Better Site DesignBetter Site Design Sustainability & Sustainability &

StormwaterStormwaterShohreh Karimipour, P.E.Shohreh Karimipour, P.E.

NYSDECNYSDEC

Presentation OutlinePresentation Outline

Better Site Design Better Site Design (LID, Sustainability, Environmental (LID, Sustainability, Environmental

Design,Design,Green Infrastructure)Green Infrastructure) CategoriesCategories

Preserve Natural Features Preserve Natural Features Reduce Impervious CoverReduce Impervious Cover Better Integrate Stormwater Better Integrate Stormwater

TreatmentTreatment PrinciplesPrinciples

Specific PracticesSpecific Practices

Better Site DesignBetter Site Design

◄Preserve Preserve undisturbed undisturbed areas areas ◄ConservatiConservation Designon Design

An approach to development An approach to development design design

that seeks to:that seeks to:

Better Site DesignBetter Site Design

◄Reduce Reduce impervious coverimpervious cover

RoadsRoads Parking lotsParking lots DrivewaysDriveways

An approach to development An approach to development design design

that seeks to:that seeks to:

Better Site DesignBetter Site Design

◄Use Use pervious pervious areas for areas for stormwater stormwater treatmenttreatment

An approach to development An approach to development design that seeks to:design that seeks to:

Good Drainage ParadigmGood Drainage Paradigm

Conventional Site DesignConventional Site Design

Collect Collect Concentrate Concentrate Convey Convey Centralized Centralized ControlControl

Credit: HWG

Rain Garden Rain Garden

Treatment Train ApproachTreatment Train Approach

Bioretention CellStorm Drain System

Bioretention Cell

Flow Path

Grass Swale Grass Filter Strip

Credit: HWG

NYS Standard PracticesNYS Standard Practices

NYS Stormwater Design Standard Overlap ( )with BSD or LID Practices

BSD Category oneBSD Category one

Avoid the Impacts:Avoid the Impacts: Preserve Natural Features Preserve Natural Features

and and

Use Conservation DesignUse Conservation Design

Preservation of Preservation of Undisturbed AreasUndisturbed Areas

Delineate on plans / in the Delineate on plans / in the field field Place in permanent Place in permanent conservation:conservation:Undisturbed Undisturbed forestforestNative Native vegetationvegetationStream Stream corridorscorridorsWetlandsWetlandsNatural terrain Natural terrain – hydrology– hydrology

US Forest Service

Preservation of BuffersPreservation of Buffers

•Delineate buffers •Protect during:

•Design•Construction•Home occupancy

•Non-structural stormwater infiltration•Consult/amend local codes

Preservation of BuffersPreservation of Buffers

Reduction of Clearing & Reduction of Clearing & GradingGrading

Establish Limit of Disturbance for:•Buildings •Roads•Utilities•Wastewater•StormwaterUse site foot-printing Limit mass gradingUse open space or cluster development

GCSWCD

Locate Sites in Less Locate Sites in Less Sensitive AreasSensitive Areas

Locate development to Locate development to avoid: avoid: Erodible Erodible

soilssoilsFloodplainsFloodplainsSteep Steep slopesslopesWetlandsWetlandsMature Mature ForestsForestsCritical Critical habitathabitat

Open Space DesignOpen Space Design

Use smaller Use smaller lot sizeslot sizesReduce Reduce impervious impervious covercoverProvide Provide more more undisturbed undisturbed open spaceopen spaceProtect Protect water water resources resources

Saves costsSaves costsreduces reduces gradinggradingreduces reduces infrastructure infrastructure

Successful Successful ExamplesExamples

Preserves conservation areasPreserves conservation areasPreserves natural hydrologyPreserves natural hydrology

Open Space DesignOpen Space Design

BSD Category TwoBSD Category Two

Reduce the Impacts:Reduce the Impacts:Reduce Impervious Reduce Impervious

SurfacesSurfaces

Design Design according to according to density and density and traffic demandtraffic demand

Minimize Minimize roadway lengths roadway lengths

Minimize Minimize roadway widthsroadway widths Consult / amend Consult / amend

local codeslocal codes Use AASHTO* Use AASHTO*

guidelinesguidelines Use alternative Use alternative

road patternsroad patterns

Roadway Roadway ReductionReduction

Shared Shared drivewdrivew

ayay

Planning Board Provide Model

Shared Driveway Agreement to applicants

Alternative materialsAlternative materials Shorter setbacksShorter setbacks Planning Board

