Arrowrock Dam
Dam in Boise County, Idaho · Boise River Snake River · forms Arrowrock Reservoir
Height
350 ft
107 m (NID height)
Length
1,150 ft
351 m
Completed
1915
Arrowrock Reservoir today
3,132.88 ft
7 days ▲ 3.43 ft
Normal storage
272,224 acre-ft
Normal for the date
Reservoir level measured Oct 23, 2026, 2:00 AM MDT. Full level page →
Facts
- Purposes
- Flood Risk Reduction; Irrigation; Fish and Wildlife Pond; Recreation; Water Supply
- Dam type
- Concrete
- Structural height
- 350 ft
- Owner
- BUREAU OF RECLAMATION (Federal)
- Maximum storage
- 272,224 acre-ft
- Surface area
- 3,256 acres
- Hydraulic height
- 257 ft
- Drainage area
- 2,217 sq mi
- Spillway
- Controlled, 372 ft wide
- Army Corps district
- Walla Walla District
- Also known as
- Arrowrock Reservoir
- NID ID
- ID00280
Facts from the U.S. Army Corps of Engineers National Inventory of Dams, record updated Oct 6, 2026. Search NID ID ID00280 at nid.sec.usace.army.mil. Project website.