfacility to meet the same requirements.
b. If the local Health Commissioner finds that a leaching system will not be effective andthat it will be necessary for the property owner to improve his existing facility or builda new sewage treatment facility if he expects to use the Highway drainage system asan outlet for his sewage treatment facility, procedures shall be followed as set forth inSection D.
c. If the property owner fails to comply with instructions within the 60-day period notedin Sec. E-1-d, the local Health Commissioner will initiate formal action to abate thenuisance. For such cases the Highway contractor will be instructed by letter from theHighway field division not to connect and to plug any private sewer from the propertyof the offender as has been determined by the local Health Commissioner. Theproperty owner will then be considered as a new user and subject to the stipulationsof Section D.
d. Permits for existing users will be issued on Form M & R 509 (Rev.) in six (6) copiesdistributed as outlined in Sec. D-5.
4. SANITARY FLOWS DISCOVERED DURING CONSTRUCTION
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
The above procedures are to be applied as the required routine by which a permit isgranted to allow continued use of the Highway facility as an outlet for sanitary flow from adischarge line which has been located and shown on the construction plans. If a pipeline discharging sanitary flow, not shown on the plans, is encountered or interceptedduring construction and its continued use requires connection to the Highway drainagesystem, the same procedures shall be followed as set forth for a known installation. If theHighway contractor’s operations can not be suspended during the period allowed theowner for approval or reconstruction of his existing facility, the outfall pipe may betemporarily connected to the Highway drainage system. If at a later date the facility isapproved, an inspection well shall be constructed by the Highway contractor. If thefacility is not approved, it shall be blocked at the property line.
PART III
INSTALLATIONS SERVING FOUR (4) OR MORE DWELLING UNITS, AND COMMERCIAL,INDUSTRIAL OR PUBLIC BUILDINGS FROM WHICH THE ESTIMATED SANITARY FLOWEXCEEDS 1500 GALLONS PER DAY.
(RESPONSIBILITY OF STATE HEALTH DEPARTMENT)
F. PROCEDURE FOR A NEW USER. (RESPONSIBILITY OF BUREAU OF MAINTENANCE)
1. PRELIMINARY REVIEW OF SITE BY DEPARTMENT OF HEALTH
a. Prior to the start of construction of a residential building containing four or moredwelling units, or any commercial, industrial, or public building from which theestimated sanitary flow exceeds 1500 gallons per day and to which public sewers arenot available, the owner and his engineer or architect shall visit the site with anengineer from the appropriate Department of Health district office to determine themost desirable, practical and economical location, size and type of sewage treatmentsystem required to serve the facility. It is highly desirable to arrange for a siteinvestigation prior to actual purchase of land if change in ownership is to occur. Insome instances an ample supply of acceptable water may not be available,topography and drainage may not be satisfactory or there may not be an acceptablepoint of discharge for the sewage treatment plant effluent.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
b. Assuming that the Highway drainage system is to be considered as a means ofdisposing of the proposed sewage treatment plant effluent, a representative from theHighway field division office may also be present at the site investigation. If it isdetermined that the Highway drainage system has adequate capacity and is to beused to receive the effluent, the owner may make application for permit as providedin Section F-3 if his business arrangements require a firm commitment prior toproceeding with design of facility and property acquisition. If the permit is issuedprior to date of formal approval of treatment plant plans by the Department of Health,the permit shall include the statement that the effective date of the permit is to beidentical with the date of Department of Health approval of treatment plant plans, andthat one (1) copy of the approved plans shall be forwarded to the Highway DivisionEngineer upon receipt from the Department of Health.
c. Following the site investigation, the Department of Health District Engineer will givethe owner or his agent general recommendations regarding sewage treatment for theproposed installation.
If a Highway drainage facility is involved, a copy of the letter of recommendations willbe directed to the Highway Division Engineer.
2. PLAN PREPARATION
a. The designing engineer or architect shall prepare detail plans in accordance with therecommendations of the Department of Health. Plans must be clearly drawn andcomplete in all detail. For information regarding details which must be shown onplans refer to the Department of Health publication “Water supply, Sewerage andSewage Treatment for Public Buildings”.
b. If a Highway drainage facility is to be used to receive the treatment plant effluent,complete details showing inspection well and its location and method of connectingto the Highway drainage facility, must be included on the plans in addition toinformation required by Section F-2-a.
c. Complete detail plans must be submitted by the owner or his agent to the appropriateDepartment of Health district office in quadruplicate for reviews. If the plans aresatisfactory they will be forwarded in triplicate by the district office to the Departmentof Health central office along with four (4) copies of he District Engineer’s report onthe plan review, for processing and formal approval.
d. After approval by the Department of Health as required by Section 3701.18 RevisedCode, the plans will be stamped “APPROVED” and distributed as follows:
(1) Two copies to the owner (See Section F-3-a)
(2) One copy for the Department of Health Central Office files for microfilming.
e. The letter of formal approval by the Department of Health will be distributed asfollows:
(1) Original to owner
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
(2) Copy to designing engineer or architect
(3) Copy to Highway Division Engineer
(4) Copy to local Health Department
(5) Copy to Department of Health district office
(6) Copy to Department of Health central office files.
One of the conditions of approval by the Department of Health will be thatconstruction shall not be started until a valid permit is obtained from the HighwayDepartment on Form M & R 509(Rev.)
f. The report of the Department of Health District Engineer relative to the review of theplans will be distributed as follows:
(1) Original to Department of Health central office files
(2) Copy to owner
(3) Copy to Highway Division Engineer
(4) Copy to Department of Health district office
3. APPLICATION FOR PERMIT FROM HIGHWAY DEPARTMENT
a. Application for permit (Form M & R 505 Rev.) shall be prepared in triplicate,completed and signed by the owner. Two copies of the application, and one copy ofthe plans stamped “APPROVED” by the Department of Health as soon as available(See Section F-2-d-(1)), will be forwarded by the owner to the Highway DivisionEngineer. The owner shall retain one copy for his files.
b. If the effluent is to enter the drainage system of a limited access Highway and privateaccess has been extinguished or denied, and Federal funds have participated in thecost of building the project, one copy each of application, and plan when available,shall be forwarded to the Bureau of Public Roads for concurrent review.
4. PERMIT
a. Permits for new users will be issued on Form M & R 509 (Rev.) in six (6) copies anddistributed as follows:
(1) One copy to the applicant with instructions that applicant is responsible fornotifying the Department of Health district office and the Highway MaintenanceSuperintendent prior to backfilling any trench or other part of the treatment plant.The applicant must be advised that failure to comply with these instructions willresult in revoking the permit.
(2) One copy to Highway division files.
(3) One copy to County Maintenance Superintendent who shall see that constructioninside the Highway right-of-way is in accordance with approved plans and permit.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
(4) One copy to the Engineer of Maintenance, State Highway Department,Columbus, Ohio.
