Rivers in Washington

Chehalis River near Grand Mound

Thurston County, WashingtonNWS CGMW1USGS 12027500Seattle office

Below flood stage
128.82ftStage

Observed Mon, Sep 21, 11:00 PM PDT

Flood stage
141.00 ft
Forecast crest
128.87 ftFri, Sep 25, 5:00 PM PDT
Record crest
147.26 ft2007

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood144.00 ft
Moderate flood142.50 ft
Minor flood141.00 ft
Action138.50 ft
  1. 146.00 ftthe Chehalis River in Thurston County will cause severe near record flooding, with deep and swift flood waters inundating the Independence Valley. Flooding will occur all along the river including headwaters, tributaries, and other streams within and near the Chehalis River Basin.
  2. 144.50 ftthe Chehalis River in Thurston County will cause major flooding, inundating roads and farm lands in Independence Valley. Deep and swift flood waters will cover SR-12 and James, Independence and Moon Roads. Flooding will occur all along the river including headwaters, tributaries, and other streams within and near the Chehalis River Basin.
  3. 142.50 ftthe Chehalis River in Thurston County will flood several roads in Independence Valley with swiftly moving water including SR-12 and James, Independence, Moon and Anderson Roads. Flood waters will cut off access to and from Chehalis Reservation and inundate nearby farm lands. Some residential structures may be threatened.
  4. 141.00 ftthe Chehalis River in Thurston County will flood several roads in Independence Valley including James Road, Independence Road, and Moon road. Flood waters will also cover nearby farm lands.
  5. 139.50 ftthe Chehalis River in Thurston County will locally spill out of its banks into nearby fields and over a few roads.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor flooding18%
Moderate flooding13%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 21, 2026.

Crest history

180 crests on NOAA’s list since 1931.

#DateStage
1December 4, 2007147.26 ft
2January 7, 2022145.21 ft
3December 11, 2025143.27 ft
4January 14, 2021142.88 ft
5December 22, 2019142.68 ft
6March 2, 2022142.59 ft
7January 4, 2021142.59 ft
8January 8, 2020142.41 ft
9December 7, 2023142.28 ft
10November 13, 2021141.41 ft
11January 28, 2024140.85 ft
12December 4, 200720.23 ft
13February 9, 199619.98 ft
14January 10, 199019.34 ft
15November 25, 198618.41 ft
16December 29, 193718.39 ft
17January 21, 197218.21 ft
18January 8, 200918.18 ft
19November 25, 199018.12 ft
20December 5, 197517.73 ft
21April 6, 199117.66 ft
22February 11, 199017.46 ft
23January 26, 197117.29 ft
24December 30, 199617.29 ft
25January 23, 193517.08 ft

Most recent crests

  • December 11, 2025: 143.27 ft
  • January 28, 2024: 140.85 ft
  • December 7, 2023: 142.28 ft
  • March 2, 2022: 142.59 ft
  • January 7, 2022: 145.21 ft
  • November 13, 2021: 141.41 ft
  • January 14, 2021: 142.88 ft
  • January 4, 2021: 142.59 ft
  • January 8, 2020: 142.41 ft
  • December 22, 2019: 142.68 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Northwest River Forecast Center. Forecasts are issued routinely year-round. River forecasts for this location take into account past and future precipitation. The stages/flows that will occur may be different if future rainfall is different than forecast.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.