Encourage shared driveways

Use Model Shared Driveway Agreement

Encourage pervious materials on pull offs for emergency

Driveway Reduction Driveway Reduction

Town of WappingerTown of Wappinger §214-74§214-74 requires cul-requires cul-de-sacs be de-sacs be circularcircular with with no center islandno center island

REVISE CODE to require developers REVISE CODE to require developers demonstrate no alternative to cul-de-sac; demonstrate no alternative to cul-de-sac; minimized paved area minimized paved area

Minimize Cul-de-SacsMinimize Cul-de-Sacs

What about New York State What about New York State Highway Law?Highway Law?

New Town roads Right-of-way = New Town roads Right-of-way = 49.5 feet49.5 feet

If not, must petition Commissioner If not, must petition Commissioner of Transportationof Transportation

Recommend: Keep 49.5 minimum Recommend: Keep 49.5 minimum – also needed for– also needed for stormwater and stormwater and snow removal.snow removal.

ButBut limit limit pavement to pavement to travel-way. travel-way.

Sidewalk ReductionSidewalk Reduction

Use alternative designsDesign on one side of street onlyUse alternative surfaces

Building Building Footprint Footprint ReductionReduction

BenefitsBenefits::Reduces Reduces impervioimpervious cover us cover & & pollutantpollutantss

Parking ReductionParking Reduction Compact Compact car spacescar spacesMinimal Minimal stall stall dimensionsdimensionsEfficient Efficient parking parking laneslanesParking Parking decksdecksPorous Porous paving in paving in overflowoverflowEliminate Eliminate unneeded unneeded spacesspaces

BSD Category 3BSD Category 3

Manage the Impacts: Manage the Impacts: Better Integrate Better Integrate

Stormwater TreatmentStormwater Treatment

Open Vegetated Open Vegetated ChannelsChannels

Convey & Convey & treat runofftreat runoff

Natural Natural drainage drainage pathspaths

Properly Properly designed & designed & constructed constructed channelschannels

On certain On certain sites use in sites use in street right-street right-of-way of-way

Vegetated Buffer/Filter StripsVegetated Buffer/Filter Strips

Forested Forested areasareas

Stream Stream buffersbuffers

Vegetated Vegetated filter stripsfilter strips

Treat & control runoff Treat & control runoff with:with:

Plant trees:•In stormwater management practices (where appropriate)•In landscape plans•Revegetate buffer areas . . .

Tree Planting

InfiltrationInfiltration

PedestriaPedestrian areasn areas

Overflow Overflow parkingparking

ResidentiResidential al drivewaysdriveways

Green Green StreetsStreets

Use permeable Use permeable pavement/pavers where site pavement/pavers where site conditions are appropriate:conditions are appropriate:

A

A

A

Ecosystem function and service: Water retention and Storage

Stream Daylighting for Stream Daylighting for RedevelopmentRedevelopment

Increases Increases aesthetics aesthetics Improves water Improves water qualityqualityPrevents flooding Prevents flooding – increased – increased storage storage Improves in-Improves in-stream habitatstream habitat Increases public Increases public useuseIncreases Increases property valuesproperty valuesSunlightSunlight

Redevelopment ProjectsRedevelopment Projects Chapter is part of Design Manual (Chapter 9)Chapter is part of Design Manual (Chapter 9) Permit coverage in 5 business days Public NoticedPermit coverage in 5 business days Public Noticed

Application CriteriaApplication Criteria An already impervious area reconstructed, andAn already impervious area reconstructed, and There is inadequate space for controlling stormwater There is inadequate space for controlling stormwater

runoff, orrunoff, or There are physical constraints on the site There are physical constraints on the site

Sizing CriteriaSizing Criteria 25% reduction in impervious area 25% reduction in impervious area Treat 25% WQv with standard practice Treat 25% WQv with standard practice Treat 75% of WQv with Alternative PracticesTreat 75% of WQv with Alternative Practices Combination of all the aboveCombination of all the above

PerformancePerformance Criteria Criteria Alternative Practices (Alternative Practices (Cisterns, Rain gardens, Green Cisterns, Rain gardens, Green

roofs, Stormwater planters, Porous and permeable roofs, Stormwater planters, Porous and permeable pavements, Select proprietary products pavements, Select proprietary products ))

