Columbia River Supply and Demand Forecast Project (2026)

Every five years the Washington State Department of Ecology’s Office of Columbia River (OCR) updates information on the implications of water supply and demand changes in the Columbia River Basin over the next 20 years. We collaborate with OCR and other partners to assess how environmental, economic and other changes affect water resources (supply) and the water demands for multiple uses.
The 2026 Columbia River Basin Long-Term Water Supply & Demand Forecast is exploring specific changes that can affect our region’s vulnerabilities, and thereby inform policy and science needs to address them. We are currently assessing the probabilities and economic implications of back-to-back drought, modeling trends in groundwater that many users depend on, assessing the effect of water conservation measures, inventory temporary farmworker housing facilities and their growing water needs, and evaluating dynamically-downscaled climate data to inform future water supply and demand modeling. We are also gathering perspectives on the value and use of past Forecasts to inform the development of the 2026 Forecast products, outreach and engagement.