The status of our water supply depends on several factors involving weather, water system resilience, and customer needs. Tacoma Water developed a new Water Supply Indicator (WSI) tool to analyze and compile these criteria into a real-time assessment of the current water supply. It also enables us to inform our customers about changing water supply trends and forecasts.
“This new tool is intended to help our customers stay informed about changing water supply conditions,” said Corey Nelson, project manager and engineer for Water Resources. “2015 and 2021 presented significant challenges to our regional water supplies, and we need a simple and robust web-browsing tool to communicate changing conditions with our customers,” Nelson added.
Water resource engineers developed the tool to monitor our primary water source, the Green River Watershed. They chose six criteria to represent water supply conditions using the Analytic Hierarchy Process (AHP) to develop a criteria weighting system for each of the six water supply indicators. These include precipitation, snowpack, temperature, Howard Hanson Dam storage, daily water consumption, and Green River natural flows.
In addition to water source in the Green River Watershed, we operate 24 groundwater wells in and around Tacoma.
Conditions can vary significantly from county to county and month to month, and the WSI provides updated water messaging to customers and stakeholders.
Each week, the WSI is updated to reflect current conditions.
To view the Water Supply Indicator, and see current water supply conditions, visit MyTPU.org/WaterSupply.