Dead Run Segment One Stream Restoration Project
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Dead Run Segment One Stream Restoration Project Public Meeting-Dominican Retreat House
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Dead Run Segment One Stream Restoration Project
- 1. A Fairfax County, VA, publication Department of Public Works and Environmental Services Working for You! Dead Run Segment One Stream Restoration Project Public Meeting Dominican Retreat House June, 2015
- 2. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Meeting Outline 2 • Fairfax County Stormwater Management • Countywide Watershed Plan Implementation • Project Scope, Status, and Next Steps • Concept Plan Overview – Basis for design – Tree save options – Floodplain analysis and review of more frequent storm impacts – Buffer restoration measures – Examples • Q&A • Walk to site
- 3. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division DPWES Organization 3 Department of Public Works and Environmental Services Land Development Services Capital Facilities Solid Waste Stormwater Stormwater Planning Division Maintenance and Stormwater Management Division Wastewater
- 4. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Stormwater Infrastructure • Conveyance System – 1,600 miles pipe and paved channel – 43,000 structures – 6,800 outfalls • Management Facilities – 1,540 County Maintained – 3,720 Privately Maintained • State Regulated Dams 4
- 5. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division 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 Bay – Local Streams 5
- 6. Dead Run– Stream Conditions 6
- 7. Dead Run Segment 1 Stream Restoration Project Countywide Watershed Planning “Healthy Watersheds, Healthy Communities” • 30 Designated Watersheds • All 15 watershed plans have been adopted by Fairfax County 7 http://www.fairfaxcounty.gov/dpwes/watersheds/
- 8. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Middle Potomac Watershed Plan 8 • Watershed Characterization – Water Quality Monitoring – Land Use Change – Pollutant Loading • Structural Project – 25 year plan • Non-Structural Practices – Policy and Regulations http://www.fairfaxcounty.gov/dpwes/watersheds/
- 9. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Dead Run Watershed Plan • Dead Run has a drainage area just over 3 mi2 • 24 priority projects identified in the watershed management plan • Pond retrofits • LID Stormwater Enhancements • Stream Restoration • Neighborhood Stormwater Improvements 9 http://www.fairfaxcounty.gov/dpwes/stormwater/ projects/project_list.htm
- 10. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Partnership LID Stormwater Enhancements - Dolley Madison Library Approximately 1/3 of the roof is covered in 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 10 Vegetated Roof- Delosperma and Allium plants in bloom
- 11. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Partnership LID Stormwater Enhancements - Dolley Madison Library Sustainable Site Design 11
- 12. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division 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. 12 http://va.water.usgs.gov/projects/ffx_co_monitoring.htm
- 13. Stormwater Planning Division Dead Run Segment 1 Stream Restoration Project Stream Restoration Pictures 13 Government Center Stream Restoration - Before & After
- 14. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Stream Restoration 14 Dead Run In Mclean Central Park – Before & After Drainage Area (acres) Phosphorous Removal (lbs/yr) Nitrogen Removal (lbs/yr) Sediment Removal (tons/yr) 415 15 283 3
- 15. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Dead Run – Stream Restoration 15
- 16. Dead Run Segment 1 Stream Restoration Project Stormwater Planning Division Dead Run –Stream Restoration 16 August 2014 January 2010
- 17. Stormwater Planning Division Dead Run Segment 1 Stream Restoration Project Project Limits 17 Segment 1– Dominican Retreat • 2,000 Linear Feet • Extends to Old Dominion Drive • Residential lots along Merrimac Drive and Van Ness Court
- 18. Stormwater Planning Divison Dead Run Segment 1 Stream Restoration Project Project timeline 18 • Project initiated: Fall, 2013. • Surveys and assessment completed: Winter, 2013 • Pre-concepts submitted: April, 2014 • First public meeting – April 23, 2014 • Acquired floodplain and storm drainage easement on the Dominican Retreat property – Ongoing • Public meeting with residents of surrounding properties – June 10, 2015
- 19. Stormwater Planning Division Dead Run Segment 1 Stream Restoration Project Next steps with target dates 19 • Receive concept design comments from residents • Inform residents of locations where project abuts their property and where work will take place within existing easements on their property • Develop 95% design plans by September, 2015 • Final design phase public meeting, late September, 2015 • Final plan authorization and bidding phase – TBD based on funding and approved budget • Target is early, 2016 • Pardon Our Dust meeting with residents and contractor before issuing construction notice to proceed.
- 20. Agenda 1Basis for Design 2 Trees 3 Design Plan 4 Critical Erosion Areas 5 Pedestrian Bridge Replacement
- 21. 1 Basis for Design • Stable Channel • Understanding of Floodplain • Address Erosion
- 22. 1 Basis for Design • Natural Channel Design (NCD) Approach – Reference Reach, Analytical, Regional Relationships and hydraulic analysis • Stream Pattern, Profile and Section • Range of Values for Stable Stream Pattern • Tree Loss is Unavoidable but Provides Opportunity to Improve Riparian Diversity
- 23. 1 Basis for Design • Establish Goals: • 1. Improve Flow Conditions in the Channel through Adjustments to Plan/Profile/Section • 2. Create a Stable Channel by Reducing Bed/Bank Erosion that has Benefit of Reducing Contributions of Nitrogen and Phosphorus (i.e. Water Quality Improvement) • 3. Improve Channel Geomorphology and Opportunities for Species Diversity (i.e. Use Structures to Stabilize Channel and Create Pool Habitats) • 4. No-Rise / No-Impact of the Floodplain
- 26. 2 Trees 12” and Larger Trees: • ~190 trees 12” and larger assessed within the project area • ~19 trees 12” and larger are “at risk” • ~11 of the “at risk” trees may be removed • Low Diversity of Species: ~45% tuliptree, ~24% red maple • ~39 Trees proposed to be removed • A few additional trees maybe removed for new storm pipe to address drainage issues.
