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WashingtonReservoir, 1,011 acres, King County

South Fork Tolt Reservoir water level

Shoreline: USGS National Hydrography Dataset

Current level

1,719.63ft NGVD29

Reading from Oct 26, 2026

Well below normal for October

Past 24 hours
-0.45ft
Past 7 days
-2.37ft
Past 30 days
-8.66ft
vs typical October
-18.52ft

South Fork Tolt Reservoir was at 1,719.63 ft on October 26, falling 2.37 ft over the past week. That is well below normal for October: the typical October level is 1,738.15 ft, so the lake is 18.52 ft below its usual mark.

Last 30 days

172017301740typicalSep 24Oct 9Oct 24

Shaded band shows the lowest and highest October monthly averages on record. Dashed line is the typical October level.

Typical level through the year

Each bar spans the range of monthly averages on record for that month. The line marks the median. The orange dot is where the lake sits now.

172017401760JFMAMJJASOND

Recent daily readings

South Fork Tolt Reservoir daily mean water level, newest first
DateLevel (ft NGVD29)Change
Oct 24, 20261,720.08-0.40
Oct 23, 20261,720.48-0.41
Oct 22, 20261,720.89-0.31
Oct 21, 20261,721.20-0.39
Oct 20, 20261,721.59-0.41
Oct 19, 20261,722.00-0.42
Oct 18, 20261,722.42-0.26
Oct 17, 20261,722.68-0.33
Oct 16, 20261,723.01-0.28
Oct 15, 20261,723.29-0.46
Oct 14, 20261,723.75-0.25
Oct 13, 20261,724.00-0.37
Oct 12, 20261,724.37-0.38
Oct 11, 20261,724.75-0.19

Reading these numbers

Readings are elevations in feet above the National Geodetic Vertical Datum of 1929 (NGVD29), the reference most older dam and lake charts use. If you compare with a newer chart in NAVD88, expect a difference of a few feet. Our glossary explains NGVD29 vs NAVD88.

On a reservoir, a few feet of drop changes the shoreline more than you would think. Low water exposes stumps, sandbars and old roadbeds that are normally well under the hull, and some ramps end before the water does.

High water brings its own problems: floating debris after storms, flooded docks and courtesy piers, and no-wake rules near flooded campgrounds. A quick look at the trend before you hitch up saves a wasted trip.

The gauge is listed by USGS as South Fork Tolt Reservoir near Carnation, WA. Wind can pile water up at one end of a big lake for a few hours, so short spikes on a windy day are normal.

South Fork Tolt Reservoir water level questions

What is the water level at South Fork Tolt Reservoir today?

South Fork Tolt Reservoir was at 1,719.63 ft on October 26, falling 2.37 ft over the past week. That is well below normal for October: the typical October level is 1,738.15 ft, so the lake is 18.52 ft below its usual mark.

Is South Fork Tolt Reservoir high or low right now?

Compared with the long-term record for October, the lake is well below normal. The October monthly average has ranged from 1,714.51 to 1,755.51 ft, with a typical value of 1,738.15 ft.

Is South Fork Tolt Reservoir rising or falling?

Over the last seven days the level has fallen (-2.37 ft), and it is -8.66 ft compared with 30 days ago.

Where does the South Fork Tolt Reservoir water level data come from?

From the U.S. Geological Survey, gauge 12147900 (South Fork Tolt Reservoir near Carnation, WA). USGS publishes provisional readings every 15 to 60 minutes; they can be revised later after quality checks.

How often is this page updated?

The page itself is rebuilt every day with the latest daily values, and the current reading refreshes straight from the USGS each time you open it.

Nearby lakes

If South Fork Tolt is blown out, these are the closest alternatives. Tap through for their water levels.