(5) One copy to the Department of Health District Engineer.
(6) One copy to the local Health Department.
G. PROCEDURE FOR AN EXISTING USER. (RESPONSIBILITY OF BUREAU OF LOCATIONAND DESIGN)
1. NOTIFICATION
a. When the construction or reconstruction of a highway on new or existing location willrequire removal of any part of a private drain carrying treated sanitary flow whichserves four or more dwelling units or an installation from which the daily sanitary flowexceeds 1500 gallons per day, the owner shall be notified by registered letter, signedby the Division Engineer or by the Design and Planning Engineer, that he mustobtain written approval of his sewage treatment plant from the Department of HealthDistrict Engineer if he expects to continue to use the Highway drainage system as anoutlet for sanitary drainage. This letter shall be sent before preliminary right-of-waynegotiations begin and shall include three copies of Form L & D 950 with theinstructions for distributing the forms. A copy of the letter shall be sent to theDepartment of Health District Engineer.
b. Upon receipt of notification from the Highway Department, the owner shall notify inwriting the Department of Health District Engineer that the Highway division officerequires written Department of Health approval of the sewage treatment facilityserving his property. This notification shall state the name, location and existingstatus of the building in question. Upon reviewing this notification from the owner, theDepartment of Health District Engineer may request additional information of anengineering nature from the owner such as reports of operation of the sewagetreatment plant, test data, availability of other drainage facilities and original approvalof plans of the sewage treatment plant by the Department of Health.
2. APPROVAL OF EXISTING SEWAGE TREATMENT FACILITIES BY THE OHIODEPARTMENT OF HEALTH
(a) If the Department of Health District Engineer finds after a review of the dataand a field inspection, that the existing sewage treatment facilities are beingmaintained in a satisfactory manner and meet the standards of theDepartment of Health, the District Engineer shall so notify the owner inwriting, in duplicate.
(b) If the Department of Health District Engineer determines that a drain or watercourse, other than the Highway drainage facility, is available to receive thedischarge of the sewage treatment plant effluent, or if the soil will permitleaching, the owner and the Highway Division Engineer shall be notified.The owner will be required to remove the treated discharge from the Highwaydrain ad convey it to the other drain or water course, or to a leaching bed.
3. PERMIT ISSUED BY HIGHWAY DEPARTMENT
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
a. Upon receipt of Department of Health notification that the existing sewage treatmentfacilities are adequate and satisfactorily maintained, the owner shall submit to theHighway Division Engineer a copy of the Department of Health District Engineer’sapproval and a completed Agreement Form (L & D 950). The highway division officeshall issue the official permit on Form M & R 509 (Rev.) in accordance with SectionF-4-a.
b. In all cases where permits are issued for an existing user, an inspection well on theeffluent line shall be provided by the State and located approximately one foot insidethe right-of-way line. In unusual instances where the treated sanitary flow dischargesto an open Highway ditch, catch basin or manhole, the inspection well may beomitted but must be built at the owner’s expense if and when the ditch is enclosedlater.
4. DISAPPROVAL OF EXISTING SEWAGE TREATMENT FACILITIES BY THE OHIODEPARTMENT OF HEALTH
a. If the owner has proceeded as outlined in Section G-1-b and the Department ofHealth District Engineer determines that the existing sewage treatment facilities donot meet the Department of Health requirements, the owner shall be required toimprove the existing treatment facilities or construct new facilities to meet Departmentof Health requirements. In this case the property owner shall follow the sameprocedure outlined in Section F.
b. If the owner fails to comply with instructions from the Department of Health and theHighway Department, the Highway contractor will be instructed by letter from theHighway field division (copies to owner and Department of Health District Engineer)not to connect and to plug any private sewer from the property of the owner.
5. SANITARY FLOWS DISCOVERED DURING CONSTRUCTION
a. Same as Section E-4.
PART IV - COMPLIANCE AND ENFORCEMENT
H. INSPECTION AND CORRECTIVE ACTIONS
1. It shall be the duty of the Highway field division to secure compliance with the terms ofthe permit or agreement during the construction of each new or reconstructed sewagetreatment facility.
a. In case of non-compliance the Highway field division shall immediately notify theapplicant and the Health Department having jurisdiction that the terms of the permitor agreement are not being followed and that unless the sewage treatment facility isconstructed as specified the work will be stopped at the right-of-way line. When it isnecessary to forcibly stop the work at the right-of-way line, the Highway field divisionshall first consult the district office of the State Highway Patrol and the CountyProsecutor having jurisdiction.
Appendix B – Directive 22-A DIRECTIVE NO. 22-A April 12, 1965
b. The Health Department having jurisdiction should inspect the sewage treatmentfacilities during their construction and after their completion to insure that they havebeen properly constructed according to the approved plans, and should report hisfindings to the Highway field division in writing.
2. Existing improper sanitary discharge to the Highway drainage system may result innuisances which may be detected during routine maintenance or through field surveysmade prior to road improvement.
a. After an improper sanitary discharge to the Highway drainage system has beendetected, the local Health Commissioner shall be notified in writing by the DivisionMaintenance Engineer of the nuisance condition, with a copy of the letter to theproperty owner, requesting the local Health Commissioner to initiate formal action forabatement of the nuisance. A copy of the action taken by the local HealthCommissioner shall be forwarded to the Division Maintenance Engineer andDepartment of Health District Engineer if sanitary flow is from four or more dwellingunits or exceeds 1500 gallons per day.
b. If the nuisance has not been abated within 30 days after the local HealthCommissioner’s order, the Division Maintenance Engineer shall advise the propertyowner in writing, copy to the local Health Commissioner, that the HighwayDepartment will block the flow from the private drain within 30 days from the date ofthe letter unless the property owner has corrected the nuisance within the timeallowed.
