To help improve the drought-resiliency of its potable water system, the Athens-Clarke County (ACC) Public Utilities Department (PUD) is evaluating the feasibility of using the Rock Hill Quarry (RHQ) as a future raw water storage reservoir. The quarry reservoir would store nearly 5 billion gallons of water from a local river, and supply the water as needed to the ACC PUD distribution system. To support the feasibility assessment and the evaluation of water treatment options, a reservoir hydrodynamic and water quality model of the quarry was developed in CE-QUAL-W2 to simulate reservoir operations and water quality dynamics over a ten-year period. Several operational scenarios and infrastructure configurations were modeled to quantify both the in-reservoir water quality dynamics and the range of water quality constituent parameter values in water withdrawn from the multi-level outlet system. Additional analysis was completed on post-processed model results to evaluate geochemical interactions between the quarry and reservoir interface, and the potential to influence long-term water quality. This talk will summarize modeling and analysis used to evaluate reservoir water quality and discuss how model results were used to support the overall feasibility assessment.
