dead run stream restoration may 2014
DESCRIPTION
Dead Run Stream Restoration May 2014 Middle Potomac Watershed Plan Implementation Public Meeting McLean Community Center April 23, 2014TRANSCRIPT
Middle Potomac Watershed Plan Implementation
Dead Run Stream Restoration Project
Public Meeting
McLean Community Center
April 23, 2014
Stormwater Planning DivisionDepartment of Public Works and Environmental Services
Meeting Outline
• Fairfax County Stormwater Management• Countywide Watershed Plan Implementation• Project Introduction and Objectives• Existing Conditions• Proposed Improvements - Options• Example Projects• Questions?
Fairfax County Department of Public Works and Environmental Services (DPWES)Department of Public Works and
Environmental Services
Land Development
Services
CapitalFacilities
Solid Waste Stormwater
Stormwater Planning Division
Maintenance and Stormwater
Management Division
Wastewater
Stormwater Infrastructure
• Conveyance System– 1,600 miles of pipe and
paved channel– 43,000 structures– 6,800 outfalls
• Management Facilities– 1,540 county maintained – 3,720 privately maintained
• State Regulated Dams
A typical outfall
A dam in Fairfax County
Service Drivers
In response to The Clean Water Act of 1972
National Pollutant Discharge Elimination System (NPDES)
Virginia Stormwater Management Program (VSMP) Regulations
Municipal Separate Storm Sewer Permit (MS4)
Total Maximum Daily Loads (TMDLs)Chesapeake BayLocal Streams
Countywide Watershed Planning
“Healthy Watersheds, Healthy Communities”
• 30 Designated Watersheds
• All 15 watershed plans have been adopted by Fairfax County
http://www.fairfaxcounty.gov/dpwes/watersheds/
Middle Potomac Watershed Plan
• Watershed Characterization– Water Quality Monitoring– Land Use Change– Pollutant Loading
• Structural Project– 25 Year Plan
• Non-Structural Practices– Policy and Regulationshttp://www.fairfaxcounty.gov/dpwes/watersheds/
Dead Run Watershed Plan
• Dead Run has a drainage area just over 3 square miles
• 24 priority projects identified in the watershed management plan• Pond retrofits• LID Stormwater Enhancements• Stream Restoration• Neighborhood Stormwater
Improvementshttp://www.fairfaxcounty.gov/dpwes/stormwater/projects/project_list.htm
Approximately one third of the roof is covered with vegetation. The benefits of a “living roof” include:
• Reduces the amount of stormwater runoff• Absorbs air pollution and carbon dioxide• Reduces the energy needed to cool the building in summer
Partnership: LID Stormwater EnhancementsDolley Madison Library
Vegetated Roof- Delosperma and Allium plants in bloom
Partnership: LID Stormwater EnhancementsDolley Madison Library
Sustainable Site Design
Dead Run – Before and After
Drainage Area(acres)
Phosphorous Removal(lbs/yr)
Nitrogen Removal(lbs/yr)
Sediment Removal(tons/yr)
415 15 283 3
Stream Restoration
Dead Run – Stream Restoration
Stream Monitoring Program
Study Objectives
1. Generate long-term monitoring data.
2. Evaluate relations between observed conditions/trends and BMP implementation.
3. Transfer the understanding gained to other less-intensively monitored watersheds.
http://va.water.usgs.gov/projects/ffx_co_monitoring.htm
Dead Run Stream Restoration
Dead Run Stream Restoration
Segment 1 – Dominican Retreat• 2,000 Linear Feet
• Extends to Old Dominion Drive
• Residential lots along Merrimac Drive and Van Ness Court
Dead Run Stream Restoration
Segment 2 – McLean Central Park• 800 Linear Feet
• Completely in Park
• Starts below previously restored section near library
Dead Run Stream Restoration
Segment 3 – McLean Central Park
• 1,500 Linear Feet
• Extends to Churchill Road
• Residential lots along Elizabeth Drive and Carol Rayes Street
Next Steps
• Conceptual Design• Land Acquisition/Coordination• Preliminary Design• Public Meeting• Final Design• Project Construction
• Funding FY2016 and FY2017• Community Coordination: Pardon Our Dust
• Maintenance and Operation
Natural Channel Design
Background and Design Approach
Stream Design Approaches Natural Channel Design
3 design approaches 1)Analog 2)Empirical 3)Analytical
Segment 1
Dominican Retreat
Segment 2 & 3
Mclean Central ParkDead Run Stream Valley Park
Alternative Access
Alternative Access
Instream Structures
Looking upstream at boulder rock toe and constructed riffle
Looking upstream at boulder rock toe – 2 and 3 courses
Modified Cross Vane
Modified Cross Vane
Cross Vane Cross Vane
Cross Vane
Step Pool
Infill mix comprised of cobbles, gravels, sand, silt, topsoil
Larger material, usually cobble
Constructed Riffle(aka Reinforced Streambed)
Riffle
Access
During May 2010
BeforeFeb. 2010
AfterSept. 2010
John Palmer
Dipmani Kumar [email protected]
Matt Meyers
Stormwater Planning Division
Department of Public Works and Environmental Services
Fairfax County12000 Government Center Parkway, Suite 449
Fairfax, Virginia 22035
Questions ?
Contact Information
A Fairfax County Publication, April 2014
To request this information in an alternate
format call 703-324-5500, TTY 711
www.fairfaxcounty.gov/dpwes/stormwater
Thank You!