Potential Climate Change Impacts On Streamflow And Recharge In Two Watersheds On The New Jersey Coastal Plain

Climate change impacts on streamflow and groundwater recharge were evaluated for two nearby watersheds, each with different development pressures and land-use patterns. Dynamically downscaled daily climate projections from a multimodel ensemble were used to drive rainfall-runoff simulations with a distributed hydrologic model. A total of 13 general circulation models (GCMs) with three different emission scenarios were used to analyze the potential impacts of streamflow and recharge in two basins in southern New Jersey. Both basins showed similar responses of streamflow to climate change with increased low flows (95% exceedance). Average annual recharge in the Batsto River basin increased by 5% by 2065, but recharge in the Maurice River basin did not increase based on simulation results. The response of groundwater recharge recharge in the summer was similar in both basins, with simulations indicating a 10-20% increase. It seems likely that different patterns of land use change, population growth, and subsequent changes in water demand will result in different responses to climate change in these basins despite their proximity. In particular, development in the Maurice basin, the need for new stormwater infrastructure, and upgrades to existing infrastructure suggest taking steps towards maximizing retention and groundwater recharge. (C) 2017 American Society of Civil Engineers.