Integrating Green Infrastructure and Floodplain Restoration. June 21, 2016

Size: px

Start display at page:

Download "Integrating Green Infrastructure and Floodplain Restoration. June 21, 2016"

Willa Neal
6 years ago
Views:

1 Integrating Green Infrastructure and Floodplain Restoration June 21, 2016 AFPM 2016 Eileen hader, CFM Jonathon Loos

2 Founded in 1973, American Rivers protects wild rivers, restores damaged rivers, and conserves clean water for people and nature. Headquartered in DC, American Rivers has offices across the country and more than 200,000 supporters, members, and volunteers nationwide

3 NBF of Floodplains and Impacts of Floodplain Loss Restoring hydrology and floodplain functions Integrated Water Management Case tudy in IWM: Milwaukee

Defining the floodplain Definition depends on who you re talking to- Land and hazard planning 100 year flood area Hydrology- Low lying lands influenced by moving water

4 Defining the floodplain Definition depends on who you re talking to- Land and hazard planning 100 year flood area Hydrology- Low lying lands influenced by moving water Ecology- Habitat areas between aquatic and terrestrial ecosystems Basically, Low-lying land adjacent to rivers that becomes covered in water during flood. Defining the Floodplain

5 A floodplain is a part of a river Natural Defining and the Beneficial FloodplainFunctions of Floodplains

6 Defining the Floodplain

7 Rivers Flood Floods drive natural processes and ecosystem functions that sustain rivers and floodplains. Natural and Beneficial Functions of Floodplains

8 Natural floodplain functions: upport unique habitat Regulate water quality Recharge groundwater flows Convey floodwaters Natural and Beneficial Functions of Floodplains

9 Natural vs. urbanized watersheds Natural Urban Impacts of Floodplain Loss

10 Results of increased runoff More frequent flooding Natural and Beneficial Functions of Floodplains Impacts of Floodplain Loss Increased flood peaks

11 Typical reaction downstream Why Impacts do we of Floodplain need to restore Loss floodplains?

12 Impacts of Floodplain Loss Unintended Consequences

flood damages to grow ource: Tockner and tanford 2002 Why Impacts we need of

13 ource: The Wetlands Institute Wetlands Damages 50% of wetlands have been lost Biggest loss is forested floodplain wetlands Average annual flood damages causes flood damages to grow ource: Tockner and tanford 2002 Why Impacts we need of Floodplain a movement Loss $8 Billion per year 82 fatalities ource: National Weather ervice

14 More flooding in the forecast AECOM U.. Global Change Research Program Impacts of Floodplain Loss

15 Reconnecting the River Replicate: Implementing green infrastructure and working with nature reduces flood flows and enhance water quality. Restore: Create space to safely accommodate floodwater and restore natural and beneficial functions of floodplains. Restoring Hydrology and Floodplain Function

16 Restore Natural Hydrology Restoring Hydrology and Floodplain Function Nebraska Extension

17 Urban Green Infrastructure = Mimics Natural Hydrologic ite Conditions Infiltration - Evapotranspiration - Capture & Use Bioretention Permeable pavements Green roofs Cisterns & rain barrels Trees & expanded tree boxes Reforestation & restoration Parking & street designs Water Conservation Restoring Hydrology and Floodplain Function

18 caling Up Outreach Metrics and Goals Local Policy Implementation Maintenance Valuing and Financing

19 Restoring Functional Floodplains Connectivity patial cale Floodplain Restoring Hydrology Restoration and Projects Floodplain Function Variable Flow Get water on the floodplain at the right time, in the right amount, and for the right duration to support a natural floodplain habitat Habitat and tructural Diversity

20 Floodplain Restoration= Give Rivers Room to afely Accommodate Flood Water OLD LEVEE NEW LEVEE etback, remove, or breach levees Flood bypass Floodplain terrace Conservation easement Property and land acquisition Restore side channels Install woody debris Passive restoration Restoring Hydrology and Floodplain Function

