Brian Kendrick, P.E.Louisiana Department of Transportation and Development

Public Works & Water Resources DivisionLouisiana Dam Safety Program

Email: Briankendrick@dotd.la.govWebpage: http://www.dotd.la.gov/intermodal/dams

Kenneth J. LaBryC. H. Fenstermaker & AssociatesEmail: kenl@fenstermaker.com

Webpage: http://www.fenstermaker.com

Acoustic Surveys and Underwater Inspections of State-Maintained Dams

February 10, 2009

• In the past 30 years, there have been over 135 fatalities and more than $2.6 billion in property damage in the U.S., resulting from dam failures (Stat. from ASDSO).

• In Louisiana, there have been only a few minor dam failures with no fatalities recorded…. yet.

• Most of the 20 State –maintained dams are over 45 years old, poorly maintained (lack of funds) and a number of them, are in critical repair needs.

On February 26, 1972, the Buffalo Creek Dam failed causing 125 fatalities. In August 1972, USC Title 33 Section 467 was passed establishing the National Dam Safety Program Act.

LOUISIANA DAM SAFETY PROGRAM

• Act 733 of the 1981 Regular Session of the Louisiana Legislature created Louisiana’s Dam Safety Program (LA. R.S. 38:21-28).

• Recognizes the inherent danger posed by impoundments of significant volumes of water.

• Requires that owners of structures which impound water (or other liquids) assume the responsibility for that danger by ensuring that such structures are designed, constructed, and maintained so as to minimize the risk to life and property.

• Regardless of the circumstances of failure, the owner is ultimately responsible for loss of life and property damages that may occur from the failure of his dam.

STATE REGULATED DAMS

Includes all dams / reservoirs which are:

a) At least 25 feet high and have a maximum water storage capacity of 15 acre-feet or more, or

b) At least Six feet high and have a maximum water storage capacity of 50 acre-feet or more

c) Excludes Toledo Bend Dam

PERMITTING REQUIREMENTS

Application for Permit:

• A permit from DOTD will be required prior to constructing any new dam or commencing any modification to an existing dam.

• All dams 6 feet high or having a maximum storage capacity greater than 15 acre-feet must submit an application for review.

FAILURE TO OBTAIN PERMIT

If the owner fails to obtain a permit prior to constructing a dam/ reservoir:

• The owner will be cited and fined under the statutory authority of LA Revised Statue, Title 38, Section 28.

• Also, the owner may be ordered to drain the reservoir until such time a permit is obtained

DAM INVENTORY IN LOUISIANA

• From 1981 to 2001, a total of 260 dams were registered with DOTD.

• In 2003, DOTD signed contracts with two engineering consultants to gather information on unregistered dams using topographic and DOQQ maps, satellite imagery, site visits, etc.

• 274 dams were located, inspected and added to the Data File (534 dams).

• There are presently 542 dams in the inventory, including 28 high hazard and 69 significant hazard.

IMPACT CLASSIFICATION OF DAMS

The Impact Classification is determined by an evaluation of the probable maximum impacts of a dam breach. There are three categories:

• Low hazard dams: if the dam fails, there will be no loss of life and only minimal economic losses (Design for 50 yr. Flood).

• Significant hazard dams: there will be possible loss of life and appreciable economic losses (Design for 100 year Flood).

• High hazard dams: loss of life will be likely and there will be excessive economic losses (Design for ½ of PMF).

DAM SAFETY INSPECTIONS

• High and significant hazard dams are inspected annually. • Low hazard dams are inspected once every five years.• Technical inspection reports are prepared and mailed to the dam

owners for their information and remediation/repair, if indicated.

• A follow-up inspection is conducted when maintenance issues are discovered during the periodic inspection.

• Proposed dam sites are also inspected to determine their hazard classification and new dams are inspected during construction and upon completion.

• 150 – 175 dams are inspected annually.

COORDINATION WITH USDA, NATURAL RESOURCES

CONSERVATION SERVICE (NRCS)

Abbreviation of the permitting process for farmers:

• If NRCS’ engineering staff provide the design, layout and construction inspection and provide DOTD all the available engineering data, then a DOTD permit will not be required.

• NRCS sponsored dams are still inspected by DOTD.

EMERGENCY ACTION PLANS (EAPs)• EAPs are required by both federal and state regulations.

• DOTD has retained Denmon Engineering to perform dam breach analyses and Aquaterra to prepare EAPs.

• Breach analyses and EAPs have been completed for all state maintained dams, including four prepared in-house.

• Table-top exercises have been held for all 20 state-maintained dams.

• DOTD is also helping local government entities having dams constructed with state funds, with their dam breach analyses and EAPs.

COMPLIANCE WITH FEDERAL REGULATIONS

As required by the National Dam Safety Act (Public Law 92-367), the LA Dam Safety Data files are electronicallysubmitted to the following agencies on an annual basis:

• National Inventory of Dams (NID) via the Corps of Engineers’Headquarters.

