Stony Brook at Princeton, NJ
River level and flood forecast · Mercer County
The river is 6.5 ft below flood stage (9 ft).
Flow: 110 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 Sun, Dec 31, 7 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 Stony Brook at Princeton to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 14 ft |
| Moderate flood stage | 11 ft |
| Flood stage | 9 ft |
| Action stage | 8 ft |
| Record crest (August 28, 2011) | 16.23 ft |
What floods at each level
From the National Weather Service, highest first.
- 16 ftSignificant flooding occurs along the brook. Several feet of water cover the Hun athletic fields. Route 206 is closed. Flooding along the brook can worsen if the Delaware and Raritan Canal is also running high.
- 13 ftThe Hun School athletic fields flood. Flooding along the brook can worsen if the Delaware and Raritan Canal is also running high.
- 11 ftMercer Street, between Province Line Road and the Stony Brook Bridge, is subject to closure due to flooding.
- 9 ftQuaker Road floods and it subject to closure. Mercer Street begins to flood.
- 8 ftAdjacent floodplain begins to flood including the Stony Brook walking trail.
Highest crests on record
- 16.23 ft — August 28, 2011
- 14.26 ft — August 28, 1971
- 14.02 ft — September 16, 1999
- 12.48 ft — August 22, 2021
- 12.27 ft — January 19, 1996
Recent crests: 10.34 ft (January 10, 2024) · 10.7 ft (December 18, 2023) · 12.48 ft (August 22, 2021) · 10.36 ft (November 25, 2018) · 11.83 ft (May 27, 2018)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (PCTN4); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.