County County Low Impact Development Low Impact Development

(LID) (LID) OutreachOutreach

BRIAN LEADERS, RLABRIAN LEADERS, RLAREGISTERED LANDSCAPE ARCHITECTREGISTERED LANDSCAPE ARCHITECT

Discussion Topics Discussion Topics ______________________________________________________________________________________________

What is a watershed?What is a watershed? Why we need a Stormwater Management Why we need a Stormwater Management

OrdinanceOrdinance Problems caused by not having a PlanProblems caused by not having a Plan Urban Conservation ProblemsUrban Conservation Problems EPA “Today”EPA “Today” BMP’s (Best Management Practices)BMP’s (Best Management Practices) Iowa DNRIowa DNR

What is a Watershed?What is a Watershed?

A watershed is a geographic A watershed is a geographic area from which water drains area from which water drains

toward a toward a commoncommon watercourse (such as a lake, watercourse (such as a lake, stream or ocean) in a natural stream or ocean) in a natural

basin. basin.

When thinking of a watershed When thinking of a watershed do not just think of water, do not just think of water,

include land, include land, landuselanduse, , topography, geology etc. All of topography, geology etc. All of

these components affect these components affect watersheds. watersheds.

Why do we need a Why do we need a Stormwater Management Stormwater Management

Ordinance?Ordinance?

This is what we are seeing now!This is what we are seeing now!

Yes this is a paved street!Yes this is a paved street!

What problems are causedWhat problems are caused by not having a by not having a

Stormwater Management Stormwater Management Plan?Plan?

Watershed Hydrology BEFORE DevelopmentWatershed Hydrology BEFORE Development

evapotranspiration: 40-50%

interflow: 20-30%

surface runoff: <1%

www.psat.wa.gov/Programs/LID.htm

Watershed Hydrology AFTER DevelopmentWatershed Hydrology AFTER Development

evapotranspiration: ~25%

interflow: 0-30%

surface runoff: ~30%

www.psat.wa.gov/Programs/LID.htm

Urban Conservation Problems Urban Conservation Problems ______________________________________________________________________

Urban Conservation Problems Urban Conservation Problems ____________________________________________________________________

10 to 20 times higher erosion than agriculture10 to 20 times higher erosion than agriculture

Urban Conservation Problems Urban Conservation Problems ______________________________________________________________________ Storm water runoff is carrying Storm water runoff is carrying high concentration of high concentration of

pollutantspollutants directly into creeks, stream and river. directly into creeks, stream and river.

Urban Conservation Problems Urban Conservation Problems ______________________________________________________________________

Developing in the fragile loess soils Developing in the fragile loess soils

Urban Conservation Problems Urban Conservation Problems ______________________________________________________________________

Rural vs. urban conflictsRural vs. urban conflicts

EPAEPAand and

Effluent Discharge LimitsEffluent Discharge Limits

Effluent Limitation GuidelinesEffluent Limitation Guidelines(ELG’s)(ELG’s)

______________________________________________________________________________________________

On December 1, 2009, the U.S. On December 1, 2009, the U.S. Environmental Protection Agency (EPA) Environmental Protection Agency (EPA) released effluent limits on stormwater released effluent limits on stormwater dischargesdischarges from many construction and from many construction and development sites (the Construction Rule). development sites (the Construction Rule). (74 Fed. Reg. 62,996)(74 Fed. Reg. 62,996)11

The Construction Rule became effective The Construction Rule became effective February 1, 2010, and imposes the February 1, 2010, and imposes the following general requirements:following general requirements:

__________________________________________________________________________________________________________________________________________________________________

1)1) Non-numericNon-numeric limitations apply to construction limitations apply to construction activity that disturbs activity that disturbs one or more acres;one or more acres;

2)2) Beginning August 2, 2011Beginning August 2, 2011, a numeric turbidity , a numeric turbidity limit and related monitoring requirements will limit and related monitoring requirements will apply to construction apply to construction activity that disturbs 20 or activity that disturbs 20 or more acres at one time;more acres at one time;

Numeric TurbidityNumeric Turbidity______________________________________________________________________________________________

20 32 50 110 178 345 412

EPA’s Numeric Turbidity Limit is 280.

