Reclamation Snowmelt Forecast for North Platte River Basin

MILLS, Wyo. - Reclamation's May forecast predicts that spring runoff from mountain snowmelt in the North Platte River Basin above Glendo Dam will be well below average this year.

Snowpack across the basin is well below average, and the Upper North Platte Basin is experiencing extreme drought conditions. From April through July, total runoff is expected to reach approximately 155,000 acre-feet, which is 17% of the 30-year average. This forecast includes approximately 70,300 acre-feet of inflow to the North Platte River Basin above Guernsey that occurred in April.

The North Platte Reservoir System has a total conservation storage capacity of approximately 2,815,800 acre-feet. As of April 30, 2026, the combined storage across the system was 1,247,627 acre-feet, which is 67% of the 30-year average.

Seminoe and Pathfinder reservoir levels are expected to remain very low. Pathfinder Reservoir will drop significantly when water deliveries begin in late June. Due to poor water supply, Glendo and Guernsey reservoirs are not expected to fill as early or as high as normal, and their levels will decline sooner in late summer. Boaters are advised to use caution and monitor reservoir levels.

Current releases:

• Seminoe Reservoir: 530 cubic feet per second (cfs) through the Miracle Mile
• Gray Reef Reservoir: 500 cfs
• Glendo Reservoir: 25 cfs
• Guernsey Reservoir: No current releases

Projected releases (Summer):

• Seminoe Reservoir: Expected to remain 530 cfs
• Gray Reef Reservoir: Expected to range from approximately 1,000 to 2,500 cfs
• Guernsey Reservoir: Expected to range from approximately 1,600 to 5,000 cfs
• Pathfinder Reservoir: Not expected to spill this spring
• North Platte Project: An allocation is expected based on the current forecast. Limited supply will likely delay irrigation releases from Guernsey Reservoir to June and irrigation releases are anticipated to end earlier than normal.
  

Reclamation's Wyoming Area Office operates seven reservoirs on the North Platte River with Seminoe Reservoir farthest upstream and Guernsey Reservoir farthest downstream. This system provides irrigation supply to hundreds of thousands of acres of farmland and produces power generation from 6 powerplants that supply power to tens of thousands of homes.