P. E. MASHETER Director
PEM:a1Attachments (4)
Appendix C – Sample Plan Notes
The Sample plan notes included in this Appendix are the most frequently used. Each note is accompanied by a “Designer Note” in an attempt to give some guidance as to when the note should be used and how to estimate quantities for some of the items where the methods for quantity calculations are not obvious. The following note categories are included:
Category
Letter Prefix
Drainage Notes D Erosion Control Notes E Water Quality Notes W
Appendix C – Sample Plan Notes
April 2004
DRAINAGE (D) ,EROSION CONTROL (E), & WATER QUALITY (W)
NUMBER NAME
D101 Item 604 - Catch Basin Grate
D102 Note Deleted (January 2002)
D103 Item Special - Fill and Plug Existing Conduit
D104 Crossings and Connections to Existing Pipes and Utilities
D105 Pipe Connections to Corrugated Metal Structures
D106 Item 603 - Tunnel Liner Plate Structure
D107 Farm Drains D108 Item 605 - Aggregate Drains
D109 Spring Drains
D110 Untreated Septic Connections
D111 Treated Septic Connections
D112 Item 603 - Conduit Bored and Jacked
D113 Review of Drainage Facilities
D114 Residential And Commercial Drainage Connections
D115 Unrecorded Sanitary Connections
D116 Manholes, Catch Basins and Inlets Removed or Abandoned
EXISTING CATCH BASINS SHALL BE MODIFIED BY REPLACING THE EXISTING GRATES WITH BICYCLE SAFE GRATES. QUANTITIES AND LOCATIONS ARE SHOWN IN THE PLANS AND SHALL BE PAID FOR AT THE CONTRACT PRICE FOR ITEM 604, EACH, CATCH BASIN GRATE, TYPE . Designer Note: The above note should be used on projects where existing catch basin grates are not bicycle safe. The size and type of grate to be supplied must be indicated. There may be more than one type and size on a project. If specific locations are not shown in the plan, or additional grates are to be included on a contingency basis, the following should either replace the second sentence in the note or be added to the note: THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER FOR REPLACEMENT OF EXISTING CATCH BASIN GRATES WITH BICYCLE SAFE GRATES: 604, CATCH BASIN GRATE, TYPE , EACH
D103 ITEM SPECIAL - FILL AND PLUG EXISTING CONDUIT THIS ITEM SHALL CONSIST OF THE CONSTRUCTION OF BULKHEADS IN AN EXISTING CONDUIT AND FILLING THE AREA THUS SEALED OFF WITH LEAN GROUT, ITEM 613, SAND OR OTHER MATERIAL APPROVED BY THE ENGINEER. BULKHEADS SHALL BE LOCATED AT THE LIMITS OF THE AREA TO BE FILLED AS INDICATED ON THE PLANS. THE BULKHEADS SHALL CONSIST OF BRICK OR CONCRETE MASONRY WITH A MINIMUM THICKNESS OF 12 INCHES [ 300 MILLIMETERS]. THE FILL MATERIAL SHALL BE PUMPED INTO PLACE, OR PLACED BY OTHER MEANS APPROVED BY THE ENGINEER, SO THAT, AFTER SETTLEMENT, AT LEAST 90 PERCENT OF THE CROSS-SECTIONAL AREA OF THE CONDUIT, FOR ITS ENTIRE LENGTH, SHALL BE FILLED. THE LENGTH OF FILLED AND PLUGGED CONDUIT TO BE PAID FOR SHALL BE THE ACTUAL NUMBER OF FEET [METERS] (MEASURED ALONG THE CENTERLINE OF EACH CONDUIT FROM OUTER FACE TO OUTER FACE OF BULKHEADS) FILLED AND PLUGGED AS DESCRIBED ABOVE. IN LIEU OF FILLING AND PLUGGING THE EXISTING CONDUIT, THE PIPE MAY BE CRUSHED AND BACKFILLED IN ACCORDANCE WITH THE PROVISIONS OF 203, OR IT MAY BE REMOVED. THE LENGTH, MEASURED AS PROVIDED ABOVE, SHALL BE PAID FOR AT THE CONTRACT PRICE PER FOOT [METER] FOR, ITEM SPECIAL, FILL AND PLUG EXISTING CONDUIT. Designer Note: The above note should be used when it is desired to abandon an existing conduit by filling and plugging rather than more conventional methods. If the conduit is in shallow fill, the designer may delete the crush and backfill option specified in the fourth paragraph.
Appendix C – Sample Plan Notes
April 2004
D104 CROSSINGS AND CONNECTIONS TO EXISTING PIPES AND UTILITIES WHERE PLANS PROVIDE FOR A PROPOSED CONDUIT TO BE CONNECTED TO, OR CROSS OVER OR UNDER AN EXISTING SEWER OR UNDERGROUND UTILITY, THE CONTRACTOR SHALL LOCATE THE EXISTING PIPES OR UTILITIES BOTH AS TO LINE AND GRADE BEFORE STARTING TO LAY THE PROPOSED CONDUIT. IF IT IS DETERMINED THAT THE ELEVATION OF THE EXISTING CONDUIT, OR EXISTING APPURTENANCE TO BE CONNECTED, DIFFERS FROM THE PLAN ELEVATION OR RESULTS IN A CHANGE IN THE PLAN CONDUIT SLOPE, THE ENGINEER SHALL BE NOTIFIED BEFORE STARTING CONSTRUCTION OF ANY PORTION OF THE PROPOSED CONDUIT WHICH WILL BE AFFECTED BY THE VARIANCE IN THE EXISTING ELEVATIONS. IF IT IS DETERMINED THAT THE PROPOSED CONDUIT WILL INTERSECT AN EXISTING SEWER OR UNDERGROUND UTILITY IF CONSTRUCTED AS SHOWN ON THE PLAN, THE ENGINEER SHALL BE NOTIFIED BEFORE STARTING CONSTRUCTION OF ANY PORTION OF THE PROPOSED CONDUIT WHICH WOULD BE AFFECTED BY THE INTERFERENCE WITH AN EXISTING FACILITY. PAYMENT FOR ALL THE OPERATIONS DESCRIBED ABOVE SHALL BE INCLUDED IN THE CONTRACT PRICE FOR THE PERTINENT 603 CONDUIT ITEM. Designer Note: The above note is to be used when the designer is unsure of the exact location of a conduit that will require an extension or where the potential for interference between proposed and existing conduits exists.
D105
PIPE CONNECTIONS TO CORRUGATED METAL STRUCTURES CONNECTIONS OF PROPOSED LONGITUDINAL DRAINAGE TO CORRUGATED METAL STRUCTURES SHALL BE MADE BY MEANS OF A SHOP FABRICATED OR FIELD WELDED STUB ON THE STRUCTURE. THE STUB SHALL MEET THE REQUIREMENTS OF 707 AND HAVE A MINIMUM LENGTH OF 2 FEET [0.6 METERS] AND A MINIMUM WALL THICKNESS OF 0.064 INCHES [1.63 MILLIMETERS]. THE LOCATION AND ELEVATION OF THE STUB ARE TO BE CONSIDERED APPROXIMATE AND MAY BE ADJUSTED BY THE ENGINEER TO AVOID CUTTING THROUGH JOINTS IN THE STRUCTURE. THE FIELD WELDED JOINT, IF USED, SHALL BE THOROUGHLY CLEANED AND REGALVANIZED OR OTHERWISE SUITABLY REPAIRED. WELDING SHALL MEET THE REQUIREMENTS OF 513.21. A MASONRY COLLAR, AS PER STANDARD DRAWING DM-1.1, WILL BE REQUIRED TO CONNECT THE LONGITUDINAL DRAINAGE TO THE STUB, WHEN PIPE OTHER THAN CORRUGATED METAL IS PROVIDED FOR THE LONGITUDINAL DRAINAGE. PAYMENT FOR CUTTING INTO THE STRUCTURE AND PROVIDING THE CONNECTION DESCRIBED, SHALL BE INCLUDED IN THE CONTRACT PRICE FOR ITEM 603 OR 522. Designer Note: Use the above note on all projects where connections are proposed to existing corrugated metal conduits.
