Rivers in Washington

Tolt River near Carnation

King County, WashingtonNWS TOLW1USGS 12148500Seattle office

Below flood stage
0.10ftStage

Observed Mon, Sep 21, 8:15 AM PDT

Forecast crest
0.17 ftFri, Sep 25, 11:00 AM PDT
Record crest
13.04 ft1959

Open the live map with the river flood outlook

Flood stages and impacts

  1. 10500.0 ftthe Tolt River will cause severe flooding. Dangerously deep and quick flood waters will cover roads and driveways...with some homes flooded. The river will likely overtop some levees. Erosion could cause serious damage and channel changes may occur. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Tolt River Basin. This river level on the Tolt corresponds to a phase 4 flood in the King County flood system.
  2. 8500.0 ftthe Tolt River will cause major flooding. Deep and quick flood waters will cover roads and driveways...cutting off access to many homes. Levees may overtop and channel changes may occur. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Tolt River Basin. This river level on the Tolt corresponds to a phase 4 flood in the King County flood system.
  3. 5000.0 ftthe Tolt River will flood Tolt River Rd NE and many driveways. Some homes in the San Souci area could be inaccessible due to deep and quick flood waters. This river level on the Tolt corresponds to a phase 3 flood in the King County flood system.
  4. 3500.0 ftthe Tolt River will spill over its banks with water over 353rd Ave NE and some driveways in the San Souci area. This river level on the Tolt corresponds to a phase 2 flood in the King County flood system.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor flooding35%
Moderate flooding18%
Major flooding12%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 20, 2026.

Crest history

231 crests on NOAA’s list since 1937.

#DateStage
1December 15, 195913.04 ft
2February 9, 195112.92 ft
3January 8, 200912.59 ft
4December 11, 195512.52 ft
5January 7, 194512.14 ft
6October 31, 194211.95 ft
7November 24, 199011.62 ft
8March 4, 195011.54 ft
9April 18, 193811.51 ft
10January 5, 196911.34 ft
11February 1, 202011.30 ft
12November 19, 196211.30 ft
13November 12, 200811.29 ft
14December 15, 199911.28 ft
15December 2, 194311.24 ft
16November 29, 199511.19 ft
17January 23, 195311.19 ft
18January 5, 201511.16 ft
19December 9, 195311.15 ft
20October 20, 200311.11 ft
21November 6, 200610.95 ft
22October 25, 194610.94 ft
23February 8, 195510.93 ft
24November 20, 195910.92 ft
25February 8, 199610.89 ft

Most recent crests

  • December 10, 2025: 10.16 ft
  • November 4, 2022: 9.41 ft
  • January 12, 2022: 9.89 ft
  • February 22, 2021: 9.19 ft
  • January 12, 2021: 8.87 ft
  • February 6, 2020: 9.71 ft
  • February 1, 2020: 11.30 ft
  • January 31, 2020: 9.97 ft
  • January 7, 2020: 9.38 ft
  • December 20, 2019: 9.62 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.