Coastal Impoundment Vulnerability and Resilience Project

If you have ever birded at Parker River NWR, Forsythe NWR (Brigantine), Bombay Hook NWR or almost any east coast wildlife refuge, then you probably know the value of coastal impoundments. These man-made water bodies are contained by embankments and have gates that allow managers to manipulate water levels. They are often drained in the spring to expose mudflats for migrating shorebirds, and then raised in fall to provide open water for ducks and other waterbirds through the winter. Their value to birds is apparent to anyone who has watched tens of thousands of shorebirds roosting and feeding in the impoundments of Heislerville WMA in southern New Jersey, or to the hundreds of thousands of annual visitors to the wildlife drives and trails at Brigantine, Heinz and Jamaica Bay wildlife refuges.

Impoundments at Forsythe NWR suffered severe damage during 2012’s Hurricane Sandy when embankments were breached in several places.

Superstorm Sandy was a powerful reminder that, in addition to being valuable, these structures are also vulnerable. Damaging and expensive breaches to embankments occurred at numerous impoundments in the path of the storm, including Forsythe NWR, Heislerville WMA, Jamaica Bay Wildlife Refuge, and Tuckahoe WMA. Impoundments at other sites, including Heinz NWR in Philadelphia, DeKorte Park in the NJ Meadowlands, and Wertheim NWR in Long Island suffered substantial erosion. Sites outside the direct path of Sandy were less affected, but many of these impoundments nevertheless have a history of repeated overtopping with large storms. It goes without saying that ongoing sea level rise, especially at the accelerating rates predicted with climate change, will greatly compound these threats.

The Coastal Impoundment Vulnerability and Resilience Project (CIVRP), funded by the Department of the Interior via the National Fish and Wildlife Foundation, aims to map and catalog all state, federal, and privately owned coastal impoundments from Virginia to Maine. In addition, we are compiling information on the ecological and societal services provided by these sites and assessing their vulnerability to sea level rise. We will develop a ranking of impoundments based on metrics related to their ecological value, importance to human populations, and potential for maintaining their structural integrity. The project is a cooperative effort of a diverse team of partners including researchers from New Jersey Audubon, National Wildlife Federation, Conservation Management Institute (Virginia Tech), Princeton Hydro, and the US Fish and Wildlife Service.

Progress and accomplishments

Thus far, we have mapped approximately 166 coastal impoundments at 45 sites from Virginia to Maine. We have gathered a variety of information on each through literature searches, GIS (geographic information system) analysis, and interviews with managers and key stakeholders. We performed a ‘desktop’ vulnerability analysis based on detailed (Lidar-based) measurements of embankment width and elevation relative to mean high water. Currently, we are researching ecological resources and biological data from each site. Engineers from Princeton Hydro are visiting a selection of sites over the winter of 2015-2016 to collect on-the-ground data about vulnerability and to assess any protective value to nearby communities.

Outcomes and Objectives

At least five major outputs will result from this project:

Output 1: Comprehensive GIS Catalog of coastal impoundments from Virginia to Massachusetts

This includes information such as location, size, elevation, proximity to human communities, and hydrological features of each of the coastal impoundments in the study area.

Output 2: Societal Importance, Ecological Value, and Climate Vulnerability Assessment

This will include an analysis of each northeastern impoundment in terms of (1) the protection that it confers on coastal human communities, from storms and sea-level rise, (2) its ecological functions and values, and (3) its vulnerability to future storms and sea-level rise. Based on this, priority impoundments will be identified based on their ability and/or potential to reduce risk to communities, and to conserve important ecological communities and habitats.

Output 3: Management/Adaptation Recommendations

For each priority impoundment, climate-smart management, restoration, and conservation actions will be developed and presented to coastal managers and conservationists. Approximate costs will also be estimated. This will represent a novel regional approach that will allow for more focused efforts to reduce vulnerability to human communities while enhancing ecosystem functioning and value (where possible using nature-based solutions to reduce risk).

Output 4: Workshops & Meetings

Workshops/meetings to educate managers and stakeholders on the utility and functionality of climate-smart management/adaptation approaches. These meetings will result in an enhanced understanding throughout coastal communities on the societal and ecological values of impoundments, and actions that can be taken by local, state, and federal partners to reduce risks to individual impoundments.

Output 5: Youth Involvement

Assessment materials will be integrated into Environmental Science classes at local New Jersey and/or New York universities. This will include site visits by college students who will create project fact sheets, web resources and other materials to share information at workshops and meetings with stakeholders. Six students from local colleges and universities will act as interns and will gain on-the-job experience from their involvement.

The overarching goal of the Coastal Impoundment Vulnerability and Resilience Project is to begin to optimize and coordinate impoundment management / adaptation strategies in an innovative way that will allow impoundments to benefit both human communities and wildlife habitats over the coming decades. Managers and planners at federal, state and local levels will benefit from gaining an understanding of which impoundments within each state and the region are vulnerable to damage from ongoing sea-level rise and/or catastrophic storm events, which provide the most protection to local communities, the number of people at risk from an impoundment failure, which sustain significant ecological resources, and which should be a priority for restoration and protection as nature-based solutions to reduce community vulnerability.