Appendix C – Sample Plan Notes
April 2004
D106 ITEM 603 - TUNNEL LINER PLATE STRUCTURE IN LIEU OF THE PROVISIONS OF 603.02, MATERIAL FURNISHED FOR THE LINER PLATE STRUCTURE SHALL BE AS MANUFACTURED BY: AMERICAN COMMERCIAL, INC.; COMMERCIAL INTERTECH, CORP.; CONTECH CONSTRUCTION PRODUCTS, INC.; OR AN APPROVED EQUAL. BASE METAL COMPOSITION, DEPTH AND SPAN OF THE CORRUGATIONS, AND SIZE AND SPACING OF BOLTS AND BOLT HOLES SHALL BE IN ACCORDANCE WITH THE DETAILS OF THE MANUFACTURER. INSTALLATION OF THE STRUCTURE SHALL BE IN ACCORDANCE WITH THE MANUFACTURER’S RECOMMENDATIONS. THE PLATE THICKNESS AND SECTION MODULUS OF THE MATERIAL FURNISHED SHALL NOT BE LESS THAN THAT INDICATED ON THE STRUCTURE DETAILS. GALVANIZING, IF SPECIFIED, SHALL BE IN ACCORDANCE WITH 707.03 AND SHALL BE DONE AFTER CORRUGATING, FORMING, AND PUNCHING THE PLATES AND BOLT HOLES. GRANULAR BEDDING WILL NOT BE REQUIRED. THE COMPLETED STRUCTURE SHALL CONFORM TO THE REQUIREMENTS OF 707. BITUMINOUS COATING, IF SPECIFIED, SHALL MEET THE REQUIREMENTS OF 707.05. Designer Note: If the space between the tunnel excavation and the tunnel liner plate is to be filled with grout, the composition of the grout and spacing of the grout couplings should be shown.
D107
FARM DRAINS ALL FARM DRAINS, WHICH ARE ENCOUNTERED DURING CONSTRUCTION, SHALL BE PROVIDED WITH UNOBSTRUCTED OUTLETS. EXISTING COLLECTORS WHICH ARE LOCATED BELOW THE ROADWAY DITCH ELEVATIONS, AND WHICH CROSS THE ROADWAY, SHALL BE REPLACED WITHIN THE (RIGHT OF WAY)( CONSTRUCTION) LIMITS BY ITEM 603 CONDUIT, TYPE B, ONE COMMERCIAL SIZE LARGER THAN THE EXISTING CONDUIT. EXISTING COLLECTORS AND ISOLATED FARM DRAINS, WHICH ARE ENCOUNTERED ABOVE THE ELEVATION OF ROADWAY DITCHES, SHALL BE OUTLETTED INTO THE ROADWAY DITCH BY 603 TYPE F CONDUIT. THE OPTIMUM OUTLET ELEVATION SHALL BE ONE FOOT [300 MILLIMETERS] ABOVE THE FLOWLINE ELEVATION OF THE DITCH. LATERAL FIELD TILES WHICH CROSS THE ROADWAY SHALL BE INTERCEPTED BY 603, TYPE E CONDUIT, AND CARRIED IN A LONGITUDINAL DIRECTION TO AN ADEQUATE OUTLET OR ROADWAY CROSSING. THE LOCATION, TYPE, SIZE AND GRADE OF REPLACEMENTS SHALL BE DETERMINED BY THE ENGINEER AND PAYMENT SHALL BE MADE ON FINAL MEASUREMENTS. EROSION CONTROL PADS AND ANIMAL GUARDS SHALL BE PROVIDED AT THE OUTLET END OF ALL FARM DRAINS AS PER STANDARD CONSTRUCTION DRAWING DM-1.1, EXCEPT WHEN THEY OUTLET INTO A DRAINAGE STRUCTURE. PAYMENT FOR THE EROSION CONTROL PADS AND ANIMAL GUARDS AND ANY NECESSARY BENDS OR BRANCHES SHALL BE INCLUDED FOR PAYMENT IN THE PERTINENT CONDUIT ITEMS. THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR THE WORK NOTED ABOVE:
Appendix C – Sample Plan Notes
April 2004
D107 FARM DRAINS (CONT.) 603 “ [mm] CONDUIT, TYPE B ________ FT. [METER] 603 “ [mm] CONDUIT, TYPE E ________ FT. [METER] 603 “ [mm] CONDUIT, TYPE F ________ FT. [METER] 601 ROCK CHANNEL PROTECTION TYPE C WITH FILTER ________ CU. YD. [CU. METER] Designer Note: The above note is to be used where excavation may conflict with existing farm drains. Use of a lateral field interceptor tile located on a temporary easement outside the limited access right of way may be appropriate on limited access facilities.
D108 ITEM 605 - AGGREGATE DRAINS AGGREGATE DRAINS SHALL BE PLACED AT 50 FOOT [10 METER] INTERVALS ON EACH SIDE OF NORMAL CROWNED SECTIONS, STAGGERED SO THAT EACH DRAIN IS 25 FEET [5 METERS] FROM THE ADJACENT DRAIN ON THE OPPOSITE SIDE, AND AT 25 FOOT [5 METER] INTERVALS ON THE LOW SIDE ONLY OF SUPERELEVATED SECTIONS. AN AGGREGATE DRAIN SHALL BE PLACED AT THE LOW POINT OF EACH SAG VERTICAL CURVE. Designer Note: This note should be used on long projects with aggregate drains. On short projects, such as bridge replacements, the station and side for aggregate drain placement should be specified in the plans.
D109 SPRING DRAINS THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN CARRIED TO THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER FOR DRAINING ANY SPRINGS SHOWN IN THE PLAN OR ENCOUNTERED DURING CONSTRUCTION. THE FOLLOWING TYPES OF PIPES MAY BE USED: 707.33, 707.41, 707.42 or 707.45 PERFORATED PER 707.31. SPRING DRAINS SHALL BE CONSTRUCTED AS SHOWN ON STANDARD CONSTRUCTION DRAWING DM-1.1 AND PAID FOR AT THE CONTRACT PRICE FOR: 605, 6" [150 mm] UNCLASSIFIED PIPE UNDERDRAINS FOR SPRINGS ________ FT. [METER] 605, AGGREGATE DRAINS FOR SPRINGS ________ FT. [METER] 604, PRECAST REINFORCED CONCRETE OUTLET ________ EACH Designer Note: This note should be used only where springs are present in the project area and/or the project area is known to have spring activity. In addition to quantities required to drain springs located by field work, estimated contingency quantities should be included for draining springs encountered during construction.
