Columbia River Basin Long-term Water Supply and Demand Forecast
Every five years, the Office of Columbia River submits an updated long-term water supply and demand forecast to the Legislature. The Draft 2026 Columbia River Basin Long-term Water Supply and Demand Forecast was created through a partnership between Ecology, Washington State University, and the Washington Water Research Center. The report will help OCR strategically fund water supply projects by improving understanding of where additional water supply is most critically needed, now and in the future.
The 2026 Forecast builds on our robust and well-established understanding of expected future changes in surface water supplies and the main out-of-stream demands, gained through the 2021 Forecast. This 2026 Forecast pivots towards understanding important drivers of changes in supplies and demands that either have not yet been fully quantified or have emerged since 2021. The goal of this 2026 Long-Term Water Supply and Demand Forecast is to advance our understanding of eastern Washington’s vulnerabilities to changing water supplies and demands by addressing key gaps in our knowledge, focusing on six questions:
- Where and how are vulnerabilities in water availability most relevant to different sectors of water users?
- How will groundwater respond in the future to changes in pumping and recharge?
- What are the benefits, complexities, and tradeoffs involved in water conservation efforts in Washington State?
- What is the added risk posed by droughts if they occur in consecutive years?
- What is the magnitude of water demand for temporary worker housing facilities, and how complex are the needs to address it?
- How can scientific advances in climate change projections help improve our understanding of the future risks climate change poses to water use sectors in eastern Washington?
Contact information
Jennifer Stephens
Environmental Specialist
jennifer.stephens@ecy.wa.gov
509-575-2396