3) 3) No later than February 2, 2014No later than February 2, 2014, the numeric , the numeric turbidity limit will apply to projects that disturbs turbidity limit will apply to projects that disturbs 10 or more acres.10 or more acres.

EPA’s EPA’s

Main GoalsMain Goals____________________________________________________________________________________________________________

Preserve and improve Preserve and improve water qualitywater quality on a on a national scale.national scale.

Reduce sediment dischargedReduce sediment discharged from from construction sites by construction sites by four billion pounds four billion pounds each year.each year.

Effective Controls and Required Effective Controls and Required BMP’sBMP’s

________________________________________________________________________________________________________________

Controls are considered Controls are considered EffectiveEffective When: When:

“…“…bare soil is uniformly and evenly coveredbare soil is uniformly and evenly covered with vegetation or other suitable materials, with vegetation or other suitable materials, storm water is controlled so that rills or storm water is controlled so that rills or gullies are not visible and channels or gullies are not visible and channels or stream banks are stream banks are not erodednot eroded. .

Selecting temporarySelecting temporary BMP’S BMP’S

(Best Management Practices)(Best Management Practices) for you!for you!

Down Gradient Perimeter Down Gradient Perimeter ControlControl

________________________________________________________________________________________________

Ditch ChecksDitch Checks______________________________________________________________________________________________

Channel ProtectionChannel Protection______________________________________________________________________________________________

Temporary PondingTemporary Ponding______________________________________________________________________________________________

Construction PhasingConstruction Phasing______________________________________________________________________________________________

Access ProtectionAccess Protection______________________________________________________________________________________________

Inlet ProtectionInlet Protection______________________________________________________________________________________________

Temporary Cover & ProtectionTemporary Cover & Protection______________________________________________________________________________________________

Spoil and Stockpile AreasSpoil and Stockpile Areas______________________________________________________________________________________________

Selecting permanentSelecting permanent BMP’S BMP’S

(Best Management Practices)(Best Management Practices) for you!for you!

Rain GardenRain Garden______________________________________________________________________________________________

Infiltration BermInfiltration Berm______________________________________________________________________________________________

Soil TestingSoil TestingInfiltration and EmbankmentInfiltration and Embankment______________________________________________________________________________________________

Sand FiltersSand Filters______________________________________________________________________________________________

Dry Detention Dry Detention ______________________________________________________________________________________________

Wet Detention Wet Detention ______________________________________________________________________________________________

Constructed Wetlands Constructed Wetlands ______________________________________________________________________________________________

Grassed Swales Grassed Swales ______________________________________________________________________________________________

Dry and Wet Swales Dry and Wet Swales ______________________________________________________________________________________________

Grassed Vegetated Grassed Vegetated Filter Strips Filter Strips ______________________________________________________________________________________________

Pervious Pavement Pervious Pavement ______________________________________________________________________________________________

Open Channel Flow Open Channel Flow ______________________________________________________________________________________________

Iowa Senate File Bills Iowa Senate File Bills ______________________________________________________________________________________________

Working on an act related to Working on an act related to

flood plain management.flood plain management.

In a nut shell… In a nut shell… ______________________________________________________________________________________________

Prohibit the reconstruction of structures and Prohibit the reconstruction of structures and infrastructureinfrastructure substantially damaged by floods in a substantially damaged by floods in a floodway.floodway.

Limit reconstruction or new construction in a flood plain.Limit reconstruction or new construction in a flood plain. Require new construction of facilities Require new construction of facilities critical for health critical for health

and safety of the public and the environmentand safety of the public and the environment to be to be located in areas that are not flood plains whenever located in areas that are not flood plains whenever practicable.practicable.