Appendix C – Sample Plan Notes
April 2004
D110
UNTREATED SEPTIC CONNECTIONS THIS PLAN MAKES NO PROVISION FOR CONNECTING, NOR SHALL THE ENGINEER OR CONTRACTOR CONNECT, ANY UNTREATED SEPTIC DRAINAGE INTO THE HIGHWAY DRAINAGE SYSTEM. ANY PIPE CARRYING UNTREATED SEPTIC FLOW SHALL BE PLUGGED WITH CLASS C CONCRETE AT THE RIGHT OF WAY LINE. PAYMENT FOR PLUGGING SHALL BE INCLUDED IN THE CONTRACT PRICE FOR THE PERTINENT 202 OR 203 ITEM. Designer Note: This note shall be used on all state maintained projects where existing sanitary sewers are available to property owners, and may be used on off-system projects under local control where the local authority requests, in writing, that this restriction apply.
D111 TREATED SEPTIC CONNECTIONS TREATED SEPTIC FLOW MAY BE DISCHARGED INTO THE HIGHWAY DRAINAGE SYSTEM PROVIDED THE OWNER HAS ACQUIRED AN OFFICIAL PERMIT FROM THE (OHIO DEPARTMENT OF TRANSPORTATION) (COUNTY) (OR) (LOCAL AUTHORITY). IN EACH CASE WHERE A PERMIT HAS BEEN ISSUED FOR MAKING A TREATED SEPTIC CONNECTION INTO A HIGHWAY DRAINAGE CONDUIT, AN INSPECTION WELL SHALL BE PROVIDED IN ACCORDANCE WITH STANDARD CONSTRUCTION DRAWING DM-3.1. THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER IN MAKING THE ABOVE CONNECTIONS: 603, ______ “ [mm] CONDUIT, TYPE C ________ FT. [METER] 604, INSPECTION WELL ________ EACH Designer Note: This note is to be used on all projects on the State system (with the exception of Interstate highways) where sanitary sewers are not available and on-site treatment systems are used. The note should be modified for projects within City corporation limits or on County highways where the local authority elects to issue a permit for making the connection. No inspection well is required if the effluent is discharged into an open ditch, channel, catch basin or manhole.
D112 ITEM 603 - CONDUIT BORED AND JACKED WHERE IT IS SPECIFIED THAT A CONDUIT BE INSTALLED BY THE METHOD OF BORING AND JACKING, NO TRENCH EXCAVATION SHALL BE CLOSER THAN FEET [METERS] TO THE (EDGE OF PAVEMENT) (NEAREST RAIL). TRENCHES SHALL BE ADEQUATELY SUPPORTED AND THE SPECIFICATION REQUIREMENTS FOR TYPE 2 BEDDING SHALL BE DISREGARDED. IF A CASING PIPE IS USED IN THE BORING AND JACKING OPERATION, THE VOID BETWEEN IT AND THE INTERIOR CARRIER PIPE SHALL BE COMPLETELY FILLED WITH ITEM 613, SAND, GROUT OR OTHER MATERIAL APPROVED BY THE ENGINEER. Designer Note: The pay item in the General Summary shall read, 603 Conduit, Bored or Jacked, “ [mm], Type , Ft. [meters]. Where a conduit is installed by this method under a railroad, the designer should coordinate with the Rail Company to determine the allowable distance from the nearest rail.
Appendix C – Sample Plan Notes
April 2004
D113
REVIEW OF DRAINAGE FACILITIES BEFORE ANY WORK IS STARTED ON THE PROJECT AND AGAIN BEFORE FINAL ACCEPTANCE BY THE STATE, REPRESENTATIVES OF THE STATE AND THE CONTRACTOR, ALONG WITH LOCAL REPRESENTATIVES, SHALL MAKE AN INSPECTION OF ALL EXISTING SEWERS WHICH ARE TO REMAIN IN SERVICE AND WHICH MAY BE AFFECTED BY THE WORK. THE CONDITION OF THE EXISTING CONDUITS AND THEIR APPURTENANCE SHALL BE DETERMINED FROM FIELD OBSERVATIONS. RECORDS OF THE INSPECTION SHALL BE KEPT IN WRITING BY THE STATE. ALL NEW CONDUITS, INLETS, CATCH BASINS, AND MANHOLES CONSTRUCTED AS A PART OF THE PROJECT SHALL BE FREE OF ALL FOREIGN MATTER AND IN A CLEAN CONDITION BEFORE THE PROJECT WILL BE ACCEPTED BY THE STATE. ALL EXISTING SEWERS INSPECTED INITIALLY BY THE ABOVE MENTIONED PARTIES SHALL BE MAINTAINED AND LEFT IN A CONDITION REASONABLY COMPARABLE TO THAT DETERMINED BY THE ORIGINAL INSPECTION. ANY CHANGE IN THE CONDITION RESULTING FROM THE CONTRACTOR’S OPERATIONS SHALL BE CORRECTED BY THE CONTRACTOR TO THE SATISFACTION OF THE ENGINEER. PAYMENT FOR ALL OPERATIONS DESCRIBED ABOVE SHALL BE INCLUDED IN THE CONTRACT PRICE FOR THE PERTINENT 603 CONDUIT ITEMS. Designer Note: This note is to be used on projects where existing drainage facilities are to remain in service.
D114
RESIDENTIAL AND COMMERCIAL DRAINAGE CONNECTIONS EXISTING ROOF DRAINS, FOOTER DRAINS, OR YARD DRAINS, DISTURBED BY THE WORK, SHALL BE PROVIDED WITH UNOBSTRUCTED OUTLETS BY CONNECTING A CONDUIT THROUGH THE CURB OR INTO A DRAINAGE STRUCTURE. THE LOCATION, TYPE, SIZE AND GRADE OF THE NEW CONDUIT REQUIRED TO REPLACE OR EXTEND THE EXISTING DRAIN WILL BE DETERMINED BY THE ENGINEER. THE FOLLOWING CONDUIT TYPES MAY BE USED: 707.33, 707.41 NON-PERFORATED, 707.42, 707.43, 707.45, 707.46, 707.47, 707.51, 707.52 SDR35. THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER FOR THE WORK NOTED ABOVE: 603, ______ “ [mm] CONDUIT, TYPE B, FOR DRAINAGE CONNECTION ________ FT. [METER] 603, ______ “ [mm] CONDUIT, TYPE C, FOR DRAINAGE CONNECTION ________ FT. [METER] 603, ______ “ [mm] CONDUIT, TYPE E, FOR DRAINAGE CONNECTION ________ FT. [METER] 603, ______“ [mm] CONDUIT, TYPE F, FOR DRAINAGE CONNECTION ________ FT. [METER]
Appendix C – Sample Plan Notes
April 2004
D114
RESIDENTIAL AND COMMERCIAL DRAINAGE CONNECTIONS (CONT.) Designer Note: This note is to be used only if there is a possibility that during construction there may be a need for additional residential and commercial connections. The designer shall make a complete investigation for the presence of existing residential and commercial drainage connections and quantities should be listed at the specific locations on the Plan & Profile sheets.
