Understanding Living Shorelines:

Transcription

1 Understanding Living Shorelines: Their use, benefits, design principles, costs, and barriers and solutions to successful implementation, VA

2 Definition Living Shoreline Treatments address erosion in lower energy situations by providing long-term protection, restoration or enhancement of vegetated shoreline habitats through strategic placement of plants, stone, sand fill and other structural or organic materials. Living Shoreline Treatments do not include structures that sever the natural processes & connections between uplands and aquatic areas.

3 Why Living Shorelines? In Virginia, the use of native riparian and wetland vegetation to stabilize eroding shorelines has been advocated for decades. However, these practices seemed to fall out of favor with hardened shoreline protection (bulkheads, seawalls, and stone revetments) resulting in the majority of permitted projects even along low energy shorelines. Loss of wetlands from shoreline hardening led to a re-examination of permitting and mitigation practices and the resurgence of living shorelines for shoreline protection and the preservation of ecosystem services. Circa 1992

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5 Benefits of Living Shorelines Flood and Erosion Protection - Tidal wetlands reduce the rate of surface water flow and temporarily store flood waters like a sponge. Wetlands receive stormwater runoff and release it gradually. They change sharp runoff peaks and discharge water flows over longer periods of time thus reduce the danger of flooding and also recharging groundwater supplies.

6 Benefits of Living Shorelines Water Quality - Just like nature's kidneys, tidal wetlands filter and trap sediments and pollutants, increase dissolved oxygen levels and reduce nutrient levels. As water flow is slowed over the marsh, sediments and chemicals drop out of the water column, high rates of productivity lead to high rates of mineral uptake, and decomposition processes take place in wetland sediments.

7 Benefits of Living Shorelines Shoreline Erosion Control - The dense stems, roots and rhizomes of tidal wetland plants buffer the adjacent shoreline by reducing wave energy and reducing current velocity thereby trapping sediments.

8 Benefits of Living Shorelines Aquatic Productivity - A complex food web is supported through the transformation of inorganic nutrients into organic matter that is useful to aquatic animals. Decaying plant matter (detritus) is colonized by microorganisms which are then consumed by larger aquatic animals such as marsh periwinkles. The wetlands ecosystem is the source of food for a variety of fish, shellfish, birds, amphibians, reptiles, and small mammals.

9 Benefits of Living Shorelines Fish and Wildlife Habitat - Wetlands provide habitat for resident and migratory species of fish, invertebrates, reptiles, birds and mammals. Wetland habitats are important for a high percentage of endangered and threatened species. Roughly two-thirds of our commercially valuable fish and shellfish use tidal wetlands as spawning or nursery areas.

10 Benefits of Living Shorelines Aesthetics - People enjoy wetlands for their beauty, ecological diversity, and solitude. Wetlands are a vast treasure of information about our cultural heritage since many Native American villages were based in these locations. Wetlands are beautiful locations for fishing, hunting, painting, photography, bird watching, hiking canoeing, crabbing and wildlife study.

11 Source: Partnership for the Delaware Estuary, Inc.

12 Types of Projects Non-structural Option: Non-structural design options are most suitable in very low energy settings with minor erosion, minor wave action and good growing conditions. Target areas include the upper reaches of tidal creeks, tidal coves, and other areas protected from excessive wind and wave action. Vegetation Management replacing lawn with riparian buffer plantings Enhancing Wetland Plantings Installation of Biodegradable Fiber (coir) Logs (breakwater or toe protection) Bank Grading

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15 Types of Projects Hybrid Options: Hybrid living shoreline options include structures that are necessary to support vegetation growth or to create wide stable beaches. These methods are used where non-structural methods would not provide enough protection. The structure's size depends on how wide the vegetation or beach buffer can be. Marsh toe revetments Marsh sill and plantings Offshore breakwaters Oyster reefs

