Urban Stream Restoration Case Studies: Challenges and Opportunities

Alabama Water Resources Conference

September 6-7, 2012

Greg Jennings, Darrell Westmoreland, Eve Brantley

Alabama Cooperative Extension System

ADEM

CAWACO RC&D

Samford University

Goodwyn Mills & Cawood

LBYD

Volkert

Stantec

Cities of Auburn, Daphne, Jasper, Montgomery, Vestavia Hills

“activities that initiate or accelerate the recovery of ecosystem health, integrity, and sustainability” (SER, 2004)

Stream Restoration

Jasper Town Creek Auburn UT Town Creek

1. Planning & Assessment

2. Engineering

3. Construction & Planting

4. Monitoring, Maintenance, Adjustments

Stream Restoration is a Systematic Process

Samford Univ Shades Creek Daphne UT D’Olive Creek

• Improve habitats & water quality

• Improve recreation & aesthetics

• Protect infrastructure & land value

• Educate citizens & decision-makers

Goals of Stream Restoration Projects

Daphne UT D’Olive Creek Samford Univ Shades Creek

JasperTown Creek

DaphneUT D’Olive Creek

Auburn UT Town Creek

Vestavia HillsLittle Shades Creek

Samford University Shades Creek

Montgomery White Slough

CaseStudies

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

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

Montgomery White Slough (2009)Project Mgmt: Auburn Univ

Funding: ADEM 319

Design: GMC, Jennings

Construction: GMC

Vegetation: GMC, Auburn Univ

2008

2010

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

Daphne UT D’Olive Creek (2010)Project Mgmt: Daphne

Funding: NRCS

Design: Volkert, Jennings

Construction: North State Environmental

Vegetation: Daphne

2010

2012

Samford University Shades Creek (2011)Project Mgmt: Samford Univ

Funding: Samford Univ

Design: LBYD, Jennings

Construction: North State Environmental

Vegetation: Auburn Univ, NSE

2010

2011

Stream Restoration as a BMP

• Sediment control

• Nutrient cycling (instream & floodplain)

• Peak discharge attenuation

• Habitats (aquatic & terrestrial)

• Infrastructure protection

1. High Flows

2. Low Flows

3. Lateral Constraints

4. Road Crossings

5. Stormwater Outfalls

6. Invasive Plants

7. Beavers & Other Critters

Challenges for Stream Restoration

• Floodplain is critical for stress relief

• Design/construct for maximum flood

1. High Flows

Shades Creek one month following construction (March 2011)

• Reconnect floodplain to carry “bankfull” flows

• Resist bed shear stress with grade controls & riffles

• Protect soil on banks & floodplain (temporary & permanent)

High Flows: Solutions

White Slough floodplain UT D’Olive Creek log vanes & weirs

2006 Town Creek Tributary 2007

Reconnect Floodplain: Priority 1Replace incised channel with shallow channel raised to existing floodplain elevation

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

Wfpa

Wbkf

Reconnect Floodplain: Priority 2Excavate wide floodplain and meander channel at a lower elevation

2008 White Slough 2010

ER = 6; W/d = 11

Wfpa

Wbkf

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

Resist Bed Shear Stress

• Log & rock weirs

• Reinforced riffles

• Vanes

Protect Soil: Temporary

• Biodegradable matting

• Straw & annual grasses

• Rushes & sedges

Protect Soil: Permanent

• Native grasses

• Rushes & sedges

• Shrubs & trees

• Maintain pools for habitat

• Connection to ground water (hyporheic zone)

2. Low Flows

Shades Creek before project – plane bed, over-wide, mid-channel bars

• Narrow low-flow channel with benches

• Bed-form diversity

• Natural substrate for hyporheic connection

Low Flows: Solutions

Shades Creek log vane & pool UT D’Olive Creek log vane & pool

• Protect infrastructure

• Optimize ecosystem services

3. Lateral Constraints

UT D’Olive Creek before project – constrained by house and hillslope

• Structures to direct flow

• Vegetated benches

• Consider flood flows

Lateral Constraints: Solutions

UT D’Olive Creek realignment, floodplain bench, structures, vegetation

Little Shades Creek

• Houses

• Sewer lines

• Roads & bridges

February 2010

Wfpa

Wbkf

Entrenchment Ratio = Wfpa / Wbkf = 60/38 = 1.6

March 2010

Wfpa

Wbkf

Entrenchment Ratio = Wfpa / Wbkf = 60/38 = 1.6

August 2010

Shades Creek

• Athletic fields

• Roads & bridges

January 2011

May 2011

Wfpa

Wbkf

Entrenchment Ratio = Wfpa / Wbkf = 55/45 = 1.2

March 2011

Saugahatchee Creek – Sewer Line Protection

3 Log Vanes

2007

2008

2009 January

2009 JulyPhoto Credit: Dan Ballard, Town of Auburn

Saugahatchee Creek – Sewer Line Protection

3 Log Vanes

• Aquatic organism passage

• Minimize geomorphic impacts

• Pass flood flows

4. Road Crossings

• Hydraulic opening to pass flows & sediment

• Vanes to direct flow & control grade

Road Crossings: Solutions

Jasper Town Creek W-vane upstream of bridge

• Bridge

• Arch culvert

• Bottomless or buried bottom

• Floodplain openings

Hydraulic Opening

• Vanes

• Cross vanes

• W-vanes

Flow Direction & Grade Control

• Minimize erosion & scour in channel

• Improve water quality

5. Stormwater Outfalls

• Energy dissipation basins

• Floodplain wetlands

• Watershed stormwater retention & infiltration

Stormwater Outfalls: Solutions

Stormwater Outfall Channels (10)• Vegetated bio-swales (low slope)

• Rock step-pools (high slope)

Stormwater Wetland Enhancement• Runoff from 90 acres

• Sediment retention (78% reduction)

• Native plants – nutrient cycling

1. Diverse native riparian plant communities

2. Self-sustaining streamside forest

6. Invasive Plants

• Long-term maintenance

• Education

Invasive Plants: Solutions

• Healthy streamside forest

• Free-flowing stream

7. Beavers & Other Critters

• Tree guards

• Eradication: beaver, deer, geese

Critters: Solutions

1. Plan for floods -- immediately & often

2. Plan for dry weather

3. Plan for vegetation maintenance

4. Understand constraints

5. Flexibility to respond to surprises

Summary: Plan for Success