Guernsey Reservoir Water Level
Wyoming · updated daily from the U.S. Bureau of Reclamation
4405.59 ft
Guernsey Reservoir is low for this time of year and falling (-6.05 ft in the last 7 days).
Change since yesterday: -1.20 ft
Reading as of 2026-08-14 · higher than 4% of August readings on record
Where Guernsey Reservoir sits historically
Today's level compared with every reading in our 5.5-year record for this lake.
Since yesterday
-1.20 ft
7-day change
-6.05 ft
30-day change
+23.63 ft
1-year change
-6.10 ft
Last 30 days
Last 12 months
Full history (5.5 years)
Guernsey Reservoir records and averages
| Current level | 4405.59 ft |
|---|---|
| Record high | 4414.28 ft (2023-06-21) |
| Record low | 0.0 ft (2021-06-15) |
| Average of all readings | 4386.34 ft |
| Data span | 5.5 years (2,000 readings) |
Frequently asked questions
Is Guernsey Reservoir full right now?
As of 2026-08-14, Guernsey Reservoir sits at 4405.59 ft, which is low for this time of year.Over the past 30 days the level has risen 23.63 ft.
What is the water level at Guernsey Reservoir today?
The most recent reading is 4405.59 ft (2026-08-14), sourced from the U.S. Bureau of Reclamation. Readings on this page refresh automatically as the agency publishes new data.
What is the highest Guernsey Reservoir has ever been?
The highest level in our records is 4414.28 ft on 2023-06-21. The lowest is 0.0 ft on 2021-06-15. Our record covers about 5.5 years of readings.
Is Guernsey Reservoir low for this time of year?
Compared with every August in our records, the current level is higher than 4% of them — low for this time of year. Seasonal comparison matters more than the raw number, because most reservoirs draw down predictably through late summer and refill over winter and spring.
Why is Guernsey Reservoir low right now?
Reservoir levels move for four main reasons: rainfall and runoff into the basin, releases through the dam for downstream water supply, power generation or flood control, evaporation during hot months, and seasonal drawdown schedules set by the operating agency. Guernsey Reservoir has risen 23.63 ft over the past 30 days. For the operational reason on any given week, check the U.S. Bureau of Reclamation directly.
How much has Guernsey Reservoir changed over the past year?
The level is -6.10 ft compared with this date last year (4405.59 ft today). The full-history chart above covers 5.5 years, with a record high of 4414.28 ft and a record low of 0.0 ft.
Nearby lakes in Wyoming
Source: the U.S. Bureau of Reclamation. Readings are provisional and subject to revision by the publishing agency. All Wyoming lake levels.