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18 circa 1992

19 Design Criteria Source: Shoreline Erosion Control The Natural Approach (Maryland DNR)

20 Design Criteria Other Factors to Consider: Shoreline Orientation: Hurricane and Nor easter direction Boat Wake Erosion: Shore Morphology: cove, headland, etc. Offshore Depth: shallow waters can attenuate waves Nearshore SAV: wave attenuation Tide Range: affects heights and footprints of sills or breakwaters Design Wave: frequency and size of wave impinging upon the shore

21 How to Choose Which Method is Appropriate? #1 Nothing Beats Experience! (Calling all PWSs!) #2 Decision Trees

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23 How Are They Working? Birdsong Wetlands

24 How Are They Working? Colley Bay

25 How Are They Working? Colley Bay

26 How Are They Working? Haven Creek

27 How Are They Working? Hermitage Foundation

28 How Are They Working? Hermitage Foundation

29 How Are They Working Holly & Columbus

30 How Are They Working? 46 th Street Terminus

31 How Are They Working? 46 th Street Terminus

32 How Are They Working? 46 th Street Terminus

33 Barrier: Fear of the Unknown: What does it Look Like? How Long Will It Last?

34 Solution: Build Demonstration Projects on Public And Private Property

35 Solution: Build Demonstration Projects

36 Solution: 1997 Point Out The Longevity Of Public Projects 2008

37 Barrier: Lack of a VA Living Shoreline Requirement: (State Preference Only)

38 Solution: Fairfax leads the way in VA Living Shorelines : Among all the options, applicants must consider a design that maintains or creates a living shoreline, as an approach for shoreline stabilization, and demonstrate to the Board why a living shoreline approach would not achieve your goals. Properly sited and designed living shorelines will be preferentially permitted over hardened shoreline approaches.

39 Barrier: Local Wetlands Board Level of Comfort in Approving LS Projects

40 Solution: Follow up Presentations to WBs Showing Successes

41 Barrier: Living Shoreline Projects Are Uncommon

42 Solution: Engage NGOs, Universities, and Citizens to Build LS Projects In All Communities Lafayette Wetlands Partnership

43 Barrier: Few Experienced Project Designers

44 Solution: Train NGOs & College Students

45 Barrier: Relatively Few Experienced Contractors

46 Solution: Spend Time in the Field to Assist Contractors and Troubleshoot

47 Barrier: Living Shorelines are Unpopular: Who s Going to Pay Me to Do What I Don t Want to Do?

48 Solution: Investigate TMDL and FEMA CRS Credits or Other Creative Incentives for Landowners General Permit Not Yet Completed in VA

49 Barrier: Living Shorelines, And In Particular Vegetative Wetlands, Are Not Perceived Like Other Types of Landscapes Worthy of Enhancement and Beautification

50 Solution: Citizen Education Native Plants for Wetland Restoration and Enhancement

51 Barrier: Common Sense of Purpose + Better Coordination Within the Regulatory Community Solution: More Collaboration

52 The Living Shoreline Summit in Virginia in 2006 and the follow-up Mid- Atlantic Living Shoreline Summit in MD in 2013 have provided information and a forum for scientists, living shoreline designers, contractors, regulators, NGOs, and others to share information, discuss emerging technologies and strategies, identify data gaps and needed research, better understand construction processes, identify barriers to implementation, and increase collaboration. Major themes included: The need for additional research in social marketing and behavior change Understanding the impacts of living shoreline construction on ecosystem services The potential overuse of rock sills in hybrid living shoreline projects Sustainability of living shorelines with sea level rise Streamlining and expediting regulatory approvals for living shorelines.

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55 Resources VA: MD: DE: ochure_feb2012.pdf NC: c2702bf97ee3 NOAA: LinkedIn Group: Living Shoreline Erosion Control Forum:

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57 Questions? Kevin Du Bois, PWS, PWD, CFM Bureau of Environmental Services 508 City Hall Building Norfolk VA USA