Philbrick’s Pond is a lagoon type estuary that formed landward of barrier beach spits in North Hampton, NH. Under a grant from the NH Coastal Program and the National Oceanic and Atmospheric Administration, CMA Engineers completed an evaluation of flooding of homes and roadways abutting the Philbrick Pond salt marsh for the town of North Hampton.
The project involved detailed hydrologic and hydraulic analysis of the effects of intensifying precipitation events and storm surges during nor’easters, at current sea level and with future projections of sea level rise. Both short term and long-term drainage improvements were recommended to control flooding and to facilitate restoration of salt marsh health. In the coming decades, similar detailed analysis will likely be needed at most coastal drainage basins to determine appropriate flood control provisions to mitigate the effects of climate change and sea level rise.
Implemented improvements included removal of a stone weir and apron at the inlet and replacing them with a precast concrete slab to improve hydraulics. Other work included regrading of the culvert inlet channel and placement of stone armoring along the channel and banks supporting the roadway.
