Lower Potomac / Little Falls Watershed Study Public Meeting


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Public meeting presentation for the Lower Potomac and Little Falls watershed study.

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  • Brief history and tidbits about MoCo.EXPLAIN imperviousPotomac 88% of MCPatuxent 12% of MC Of the 184 languages spoken the top 5 non English spoken are: Spanish, Chinese (Mandarin), Korean,Vietnamese, Amharic (Ethiopia)
  • Brief history and tidbits about MoCo.EXPLAIN imperviousStormwater is water that originates from storms… becomes runoff
  • Federal Clean Water ActNPDES: National Pollutant Discharge Elimination System MS4: Municipal Separate Storm Sewer System PermitMS4 Permit sets priorities for all Watershed TMDL: Total Maximum Daily LoadTMDL sets the pollution diet for a specific water body
  • Revise
  • JV Team starts here
  • Focused on Unmanaged areas within County MS4 and some rural zoning (large lot residential)We conducted 4 field assessments. There were 3 types of upland assessments: RainScapes Neighborhoods, New Stormwater BMPs, and Reforestation Areas. The stream assessment focused on identifying environmental problems and characterizing their severity, correctability and accessibility in order to help prioritize future restoration work.
  • Focused on Unmanaged areas within County MS4 and some rural zoning (large lot residential)Desktop analysis was necessary to target assessment sites.
  • County has walked most of their stream corridorsThis effort was used to fill in data gaps
  • The prioritization step was a systematic prioritization to rank projects within each assessment based on restoration opportunity (i.e., top stream restoration opportunities, top reforestation opportunities, etc.). This prioritization relies on data collected on field forms and at a level of analysis that focuses on core design considerations.  The prioritization was used to determine which project would be candidates for a limited number on concept designs.Each factor was given a range of scoresImpervious cover treated was given the highest weightPoor stream biological condition given priority (rather than Excellent quality streams)Team produced maps of potential projects with scores, reviewed with DEP
  • After prioritizing projects within each assessment, projects sites were selected to take to the concept level. Concepts provide a brief description of the site, available opportunities (neighborhoods) or proposed restoration opportunities (BMPs and streams), and estimated pollutant load removals.Address lack of reforestation sites, inadequate buffer, and trash concepts.The County is focused on smaller scale stormwater practices (sometimes called Env Site Design or Low Impact Development). Different than a pond for the whole siteOutfall repairs with Regenerative Stormwater Conveyances or Step Pool Stormwater ConveyancesPollutant load reduction estimated for all concepts
  • For each Watershed, determine the Restoration Potential or “Everything everywhere” approachCompare to the necessary wasteload allocationDetermine level of implementation necessary to achieve goals
  • Lower Potomac / Little Falls Watershed Study Public Meeting

    1. 1. Watershed Assessment and Implementation 1 Little Falls and Lower Potomac Direct February 27, 2014 www.montgomerycountymd.gov/watershedrestoration
    2. 2. Introductions  Darian Copiz  Watershed Planner, Montgomery County DEP  Pamela Rowe  RainScapes Program Specialist, Montgomery County DEP  Leslie Wilcox  Outreach Planner, Montgomery County DEP  Rebecca Winer-Skonovd  Water Resources Scientist, Brown & Caldwell 2
    3. 3. Today’s Agenda  Watershed 101  What is the County Doing to Protect our Streams?  Purpose of this Public Meeting  Watershed Study Process  Schedule  Questions 3
    4. 4. Watershed 101 Sources of Water  About 97% is salt water  About 2% is frozen  Only 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 4
    5. 5. Watershed 101 Montgomery County, MD  507 sq. miles  1,000,000 people  Second only to Baltimore City within Maryland in average people per square mile  184 languages spoken  About 12% impervious surface overall  About the size of Washington DC  Over 1,500 miles of streams  Two major river basins:  Potomac  Patuxent  Eight local watersheds 5 District of Columbia Impervious Not allowing water to soak through the ground
    6. 6. Watershed 101 What 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 Bay  Eight local watersheds  Neighborhood (to a storm drain) 6
    7. 7. Watershed 101 What 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 7 Two Major Issues: Volume/Timing of Runoff Water Quality
    8. 8. Watershed 101 Urban Impacts to Streams 8 Eroded Stream Banks Polluted Runoff from Parking Lots Failing Infrastructure
    9. 9. Watershed 101 What is the County doing to protect and restore our Streams?  Must meet regulatory requirements  Federal Clean Water Act permit program  MS4 = Municipal Separate Storm Sewer System  Applies to all large and medium Maryland jurisdictions  County 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 9
    10. 10. Montgomery County MS4 Area 10 Municipal 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
    11. 11. Watershed 101 What is a TMDL? It’s a Pollution Diet  Total Maximum Daily Load  Maximum amount of pollutant that can be received by a water body and still meet standards  Set by MDE and approved by EPA 11
    12. 12. 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 construction  2,815 acres through projects under design 12
    13. 13. Status of County Watershed Studies 13
    14. 14. Purpose of this Meeting  Present watershed study process and areas identified for project development  Receive feedback on watershed study and areas identified for project development 14
    15. 15. Watershed Study Process 1. Identify Watershed 2. Data Collection 3. Data Analysis and Prioritize Projects 4. Draft Watershed Assessment 5. Public Meeting 6. Finalize and Publish Watershed Assessment 7. Watershed Implementation Plan 15
    16. 16. Identify Watershed Lower Potomac Direct  Drainage Area includes >7,500 acres  Rock Run subwatershed  Rock Run Imperviousness = 11%  Notable developments include Potomac, Great Falls and Cabin John  Land Use; mix of open land, forest, institutional, low density residential  Stream habitat is generally good b/c of forested stream valleys  Despite this, biological community showing signs of impairment 16
    17. 17. Identify Watershed Little Falls  Drainage area > 5,000 acres  Imperviousness = 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 17
    18. 18. Data Collection Upland Assessments  RainScapes Neighborhoods  New Best Management Practices (BMPs)  Reforestation Sites Stream Corridor Assessment  Erosion  Inadequate Buffers 18
    19. 19. Data Collection Lower Potomac and Little Falls MS4 Area 19
    20. 20. Upland Assessments Desktop Analysis  Large stormwater outfalls  Large contiguous impervious surfaces  Neighborhoods  With civic associations & good communication structure  with HOAs  medium sized lots  high property ownership  Large unforested areas  Focus in the MS4 area 20
    21. 21. Upland Assessments Field Assessments 21
    22. 22. Stream Assessments Desktop Analysis  Stream corridors not previously assessed 22
    23. 23. Stream Assessments Field Assessments 23
    24. 24. Data Analysis Lower Potomac Direct Little Falls 24 Assessment # of Assessed Units Streams 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 Units Streams 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)
    25. 25. Prioritize Projects Ranking Factors:  Potential Effectiveness  Feasibility  Accessibility  Stream Condition  Public Input 25
    26. 26. Draft Watershed Assessment Upland Concepts  RainScapes Neighborhoods  New Best Management Practices Stream Restoration Concepts 26
    27. 27. Watershed Implementation Plan  Identifies stormwater management projects, watershed restoration projects and programmatic actions  Estimates potential pollutant load reduction  Determines ability to meet applicable TMDLs  Provided a schedule and cost estimate for meeting TMDLs 27
    28. 28. WE ARE HERE Watershed Assessment and Implementation Project Schedule (Tentative) 28 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
    29. 29. Questions? FOR MORE INFORMATION: Darian Copiz 240-777-7774 darian.copiz@montgomerycountymd.gov Projects Webpage: www.montgomerycountymd.gov/watershedrestoration 29