In a nut shell… In a nut shell… ______________________________________________________________________________________________

Conduct a subsurface tiling studyConduct a subsurface tiling study to determine the to determine the impact that tile drainage has impact that tile drainage has on infiltration, surface on infiltration, surface runoff, and flooding.runoff, and flooding.

Evaluate the feasibility of seasonal retention of water Evaluate the feasibility of seasonal retention of water in in

tile drained fields as a drainage management strategy.tile drained fields as a drainage management strategy.

Integrate multipurpose wetlandsIntegrate multipurpose wetlands into watersheds. into watersheds.

In a nut shell… In a nut shell… ______________________________________________________________________________________________

DNR will seek funding to plan, implement, and monitor a DNR will seek funding to plan, implement, and monitor a watershed demonstration pilot project watershed demonstration pilot project for urban and rural for urban and rural areas involving a twelve=digit hydrologic unit code areas involving a twelve=digit hydrologic unit code subwatershed as defined by the United States geological subwatershed as defined by the United States geological survey. survey.

In a nut shell… In a nut shell… ____________________________________________________________________________________________

IOWA DNR WILL CONDUCT A STUDY PROJECT THATIOWA DNR WILL CONDUCT A STUDY PROJECT THAT

SHALL INCLUDE FEATURES THAT SEEK TO DO THESHALL INCLUDE FEATURES THAT SEEK TO DO THE

FOLLOWING:FOLLOWING:

11. Maximize soil water holding capacity. Maximize soil water holding capacity from rain. from rain.

2. 2. Minimize severe scour erosion Minimize severe scour erosion and sand depositionand sand deposition

during floods. during floods.

3. 3. Manage water runoff in uplandsManage water runoff in uplands under saturated soil under saturated soil

moisture conditions.moisture conditions.

4. 4. Reduce and mitigateReduce and mitigate structural and nonstructural structural and nonstructural floodflood

damage.damage.

In a nut shell… In a nut shell… ______________________________________________________________________________________________

DNR will change DNR will change climate criteria climate criteria due to due to weather changes. weather changes.

Adopt minimum storm water standards Adopt minimum storm water standards to to be implemented be implemented July 1,2011 July 1,2011 to limit:to limit:

1.1. Limit water runoffLimit water runoff

2.2. Reduce potential future flood damageReduce potential future flood damage

3.3. Assess effects of stream channelizationAssess effects of stream channelization

4.4. Improve watershed management for both water quantity Improve watershed management for both water quantity and quality.and quality.

In a nut shell… In a nut shell… ______________________________________________________________________________________________

Modify Modify NPDESNPDES permits permits to require the mitigation of to require the mitigation of soil soil compaction and replacement of topsoilcompaction and replacement of topsoil as part of the as part of the completion of construction for permitted actions completion of construction for permitted actions involving involving one or more acresone or more acres of disturbed land. of disturbed land.

Stormwater Management is Stormwater Management is here.here.

Questions? Questions? ______________________________________________________________________________________________

Special thanks to the following sources:Special thanks to the following sources:

Mike Isensee CPESC, Urban ConservationistMike Isensee CPESC, Urban Conservationist

Farmington, MinnesotaFarmington, Minnesota

Blayne W. Renner, NPDES Stormwater CoordinatorBlayne W. Renner, NPDES Stormwater Coordinator

Iowa Department of Ag. And Land StewardshipIowa Department of Ag. And Land Stewardship

Natural Resource Conservation ServicesNatural Resource Conservation Services

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______________________________________________________________________________________________________________________________BRIAN LEADERS, RLA BRIAN LEADERS, RLA

REGISTERED LANDSCAPE ARCHITECTREGISTERED LANDSCAPE ARCHITECT

25966 ROSEWOOD ROAD25966 ROSEWOOD ROAD

UNDERWOOD, IOWA 51576UNDERWOOD, IOWA 51576

402-670-9700402-670-9700