Skip Navigation Link weather.gov  
NOAA logo - Click to go to the NOAA homepage National Weather Service NWS logo - Click to go to the NWS homepage
Advanced Hydrologic Prediction Service
Image background of Navigation bar Left Home News Organization
Bookmark and Share Navigation Bar End Cap

  

National Conditions
    Rivers
    Satellite
    Climate
    Observed Precip

Local Conditions
    Warnings
    Weather Forecast
    Radar

AHPS Documentation
    User Guide
    User Brochure

What is AHPS?
    Facts
    Our Partners

Feedback/Questions
    Provide Feedback
    Ask Questions

When flooded turn around don't drown
FloodSmart
USA.gov Official Web Portal
 



Hydrograph River at a Glance Download Inundation
Mapping
Millstone River at Blackwells Mills Stage (ft)Flow (kcfs)Highest Observation: 2.7 ft at 7:30PM May 15, 2022Highest Observation: 2.7 ft at 7:45PM May 15, 2022Observed: 2.68 ft at 8:00PM May 15, 2022Observed: 2.67 ft at 8:15PM May 15, 2022Observed: 2.67 ft at 8:30PM May 15, 2022Observed: 2.67 ft at 8:45PM May 15, 2022Observed: 2.67 ft at 9:00PM May 15, 2022Observed: 2.65 ft at 9:15PM May 15, 2022Observed: 2.65 ft at 9:30PM May 15, 2022Observed: 2.65 ft at 9:45PM May 15, 2022Observed: 2.65 ft at 10:00PM May 15, 2022Observed: 2.64 ft at 10:15PM May 15, 2022Observed: 2.64 ft at 10:30PM May 15, 2022Observed: 2.62 ft at 10:45PM May 15, 2022Observed: 2.62 ft at 11:00PM May 15, 2022Observed: 2.62 ft at 11:15PM May 15, 2022Observed: 2.62 ft at 11:30PM May 15, 2022Observed: 2.62 ft at 11:45PM May 15, 2022Observed: 2.6 ft at 12:00AM May 16, 2022Observed: 2.6 ft at 12:15AM May 16, 2022Observed: 2.6 ft at 12:30AM May 16, 2022Observed: 2.6 ft at 12:45AM May 16, 2022Observed: 2.6 ft at 1:00AM May 16, 2022Observed: 2.6 ft at 1:15AM May 16, 2022Observed: 2.59 ft at 1:30AM May 16, 2022Observed: 2.59 ft at 1:45AM May 16, 2022Observed: 2.58 ft at 2:00AM May 16, 2022Observed: 2.58 ft at 2:15AM May 16, 2022Observed: 2.58 ft at 2:30AM May 16, 2022Observed: 2.57 ft at 2:45AM May 16, 2022Observed: 2.57 ft at 3:00AM May 16, 2022Observed: 2.56 ft at 3:15AM May 16, 2022Observed: 2.56 ft at 3:30AM May 16, 2022Observed: 2.56 ft at 3:45AM May 16, 2022Observed: 2.56 ft at 4:00AM May 16, 2022Observed: 2.56 ft at 4:15AM May 16, 2022Observed: 2.55 ft at 4:30AM May 16, 2022Observed: 2.55 ft at 4:45AM May 16, 2022Observed: 2.54 ft at 5:00AM May 16, 2022Observed: 2.54 ft at 5:15AM May 16, 2022Observed: 2.54 ft at 5:30AM May 16, 2022Observed: 2.54 ft at 5:45AM May 16, 2022Observed: 2.53 ft at 6:00AM May 16, 2022Observed: 2.53 ft at 6:15AM May 16, 2022Observed: 2.52 ft at 6:30AM May 16, 2022Observed: 2.52 ft at 6:45AM May 16, 2022Observed: 2.52 ft at 7:00AM May 16, 2022Observed: 2.52 ft at 7:15AM May 16, 2022Observed: 2.51 ft at 7:30AM May 16, 2022Observed: 2.51 ft at 7:45AM May 16, 2022Observed: 2.51 ft at 8:00AM May 16, 2022Observed: 2.5 ft at 8:15AM May 16, 2022Observed: 2.5 ft at 8:30AM May 16, 2022Observed: 2.5 ft at 8:45AM May 16, 2022Observed: 2.5 ft at 9:00AM May 16, 2022Observed: 2.49 ft at 9:15AM May 16, 2022Observed: 2.48 ft at 9:45AM May 16, 2022Observed: 2.48 ft at 10:00AM May 16, 2022Observed: 2.46 ft at 10:15AM May 16, 2022Observed: 2.46 ft at 10:30AM May 16, 2022Observed: 2.46 ft at 10:45AM May 16, 2022Observed: 2.46 ft at 11:00AM May 16, 2022Observed: 2.46 ft at 11:15AM May 16, 2022Observed: 2.46 ft at 11:30AM May 16, 2022Observed: 2.46 ft at 11:45AM May 16, 2022Observed: 2.46 ft at 12:00PM May 16, 2022Observed: 2.46 ft at 12:15PM May 16, 2022Observed: 2.46 ft at 12:30PM May 16, 2022Observed: 2.46 ft at 12:45PM May 16, 2022Observed: 2.46 ft at 1:00PM May 16, 2022Observed: 2.44 ft at 1:15PM May 16, 2022Observed: 2.44 ft at 1:30PM May 16, 2022Observed: 2.43 ft at 1:45PM May 16, 2022Observed: 2.43 ft at 2:00PM May 16, 2022Observed: 2.43 ft at 2:15PM May 16, 2022Observed: 2.43 ft at 2:30PM May 16, 2022Observed: 2.43 ft at 2:45PM May 16, 2022Observed: 2.43 ft at 3:00PM May 16, 2022Observed: 2.43 ft at 3:15PM May 16, 2022Observed: 2.43 ft at 3:30PM May 16, 2022Observed: 2.43 ft at 3:45PM May 16, 2022Observed: 2.43 ft at 4:00PM May 16, 2022Observed: 2.43 ft at 4:15PM May 16, 