Overview
Moses Lake is an approximately 6,800-acre lake in the Columbia Basin of central Washington, enlarged and regulated as part of the Bureau of Reclamation's Columbia Basin Project and local irrigation operations. The Moses Lake Irrigation & Rehabilitation District helps manage lake levels for irrigation, water quality, and recreation in and around the City of Moses Lake. Columbia Basin irrigation return flows are a major hydrologic input alongside natural Crab Creek drainage.
Mean depth is about 18-19 feet and maximum depth about 38 feet, with roughly 59 miles of shoreline across connected arms and shallows. Irrigation return flows and Crab Creek inflows strongly influence water quality and habitat. Connected arms and shallows warm quickly in summer and can support dense aquatic vegetation.
The lake is a popular local fishery for bass, walleye, panfish, and other species managed by the Washington Department of Fish and Wildlife. City parks, ramps, and waterfront access support boating and day use. The City of Moses Lake waterfront and local parks concentrate day-use boating and events.
Operating levels commonly range from a winter band near 1,041 feet toward a full-pool target near 1,046-1,047 feet. Because the lake is shallow and linked to Potholes Reservoir downstream, monitoring current lake levels matters for ramps, weeds, and fishing. Coordination with Potholes operations means irrigation season can change both lakes usable shorelines.
Current Conditions
Moses Lake is currently 0.31 feet below full pool and has remained relatively stable over the past seven days.
- 7-day trendStableLatest movement can differ from the seven-day trend.
- 7-day changeDown 0.01 ft
- 30-day changeUp 0.03 ft
- Drought conditionsModerate Drought
About This Lake
Learn how this lake is managed, what affects its water level, and where Lake Insights gets its data.
Moses Lake is a 6,800-acre reservoir on the Crab Creek managed by Moses Lake Irrigation & Rehabilitation District; USBR Columbia Basin Project.