21 caling up Foster and Provide Leadership Develop Landowner Incentives Identify and Direct Funding Clarify and Guide Regulations Train Project Managers Manage Projects

Integrated Water Management The One Water approach considers the urban water cycle as a single integrated system, in which all urban water flows are recognized as potential resources, and the

22 Integrated Water Management The One Water approach considers the urban water cycle as a single integrated system, in which all urban water flows are recognized as potential resources, and the interconnectedness of water supply, groundwater, stormwater and wastewater is optimized, and the combined impact on flooding, water quality, wetlands, watercourses, estuaries and coastal waters are recognized. Using an Integrated Approach Courtesy of Water Environment Research Foundation

Integrated Flood Management Milwaukee s Experience 2035 VIION Zero sanitary sewer overflows Zero combined sewer overflows Zero homes in the 100 year floodplain Acquire an additional 10,000 acres of

23 Integrated Flood Management Milwaukee s Experience 2035 VIION Zero sanitary sewer overflows Zero combined sewer overflows Zero homes in the 100 year floodplain Acquire an additional 10,000 acres of river buffers through Greenseams Use green infrastructure to capture the first 0.5 inch of rainfall Harvest the first 0.25 gallon per square foor of are of rainfall Using and Integrated Approach: Milwaukee

24 Replicate Natural Hydrology Upstream Using an Integrated Approach: Milwaukee

25 Restore Floodplain Functions Downstream Using an Integrated Approach: Milwaukee

26 How to get more floodplain restoration? Nag, nudge, inspire and make friends

Eileen hader Jonathon Loos eshader@americanrivers.org jloos@americanrivers.

27 Eileen hader Jonathon Loos Reconnecting Rivers to Floodplains Integrated Water Management Resource Center

28 Yolo Bypass Expansion, California Floodplain Restoration Projects

29 Floodplains by Design, Washington Floodplain Restoration Projects

30 Floodplains by Design, Washington Floodplain Restoration Projects

31 Missouri River, Iowa NEW LEVEE Floodplain Restoration Projects OLD LEVEE

32 Floodplains on Commercial Parcels - Rock Lititz, PA Restore floodplain to manage stormwater, free up land, reduce costs 49 of 96 acres for conventional stormwater management and setbacks Alternative: Restore creek floodplain Multi-benefit returns: Avoided cost of stormwater infrastructure ediment and nutrient retention 9 acres recaptured land

33 Rock Lititz, PA Removed legacy sediment to increase floodwater storage capacity (Economic Ecology: Floodplain Restoration Landtudies, Inc. Online:

34 Using and Integrated Approach: Milwaukee

infrastructure Watershed approach to managing water Reduce

35 Urban Floodplain Reconnection Cobbs Creek, Philadelphia Combining floodplain reconnection with green stormwater infrastructure Watershed approach to managing water Reduce impervious surface runoff Utilize floodplain wetlands Improve stream conditions

36 Returned natural channel form Floodplains reconnected 1.7M gallons of stormwater reduced annually Cobbs Creek Environmental Education Center

37 Functions of Natural Floodplains Courtesy of NAA

38 Capturing Runoff Reduces Cost of Localized & Regional Flooding 2011 $ 8.41 billion flood damages 25% due to urbanized flooding Long term indirect costs Photo: Adam Kurbin Green infrastructure effective on multiple levels

39 How much flooding can be reduced? Typical GI design retains 1.0 to 1.5 storm (could be designed much higher) Effect is large for small events, say 3 storm Effect is not noticeable at major storms BUT 80% to 90% of annual rainfall is <1.5 In 80% to 90% of storms would have no effect on flooding

Rainwater Harvesting:

Rainwater Harvesting: Using and Reducing the Water that Goes to Waste. By Steve Williams 2012 An Answer to Urban Water Quantity and Quality Problems Urban Ecosystem Analysis The City of Atlanta Tree loss