Penobscot River above Grindstone
Future / Actual / Minor
OWP 2.0 WWA Modal Title
01/11/2021, 10:04 PM UTC through 01/11/2021, 10:04 PM UTC
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Observed (OBS) 04/01/2025 12:00 PM EDTOfficial Forecast (FCST) 04/01/2025 11:24 AM EDTRecord: 16.9 ftCATEGORY STAGE 
Major Flooding 17 ft Moderate Flooding 16 ft Minor Flooding 14 ft Action 11.5 ft Reliability of the Forecast:
NOTE: Forecasts are issued routinely year-round.
Gauge reading may be affected by ice. Forecast flows are unadjusted for ice.
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
- 17 - Widespread flooding of State Route 11 from Hay Brook to Grindstone to Medway. Numerous homes, camps and campgrounds inundated. Flooding similar to April 1923. Penobscot River Trails inaccessible. Widespread flooding upstream to the Swift Brook Road in T3 R7 Wels.
- 16 - State Route 11 significantly flooded and impassable to all travel in several areas between Medway and the Penobscot River Trails in Grindstone. Homes and camps inundated. Logging roads west and near the river will be flooded. Hathaway Road flooded near the river.
- 14.5 - State Route 11 becomes impassable between the Penobscot River Trails road and Hay Brook with significant backwater flooding. Additional flooding of State Route 11 near Frazier Road to the Grindstone Falls Rest Area. 1-2 feet of inundation of State Route 11 near the USGS gage at the railroad trestle. Low lying structures are threatened downstream to Medway.
Gauge Info
| Coordinates | 45.7313, -68.5893 |
| RFC | NERFC |
| State | ME |
| WFO | CAR |
| County | Penobscot |
| Data Provider(s) | |
| US Geological Survey | USGS--Water Resources of the United States |
| USGS | 01029500 |
Gauge Location
Recent Crests
| 1. | 14.67 ft | on 12-19-2023 |
| 2. | 11.22 ft | on 10-19-2022 |
| 3. | 10.70 ft | on 04-14-2020 |
| 4. | 12.50 ft | on 04-28-2019 |
| 5. | 12.22 ft | on 04-27-2018 |
Recent Crests
| 1. | 14.67 ft | on 12-19-2023 |
| 2. | 11.22 ft | on 10-19-2022 |
| 3. | 10.70 ft | on 04-14-2020 |
| 4. | 12.50 ft | on 04-28-2019 |
| 5. | 12.22 ft | on 04-27-2018 |
| 6. | 11.87 ft | on 04-16-2014 |
| 7. | 12.49 ft | on 12-14-2010 |
| 8. | 15.02 ft | on 04-30-2008 |
| 9. | 10.41 ft | on 11-17-2007 |
| 10. | 14.71 ft | on 04-29-1973 |
| 11. | 14.00 ft | on 03-20-1936 |
| 12. | 16.90 ft | on 04-30-1923 |
| 13. | 14.30 ft | on 09-29-1909 |
Historic Crests
| 1. | 16.90 ft | on 04-30-1923 |
| 2. | 15.02 ft | on 04-30-2008 |
| 3. | 14.71 ft | on 04-29-1973 |
| 4. | 14.67 ft | on 12-19-2023 |
| 5. | 14.30 ft | on 09-29-1909 |
Historic Crests
| 1. | 16.90 ft | on 04-30-1923 |
| 2. | 15.02 ft | on 04-30-2008 |
| 3. | 14.71 ft | on 04-29-1973 |
| 4. | 14.67 ft | on 12-19-2023 |
| 5. | 14.30 ft | on 09-29-1909 |
| 6. | 14.00 ft | on 03-20-1936 |
| 7. | 12.50 ft | on 04-28-2019 |
| 8. | 12.49 ft | on 12-14-2010 |
| 9. | 12.22 ft | on 04-27-2018 |
| 10. | 11.87 ft | on 04-16-2014 |
| 11. | 11.22 ft | on 10-19-2022 |
| 12. | 10.70 ft | on 04-14-2020 |
| 13. | 10.41 ft | on 11-17-2007 |
Vertical Datum Table
| type | NGVD29 |
|---|---|
| major Flooding | 311.74 ft |
| moderate Flooding | 310.74 ft |
| minor Flooding | 308.74 ft |
| action | 306.24 ft |
| Latest Value | 302.09 ft |
| Gauge Zero | 294.74 ft |
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.
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.