• Electronic submittal of LA Dam Safety Annual Report to theNational Dam Safety Review Board (NDSRB).

• DOTD Maintains FEMA Dam Safety Program Certification. • In 2007, Louisiana was Ranked 3rd in the nation.

RESERVOIR PRIORITY & DEVELOPMENT PROGRAM

• DOTD provides oversight of the planning, design and construction of eleven existing state funded reservoirs and ensures state funds are spent in accordance with legislative mandates and other requirements.

• DOTD is responsible for administering the state’s Reservoir Priority & Development Program and to develop a Master Plan for all future state-funded reservoirs.

• MWH Americas, Inc. has been retained to develop the Reservoir Priority & Development Master Plan.

20 STATE-MAINTAINED DAMSLegislative Authorization: R.S. 38:26

• DOTD operates and maintains 20 dams and reservoirs.

• DOTD is responsible for ensuring these man-made structures are safe and that life and property are protected.

• Most of these dams were constructed more than 45 years ago and they are in need of critical repairs.

DOTD-MAINTAINED DAMS

Dam Name Parish Completed Height Ft. Surface Area

BAYOU COCODRIE RAPIDES 1959 28 6100

BAYOU DARBONNE UNION 1961 54 15250BLACK BAYOU CADDO 1955 20 3860

BLACK LAKE NATCHITOCHES 1990 37 13800

BUNDICKS CREEK BEAUREGARD 1963 40 1750CANEY CREEK JACKSON 1986 73 4970

CHICOT LAKE DAM EVANGELINE 1940 29 1625

CHIVERY DAM NATCHITOCHES 1934 30 10500GRAND BAYOU RED RIVER 1994 30 2700IATT LAKE DAM GRANT 1956 36 7100

DOTD-MAINTAINED DAMS (CONTINUED)

Dam Name Parish Completed Height Ft. Surface AreaIVAN LAKE DAM BOSSIER 1958 21 520KEPLER CREEK BIENVILLE 1958 28 1825LAKE BISTINEAU BOSSIER 1941 27 17200

LAKE CLAIBORNE CLAIBORNE 1966 50 6300

LOWER ANACOCO VERNON 1951 37 2600

NANTACHIE LAKE GRANT 1964 37 1580

SALINE LAKE DAM NATCHITOCHES 1959 23 8450

SMITHPORT LAKE DESOTO 1953 18 3028TURKEY CREEK FRANKLIN 1953 40 3845VERNON LAKE VERNON 1961 43 4250

BAYOU D’ARBONNE

In March 2003 and again in 2004, D’Arbonne Lake experienced extensive flooding. Local officials reported extensive vibrations at the spillway.

Underwater Inspections

DOTD MAINTENANCE SCHEDULE

• In order to identify critical structural repairs for D’Arbonne Lake Spillway and drawdown gates, DOTD and the D’Arbonne Lake Watershed Commission secured the services of Fenstermaker & Associates, Inc. to perform acoustic imaging and profiling and Glenn Underwater to perform underwater inspection. The work was successfully completed in 2008 and $1.6M in repairs are currently underway.

• The D’Arbonne Lake project is being used as a template to inspect and evaluate the remaining 19 State-maintained dams. DOTD has signed an agreement with Fenstermaker & Associate, Inc. and Glenn Underwater to perform acoustic imaging and profiling and underwater inspection services for the remaining State-maintained dams.

REPAIR PROJECTS COMPLETED

1. Acoustic Survey & Underwater Inspection for Lake D’Arbonne Spillway and Drawdown gates (State Project No. 700-99-0459)

2. Lake Bistineau Erosion Remediation, Planning & Construction (State Project No. 577-04-0001)

3. Anacoco Gate Repairs (State Project No. 508-58-0034)

4. Lake D’Arbonne Spillway and Drawdown Gate Repairs (SPN 505-56-0031)(Construction to be completed by July 09)

AS-FOUND DAM AND RESERVOIR SYSTEM, MAPPING AND MODELING

Bayou D’Arbonne LakeDam and Spillway Inspection

Performed for the Louisiana Department of

Transportation & DevelopmentPublic Works & Water Resources Division

D’Arbonne DamDesigned mid to late 1950’s

Construction Completed in 1963

Dam Details• Total Length – 2445 feet

• Concrete Spillway – 799 feet

• Height – 54 feet

• Hydraulic Height – 51 feet

• Normal Pool Elevation – 80.0 feet (MSL)

• Drainage area 1,585 square miles

• Reservoir Surface Area – 15,250 acres

Bayou D’Arbonne Dam

Bayou D’Arbonne Dam

Bayou D’Arbonne Dam – November 1967

Bayou D’Arbonne Dam – January 1998

Bayou D’Arbonne Dam – September 2004

D’Arbonne DamVisual Safety Inspection, Measurement and Evaluation through High Definition Survey

and Underwater Acoustic Imaging / Profiling

Project Components

• Visual Safety Inspection

• High Definition Survey (HDS)

• Underwater Acoustic Survey

Survey Control

POINT CLOUD

POINT CLOUD

1. Secondary Control - 2• 5/8” Dia. X 3’ Iron Rebar

2. Primary Control - 1• 3D Monument

• 9/16” Dia. X 24’ Stainless Steel Rod

3. RTK GPS Secondary Control Installation Diagram

Monument – Data Sheet

POINT CLOUD

Data Collection• Establish autonomous GPS position on monument to begin work.

