The Spokane Valley-Rathdrum Prairie (SVRP) Aquifer in northeastern Washington and northern Idaho is the sole source of drinking water supply for the rapidly growing Spokane/Coeur d’Alene metropolitan region. The SVRP Aquifer is one of the world’s most prolific aquifers, consisting of catastrophic glacial flood deposits of sands, gravels, cobbles, and boulders. Perimeter lakes and the upper reaches of the Spokane River provide substantial recharge to the aquifer, and most natural groundwater discharge occurs as baseflow to downstream reaches of the Spokane River and the Little Spokane River. The Spokane River interacts closely with the aquifer and is a highly valued natural, cultural, and recreational resource for the region. As a result, local water purveyors conduct their groundwater supply planning and management activities with the river’s health in mind. This presentation will discuss how purveyor-led field and modeling studies during the past three decades have (1) dramatically improved the understanding and current state of knowledge of the region’s hydrogeology and river-aquifer interactions and (2) allowed science-based planning work to occur that accounts for how future possible changes in land use, water demands, and climate conditions in the aquifer and its many contributing watersheds could affect the health of the SVRP Aquifer and the Spokane River.