Reclamation issues snowmelt forecast for Bighorn River Basin

MILLS, Wyo. - Reclamation's April Forecast of the April through July water runoff predicted for the Bighorn River Basin is as follows:

• Bighorn Lake - Bighorn River April through July inflow to Bighorn Lake is forecast to be approximately 528,000 acre-feet (af), which is 42% of the 30-year average of 1,250,000 af. As of April 1, Bighorn Lake is 77% full.
• Buffalo Bill Reservoir - Shoshone River April through July inflow to Buffalo Bill Reservoir is forecast at 480,000 af, which is 64% of the 30-year average of 753,000 af. As of April 1, Buffalo Bill was 68% full. *
• Boysen Reservoir - Wind River April through July inflow to Boysen Reservoir is forecast at 200,000 af, which is 33% of the 30-year average of 606,000 af. As of April 1, Boysen Reservoir was 72% full. *
• Bull Lake Reservoir - April through July snowmelt runoff into Bull Lake Reservoir from Bull Lake Creek is expected to be 100,000 af, which is 70% of the 30-year average of 144,000 af. As of April 1, Bull Lake Reservoir was 29% full. *

*Reservoir is considered "full" when the pool elevation is at top of active conservation or joint-use pool. The percentage is based on total reservoir volume below that level.

The Bighorn Basin is a plateau region and intermontane basin, approximately 100 miles (160 km) wide, in north-central Wyoming. It is bounded by the Absaroka Range on the west, the Pryor Mountains on the north, the Bighorn Mountains on the east, and the Wind River and Granite Mountains on the south. It is drained to the north by tributaries of the Bighorn River, which enters the basin from the southwest, and passes through a gap between the Owl Creek and Bridger Mountains as the Wind River before changing its name to the Bighorn River at Wedding of the Waters, south of Thermopolis.

Reclamation's storage reservoirs in the basin have a combined storage capacity of 2.6 million acre-feet and most of that capacity is attributed to Bull Lake, Boysen and Buffalo Bill Reservoirs in Wyoming and Bighorn Lake in Montana. Hydropower is produced at Boysen Powerplant and four powerplants supplied by Buffalo Bill Reservoir in Wyoming and at Yellowtail Powerplant in Montana.

For additional information on Buffalo Bill, Boysen, and Bull Lake Reservoirs, contact Wyoming Area Manager Lyle Myler at 307-261-5671. For additional information on Bighorn Lake (Yellowtail), contact Montana Area Manager Ryan Newman at 406-247-7298.