Water Resources Research Act Program

Details for Project ID 2011NC158B

Uncertainty in Surface Water Availability over North Carolina due to climate and land use changes

Institute: North Carolina
Year Established: 2011 Start Date: 2011-03-01 End Date: 2012-02-29
Total Federal Funds: $25,664 Total Non-Federal Funds: $44,601

Principal Investigators: Sankarasubramanian Arumugam, Tushar Sinha

Abstract: Despite abundant water resources in North Carolina (NC), increasing demand from urban development have forced the local/regional water supply systems to update their water supply plans once in five years. Development of these water supply plans requires reliable assessment of both water availability and demand over the planning horizon. But, assessment of water availability and demand are interdependent tasks, since increased demand due to development could lead to changes in land use resulting in reduced baseflow and increased overland runoff. Such impacts, in addition to regional and global climate change, could create considerable uncertainty in the developed water supply plans. The intent of this study is to quantify surface water availability and its uncertainty in the next 10-30 years under potential climate and land use change scenarios over NC. Specifically, we will: 1) Quantify the uncertainty on surface water availability under climate change and land use change over the near-term (10-30 years) in the Upper Cape Fear River basin, 2) Investigate alternate water allocation strategies for Lake Jordan by incorporating the uncertainty in surface water availability for the projected water demand scenarios and 3) Project the changes in monthly streamflow for other watersheds (e.g., Neuse, Catawba and other coastal watersheds) that are experiencing similar pressure on water supply due to urban development. We will use a physically based Soil and Water Assessment Tool (SWAT) model to estimate the uncertainty in surface water – expressed as ensembles of monthly streamflows – under future climate and land use change scenarios over Upper Cape Fear River basin, which is expected to experience population growth around 10-20% in the next three decades. Combining these ensembles with a reservoir model for Lake Jordan, we will quantify the reliability of meeting the increased demand from the upper cape fear basin. Based on the calibrated SWAT model, we will also develop ensembles of mean monthly runoff for different climate and land use scenarios for various target river basins in NC. By presenting the research findings in the annual water conferences hosted by NC WRRI, we will motivate water managers and city planners to incorporate the uncertainty in future streamflow for developing water supply plans and in estimating system reliability.