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Urban Stream Restoration Case Studies: Challenges and Opportunities

Urban Stream Restoration Case Studies: Challenges and Opportunities. Alabama Cooperative Extension System ADEM CAWACO RC&D Samford University Goodwyn Mills & Cawood LBYD Volkert Stantec Cities of Auburn, Daphne, Jasper, Montgomery, Vestavia Hills. Alabama Water Resources Conference

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Urban Stream Restoration Case Studies: Challenges and Opportunities

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  1. Urban Stream Restoration Case Studies: Challenges and Opportunities Alabama Cooperative Extension System ADEM CAWACO RC&D Samford University Goodwyn Mills & Cawood LBYD Volkert Stantec Cities of Auburn, Daphne, Jasper, Montgomery, Vestavia Hills Alabama Water Resources Conference September 6-7, 2012 Greg Jennings, Darrell Westmoreland, Eve Brantley

  2. Stream Restoration “activities that initiate or accelerate the recovery of ecosystem health, integrity, and sustainability” (SER, 2004) Jasper Town Creek Auburn UT Town Creek

  3. Stream Restoration is a Systematic Process Planning & Assessment Engineering Construction & Planting Monitoring, Maintenance, Adjustments SamfordUniv Shades Creek Daphne UT D’Olive Creek

  4. Goals of Stream Restoration Projects • Improve habitats & water quality • Improve recreation & aesthetics • Protect infrastructure & land value • Educate citizens & decision-makers Daphne UT D’Olive Creek SamfordUnivShades Creek

  5. Case Studies Jasper Town Creek Vestavia Hills Little Shades Creek Samford University Shades Creek Auburn UT Town Creek Montgomery White Slough Daphne UT D’OliveCreek

  6. Auburn Town Creek Trib (2008) Project Mgmt: Auburn Univ Funding: ADEM 319, USEPA Design:Stantec, Jennings Construction: North State Environmental Vegetation:Auburn Univ 2007 2009

  7. Jasper Town Creek (2008) Project Mgmt: CAWACO RC&D Funding: ADEM 319 Design:Stantec, Jennings Construction: North State Environmental Vegetation:Auburn Univ, NSE 2007 2010

  8. Montgomery White Slough (2009) Project Mgmt: Auburn Univ Funding: ADEM 319 Design: GMC, Jennings Construction: GMC Vegetation:GMC, Auburn Univ 2008 2010

  9. Vestavia Hills Little Shades Creek (2010) Project Mgmt: CAWACO RC&D Funding: ADEM 319 Design: GMC, Jennings Construction: North State Environmental Vegetation:Auburn Univ, NSE 2009 2011

  10. Daphne UT D’OliveCreek (2010) Project Mgmt: Daphne Funding:NRCS Design:Volkert, Jennings Construction: North State Environmental Vegetation:Daphne 2010 2012

  11. Samford University Shades Creek (2011) Project Mgmt:SamfordUniv Funding:SamfordUniv Design: LBYD, Jennings Construction: North State Environmental Vegetation:Auburn Univ, NSE 2010 2011

  12. Stream Restoration as a BMP • Sediment control • Nutrient cycling (instream & floodplain) • Peak discharge attenuation • Habitats (aquatic & terrestrial) • Infrastructure protection

  13. Challenges for Stream Restoration High Flows Low Flows Lateral Constraints Road Crossings Stormwater Outfalls Invasive Plants Beavers & Other Critters

  14. 1. High Flows • Floodplain is critical for stress relief • Design/construct for maximum flood Shades Creek one month following construction (March 2011)

  15. High Flows: Solutions • Reconnect floodplain to carry “bankfull” flows • Resist bed shear stress with grade controls & riffles • Protect soil on banks & floodplain (temporary & permanent) White Slough floodplain UT D’OliveCreek log vanes & weirs

  16. Reconnect Floodplain: Priority 1 Replace incised channel with shallow channel raised to existing floodplain elevation 2006 Town Creek Tributary 2007

  17. Entrenchment Ratio = Wfpa / Wbkf = 180/10 = 18 Wfpa Wbkf

  18. Reconnect Floodplain: Priority 2 Excavate wide floodplain and meander channel at a lower elevation ER = 6; W/d = 11 2008 White Slough 2010

  19. Entrenchment Ratio = Wfpa / Wbkf = 84/14 = 6 Wfpa Wbkf

  20. Resist Bed Shear Stress • Log & rock weirs • Reinforced riffles • Vanes

  21. Protect Soil: Temporary • Biodegradable matting • Straw& annual grasses • Rushes & sedges

  22. Protect Soil: Permanent • Native grasses • Rushes & sedges • Shrubs & trees

  23. 2. Low Flows • Maintain pools for habitat • Connection to ground water (hyporheic zone) Shades Creek before project – plane bed, over-wide, mid-channel bars

  24. Low Flows: Solutions • Narrow low-flow channel with benches • Bed-form diversity • Natural substrate for hyporheic connection Shades Creek log vane & pool UT D’OliveCreek log vane & pool

  25. 3. Lateral Constraints • Protect infrastructure • Optimize ecosystem services UT D’OliveCreek before project – constrained by house and hillslope

  26. Lateral Constraints: Solutions • Structures to direct flow • Vegetated benches • Consider flood flows UT D’OliveCreek realignment, floodplain bench, structures, vegetation

  27. Little Shades Creek • Houses • Sewer lines • Roads & bridges February 2010

  28. Entrenchment Ratio = Wfpa / Wbkf = 60/38 = 1.6 Wfpa Wbkf March 2010

  29. Entrenchment Ratio = Wfpa / Wbkf = 60/38 = 1.6 Wfpa Wbkf August 2010

  30. Shades Creek • Athletic fields • Roads & bridges January 2011

  31. Entrenchment Ratio = Wfpa / Wbkf = 55/45 = 1.2 Wfpa Wbkf May 2011

  32. March 2011

  33. Saugahatchee Creek – Sewer Line Protection 3 Log Vanes 2007 2008

  34. Saugahatchee Creek – Sewer Line Protection 3 Log Vanes 2009 January 2009 July Photo Credit: Dan Ballard, Town of Auburn

  35. 4. Road Crossings • Aquatic organism passage • Minimize geomorphic impacts • Pass flood flows

  36. Road Crossings: Solutions • Hydraulic opening to pass flows & sediment • Vanes to direct flow & control grade Jasper Town Creek W-vane upstream of bridge

  37. Hydraulic Opening • Bridge • Arch culvert • Bottomless or buried bottom • Floodplain openings

  38. Flow Direction & Grade Control • Vanes • Cross vanes • W-vanes

  39. 5. Stormwater Outfalls • Minimize erosion & scour in channel • Improve water quality

  40. Stormwater Outfalls: Solutions • Energy dissipation basins • Floodplain wetlands • Watershed stormwater retention & infiltration

  41. Stormwater Outfall Channels (10) • Vegetated bio-swales (low slope) • Rock step-pools (high slope)

  42. Stormwater Wetland Enhancement • Runoff from 90 acres • Sediment retention (78% reduction) • Native plants – nutrient cycling

  43. 6. Invasive Plants Diverse native riparian plant communities Self-sustaining streamside forest

  44. Invasive Plants: Solutions • Long-term maintenance • Education

  45. 7. Beavers & Other Critters • Healthy streamside forest • Free-flowing stream

  46. Critters: Solutions • Tree guards • Eradication: beaver, deer, geese

  47. Summary: Plan for Success Plan for floods -- immediately & often Plan for dry weather Plan for vegetation maintenance Understand constraints Flexibility to respond to surprises

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