2022Observed: 2.43 ft at 4:30PM May 16, 2022Observed: 2.43 ft at 4:45PM May 16, 2022Observed: 2.43 ft at 5:00PM May 16, 2022Observed: 2.43 ft at 5:15PM May 16, 2022Observed: 2.43 ft at 5:30PM May 16, 2022Observed: 2.43 ft at 5:45PM May 16, 2022Observed: 2.43 ft at 6:00PM May 16, 2022Observed: 2.43 ft at 6:15PM May 16, 2022Observed: 2.43 ft at 6:30PM May 16, 2022Observed: 2.43 ft at 6:45PM May 16, 2022Observed: 2.43 ft at 7:00PM May 16, 2022Observed: 2.43 ft at 7:15PM May 16, 2022Observed: 2.43 ft at 7:30PM May 16, 2022Observed: 2.43 ft at 7:45PM May 16, 2022Observed: 2.43 ft at 8:00PM May 16, 2022Observed: 2.43 ft at 8:15PM May 16, 2022Observed: 2.43 ft at 8:30PM May 16, 2022Observed: 2.43 ft at 8:45PM May 16, 2022Observed: 2.43 ft at 9:00PM May 16, 2022Observed: 2.43 ft at 9:15PM May 16, 2022Observed: 2.44 ft at 9:30PM May 16, 2022Observed: 2.44 ft at 9:45PM May 16, 2022Observed: 2.44 ft at 10:00PM May 16, 2022Observed: 2.44 ft at 10:15PM May 16, 2022Observed: 2.44 ft at 10:30PM May 16, 2022Observed: 2.44 ft at 10:45PM May 16, 2022Observed: 2.45 ft at 11:00PM May 16, 2022Observed: 2.45 ft at 11:15PM May 16, 2022Observed: 2.45 ft at 11:30PM May 16, 2022Observed: 2.45 ft at 11:45PM May 16, 2022Observed: 2.47 ft at 12:00AM May 17, 2022Observed: 2.47 ft at 12:15AM May 17, 2022Observed: 2.47 ft at 12:30AM May 17, 2022Observed: 2.47 ft at 12:45AM May 17, 2022Observed: 2.48 ft at 1:00AM May 17, 2022Observed: 2.48 ft at 1:15AM May 17, 2022Observed: 2.49 ft at 1:30AM May 17, 2022Observed: 2.5 ft at 1:45AM May 17, 2022Observed: 2.5 ft at 2:00AM May 17, 2022Observed: 2.51 ft at 2:15AM May 17, 2022Observed: 2.52 ft at 2:30AM May 17, 2022Observed: 2.52 ft at 2:45AM May 17, 2022Observed: 2.53 ft at 3:00AM May 17, 2022Observed: 2.54 ft at 3:15AM May 17, 2022Observed: 2.54 ft at 3:30AM May 17, 2022Observed: 2.54 ft at 3:45AM May 17, 2022Observed: 2.54 ft at 4:00AM May 17, 2022Observed: 2.55 ft at 4:15AM May 17, 2022Observed: 2.55 ft at 4:30AM May 17, 2022Observed: 2.55 ft at 4:45AM May 17, 2022Observed: 2.55 ft at 5:00AM May 17, 2022Observed: 2.55 ft at 5:15AM May 17, 2022Observed: 2.55 ft at 5:30AM May 17, 2022Observed: 2.55 ft at 5:45AM May 17, 2022Observed: 2.55 ft at 6:00AM May 17, 2022Observed: 2.55 ft at 6:15AM May 17, 2022Observed: 2.55 ft at 6:30AM May 17, 2022Observed: 2.55 ft at 6:45AM May 17, 2022Observed: 2.55 ft at 7:00AM May 17, 2022Observed: 2.54 ft at 7:15AM May 17, 2022Observed: 2.54 ft at 7:30AM May 17, 2022Observed: 2.54 ft at 7:45AM May 17, 2022Observed: 2.54 ft at 8:00AM May 17, 2022Observed: 2.54 ft at 8:15AM May 17, 2022Observed: 2.52 ft at 8:30AM May 17, 2022Observed: 2.52 ft at 8:45AM May 17, 2022Observed: 2.52 ft at 9:00AM May 17, 2022Observed: 2.52 ft at 9:15AM May 17, 2022Observed: 2.52 ft at 9:30AM May 17, 2022Observed: 2.5 ft at 9:45AM May 17, 2022Observed: 2.5 ft at 10:00AM May 17, 2022Observed: 2.5 ft at 10:15AM May 17, 2022Observed: 2.5 ft at 10:30AM May 17, 2022Observed: 2.5 ft at 10:45AM May 17, 2022Observed: 2.5 ft at 11:00AM May 17, 2022Observed: 2.5 ft at 11:15AM May 17, 2022Forecast: 2.1 ft 8:00PM May 18, 2022Forecast: 2.1 ft 2:00AM May 19, 2022Forecast: 2.2 ft 8:00AM May 19, 2022Forecast: 2.4 ft 2:00PM May 19, 2022Highest Forecast: 2.5 ft 8:00PM May 19, 2022Highest Forecast: 2.5 ft 2:00AM May 20, 2022Highest Forecast: 2.5 ft 8:00AM May 20, 2022Highest Forecast: 2.5 ft 2:00PM May 20, 2022Forecast: 2.4 ft 8:00PM May 20, 2022Forecast: 2.3 ft 2:00AM May 21, 2022Forecast: 2.2 ft 8:00AM May 21, 2022USGS--Water Resources of the United StatesBKWN4(plotting HGIR2) Graph Created (7:18PM May 18, 2022)ObservedForecast (issued 9:28AM May 18)Latest observed value: 2.5 ft at 11:15 AM EDT 17-May-2022. Flood Stage is 9 ft
Printable Image
About this graph
Tabular Data (UTC)
Tabular Data (EDT)
XML Data
RSS Files
Datum: NGVD29
Metadata
NOTE: Forecasts for the Millstone River at Blackwells Mills are issued routinely year-round.
Return to Area Map
Upstream Gauge - at Griggstown Upstream Gauge Downstream Gauge Downstream Gauge - at Weston
Flood Categories (in feet)
Major Flood Stage: 15
Moderate Flood Stage: 10
Flood Stage: 9
Action Stage: 7
Low Stage (in feet): 0