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CisternsCisterns

ApplicationsApplications Capture and store stormwater runoff Capture and store stormwater runoff

for reuse or irrigationfor reuse or irrigation LimitationsLimitations

MaintenanceMaintenance Water use managementWater use management Cold Climate Cold Climate Community AcceptanceCommunity Acceptance

Sizing Sizing based on the contributing based on the contributing area:area: Vol = WQv * 7.5 gals/ftVol = WQv * 7.5 gals/ft33

CisternsCisterns

Rain Rain GardensGardens

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ApplicationsApplications Manage and treat small volumes of runoffManage and treat small volumes of runoff Use conditioned planting soil bed and planting Use conditioned planting soil bed and planting

materialmaterial Filter runoff stored within a shallow depressionFilter runoff stored within a shallow depression

LimitationsLimitations Steep slopesSteep slopes Compacted and clay soilsCompacted and clay soils Sheet / shallow concentrated flowSheet / shallow concentrated flow Roof drain downspout < 1,000 square feetRoof drain downspout < 1,000 square feet Heavy tree cover or root systems Heavy tree cover or root systems

Sizing based on WQ volume reductionSizing based on WQ volume reduction

Rain GardensRain Gardens

Green Green RoofsRoofs

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Intensive Intensive Green RoofGreen Roof

Extensive Extensive Green RoofGreen Roof

Green RoofsGreen Roofs ApplicationsApplications

Reducing total annual runoff volumes Reducing total annual runoff volumes    Insulation from the heat and cold, energy Insulation from the heat and cold, energy

conservationconservation Reduce the urban heat island effect Reduce the urban heat island effect Creates habitat, aesthetically pleasing Creates habitat, aesthetically pleasing   

LimitationsLimitations Damage to or failure of waterproofingDamage to or failure of waterproofing plant survival plant survival MaintenanceMaintenance

Sizing based on WQv reduction, soil Sizing based on WQv reduction, soil engineering, evapotranspirationengineering, evapotranspiration

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Stormwater Stormwater PlantersPlanters

Stormwater PlantersStormwater Planters ApplicationsApplications

On-site soils, high GW table not suitable for infiltrationOn-site soils, high GW table not suitable for infiltration   Reduction of discharge volume, velocity from impervious Reduction of discharge volume, velocity from impervious

areasareas Aesthetic landscape element and micro-habitatAesthetic landscape element and micro-habitat

LimitationsLimitations Not designed to treat roadway runoffNot designed to treat roadway runoff Overflow needs to be directed to a Overflow needs to be directed to a

secondary treatment systemsecondary treatment system Sizing Sizing

WQV based on surface area, depth WQV based on surface area, depth

Of soil medium, hydraulic conductivityOf soil medium, hydraulic conductivity

Permeable Permeable PavingPaving

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Photo Copyright 1999, Center for Watershed Protection

Permeable PavingPermeable PavingPermeable PavingPermeable Paving

http://www.wbdg.org/design/lidtech.php

Porous PavementPorous PavementPorous PavementPorous Pavement

Photo Copyright 1999, Center for Watershed Protection

Permeable PavingPermeable PavingPermeable PavingPermeable PavingPermeable PaversPermeable PaversPermeable PaversPermeable Pavers

ApplicationsApplications low-traffic areaslow-traffic areas overflow parkingoverflow parking Residential single family homeResidential single family home GW recharge GW recharge

LimitationsLimitations suitability of the site gradessuitability of the site grades SubsoilsSubsoils Drainage characteristicsDrainage characteristics Groundwater conditionsGroundwater conditions

Sizing Sizing based on surface areabased on surface area

Summary:Summary:

Improve development Improve development projects & communities with projects & communities with Better Site DesignBetter Site Design Preserve undisturbed areasPreserve undisturbed areas

Reduce impervious coverReduce impervious cover

Use pervious areas for Use pervious areas for stormwater treatmentstormwater treatment

Achieve a marketable, cost-Achieve a marketable, cost-effective producteffective product

Questions?Questions?

Shohreh Karimipour, P.E.sxkarimi@gw.dec.state.ny.us

(518) 402-8102

Angus Eaton, P.E.akeaton@gw.dec.state.ny.us

(518) 402-8123