Rivers in Maine
Penobscot River above Grindstone
Below flood stage
4.53ftStage
Observed Wed, Sep 23, 9:00 AM EDT
- Flood stage
- 14.00 ft
- Forecast crest
- 4.50 ftWed, Sep 23, 2:00 PM EDT
- Record crest
- 16.90 ft1923
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 17.00 ft |
| Moderate flood | 16.00 ft |
| Minor flood | 14.00 ft |
| Action | 11.50 ft |
- 17.00 ftWidespread 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.
- 16.00 ftState 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.
- 14.50 ftState 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.
- 14.00 ftState Route 11 flooded in places but remains passable. Homes and camps begin to get threatened. Significant flooding of Penobscot River Trails and unaccessable. Moderate backwater flooding of Mud & Hay Brooks.
- 13.00 ftMinor flooding of the flood plain through Penobscot River Trails cutting some trails off from access.
- 12.00 ftRiver rising nearing bankfull with minor floodplain flooding along the Penobscot River Trails.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | Under 5% |
| Moderate flooding | Under 5% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 21, 2026.
Crest history
13 crests on NOAA’s list since 1909.
| # | Date | Stage |
|---|---|---|
| 1 | April 30, 1923 | 16.90 ft |
| 2 | April 30, 2008 | 15.02 ft |
| 3 | April 29, 1973 | 14.71 ft |
| 4 | December 19, 2023 | 14.67 ft |
| 5 | September 29, 1909 | 14.30 ft |
| 6 | March 20, 1936 | 14.00 ft |
| 7 | April 28, 2019 | 12.50 ft |
| 8 | December 14, 2010 | 12.49 ft |
| 9 | April 27, 2018 | 12.22 ft |
| 10 | April 16, 2014 | 11.87 ft |
| 11 | October 19, 2022 | 11.22 ft |
| 12 | April 14, 2020 | 10.70 ft |
| 13 | November 17, 2007 | 10.41 ft |
Most recent crests
- December 19, 2023: 14.67 ft
- October 19, 2022: 11.22 ft
- April 14, 2020: 10.70 ft
- April 28, 2019: 12.50 ft
- April 27, 2018: 12.22 ft
- April 16, 2014: 11.87 ft
- December 14, 2010: 12.49 ft
- April 30, 2008: 15.02 ft
- November 17, 2007: 10.41 ft
- April 29, 1973: 14.71 ft
Nearby
Upstream, downstream and the gauges around this one.
What this means
Forecasts by the Northeast River Forecast Center. Forecasts are issued routinely year-round. Gauge reading may be affected by ice. Forecast flows are unadjusted for ice. Gauge reading may be affected by ice. Forecast flows are unadjusted for ice.
Sources
Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.