Lamprey River Flood Damage

Analysis and communications of flood damage cost avoidance in the Lamprey River watershed of New Hampshire

Cameron Wake, Research Associate Professor of Climatology and Glaciology, UNH (603.862.2329) and Robert Roseen, Geosyntec Consultants (617.992.9067)

The magnitude and frequency of freshwater flooding is increasing in the N.H. Seacoast, due in large part to more impervious surfaces and land development within the Great Bay watershed as well as changing rainfall patterns and more frequent extreme weather events. Recently updated maps delineating the new 100-year floodplains were disseminated to communities within the Lamprey River watershed, but they did not provide decision-makers with information regarding the potential economic and social impacts of flooding. With significant development pressures on coastal communities and the resulting impacts to coastal resources, it is imperative that these decision makers have sound information on which to base land-use decisions.

Wake and research colleagues will help inform efforts to build community resilience to future freshwater flooding by first updating hydrological computer models to improve estimates of potential flood damage and cost avoidance resulting from different land use management strategies in the Lamprey River watershed. In close collaboration with N.H.’s Natural Resources Outreach Coalition, they will train municipal officials and regional planners on the use of the new 100-year floodplain maps, present the results of a recent legal analysis of the maps and provide analyses of economic flood damage and cost avoidance measures.

Researchers will work with local and national communications experts to develop and implement audience-specific, innovative and integrated plans to communicate both the risk of climate change and the cost avoidance benefits of land use management decisions and their contribution to resiliency. This research will provide a broader understanding of the risk and economic impact of current and future flooding as a result of land use and climate change by residents across the watershed to support more informed community decisions.