Souhegan River at Merrimack
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
- Upstream gauge unavailableDownstream gauge unavailableWarning: 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) 04/04/2025 9:30 AM EDTOfficial Forecast (FCST) 04/03/2025 11:37 AM EDTRecord: 16.2 ftCATEGORY STAGE 
Major Flooding 13 ft Moderate Flooding 11 ft Minor Flooding 9 ft Action 8 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 - Significant flooding affects homes in the area of Beacon Drive in Merrimack. Other low lying sections upstream into Amherst and Milford experience flooding.
- 11 - In Merrimack, homes in the Beacon Drive area flood. Other low lying areas upstream into Amherst and Milford flood.
- 10 - In Merrimack, several homes along a small portion of Beacon Drive begin to flood. In Amherst, low lying areas begin to flood.
Gauge Info
| Coordinates | 42.8575, -71.5067 |
| RFC | NERFC |
| State | NH |
| WFO | GYX |
| County | Hillsborough |
| Data Provider(s) | |
| US Geological Survey | USGS--Water Resources of the United States |
| USGS | 01094000 |
Gauge Location
Recent Crests
| 1. | 7.52 ft | on 12-26-2020 |
| 2. | 7.30 ft | on 12-15-2019 |
| 3. | 7.26 ft | on 01-25-2019 |
| 4. | 8.14 ft | on 10-31-2017 |
| 5. | 7.06 ft | on 04-07-2017 |
Recent Crests
| 1. | 7.52 ft | on 12-26-2020 |
| 2. | 7.30 ft | on 12-15-2019 |
| 3. | 7.26 ft | on 01-25-2019 |
| 4. | 8.14 ft | on 10-31-2017 |
| 5. | 7.06 ft | on 04-07-2017 |
| 6. | 9.19 ft | on 03-31-2010 |
| 7. | 9.85 ft | on 03-15-2010 |
| 8. | 12.71 ft | on 04-17-2007 |
| 9. | 9.88 ft | on 05-15-2006 |
| 10. | 9.84 ft | on 04-02-2004 |
| 11. | 9.96 ft | on 10-22-1996 |
| 12. | 8.86 ft | on 04-17-1996 |
| 13. | 8.16 ft | on 12-25-1994 |
| 14. | 7.71 ft | on 03-31-1993 |
| 15. | 10.25 ft | on 04-07-1987 |
| 16. | 8.22 ft | on 01-31-1986 |
| 17. | 8.50 ft | on 04-06-1984 |
| 18. | 8.74 ft | on 03-22-1983 |
| 19. | 8.00 ft | on 12-22-1973 |
| 20. | 8.48 ft | on 02-11-1970 |
| 21. | 8.54 ft | on 03-19-1968 |
| 22. | 7.65 ft | on 12-07-1963 |
| 23. | 7.65 ft | on 12-07-1962 |
| 24. | 8.80 ft | on 04-02-1962 |
| 25. | 8.36 ft | on 04-03-1959 |
| 26. | 10.00 ft | on 01-10-1956 |
| 27. | 10.30 ft | on 10-16-1955 |
| 28. | 8.62 ft | on 09-12-1954 |
| 29. | 8.34 ft | on 04-06-1952 |
| 30. | 8.10 ft | on 03-23-1948 |
| 31. | 10.88 ft | on 06-25-1944 |
| 32. | 8.05 ft | on 03-10-1942 |
| 33. | 8.34 ft | on 04-13-1940 |
| 34. | 12.78 ft | on 09-21-1938 |
| 35. | 9.01 ft | on 11-29-1937 |
| 36. | 9.92 ft | on 11-14-1937 |
| 37. | 16.20 ft | on 03-19-1936 |
| 38. | 10.60 ft | on 03-13-1936 |
| 39. | 10.66 ft | on 04-13-1934 |
| 40. | 9.73 ft | on 11-05-1927 |
| 41. | 11.82 ft | on 04-08-1924 |
| 42. | 8.09 ft | on 05-06-1922 |
| 43. | 9.18 ft | on 12-15-1920 |
| 44. | 8.04 ft | on 03-28-1920 |
| 45. | 8.68 ft | on 02-27-1916 |
| 46. | 9.60 ft | on 08-05-1915 |
Historic Crests
| 1. | 16.20 ft | on 03-19-1936 |
| 2. | 12.78 ft | on 09-21-1938 |
| 3. | 12.71 ft | on 04-17-2007 |
| 4. | 11.82 ft | on 04-08-1924 |
| 5. | 10.88 ft | on 06-25-1944 |
Historic Crests
| 1. | 16.20 ft | on 03-19-1936 |
| 2. | 12.78 ft | on 09-21-1938 |
| 3. | 12.71 ft | on 04-17-2007 |
| 4. | 11.82 ft | on 04-08-1924 |
| 5. | 10.88 ft | on 06-25-1944 |
| 6. | 10.66 ft | on 04-13-1934 |
| 7. | 10.60 ft | on 03-13-1936 |
| 8. | 10.30 ft | on 10-16-1955 |
| 9. | 10.25 ft | on 04-07-1987 |
| 10. | 10.00 ft | on 01-10-1956 |
| 11. | 9.96 ft | on 10-22-1996 |
| 12. | 9.92 ft | on 11-14-1937 |
| 13. | 9.88 ft | on 05-15-2006 |
| 14. | 9.85 ft | on 03-15-2010 |
| 15. | 9.84 ft | on 04-02-2004 |
| 16. | 9.73 ft | on 11-05-1927 |
| 17. | 9.60 ft | on 08-05-1915 |
| 18. | 9.19 ft | on 03-31-2010 |
| 19. | 9.18 ft | on 12-15-1920 |
| 20. | 9.01 ft | on 11-29-1937 |
| 21. | 8.86 ft | on 04-17-1996 |
| 22. | 8.80 ft | on 04-02-1962 |
| 23. | 8.74 ft | on 03-22-1983 |
| 24. | 8.68 ft | on 02-27-1916 |
| 25. | 8.62 ft | on 09-12-1954 |
| 26. | 8.54 ft | on 03-19-1968 |
| 27. | 8.50 ft | on 04-06-1984 |
| 28. | 8.48 ft | on 02-11-1970 |
| 29. | 8.36 ft | on 04-03-1959 |
| 30. | 8.34 ft | on 04-13-1940 |
| 31. | 8.34 ft | on 04-06-1952 |
| 32. | 8.22 ft | on 01-31-1986 |
| 33. | 8.16 ft | on 12-25-1994 |
| 34. | 8.14 ft | on 10-31-2017 |
| 35. | 8.10 ft | on 03-23-1948 |
| 36. | 8.09 ft | on 05-06-1922 |
| 37. | 8.05 ft | on 03-10-1942 |
| 38. | 8.04 ft | on 03-28-1920 |
| 39. | 8.00 ft | on 12-22-1973 |
| 40. | 7.71 ft | on 03-31-1993 |
| 41. | 7.65 ft | on 12-07-1963 |
| 42. | 7.65 ft | on 12-07-1962 |
| 43. | 7.52 ft | on 12-26-2020 |
| 44. | 7.30 ft | on 12-15-2019 |
| 45. | 7.26 ft | on 01-25-2019 |
| 46. | 7.06 ft | on 04-07-2017 |
Vertical Datum Table
| type | NAVD88 |
|---|---|
| major Flooding | 172.88 ft |
| moderate Flooding | 170.88 ft |
| minor Flooding | 168.88 ft |
| action | 167.88 ft |
| Latest Value | 164.70 ft |
| Gauge Zero | 159.88 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) | 7 Day (NAEFS) | 7 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.
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.