River Flows & Lake Levels
River flows as of April 12
Get our latest parks and recreation COVID-19 updates at MyTPU.org/Parks.
Cowlitz River below Mayfield Dam – about 8,050 cubic feet per second (cfs)
Mayfield flow forecast (typically updated on Monday and Thursday afternoons) as of Monday, April 12: We plan to remain at this discharge through at least Wednesday. It’s possible that discharge may decrease to about 5,000 cfs by the end of the weekend.
Nisqually River below LaGrande Dam – 1,100 cfs
Wynoochee River above Black Creek – 558 cfs
Wynoochee River at Grisdale – 203 cfs
Green River at Palmer (Tacoma Water’s headworks) – 676 cfs
North Fork Skokomish River below Cushman Dam No. 2 – 254 cfs
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 as of April 12
Riffe Lake – 703.17 feet of elevation (maximum of approx. 749 ft) *Please see below for information about the current Riffe Lake elevation and boat launch availability.
Learn about changes to Riffe Lake levels.
Mossyrock Park boat launch is closed. The day-use area is open.
Taidnapam North boat launch is closed.
Kosmos boat launch and parking lot are closed.
Taidnapam Park boat launch and swim area are closed.
Mossyrock Park swim area is closed.
Alder Lake – 1,183.19 feet of elevation (maximum of 1,207 ft)
Alder Lake Park boat launch and day-use area are open.
Rocky Point boat launch, day-use area, and campground are closed.
Stacel Point day-use area is closed for construction April 1-3. The swim area is closed.
Sunny Beach Point is closed.
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. Campsites reopen April 15.
Lake Cushman – 726.53 feet of elevation (maximum of 738 ft)
The Lake Kokanee boat launch is open.
There is currently no public access to Lake Cushman.
Get information about Skokomish Park at Lake Cushman.
Wynoochee Lake – 779.37 feet of elevation (maximum of 800 ft)
The day-use area is open.
Coho Campground and boat launch are closed.
Get current campfire rules on the Parks & Recreation homepage.
*Riffe Lake boat launch availability as of April 8: We sincerely apologize for the inconvenience, but we are unable to provide an exact date at this time as to when the Riffe Lake boat launches will be available again. Our operations are based on balancing multiple factors, such as maintaining downstream flows for fish, energy grid reliability, power load demands, and recreation needs, all while ensuring public safety. The reservoir level is currently lower than normal for three reasons:
- Inflows into Riffe Lake in March were well below average due to a combination of drier weather and unseasonably cold temperatures. These trends have continued into April. The colder temperatures have led to snowpack levels of 140% of normal. This is much higher than what we typically experience at this time. In anticipation of the runoff in May/June, we plan to keep Riffe Lake at approximately 705 feet or lower throughout April.
- We have a construction project at the Barrier Dam at the Cowlitz Salmon Hatchery this summer. The work will require us to keep our water releases lower than usual for a portion of the construction project. We need to leave room in the reservoir to capture inflows from runoff and precipitation since the amount of water we can release will be limited during that time.
- In the interest of public safety, we are still operating at a long-term lower general level while we evaluate alternatives to address potential seismic impacts to Mossyrock Dam’s spillway piers.
If we see major changes in the weather during April, we may be able to refill the reservoir sooner, but at this point, it appears that the boat launches will likely not be available until we see the runoff in May.
Here are the usable elevation levels:
- Mossyrock Park boat launch: The short lane closes around 723 feet; the long lane around 708 feet. The dock is pulled out around 721 feet.
- Taidnapam North boat launch: Closes around 719 feet. The dock is pulled out around 731 feet.
The Mayfield Lake Park boat launch is not affected and remains open.
Again, we sincerely apologize for the inconvenience. We will update this page with any changes.