River Flows and Lake Levels
River flows and lake levels can fluctuate throughout the year due to weather, precipitation, power demand, operational needs, measures to support fish and river health, and other changing conditions.
Actual lake levels may vary from forecasts or expected operating ranges. Use the information below to view current and recent water conditions at Tacoma Power’s hydroelectric projects, and check lake levels and boat launch conditions before your visit.
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For real-time flow information:
- Select the link below for each river.
- Select data to graph.
- Select “Discharge, cubic feet per second.
Cowlitz River Project
Cowlitz River
Weekly Mayfield flow forecast (subject to change):Current discharge on Monday, October 5 is 3,660 cfs. Discharge is planned to remain at the current level through the week.
Cushman Hydro Project
Nisqually River below LaGrande Dam
Wynoochee River above Black Creek
Wynoochee River at Grisdale
Green River at Palmer (Tacoma Water’s headworks)
North Fork Skokomish River below Cushman Dam No. 2
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For real-time lake level information:
- Select the link below.
- Find the corresponding lake name in the “description” column.
- View the “stage” column.
Riffe Lake (Mossyrock Reservoir)
(maximum of approx. 749 ft)
- Mossyrock Park boat launch – Both boat launches are closed (updated Oct. 8). The dock has been removed due to low water levels. The day-use area is open; the swim beach is closed. Watch the live stream here.
- The North Shore Fishing Area at Mossyrock Dam is open (updated Saturday, Dec. 23).
- Taidnapam North boat launch – The dock is no longer in the water, and both launches are closed (updated October 1, 2026)
- Kosmos boat launch and parking lot are closed.
- Taidnapam Park boat launch is closed.
Alder Lake (Nisqually – Alder Reservoir)
(maximum of 1,207 ft)
- Alder Lake Park boat launch – Open. (The launch is open whenever lake levels are at or above elevation 1171 ft. It will close if water drops below that elevation.)
- Rocky Point boat launch – Closed. Hand-launch only; day-use area and campground are open.
- Stacel Point day-use area is open.
- Sunny Beach Point is open. (Open May 15 to Sept. 15. Closed Sept. 16 to May 14.)
Mayfield Lake
(Our FERC license operating range is 415–425 feet. Our current operations are expected to be in the range of 419-425.)
- Mayfield Lake Park boat launch and day-use area are open.
Lake Cushman (Cushman Dam)
(maximum of 738 ft)
- Lake Kokanee boat launch – Open.
- Get information about Skokomish Park at Lake Cushman.
Wynoochee Lake (Wynoochee Dam)
(maximum of 800 ft)
- The day-use area is open.
- Coho Campground and boat launch – Open (seasonal from mid-May to October). Update as of Aug. 27, 2025: The Coho Campground boat launch is closed to trailered boats until further notice. Hand-launch access remains available for kayaks, canoes, and other small car-top boats.
