Surface Water Availability

The Surface Water Availability assessment will measure the amount of water that can be used from the rivers and lakes of Georgia without substantially altering the desired hydrologic flow regime and the opportunities for use of water supported by that flow regime. Together with the Groundwater Availability Assessment, they form the "consumptive use assessment" described in the State Water Plan.

EPD and its contractors will use the "River Basin Planning Tool," developed by the Georgia Water Resources Management Institute at Georgia Tech, to model flows in Georgia’s river systems. The River Basin Planning Tool will allow EPD to convert existing data on the 14 river basins in Georgia into smaller planning units or sub-basins, and measure the quantity of water available for consumptive use in each sub-basin. Consumptive use refers to the amount of water used but not returned without undue delay from either surface water or groundwater.

Critical inputs for the model include: the desired flow of the river system, expected return of treated wastewater to the system, the desired water supply, and the desired reliability of the water supply.