Boysen Reservoir Storage

Boysen Reservoir, located in the Wind-Bighorn-Missouri basin of Wyoming, is currently holding 551,518 acre-feet (af) of water as of July 7, 2026 — a level 24% below the 5-year median.

Current Status

Weekly trend: Storage edged down 0.8% week-over-week, declining from 555,907 af.

Monthly trend: Storage gained 2.5% month-over-month, recovering from the June low of 538,068 af.

Annual comparison: Year-over-year, storage is down 10.4% compared to the same date last year (615,243 af), reflecting tighter-than-normal supply across the basin.

Median comparison: Current levels are notably depressed, sitting 23.8% below the 5-year median of 723,338 af, indicating sustained drought or above-average demand conditions.

Key Takeaway

While recent weeks show modest recovery (intra-month gains), Boysen remains in a below-normal supply position relative to historical precedent. Continued monitoring of inflows and outflows will be essential to assess whether this upward trajectory continues or reverses.