D115 UNRECORDED SANITARY CONNECTIONS ANY UNRECORDED ACTIVE CONNECTION TO A SANITARY SEWER ENCOUNTERED DURING CONSTRUCTION SHALL BE RECONNECTED TO THE EXISTING SANITARY SEWER TO THE SATISFACTION OF THE ENGINEER. THE FOLLOWING CONDUIT TYPES MAY BE USED: 707.42, 707.43, 707.44, 707.45, 707.46, 707.47, 707.51, 707.52 SDR35, 706.01, 706.02, OR 706.08 WITH JOINTS AS PER 706.11 OR 706.12. THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER FOR THE WORK NOTED ABOVE: 603, ______ “ [mm] CONDUIT, TYPE B, FOR SANITARY ______ FT. [METER] 603, ______ “ [mm] CONDUIT, TYPE C, FOR SANITARY ______ FT. [METER] Designer Note: This note should be used in conjunction with note D110, Untreated Septic Connections, when there is a possibility that during construction there may be a need for additional sanitary connections. The Designer shall make a complete investigation for the presence of existing sanitary connections. Quantities should be listed at the specific locations on the Plan & Profile sheets.
D116 MANHOLES, CATCH BASINS AND INLETS REMOVED OR ABANDONED ALL CASTINGS SHALL BE CAREFULLY REMOVED AND STORED WITHIN THE RIGHT OF WAY FOR SALVAGE BY (STATE) (CITY) (VILLAGE) (COUNTY) FORCES. PAYMENT FOR ALL OF THE ABOVE SHALL BE INCLUDED IN THE CONTRACT PRICE FOR THE PERTINENT 202 ITEM. Designer Note: This note shall only be used where it has been determined that the owner desires to retain the existing castings.
D117
SANITARY WORK THE FOLLOWING CONDUIT TYPES MAY BE USED: 707.42, 707.43, 707.44, 707.45, 707.46, 707.47, 707.51, 707.52 SDR35, 706.01, 706.02 OR 706.08 WITH JOINTS AS PER 706.11 OR 706.12. THE PAY ITEM MEASURED PER FT. [METER] SHALL BE:
Appendix C – Sample Plan Notes
April 2004
D117
SANITARY WORK (CONT.) 603, ______ “ [mm] CONDUIT, TYPE , FOR SANITARY Designer Note: This note is to be used whenever sanitary lines are specified in the plans.
D118 ITEM SPECIAL- MISCELLANEOUS METAL EXISTING CASTINGS MAY PROVE TO BE UNSUITABLE FOR REUSE, AS DETERMINED BY THE ENGINEER. IT SHALL BE THE CONTRACTOR’S RESPONSIBILITY TO PROVIDE THE CASTINGS OF THE REQUIRED TYPE, SIZE AND STRENGTH (HEAVY OR LIGHT DUTY) FOR THE PARTICULAR STRUCTURE IN QUESTION. ALL MATERIAL SHALL MEET ITEM 604 OF THE SPECIFICATIONS AND SHALL HAVE THE PRIOR APPROVAL OF THE ENGINEER. THE FOLLOWING ESTIMATED QUANTITY HAS BEEN CARRIED TO THE GENERAL SUMMARY FOR USE AS DIRECTED BY THE ENGINEER. SPECIAL, MISCELLANEOUS METAL _____ POUNDS [KILOGRAMS] THE CONTRACTOR IS CAUTIONED TO USE EXTREME CARE IN THE REMOVAL, STORAGE AND REPLACEMENT OF ALL EXISTING CASTINGS. CASTINGS DAMAGED BY THE NEGLIGENCE OF THE CONTRACTOR, AS DETERMINED BY THE ENGINEER, SHALL BE REPLACED WITH THE PROPER NEW CASTINGS AT THE EXPENSE OF THE CONTRACTOR. Designer Note: Use this note if existing castings are to be reused and which may be unsuitable.
D119 ITEM 603 - SLOTTED DRAIN: ( )” [mm], TYPE ( ) THIS ITEM SHALL CONSIST OF ____ INCH [MILLIMETER] DIAMETER SLOTTED DRAIN BITUMINOUS COATED STEEL CONDUIT 707.05 (14 GAUGE) WITH 6 INCH BY 3/16 INCH [150 mm BY 4.7 mm] GALVANIZED SOLID BAR GRATE AS APPROVED BY THE ENGINEER. ALL COSTS FOR LABOR AND MATERIALS, INCLUDING TYPE 2 BEDDING, AND BACKFILLING AS DETAILED ON STANDARD CONSTRUCTION DRAWING DM-1.3 SHALL BE INCLUDED IN THE PRICE BID PER FOOT [METER] FOR ITEM 603 - SLOTTED DRAIN: ____ INCH [MILLIMETER], TYPE ____ . Designer Note: This plan note should be used in conjunction with Standard Construction Drawing DM-1.3.
D120
ITEM SPECIAL - PIPE CLEANOUT THIS WORK SHALL CONSIST OF REMOVING SEDIMENT AND DEBRIS FROM THE EXISTING DRAINAGE CONDUITS SPECIFIED IN THE PLANS. ALL MATERIAL REMOVED SHALL BE DISPOSED OF AS PER 105.16 AND 105.17. ALL SEWERS SHALL BE CLEANED OUT TO THE SATISFACTION OF THE ENGINEER. CLEANOUT OF THE PIPE SHALL BE PAID FOR AT THE UNIT PRICE BID FOR ITEM SPECIAL - PIPE CLEANOUT. THIS PRICE SHALL INCLUDE THE COST FOR MATERIAL, EQUIPMENT, LABOR, AND ALL INCIDENTALS REQUIRED TO COMPLETE THE CLEANOUT.
Appendix C – Sample Plan Notes
April 2004
D120 ITEM SPECIAL - PIPE CLEANOUT (CONT.) THE FOLLOWING ESTIMATED QUANTITIES HAVE BEEN INCLUDED IN THE GENERAL SUMMARY FOR THE ABOVE NOTED WORK: SPECIAL, PIPE CLEANOUT ________ FT. [METER] Designer Note: This item may not be eligible for federal participation.
