Current Stage
4.31 ft
Flood: 18.0 ft • Major: 23.0 ft
Current Flow
1.31 kcfs
6-Hour Trend
Steady
0.06 ft in 6h
Last Observed
1 hour, 29 minutes ago
Aug 18, 3:30 PM
Hydrograph
The solid line shows recent observed water levels, and the dotted line shows the forecast. Colored horizontal bands mark flood thresholds. Auto-refreshes every 5 min.
Historical Record
Same hydrograph with colored shading behind it showing historical flood categories. This puts the current river level in context with past flood events at this gauge.
Flood Thresholds
Forecast
Forecast Peak
4.35 ft
Expected
Aug 18, 7:00 PM
Category
No_Flooding10-Day River Level Probabilities
Instead of a single forecast line, this chart shows a range of possible river levels over the next 10 days. The shaded bands represent different likelihoods — darker shading means more likely outcomes, lighter shading means less likely but still possible. Colored horizontal lines mark flood thresholds. This helps you see not just what's expected, but how confident the forecast is.
Weekly Chance of Exceeding Levels
Each colored bar represents one week over a 90-day period. The colors show the probability that the river's peak level will exceed a given height during that week — warmer colors mean a higher chance. Read up the vertical axis to find a water level you care about, then check the bar color to see how likely the river is to reach it. This is useful for spotting which weeks carry the most flood risk.
Learn more about this chart →Stage
Flow
Volume
90-Day Chance of Exceeding Levels
These charts compare the current flood outlook to historical averages over the next 90 days. Two lines are shown: a current forecast line and a historical average line. When the current forecast line is above the historical line, the river is more likely than normal to reach higher levels. When it's below, conditions are expected to be calmer than usual. The horizontal axis shows water levels, and the vertical axis shows the percent chance of exceeding them.
Learn more about this chart →Stage
Flow
Volume
Flood Impacts by Stage
23 ft
the Nooksack River will cause major near record flooding from near Ferndale downstream to the mouth, overtopping levees on both sides of the river and flooding roadways on the Lummi Peninsula including Hexton Way. Deep and swift flood waters will inundate residential areas...farm lands...and roads. In addition...flood waters could overflow and flood the Sumas drainage. Flooding will occur all along the river including headwaters...tributaries...and other streams within and near the Nooksack River Basin.
22 ft
the Nooksack River will overflow levees and banks along the east bank of the river from Hovander Park downstream to Marietta, causing widespread flooding from near Ferndale downstream to the mouth...with swift waters in residential areas and over farmlands and roads. Erosion may damage some river banks. Flooding within the City of Ferndale affects Main Street in the vicinity of the Whatcom Transportation Authority Station.
20.5 ft
the Nooksack River will overflow levees and banks along the east bank of the river from Hovander Park downstream to Marietta, causing widespread flooding from near Ferndale downstream to the mouth...with swift waters in residential areas and over farm lands and roads. Erosion may damage some river banks.
20 ft
the river will flood additional areas within the City of Ferndale including low-lying residential areas and roads including Washington Street, Portal Way and Second Avenue.
18 ft
the river begins overtopping its banks within the City of Ferndale flooding low-lying areas within the City and low pasture lands along the river from near Ferndale downstream to the mouth.
17 ft
the Nooksack River will overtop levees along Bertrand Creek and near Marine Drive, causing shallow flooding of low pasture lands along the river and additional roadways within the floodplain including Slater Road.
16 ft
the river begins spilling over its banks into low pasture lands flooding some roadways that are not protected by levees including Marine Drive and Ferndale Road.
Recent Crests
A crest is the highest water level reached during a flood event. These are the most recent recorded peaks at this gauge — useful for comparing current conditions to past floods you may remember.
| Date | Stage (ft) |
|---|---|
|
Dec 11, 2025 8 months ago |
22.39 |
|
Jan 29, 2024 2 years, 6 months ago |
18.52 |
|
Dec 1, 2021 4 years, 8 months ago |
18.16 |
|
Nov 29, 2021 4 years, 8 months ago |
21.22 |
|
Nov 16, 2021 4 years, 9 months ago |
23.81 |