Millstone River at Blackwells Mills
Air Quality Alert
Future / Actual / Minor
OWP 2.0 WWA Modal Title
01/11/2021, 10:04 PM UTC through 01/11/2021, 10:04 PM UTC
Sender
Sent
- Warning: no valid ratings curve available. Transformations to and from FEET/CFS/KCFS will not happen.
Traces and Thresholds Click to turn on/off display
Observed (OBS) 06/13/2025 7:15 PM EDTOfficial Forecast (FCST) 06/13/2025 9:34 AM EDTRecord: 21.2 ftLow Threshold: 0 ftCATEGORY STAGE 
Major Flooding 15 ft Moderate Flooding 10 ft Minor Flooding 9 ft Action 7 ft Reliability of the Forecast:
NOTE: Forecasts are issued routinely year-round.
National Water Model Hydrograph
Official NWS streamflow forecasts are produced by NWS hydrologic forecasters for river gauge locations using hydrologic models which are calibrated to that location. This process considers additional guidance and information, including local expertise and experience, to produce the best forecast possible. The NWM output provides supplemental guidance to NWS forecasters and should not be considered an official NWS river forecast.
Flood Impacts
- 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.
Gauge Info
| Coordinates | 40.4750, -74.5758 |
| RFC | MARFC |
| State | NJ |
| WFO | PHI |
| County | Somerset |
| Data Provider(s) | |
| US Geological Survey | USGS--Water Resources of the United States |
| USGS | 01402000 |
Gauge Location
Recent Crests
| 1. | 13.29 ft | on 01-10-2024 |
| 2. | 10.03 ft | on 12-29-2023 |
| 3. | 14.22 ft | on 12-19-2023 |
| 4. | 10.84 ft | on 04-08-2022 |
| 5. | 20.81 ft | on 09-02-2021 |
Recent Crests
| 1. | 13.29 ft | on 01-10-2024 |
| 2. | 10.03 ft | on 12-29-2023 |
| 3. | 14.22 ft | on 12-19-2023 |
| 4. | 10.84 ft | on 04-08-2022 |
| 5. | 20.81 ft | on 09-02-2021 |
| 6. | 14.30 ft | on 08-23-2021 |
| 7. | 9.50 ft | on 12-26-2020 |
| 8. | 9.44 ft | on 12-01-2020 |
| 9. | 9.02 ft | on 11-28-2018 |
| 10. | 12.02 ft | on 11-26-2018 |
| 11. | 12.58 ft | on 05-28-2018 |
| 12. | 9.68 ft | on 01-19-2015 |
| 13. | 15.87 ft | on 05-01-2014 |
| 14. | 9.94 ft | on 03-31-2014 |
| 15. | 13.77 ft | on 09-09-2011 |
| 16. | 21.24 ft | on 08-28-2011 |
| 17. | 9.19 ft | on 03-12-2011 |
| 18. | 9.88 ft | on 03-07-2011 |
| 19. | 11.89 ft | on 03-31-2010 |
| 20. | 16.15 ft | on 03-14-2010 |
| 21. | 19.24 ft | on 04-16-2007 |
| 22. | 11.41 ft | on 04-03-2005 |
| 23. | 11.87 ft | on 12-12-2003 |
| 24. | 9.92 ft | on 11-20-2003 |
| 25. | 11.02 ft | on 06-05-2003 |
| 26. | 7.42 ft | on 05-19-2002 |
| 27. | 21.01 ft | on 09-17-1999 |
| 28. | 10.46 ft | on 03-22-1999 |
| 29. | 9.69 ft | on 05-11-1998 |
| 30. | 9.83 ft | on 01-24-1998 |
| 31. | 11.03 ft | on 07-25-1997 |
| 32. | 10.49 ft | on 12-02-1996 |
| 33. | 15.53 ft | on 10-20-1996 |
| 34. | 8.67 ft | on 08-01-1996 |
| 35. | 9.89 ft | on 01-28-1996 |
| 36. | 15.09 ft | on 01-20-1996 |
| 37. | 12.58 ft | on 03-11-1994 |
| 38. | 13.88 ft | on 01-29-1994 |
| 39. | 12.97 ft | on 12-12-1992 |
| 40. | 14.42 ft | on 09-21-1989 |