E101
SEEDING AND MULCHING THE FOLLOWING QUANTITIES ARE PROVIDED TO PROMOTE GROWTH AND CARE OF PERMANENT SEEDED AREAS: 659, SOIL ANALYSIS TEST ____ EACH 659, TOPSOIL ____ CU. YD. (CU. METER) 659, SEEDING AND MULCHING ____ SQ. YD. (SQ. METER) 659, REPAIR SEEDING AND MULCHING ____ SQ. YD. (SQ. METER) 659, INTER-SEEDING ____ SQ. YD. (SQ. METER) 659, COMMERCIAL FERTILIZER ____ TON (KILOGRAM) 659, LIME ____ ACRES (HECTARES) 659, WATER ____ M. GAL. (CU. METER) 659, MOWING ____ M. SQ. FT. (SQ. METER) SEEDING AND MULCHING SHALL BE APPLIED TO ALL AREAS OF EXPOSED SOIL BETWEEN THE RIGHT-OF-WAY LINES, AND WITHIN THE CONSTRUCTION LIMITS FOR AREAS OUTSIDE THE RIGHT-OF-WAY LINES COVERED BY WORK AGREEMENT OR SLOPE EASEMENT. QUANTITY CALCULATIONS FOR SEEDING AND MULCHING ARE BASED ON THESE LIMITS. Designer Note: The above quantities should be used on all projects that require grading work. The following is a basic guideline for estimating quantities for the above items. These quantities may be omitted from the note if they are itemized elsewhere in the plan. Calculations for all items should be shown in the plans. 659, Soil Analysis Test (Each) Soil Analysis Tests are used to field adjust the rate of Lime based on soil conditions. A. Soil Analysis Test is not specified.
1. The standard rate for Lime will be used without adjustment.
B. Soil Analysis Test is specified. If specified, minimum of two tests.
1. If no Topsoil to be placed - One test per 10 Acres (one test per 48400 Sq. Yd.)[one test per 40000 Sq. Meters] of permanent seeded area and sodded area.
2. If placing Topsoil - One test per 10000 Cu. Yds. [7600 Cu. Meters] of Topsoil.
Appendix C – Sample Plan Notes
April 2004
E101
SEEDING AND MULCHING (CONT.) 659, Topsoil (Cu. Yd.)[Cu. Meter] 111 Cu. Yds. per 1000 Sq. Yd. [0.10 Cu. Meter per Sq. Meter] of permanent seeded area. Topsoil is optional. However, it is recommended, especially for projects involving A4 silty materials, granular embankment or granular materials due to severe erosion problems.
659, Seeding and Mulching (Sq. Yd.)[Sq. Meter]
This quantity is usually calculated by the end width method using the cross sections. On short projects, seeding quantities may be determined by other methods. For example, the area for seeding may be estimated by calculating an area per Plan & Profile sheet determined by multiplying an average width (based on construction limits or right-of -way lines) by the distance on each sheet, and then deducting for paved surface areas. A deduction should be taken for 660 and 670 items. 659, Repair Seeding and Mulching (Sq. Yd.) [Sq. Meter] 5 % of the permanent seeding and mulching area. 659, Inter-seeding (Sq. Yd.)[Sq. Meter] 5% of the permanent seeding and mulching area.
659, Commercial Fertilizer (Ton)[Kilogram]
30 pounds per 1000 Sq. Ft. ( one Ton per 7410 Sq. Yd.)[0.15 Kg/Sq. Meter] of permanent seeded area. This rate includes 20 pounds per 1000 Sq. Ft. [0.10 kg per Sq. Meter] for the first application and 10 pounds per 1000 Sq. Ft. [0.05 kg per Sq. meter] for the second application. If Inter-seeding is provided, use an additional 20 pounds per 1000 Sq. Ft. of commercial fertilizer for the Inter-seeding area. 659 Lime (Acre)[Hectare] Apply over permanent seeded area. 659, Water (M. Gal.)[Cu. Meter] Two applications each at 300 Gallons per 1000 Sq. Ft. (0.0027 M Gallons per Sq. Yd.) [12.2 Cu. Meters per 1000 Sq. Meters] of permanent seeded area. The above rate is for a single application. If Inter-seeding is provided, use an additional 300 Gallons per 1000 Sq. Ft. of water for the Inter-seeded area. 659, Mowing (M. Sq. Ft.)[Sq. Meter]
25 % of the permanent seeded area for projects expected to last more than one construction season.
E102
SODDING THE FOLLOWING QUANTITIES ARE PROVIDED TO PROMOTE GROWTH AND CARE OF PERMANENT SODDED AREAS.
Appendix C – Sample Plan Notes
April 2004
E102
SODDING (CONT.) 659, SOIL ANALYSIS TEST ____ EACH 659, TOPSOIL ____ CU. YD. (CU. METER) 659, COMMERCIAL FERTILIZER ____ TON (KILOGRAM) 659, LIME ____ ACRE (HECTARE) 659, WATER ____ M. GAL. (CU. METER) 660, SODDING, UNSTAKED, STAKED, REINFORCED ____ SQ. YD. (SQ. METER) Designer Note: The above quantities should be used on all projects that have pay item(s) for permanent sodding. The following is a basic guideline for estimating quantities for the above items. These quantities may be omitted from the note if they are itemized elsewhere in the plan. Calculations for all items should be shown in the plans. 659, Soil Analysis Test (Each) Soil Analysis Tests are used to field adjust the rate of Lime based on soil conditions. C. Soil Analysis Test is not specified.
1. The standard rate for Lime will be used without adjustment.
D. Soil Analysis Test is specified. If specified, minimum of two tests.
1. If no Topsoil to be placed - One test per 10 Acres (one test per 48400 Sq. Yd.)[one test per 40000 Sq. Meters] of permanent sodded area.
2. If placing Topsoil - One test per 10000 Cu. Yds. [7600 Cu. Meters] of Topsoil.
659, Topsoil (Cu. Yd.)[Cu. Meter] 111 Cu. Yds. per 1000 Sq. Yd. [0.10 Cu. Meter per Sq. Meter] of permanent sodded area. Topsoil is optional. However, it is recommended, especially for projects involving A4 silty materials, granular embankment or granular materials due to severe erosion problems. 659, Commercial Fertilizer (Ton)[Kilogram] 30 pounds per 1000 Sq. Ft. ( one Ton per 7410 Sq. Yd.)[0.15 Kg/Sq. Meter] of permanent sodded area. This rate includes 20 pounds per 1000 Sq. Ft. [0.10 kg per Sq. Meter] for the first application and 10 pounds per 1000 Sq. Ft. [0.05 kg per Sq. meter] for the second application. 659, Lime (Acre)[Hectare] Apply over permanent sodded area. 659, Water (M. Gal.)[Cu. Meter] 1 application every 7 days for an additional 2 months beyond the requirements of 660.09. The rate shall be 300 gallons per 1000 Sq. Ft. (0.0027 M. Gallons per Sq. Yd.) [12.2 Cu. Meters per 1000 Sq. Meters] of permanent sodded area. 660, Sodding (Sq. Yd.)[Sq. Meter] This is the actual number of Sq. Yds. [Sq. Meters] of permanent sodded area.
