Fontenelle Reservoir storage

Reservoir storage in Green-Colorado basin, Wyoming

Last updated Jul 8, 2026

Now 262,554 af, 9% below the 5-yr median.

Fontenelle Reservoir Storage

Current Status: 262,554 acre-feet (af) — 9% below the 5-year median

Recent Trends:

Week-over-week storage is up 3.9% (+9,824 af), showing recent inflow gains
Month-over-month storage is up 31.3% (+62,546 af), indicating sustained spring runoff recovery
Year-over-year storage is down 8.6% (−24,836 af), reflecting below-normal conditions compared to July 2025
Against the 5-year median, storage is 9.2% below normal (−26,533 af), positioning the reservoir in the lower-normal range

Interpretation: Fontenelle is tracking below its historical median for early July, consistent with the 2026 Upper Colorado Basin's below-average snowpack year. However, the strong month-over-month gain suggests spring runoff is still contributing meaningfully. Current levels are sustainable for near-term operations but warrant monitoring if summer evaporation accelerates without additional inflow. The week-over-week stability indicates the current inflow-withdrawal balance is holding.

The numbers
Period	Current	Prior	Change
Week over week	262,554 af	252,730 af	+3.9%
Month over month	262,554 af	200,008 af	+31.3%
Year over year	262,554 af	287,390 af	-8.6%
vs 5-yr median	262,554 af	289,087 af	-9.2%

From the brief

Read this week's brief →