O'sullivan Dam
Dam in Grant County, Washington · Lower Crab Creek · forms Potholes Reservoir
Height
200 ft
61 m (NID height)
Length
19,000 ft
5,791 m
Completed
1949
Potholes Reservoir today
1,033.13 ft
7 days ▲ 1.68 ft
Normal storage
511,700 acre-ft
Reservoir level measured Oct 21, 2026, 12:00 AM PDT. Full level page →
Facts
- Purposes
- Flood Risk Reduction; Irrigation; Navigation; Hydroelectric
- Dam type
- Earth
- Structural height
- 200 ft
- Owner
- BUREAU OF RECLAMATION (Federal)
- Maximum storage
- 546,300 acre-ft
- Surface area
- 27,800 acres
- Hydraulic height
- 153 ft
- Drainage area
- 79,162 sq mi
- Spillway
- Controlled, 96 ft wide
- Army Corps district
- Seattle District
- Also known as
- Potholes Reservoir
- NID ID
- WA00268
Facts from the U.S. Army Corps of Engineers National Inventory of Dams, record updated Oct 22, 2025. Search NID ID WA00268 at nid.sec.usace.army.mil. Project website.