| 41. | 10.76 ft | on 06-10-1989 |
| 42. | 11.02 ft | on 04-05-1987 |
| 43. | 12.87 ft | on 05-30-1984 |
| 44. | 14.02 ft | on 01-27-1978 |
| 45. | 13.47 ft | on 09-25-1975 |
| 46. | 14.63 ft | on 07-21-1975 |
| 47. | 16.84 ft | on 07-15-1975 |
| 48. | 13.21 ft | on 12-21-1973 |
| 49. | 18.68 ft | on 08-28-1971 |
| 50. | 12.12 ft | on 08-19-1955 |
| 51. | 15.29 ft | on 09-21-1938 |
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 |
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 |
| 6. | 16.84 ft | on 07-15-1975 |
| 7. | 16.15 ft | on 03-14-2010 |
| 8. | 15.87 ft | on 05-01-2014 |
| 9. | 15.53 ft | on 10-20-1996 |
| 10. | 15.29 ft | on 09-21-1938 |
| 11. | 15.09 ft | on 01-20-1996 |
| 12. | 14.63 ft | on 07-21-1975 |
| 13. | 14.42 ft | on 09-21-1989 |
| 14. | 14.30 ft | on 08-23-2021 |
| 15. | 14.22 ft | on 12-19-2023 |
| 16. | 14.02 ft | on 01-27-1978 |
| 17. | 13.88 ft | on 01-29-1994 |
| 18. | 13.77 ft | on 09-09-2011 |
| 19. | 13.47 ft | on 09-25-1975 |
| 20. | 13.29 ft | on 01-10-2024 |
| 21. | 13.21 ft | on 12-21-1973 |
| 22. | 12.97 ft | on 12-12-1992 |
| 23. | 12.87 ft | on 05-30-1984 |
| 24. | 12.58 ft | on 03-11-1994 |
| 25. | 12.58 ft | on 05-28-2018 |
| 26. | 12.12 ft | on 08-19-1955 |
| 27. | 12.02 ft | on 11-26-2018 |
| 28. | 11.89 ft | on 03-31-2010 |
| 29. | 11.87 ft | on 12-12-2003 |
| 30. | 11.41 ft | on 04-03-2005 |
| 31. | 11.03 ft | on 07-25-1997 |
| 32. | 11.02 ft | on 06-05-2003 |
| 33. | 11.02 ft | on 04-05-1987 |
| 34. | 10.84 ft | on 04-08-2022 |
| 35. | 10.76 ft | on 06-10-1989 |
| 36. | 10.49 ft | on 12-02-1996 |
| 37. | 10.46 ft | on 03-22-1999 |
| 38. | 10.03 ft | on 12-29-2023 |
| 39. | 9.94 ft | on 03-31-2014 |
| 40. | 9.92 ft | on 11-20-2003 |
| 41. | 9.89 ft | on 01-28-1996 |
| 42. | 9.88 ft | on 03-07-2011 |
| 43. | 9.83 ft | on 01-24-1998 |
| 44. | 9.69 ft | on 05-11-1998 |
| 45. | 9.68 ft | on 01-19-2015 |
| 46. | 9.50 ft | on 12-26-2020 |
| 47. | 9.44 ft | on 12-01-2020 |
| 48. | 9.19 ft | on 03-12-2011 |
| 49. | 9.02 ft | on 11-28-2018 |
| 50. | 8.67 ft | on 08-01-1996 |
| 51. | 7.42 ft | on 05-19-2002 |
Vertical Datum Table
| type | NGVD29 |
|---|---|
| major Flooding | 41.97 ft |
| moderate Flooding | 36.97 ft |
| minor Flooding | 35.97 ft |
| action | 33.97 ft |
| Latest Value | 28.93 ft |
| Gauge Zero | 26.97 ft |
Gauge Photos
No Images Found
Unique Local Info
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Potential River Levels Used to Estimate the Chance of Flooding and the Range of Possible River Levels |
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| 10 Day (HEFS) | 10 Day (NAEFS) | 10 Day (GEFS) |
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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.Collaborative Agencies
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.
Resources
Hydrologic Resource Links
Additional Resource Links
WFO Information
Weather Forecast Office
Philadelphia/Mount Holly
732 Woodlane Road
Mount Holly, NJ 08060-9615
Official Homepage