Water runoff prediction for Boysen at average level

The Bureau of Reclamation’s March Forecast of the April through July water runoff predicted for Boysen Reservoir is 620,000 af, which is 99% of the 30-year average of 625,000 af. As of March 1, Boysen Reservoir was 84% full. A 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.

Forecasts for the rest of the Bighorn River Basin include:

•Buffalo Bill Reservoir - Shoshone River April through July inflow to Buffalo Bill Reservoir is forecast at 560,000 af, which is 74% of the 30-year average of 754,000 af. As of March 1, Buffalo Bill was 74% full.

•Bighorn Lake - Bighorn River April through July inflow to Bighorn Lake is forecasted to be approximately 852,000 acre-feet (af), which is 67% of the 30-year average of 1,264,000 af. As of March 1, Bighorn Lake was 84% full.

•Bull Lake Reservoir - April through July snowmelt runoff into Bull Lake Reservoir from Bull Lake Creek is expected to be 150,000 af, which is 103% of the 30-year average of 146,000 af. As of March 1, Bull Lake Reservoir was 47% full.

 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 more information on Boysen, Buffalo Bill and Bull Lake Reservoirs, contact Wyoming Area Manager Lyle Myler at 307-261-5671.