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Watershed Assessmentand Implementation

Little Falls and Lower Potomac Direct

February 27, 2014

www.montgomerycountymd.gov/watershedrestoration

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IntroductionsDarian Copiz

Watershed Planner, Montgomery County DEPPamela Rowe

RainScapes Program Specialist, Montgomery County DEPLeslie Wilcox

Outreach Planner, Montgomery County DEPRebecca Winer-Skonovd

Water Resources Scientist, Brown & Caldwell

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Today’s AgendaWatershed 101What is the County Doing to Protect our Streams?Purpose of this Public MeetingWatershed Study ProcessScheduleQuestions

Watershed 101Sources of Water

About 97% is salt waterAbout 2% is frozenOnly 1% is available for drinking water

Across the Country, about 57% comes from surface water sources In Maryland, 74% is from surface water sources

Potential for greater impacts from runoff in Maryland

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Watershed 101Montgomery County, MD507 sq. miles1,000,000 people

Second only to Baltimore City withinMaryland in average people per square mile

184 languages spokenAbout 12% impervious surface overall

About the size of Washington DCOver 1,500 miles of streamsTwo major river basins:

Potomac Patuxent

Eight local watersheds

District of Columbia

ImperviousNot allowing water to soak

through the ground

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Watershed 101What is a Watershed?A watershed is an area from which

the water above and below ground drains to the same place.

Different scales of watersheds:Chesapeake BayEight local watershedsNeighborhood (to a storm drain)

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Watershed 101What is Runoff?Water that does not soak into the

ground becomes surface runoff. Runoff flows over hard surfaces like rooftops, driveways and parking lots collecting potential contaminants and flows:Directly into streams Into storm drain pipes, then streams Into BMPs, then streams

Two Major Issues:Volume/Timing of Runoff

Water Quality

Watershed 101Urban Impacts to Streams

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Eroded Stream Banks

Polluted Runoff from Parking Lots

Failing Infrastructure

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Watershed 101What is the County doing toprotect and restore our Streams?Must meet regulatory requirements

Federal Clean Water Act permit programMS4 = Municipal Separate Storm Sewer System

Applies to all large and medium Maryland jurisdictionsCounty Program Goals

Restore our streams and watersheds Add runoff management

Meet water quality protection goals (TMDLs) Reduce pollutants getting into our streams

Educate and engage all stakeholders Individual actions make a difference

Focus on watersheds showing greatest impacts

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Montgomery County MS4 AreaMunicipal Separate Storm Sewer System

Does not include Gaithersburg, Rockville, or Takoma Park

Does not include MNCPPC, WSSC, Federal or State properties

Does not include agricultural lands

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Watershed 101What is a TMDL?It’s a Pollution Diet

Total Maximum Daily LoadMaximum amount of

pollutant that can be received by a water body and still meet standards

Set by MDE and approved by EPA

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What is the County Doing to Restore our Streams?DEP must add stormwater management for 20% of impervious

surfaces (4,292 acres = 6.7 square miles)About three times the size of Takoma Park.That’s equivalent to 3,307 football fields!Progress during this Permit Cycle (ends February 2015)

Equivalent of 400 impervious acres added or under construction2,815 acres through projects under design

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Status of County Watershed Studies

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Purpose of this MeetingPresent watershed study

process and areas identified for project development

Receive feedback on watershed study andareas identified for project development

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Watershed Study Process1. Identify Watershed2. Data Collection3. Data Analysis and Prioritize Projects4. Draft Watershed Assessment5. Public Meeting6. Finalize and Publish Watershed Assessment7. Watershed Implementation Plan

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Identify WatershedLower Potomac DirectDrainage Area includes >7,500 acres

Rock Run subwatershedRock Run Imperviousness = 11%Notable developments include Potomac,

Great Falls and Cabin JohnLand Use; mix of open land, forest,

institutional, low density residentialStream habitat is generally good b/c of

forested stream valleysDespite this, biological community showing signs

of impairment

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Identify WatershedLittle FallsDrainage area > 5,000 acresImperviousness = 25%One of the County’s most urban watersheds

and contains some of the oldest developed areas of the County

Land Use: dominated by medium density residential

Stream conditions are generally poor due to uncontrolled stormwater runoff

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Data CollectionUpland AssessmentsRainScapes NeighborhoodsNew Best Management Practices (BMPs)Reforestation Sites

Stream Corridor AssessmentErosionInadequate Buffers

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Data CollectionLower Potomac and Little Falls MS4 Area

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Upland AssessmentsDesktop AnalysisLarge stormwater outfallsLarge contiguous

impervious surfacesNeighborhoods

With civic associations & good communication structure

with HOAsmedium sized lotshigh property ownership

Large unforested areasFocus in the MS4 area

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Upland AssessmentsField Assessments

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Stream AssessmentsDesktop AnalysisStream corridors not

previously assessed

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Stream AssessmentsField Assessments

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Data AnalysisLower Potomac Direct

Little Falls

Assessment # of Assessed UnitsStreams 6 Stream Miles

New Best Management Practices 47 Sites (e.g., parking lot)RainScapes Neighborhoods 6 / 860 Neighborhoods / Properties

Reforestation Areas 1 Sites (e.g., unforested lots)

Assessment # of Assessed UnitsStreams 32 Stream Miles

New Best Management Practices 7 Sites (e.g., parking lot)RainScapes Neighborhoods 5 / 1073 Neighborhoods / Properties

Reforestation Areas 7 Sites (e.g., unforested lot)

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Prioritize ProjectsRanking Factors:Potential EffectivenessFeasibilityAccessibilityStream ConditionPublic Input

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Draft Watershed AssessmentUpland ConceptsRainScapes NeighborhoodsNew Best Management Practices

Stream Restoration Concepts

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Watershed Implementation PlanIdentifies stormwater management projects, watershed

restoration projects and programmatic actionsEstimates potential pollutant load reductionDetermines ability to meet applicable TMDLsProvided a schedule and cost estimate for meeting TMDLs

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WE ARE HERE

Watershed Assessmentand ImplementationProject Schedule (Tentative)

 

Step Anticipated Dates

1. Identify Watershed Fall 2012

2. Data Collection Summer 2013

3. Data Analysis and Prioritize Projects Fall 2013

4. Draft Watershed Assessment Winter 2014

5. Public Meeting Winter 2014

6. Finalize and Publish Watershed Assessment Summer 2014

7. Implementation Plan Summer 2014

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Questions?

FOR MORE INFORMATION:

Darian Copiz240-777-7774 darian.copiz@montgomerycountymd.govProjects Webpage:www.montgomerycountymd.gov/watershedrestoration