Millstone River at Blackwells Mills, NJ
River level and flood forecast · Somerset County
The river is 3.2 ft below flood stage (9 ft).
Forecast to fall to 2.3 ft by Thu, Oct 15, 2 PM.
Flow: 1,830 cubic feet per second (USGS).
River camera
Watch the time-lapse
Camera by the U.S. Geological Survey. Most take a picture every hour, some every few minutes; many stop at night.
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 3:03 PM. Forecasts change as rain falls and as upstream water arrives.
Get flood alerts for this river
An email when the National Weather Service forecasts Millstone River at Blackwells Mills to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 15 ft |
| Moderate flood stage | 10 ft |
| Flood stage | 9 ft |
| Action stage | 7 ft |
| Record crest (August 28, 2011) | 21.24 ft |
What floods at each level
From the National Weather Service, highest first.
- 13 ftWashington Street and several businesses are flooded.
- 10 ftThe D&R Canal is flooded by the Millstone River.
- 9 ftFlood stage reached with flooding now along River Road in Blackwells Mills and S. River Street in Millstone. Base of Route 533 bridge floods. River Road between Yorktown and Amsterdam is subject to closure. Canal Road near Suydam Road floods.
- 7 ftSeveral more causeways are closed due to flooding.
- 6 ftThe Griggstown Causeway is closed due to flooding.
Highest crests on record
- 21.24 ft — August 28, 2011
- 21.01 ft — September 17, 1999
- 20.81 ft — September 2, 2021
- 19.24 ft — April 16, 2007
- 18.68 ft — August 28, 1971
Recent crests: 13.29 ft (January 10, 2024) · 10.03 ft (December 29, 2023) · 14.22 ft (December 19, 2023) · 10.84 ft (April 8, 2022) · 20.81 ft (September 2, 2021)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (BKWN4); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.