- 27. 3 Design Plan - Overall Map of the entire project limits with property lines and easements shown
- 28. 3 Design Plan - Overall Map of the entire project limits with property lines and easements shown
- 29. 3 Design Plan - Overall
- 30. 3 Design Plan - Overall
- 31. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 32. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 33. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 34. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 35. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 36. 3 Design Plan Exhibits where the limits of disturbance enters individual property owners’ lots
- 37. 4 Critical Erosion Areas
- 38. 4 Critical Erosion Areas Left Bank Left Bank Right Bank Driveway
- 39. 5 Pedestrian Bridge – Wood Bridge Two new bridges and one fair weather crossing.
- 40. 5 Pedestrian Bridge – Wood Bridge Two new bridges locations Bridge #1 Bridge #2
- 41. 5 Pedestrian Bridge – Fair Weather Crossing Two new bridges and one fair weather crossing.
- 42. 5 Pedestrian Bridge – Wood Bridge Fairweather Crossing
- 43. 43 Joe Riley-Ryan, Joseph.Riley-Ryan@fairfaxcounty.gov Dipmani Kumar, Dipmani.Kumar@fairfaxcounty.gov Matt Meyers, Matthew.Meyers@fairfaxcounty.gov Stormwater Planning Division Department of Public Works and Environmental Services Fairfax County 12000 Government Center Parkway, Suite 449 Fairfax, Virginia 22035 www.fairfaxcounty.gov/dpwes/stormwater • Contact Information A Fairfax County Publication, April 2014 ADA Statement: To request this information in an alternate format call 703-324-5500, TTY 711
Hinweis der Redaktion
- STN 1. A summary of the number of trees impacted by the project 2. Map of the entire project limits with property lines and easements shown 3. Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown 4. Critical erosion areas (immediately downstream of 2nd pedestrian bridge with sharp bands, property on left bank at bottom of project where stream is encroaching driveway, etc.) highlighted with pictures included 5. Include attached picture of a finished bridge and highlight the two new bridges and fair weather crossing.
- GR - Basis for design (brief, to the point, where the overall design goal is clearly explained, the approaches (reference reach, analytical), and the typical range in parameters that define the proposed stream pattern, profile, and cross-section). GR talk highlights: Basis for design…We want a stable channel, Understanding of floodplain, flooding concerns were taken into consideration when establishing the final stream pattern and the modeled proposed conditions show a drop in the water surface elevation for storms up to the 100-year event riparian corridor that address erosion NCD design approach. Streams Pyramid. Starts with understanding of hydrology and works up to understanding biology.
- GR - Basis for design (brief, to the point, where the overall design goal is clearly explained, the approaches (reference reach, analytical), and the typical range in parameters that define the proposed stream pattern, profile, and cross-section). GR talk highlights: NCD includes use of stable reference reaches, analytical, use of regional curves and data for stable channel design, and engineering studies to verify hydraulics. Analysis the stream pattern, profile and section. emphasize that you have a range of allowable values to achieve a stable stream pattern which gives you a certain amount of flexibility in the design and allowed us to tweak the alignment to avoid trees to be saved. However, make it clear that in order to achieve a stable pattern, a certain amount of tree loss is unavoidable, and also emphasize that it does give us an opportunity to improve the diversity of the buffer system.
- GR - Basis for design (brief, to the point, where the overall design goal is clearly explained, the approaches (reference reach, analytical), and the typical range in parameters that define the proposed stream pattern, profile, and cross-section). GR talk highlights: Establish Goals Our goals are: 1. Improve flow conditions in the channel by changing channel shape (plan/profile/section). 2. create a stable channel by reducing bed/bank erosion that includes reduced contribution of nitrogen and phosphorus by arresting bank erosion. 3. Improve channel geomorphology and opportunities for species diversity. i.e use structures to stabilize channel and create pool habitats.
- “at risk” is dead, leaning or exposed roots tree. Only 6 oaks >12” GR talk highlights: Current summary of trees 12” Small amount of diversity in species. – opportunities to improve. Est ~40 trees to be removed in concept design. To be refined as we progress.
- Overall design plan of the upper half of the project
- Overall design plan of the lower half of the project
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Exhibits of each location where the limits of disturbance enters individual property owners’ lots with property lines, existing and proposed conditions, and easements shown
- Critical erosion areas in red/yellw and black/dark green Photos represents worst sections of Seg 1
- Critical erosion on the RB (yellow) Some stable areas on RB and LB (blue) Want to restore the RB and see if we can take softer approach to the LB Also recall there is SS on the LB