Tolt River - South Fork
Dam in King County, Washington · South Fork Tolt River · forms South Fork Tolt Reservoir
Height
200 ft
61 m (NID height)
Length
980 ft
299 m
Completed
1962
South Fork Tolt Reservoir today
1,720.79 ft
7 days ▼ 2.34 ft
Normal storage
57,500 acre-ft
Much below normal for the date
Reservoir level measured Oct 23, 2026, 11:00 AM PDT. Full level page →
Facts
- Purposes
- Water Supply; Hydroelectric
- Dam type
- Earth
- Owner
- City of Seattle (Local Government)
- Maximum storage
- 68,400 acre-ft
- Surface area
- 1,040 acres
- Hydraulic height
- 190 ft
- Drainage area
- 19 sq mi
- Spillway
- Uncontrolled
- Army Corps district
- Seattle District
- Also known as
- Tolt Main Dam
- NID ID
- WA00177
Facts from the U.S. Army Corps of Engineers National Inventory of Dams, record updated Aug 26, 2026. Search NID ID WA00177 at nid.sec.usace.army.mil. Project website.