Appendix C – Sample Plan Notes
April 2004
W99 POST CONSTRUCTION STORM WATER TREATMENT THIS PLAN UTILIZES STRUCTURAL BEST MANAGEMENT PRACTICES (BMP’S) FOR POST CONSTRUCTION STORM WATER TREATMENT. THE FOLLOWING BMP’S HAVE BEEN DESIGNED INTO THE PLANS: Designer Note: This plan note shall be used on all projects that have post construction storm water management BMP’s. The note shall be followed by the below notes if applicable.
W100 VEGETATED STRIPS (& SWALES)
VEGETATED STRIPS (& SWALES) HAVE BEEN IDENTIFIED IN THIS PLAN. TAKE CARE TO GRADE THESE AREAS AS THE PLAN INDICATES. STABILIZE THE STRIP (& SWALE) WITH THE PERMANENT DITCH EROSION PROTECTION UPON FINAL GRADING. PAYMENT SHALL BE INCLUDED IN THE PERMANENT DITCH EROSION PROTECTION ITEMS. Designer Note: This plan note shall be used on all projects that have vegetated strips or swales identified in the plan.
W101 BIORETENTION CELL(S)
CONSTRUCT THE BIORETENTION CELL(S) AFTER ALL CONTRIBUTING DRAINAGE AREAS ARE STABILIZED AS SHOWN ON THE CONTRACT PLANS AND TO THE SATISFACTION OF THE ENGINEER. DO NOT USE THE COMPLETED BIORETENTION CELL(S) AS TEMPORARY SEDIMENT CONTROL FACILITIES DURING CONSTRUCTION. DO NOT OPERATE HEAVY EQUIPMENT WITHIN THE PERIMETER OF A BIORETENTION FACILITY DURING EXCAVATION, UNDERDRAIN PLACEMENT, BACKFILLING, PLANTING, OR MULCHING OF THE FACILITY. USE ALL SUITABLE EXCAVATED MATERIAL IN THE WORK. ALTERNATIVELY, LEGALLY USE, RECYCLE, OR DISPOSE OF ALL EXCAVATED MATERIALS ACCORDING TO 105.16 AND 105.17. EXCAVATE THE BIORETENTION CELL(S) TO THE DIMENSIONS, SIDE SLOPES, AND ELEVATIONS SHOWN ON THE CONTRACT PLANS. MINIMIZE THE COMPACTION OF THE BOTTOM OF THE BIORETENTION FACILITY BY THE METHOD OF EXCAVATION. EMBANKMENT WILL BE MEASURED AND PAID AS ITEM 203, EMBANKMENT, USING NATURAL SOIL, 703.16.A. THE BIORETENTION SOIL SHALL BE A UNIFORM MIX THAT IS FREE OF STONES, STUMPS, ROOTS, OR ANY OTHER OBJECT THAT IS LARGER THAN TWO INCHES. THE SOIL MAY CONSIST OF EXISTING SOIL, FURNISHED SOIL, OR A COMBINATION OF BOTH PROVIDED THAT IT MEETS THE FOLLOWING REQUIREMENTS: THOROUGHLY MIX THE BIORETENTION SOIL PRIOR TO PLACEMENT. TEST AND ADJUST THE
PH RANGE: 5.2-7.0
COMPOSITION BY VOLUME
4 PARTS SAND – CMS FINE AGGREGATE AS PER 703
2 PARTS COMPOST – CMS 659.06
2 PARTS TOPSOIL – CMS 659.05
Appendix C – Sample Plan Notes
April 2004
PH AS PER CMS 659.02.B. ALL SAND USED SHALL MEET CMS 203.02.H, NATURAL GRANULAR MATERIALS. PLACE THE SOIL IN 12 INCH LIFTS AND CONSOLIDATE BY WATERING UNTIL SATURATED. CONSTRUCT THE UNDERDRAIN SYSTEM AS PER CMS 605. PLACE THE GRANULAR BACKFILL MATERIAL TO THE INVERT OF THE BIORETENTION SOIL. ENSURE A MINIMUM OF 2 INCHES OF GRANULAR COVER OVER THE UNDERDRAIN PRIOR TO PLACEMENT OF THE BIORETENTION SOIL. PLACE OBSERVATION WELLS AND CLEANOUTS WHERE SHOWN IN THE PLANS. CONNECT THE WELLS/CLEANOUTS TO THE PERFORATED UNDERDRAIN WITH THE APPROPRIATE MANUFACTURED CONNECTIONS. THE WELLS/CLEANOUTS SHALL EXTEND 6 INCHES ABOVE THE TOP ELEVATION OF THE BIORETENTION FACILITY MULCH. CAP THE WELLS/CLEANOUTS WITH A THREADED SCREW CAP. CAP THE ENDS OF UNDERDRAIN PIPES NOT TERMINATING IN AN OBSERVATION WELL/CLEANOUT OR CONNECTED TO OTHER CONDUITS. PLACE TREES, SHRUBS, AND OTHER PLANT MATERIALS SPECIFIED FOR BIORETENTION FACILITIES AS SPECIFIED IN THE PLANS. PLANT MATERIALS WILL BE MEASURED AND PAID FOR PER CMS ITEM 661. APPLY NO PESTICIDES, HERBICIDES, AND FERTILIZERS DURING PLANTING, ESTABLISHMENT, OR MAINTENANCE UNDER ANY CIRCUMSTANCES. BIORETENTION CELLS WILL BE PAID FOR AS ITEM SPECIAL, BIORETENTION CELL AT THE CONTRACT BID LUMP SUM PRICE. THE PAYMENT WILL BE FULL COMPENSATION FOR ALL APPLICABLE INCIDENTALS NECESSARY TO SATISFACTORILY COMPLETE THE WORK. Designer Note: This plan note shall be used on all projects that have bioretention cell(s) identified in the plan. Embankment work to create the impoundment will be constructed and paid for as Item 203 Embankment, using natural soils, 703.16.A.
W102 INFILTRATION TRENCH (OR BASIN)
THIS PLAN UTILIZES INFILTRATION FOR POST CONSTRUCTION STORM WATER TREATMENT. CONSTRUCT THE COMPLETED INFILTRATION TRENCH(ES) (AND OR BASIN(S)) AFTER ALL CONTRIBUTING DRAINAGE AREAS ARE STABILIZED AS SHOWN IN THE CONTRACT PLANS AND TO THE SATISFACTION OF THE ENGINEER. DO NOT USE INFILTRATION DEVICES AS TEMPORARY SEDIMENT CONTROL FACILITIES DURING CONSTRUCTION. DO NOT OPERATE HEAVY EQUIPMENT WITHIN THE PERIMETER OF AN INFILTRATION DEVICE DURING EXCAVATION OR BACKFILLING OF THE FACILITY. Designer Note: This plan note shall be used on all projects that have infiltration trenches and or basins identified in the plan. Embankment work to create the impoundment will be constructed and paid for as Item 203 Embankment, using natural soils, 703.16.A.