Historic Crests
(1) 21.24 ft on 08/28/2011
(2) 21.01 ft on 09/17/1999
(3) 20.81 ft on 09/02/2021
(4) 19.24 ft on 04/16/2007
(5) 18.68 ft on 08/28/1971
Show More Historic Crests

(P): Preliminary values subject to further review.

Recent Crests
(1) 10.84 ft on 04/08/2022
(2) 20.81 ft on 09/02/2021
(3) 14.30 ft on 08/23/2021
(4) 9.50 ft on 12/26/2020
(5) 9.44 ft on 12/01/2020
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
(1) 1.15 ft on 09/16/1923

For more information on your flood risk go to www.floodsmart.gov.
Zoom Level:16
KML Image
Gauge LocationGauge Map Marker
 Disclaimer
Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.
Flood Impacts & Photos Collapse
If you notice any errors in the below information, please contact our Webmaster
13 Washington Street and several businesses are flooded.
10 The D&R Canal is flooded by the Millstone River.
9 Flood 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 Several more causeways are closed due to flooding.
6 The Griggstown Causeway is closed due to flooding.
About This Location Collapse

Latitude: 40.475000° N, Longitude: 74.575833° W, Horizontal Datum: NAD83/WGS84

River Stage
Reference Frame		 Gauge Height Flood Stage Uses
NWS stage 0 ft 9 ft Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps
Vertical Datum Elevation
(gauge height = 0)		 Elevation
(gauge height = flood stage)		 Elevation information source
NAVD88 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps
NGVD 29 26.97 ft 35.97 ft Older USGS topographic maps, NGVD29 benchmarks
MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks
Other Not Available Not Available  

Current/Historical Observations:
Additional Information Collapse
Potential River Levels - Used to
Potential River Levels
Used to Estimate the Chance of Flooding and the Range of Possible River Levels
10 Day (HEFS) 7 Day (NAEFS) 7 Day (GEFS)
HEFS Ensemble NAEFS Ensemble GEFS Ensemble

Note: Use the official hydrograph at the top of this web page for river levels within the next 72 hours.

Click individual graphics to enlarge.

During winter months, cold and ice may result in inaccurate real-time stream stage and streamflow data. Adjustments or deletions of this data can only be done after detailed analysis.
Resources Collapse
Hydrologic Resources Additional Resources
Collaborative Agencies Collapse
The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.
NWS Information
National Weather Service
Philadelphia/Mount Holly Weather Forecast Office
732 Woodlane Road
Mount Holly, NJ 08060-9615
(609) 261-6600
Ask Questions/Webmaster
Page last modified: 2-Nov-2020 7:30 PM 		Disclaimer
Credits
Glossary 		Privacy Policy
About Us
Career Opportunities