Grassy Lake Water Level

Wyoming · updated daily from the U.S. Bureau of Reclamation

7180.69 ft

Grassy Lake is low for this time of year and rising (+0.25 ft in the last 7 days).

Change since yesterday: +0.08 ft

Reading as of 2026-08-14 · higher than 7% of August readings on record

Where Grassy Lake sits historically

TODAY 7180.69 ftRECORD LOW7180.2 ft2026-07-27RECORD HIGH7210.83 ft2022-06-07

Today's level compared with every reading in our 4.5-year record for this lake.

Since yesterday

+0.08 ft

7-day change

+0.25 ft

30-day change

-9.78 ft

1-year change

-8.59 ft

Last 30 days

2026-07-157179.0–7191.7 ft2026-08-14

Last 12 months

2025-08-147176.7–7212.8 ft2026-08-14

Full history (4.5 years)

2022-02-207176.7–7214.3 ft2026-08-13

Grassy Lake records and averages

Current level7180.69 ft
Record high7210.83 ft (2022-06-07)
Record low7180.2 ft (2026-07-27)
Average of all readings7198.23 ft
Data span4.5 years (2,000 readings)

Frequently asked questions

Is Grassy Lake full right now?

As of 2026-08-14, Grassy Lake sits at 7180.69 ft, which is low for this time of year.Over the past 30 days the level has fallen 9.78 ft.

What is the water level at Grassy Lake today?

The most recent reading is 7180.69 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 Grassy Lake has ever been?

The highest level in our records is 7210.83 ft on 2022-06-07. The lowest is 7180.2 ft on 2026-07-27. Our record covers about 4.5 years of readings.

Is Grassy Lake low for this time of year?

Compared with every August in our records, the current level is higher than 7% 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 Grassy Lake changing 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. Grassy Lake has fallen 9.78 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 Grassy Lake changed over the past year?

The level is -8.59 ft compared with this date last year (7180.69 ft today). The full-history chart above covers 4.5 years, with a record high of 7210.83 ft and a record low of 7180.2 ft.

Nearby lakes in Wyoming

Jackson Lake water level
6748.67 ft · falling
Buffalo Bill Reservoir water level
5381.16 ft · falling
Bull Lake Reservoir water level
5791.47 ft · falling
Anchor Reservoir water level
6368.2 ft · rising
Fontenelle Reservoir water level
6500.34 ft · steady
Pilot Butte Reservoir water level
5451.39 ft · falling

Source: the U.S. Bureau of Reclamation. Readings are provisional and subject to revision by the publishing agency. All Wyoming lake levels.