• Simultaneously observe 2 - 8 hour static GPS observations on monument while setting secondary control and conducting HDS Survey.

• Adjusted autonomous position with NGS “Online Positioning User Service” (OPUS).

HDS Target Distribution

POINT CLOUD

1. Scan Control

• Laminated Targets

• 4 per instrument setup

HDS Survey

Slope DrainsPop-out

Exposed Reinforcement

Leaking Buttress 42(Moisture Accentuated by Scanner)

HDS Survey

GatedAccess to

Gallery

Sluice Gates

HDS Survey

Deep Rod Monument

Damaged Water Stop

Acoustic Imaging & Profiling

• Dual element system, optimized for high Turbidity, high flow environments

• Capable of profiling under floating and surface obstructions and structures

• Capable of profiling between closely spaced structures

• Provides unparalleled underwater visualization capabilities

In The Beginning

Dual Element Remote Sensing UnitBased on A Kongsberg Mesotech MS1000

Acoustic Profiling System

Footprint

And

Methodology

Acoustic Profiling Patterns

Visualization is accomplished by utilizing the Steered, fan acoustic beam, which is multi-axis steerable.

Acoustic Remote Sensor UnitIn One of Many Deployment Configurations

Steered

Imaging Beam

Acoustic sensor

The imaging component provides

visualization of features to a resolution of

19mm or .75"

HDS/UAS 3D Mesh

Survey Vessel Deploying Acoustic Imaging System

Survey Vessel Performing Acoustic Profile Mapping

Of Submerged Structure Components and The Water Bottom

Reservoir Water Bottom and Dam Sub-structureImagery and Topography

Distinctive features

warranting further

investigation

Holes at the toe of the reservoir side of

the DamLinear signature dissipating

over edge of Dam Apron

UAI SurveyCritical Acoustic Imaging Observations

Hole Definition at Time of Discovery &Hole Definition at Time of Dive Investigation

Hole definition on return excursion January 16th, 2008

Holes in sediment accumulation at the toe of the Dam on the reservoir side

Hole definition November 6th, 2007

Holes in sediment accumulation at the toe of the Dam on the reservoir side

Along with increased safety for diving personnel

And construction operations

By providing a visual representation of the working environment

Safety First

UAI Survey

Trash Log protection for the Sluice Gates

Notice Debris against protective

grid

Chute Blocks

Floor Blocks

Debris Laying across blocks

HDS/UAI 3D Mesh

Integrated HDS and Underwater Acoustic Imaging and Profiling Model

With Spot Elevations Depicted

Integrated HDS and Underwater Acoustic Imaging and Profiling Model

With Spot Elevations Depicted

Integrated HDS and Underwater Acoustic Imaging and Profiling Model

With Spot Elevations Depicted

Integrated, as-found model

generated from the combination of

HDS and Underwater Acoustic

Imaging & Profiling

• Provides a comprehensive system model

• Capable of being utilized for advanced computational evaluation and comparison

• Establishing a baseline for periodic and event prompted comparison of problem areas

Synopsis of Recommendations• 1. Armor the toe of the south embankment of the spillway where significant erosion

is occurring, and investigate removal of the flow obstructing peninsula created by the erosion.

• 2. Repair leaking water stops, seals and concrete damage at slab joints and buttress joints.

• 3. Extend stop log retainer to the crown of the spillway and repair sluice gates and operating mechanisms. Implementing torque limiter stops to prevent gate over-runs.

• 4. Clear vegetation on the upstream slope of the embankment.

• 5. Rehabilitate spillway gallery steps and walkway to adequate serviceability and examine feasibility of lighting installation in the gallery.

• 6. Regular monitoring of relative alignment and elevations of spillway slabs for indications of differential settling or uplift that may eventually result from previously documented voids beneath the slabs.

Temporary Cofferdam

Scour Aeseal All Joints

Increase Height of Stop Logs

Task Order 1 – currently 60% Complete

Task Order – 2

Task Order - 3

Preliminary results from the Bundicks Creek Dam Investigation

Accumulation of

debris

Scour at edge of rip-rap

Preliminary finding from acoustic imaging data at

Bundicks Creek drawdown structure

Crack in concrete

Acknowledgements:State of Louisiana Department of Transportation and Development –

Public Works & Water Resources Division

ARCADIS

Glenn Diving

Riley Company of Louisiana

Experience ∙ Innovation · Results

Engineers ∙ Surveyors · Environmental Consultants

THANK YOU.

QUESTIONS?