Chehalis River at Porter, WA
River level and flood forecast · Grays Harbor County
The river is 17.4 ft below flood stage (48 ft).
Forecast to hold near 30.6 ft through Mon, Oct 19, 5 PM.
Flow: 364 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 8:27 AM. Forecasts change as rain falls and as upstream water arrives.
Get flood alerts for this river
An email when the National Weather Service forecasts Chehalis River at Porter to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 52 ft |
| Moderate flood stage | 50 ft |
| Flood stage | 48 ft |
| Action stage | 45.5 ft |
| Record crest (December 5, 2007) | 53.17 ft |
What floods at each level
From the National Weather Service, highest first.
- 52 ftthe Chehalis River in Grays Harbor will cause major near record flooding from Oakville downstream to Grays Harbor. Deep and swift flood waters will inundate numerous farms and roads...including SR 12. High tidal levels at Aberdeen will worsen flooding along the lower reaches. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Chehalis River Basin.
- 50 ftfeet...the Chehalis River in Grays Harbor will flood numerous farms and roads including SR 12. High tidal levels at Aberdeen will worsen flooding along the lower reaches.
- 49 ftthe Chehalis River in Grays Harbor will flood pasture lands and many roads...including SR 12 between Oakville and Rochester. High tidal levels at Aberdeen will worsen flooding along the lower reaches.
- 48 ftthe Chehalis River in Grays Harbor will flood low pasture lands and some roads. High tidal levels at Aberdeen will worsen flooding along the lower reaches.
- 46 ftthe Chehalis River in Grays Harbor County will locally spill over its banks with shallow water on several roads.
Highest crests on record
- 53.17 ft — December 5, 2007
- 52.01 ft — January 8, 2022
- 49.64 ft — December 12, 2025
- 49.18 ft — January 15, 2021
- 48.99 ft — January 9, 2020
Recent crests: 48.14 ft (December 21, 2025) · 49.64 ft (December 12, 2025) · 48.54 ft (December 8, 2023) · 48.79 ft (March 3, 2022) · 48.36 ft (January 13, 2022)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (CRPW1); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.