Rock Island
Dam in Douglas County, Washington · Columbia River · forms Rock Island Lake
Height
71 ft
22 m (NID height)
Length
3,108 ft
947 m
Completed
1932
Rock Island Lake today
611.98 ft
7 days ▲ 0.03 ft
Normal storage
113,700 acre-ft
Much below normal for the date
Reservoir level measured Oct 23, 2026, 12:00 AM PDT. Full level page →
Facts
- Purposes
- Hydroelectric; Flood Risk Reduction
- Dam type
- Gravity
- Structural height
- 61 ft
- Owner
- PUD #1 of Chelan County, WA (Public Utility)
- Maximum storage
- 131,000 acre-ft
- Surface area
- 3,120 acres
- Hydraulic height
- 55 ft
- Drainage area
- 89,400 sq mi
- Spillway
- Controlled
- Army Corps district
- Seattle District
- NID ID
- WA00084
Facts from the U.S. Army Corps of Engineers National Inventory of Dams, record updated Aug 26, 2026. Search NID ID WA00084 at nid.sec.usace.army.mil. Project website.