Arrowrock Reservoir Water Level
Idaho · updated daily from the U.S. Bureau of Reclamation
3110.97 ft
Arrowrock Reservoir is low for this time of year and falling (-9.09 ft in the last 7 days).
Change since yesterday: +0.35 ft
Reading as of 2026-08-14 · higher than 10% of August readings on record
Where Arrowrock Reservoir sits historically
Today's level compared with every reading in our 4.5-year record for this lake.
Since yesterday
+0.35 ft
7-day change
-9.09 ft
30-day change
-47.43 ft
1-year change
-9.97 ft
Last 30 days
Last 12 months
Full history (4.5 years)
Arrowrock Reservoir records and averages
| Current level | 3110.97 ft |
|---|---|
| Record high | 3215.07 ft (2026-04-18) |
| Record low | 3107.51 ft (2022-08-15) |
| Average of all readings | 3171.36 ft |
| Data span | 4.5 years (2,000 readings) |
Frequently asked questions
Is Arrowrock Reservoir full right now?
As of 2026-08-14, Arrowrock Reservoir sits at 3110.97 ft, which is low for this time of year.Over the past 30 days the level has fallen 47.43 ft.
What is the water level at Arrowrock Reservoir today?
The most recent reading is 3110.97 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 Arrowrock Reservoir has ever been?
The highest level in our records is 3215.07 ft on 2026-04-18. The lowest is 3107.51 ft on 2022-08-15. Our record covers about 4.5 years of readings.
Is Arrowrock Reservoir low for this time of year?
Compared with every August in our records, the current level is higher than 10% 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 Arrowrock 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. Arrowrock Reservoir has fallen 47.43 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 Arrowrock Reservoir changed over the past year?
The level is -9.97 ft compared with this date last year (3110.97 ft today). The full-history chart above covers 4.5 years, with a record high of 3215.07 ft and a record low of 3107.51 ft.
Nearby lakes in Idaho
Source: the U.S. Bureau of Reclamation. Readings are provisional and subject to revision by the publishing agency. All Idaho lake levels.