Extending the Decision-Making Lead time of Municipal Water System Management Using Teleconnections to Support Supply and Demand Estimates

Western United States municipal water system management requires estimates of system performance with sufficient lead time to identify and mitigate potential vulnerabilities. Given their dependence on winter snowpack and the resulting timing of surface water availability contrasting that of peak water demand, there is a need to deliver earlier estimates of system performance to increase the lead time for decision-making. Addressing this need, we develop a long to short-term water systems operations workflow that provides operators with estimates of performance with up to a ten-month lead time and demonstrate the workflow using the Salt Lake City Department of Public Utilities in Northern Utah, United States. The workflow leverages teleconnections with global climate signals to estimate the precipitation, surface water yield, and demand for up to a ten-month forecast horizon. We use the estimates of supply and demand to drive a water systems model that provides a range of likely reservoir levels, groundwater withdrawal volumes, and volume of out-of-district water needs to determine potential system vulnerabilities needed to evaluate and develop mitigation measures.