Arrowrock Lake Water Level Today

Idaho · near Boise · Well below full pool

Flood pool3,219.8Full pool3,215.8
Elevation
3,129.91 ft
From full pool
−85.84 ft
Percent of pool
n/a
24-hour change
+0.23 ft
7-day change
+2.01 ft
Reading
Sep 21, 2026 · USACE

Last year at Arrowrock Lake

3,110.43,165.13,219.8full poolflood poolAug 25Nov 25Feb 26May 26Aug 26
Daily mean elevation in feet, last 391 days. Dashed lines mark the published pool elevations.

Arrowrock Lake is 85.84 ft below full pool, at 3,129.91 ft, up 0.23 ft in the last 24 hours. The top of the flood pool is 89.8 ft higher, at 3,219.75 ft.

Over the last 7 days the level rose 2.01 ft, and over 30 days it rose 17.07 ft. In the 391 days of readings on this page the high was 3,215.06 ft on Apr 18, 2026 and the low was 3,110.43 ft on Aug 20, 2025, a range of 104.63 ft.

The reading is the U.S. Army Corps of Engineers gauge at Arrowrock Dam, near Boise, taken Sep 21, 2026 and referenced to the NGVD29 datum. This page is rebuilt once a day from the agency feed; it is not a live gauge, so during a fast rise or a scheduled release check the USACE page for hourly values.

Arrowrock Lake pool elevations

Current elevation3,129.91 ft
Full pool (top of conservation)3,215.75 ft
Top of flood pool3,219.75 ft
Top of dam3,219.75 ft
Inflow739 cfs
Outflow629 cfs
30-day change+17.07 ft
1-year high3,215.06 ft (Apr 18, 2026)
1-year low3,110.43 ft (Aug 20, 2025)
Vertical datumNGVD29
Operating agencyU.S. Army Corps of Engineers, NWW district

Source: U.S. Army Corps of Engineers. Read what full pool and flood pool mean.

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Arrowrock Lake level questions

What is the water level of Arrowrock Lake today?

Arrowrock Lake is at 3,129.91 ft as of Sep 21, 2026, −85.84 ft relative to full pool (3,215.75 ft). The 24-hour change is +0.23 ft.

What is full pool at Arrowrock Lake?

Full pool, the top of the conservation pool, is 3,215.75 ft (NGVD29). Above that, water is stored temporarily in the flood pool up to 3,219.75 ft.

Is Arrowrock Lake rising or falling?

Over the last 24 hours the level is +0.23 ft; over 7 days it rose 2.01 ft, and over 30 days it rose 17.07 ft.

Where does this Arrowrock Lake level come from?

From the U.S. Army Corps of Engineers (USACE) public data feed for Arrowrock Dam. Lake Levels Today republishes the agency's daily value without adjustment and links to the source below.