River Flows & Lake Levels

River flows

For real-time flow information:

1. Select the link below for each river.
2. Scroll down to “Select data to graph.”
3. Select “Discharge, cubic feet per second.”

Cowlitz River 
Mayfield flow forecast (typically updated on Monday and Thursday afternoons):
As of Dec. 9: this update has been temporarily paused.

•  Click here to sign up for our Cowlitz River Project email list.
  

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

• Click here to sign up for our Cushman Hydro Project email list.

Related resources

• Check out water safety resources. River flows can change at any time.
• Subscribe to available Water Alerts provided by the US Geological Survey.

Lake levels and boat launches

For real-time lake level information:

1. Select the link below.
2. Find the corresponding lake name in the “description” column.
3. View the “stage” column.

Riffe Lake (Mossyrock Reservoir) (maximum of approx. 749 ft)

• Mossyrock Park boat launch – Both the left and right launches are closed as of Dec. 9, 2025. The dock is removed and will not be usable for the remainder of the season. The day-use area remains open, and the swim beach is closed.
• The North Shore Fishing Area at Mossyrock Dam is closed (updated Saturday, Nov. 15).
• Taidnapam North boat launch – The north launch is closed (updated Dec. 9, 2025).
• Kosmos boat launch and parking lot are closed due to operational constraints. The launch is not usable below 747 feet and cannot be extended.
• Taidnapam Park boat launch is closed due to operational constraints. It is not usable below 760 feet and cannot be extended.
• Click here to sign up for our Cowlitz River Project email list.

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 – may fluctuate 4 feet weekly, between 421 and 425 feet of elevation (maximum of 425 ft)

• 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.
• Click here to sign up for our Cushman Hydro Project email list.

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.

Get current campfire rules on the Parks & Recreation homepage.

River flows could change at any time so boaters and anglers should remain alert for this possibility.