Penobscot River above Grindstone, ME
River level and flood forecast · Penobscot County
The river is 9.6 ft below flood stage (14 ft).
Forecast to rise to 5.2 ft Thu 8 AM, below the 14 ft flood stage.
Flow: 292 cubic feet per second (USGS).
Lower than normal for October 13.
Usual for October 13: 456 to 1,310 cubic feet per second (the middle half of 105 years).
The last 7 days and the forecast
NWS forecast issued Mon, Oct 12, 11:14 AM. Forecasts change as rain falls and as upstream water arrives.
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An email when the National Weather Service forecasts Penobscot River above Grindstone to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 17 ft |
| Moderate flood stage | 16 ft |
| Flood stage | 14 ft |
| Action stage | 11.5 ft |
| Record crest (April 30, 1923) | 16.9 ft |
What floods at each level
From the National Weather Service, highest first.
- 17 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 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.
- 14.5 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 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 ftMinor flooding of the flood plain through Penobscot River Trails cutting some trails off from access.
- 12 ftRiver rising nearing bankfull with minor floodplain flooding along the Penobscot River Trails.
Highest crests on record
- 16.9 ft — April 30, 1923
- 15.02 ft — April 30, 2008
- 14.71 ft — April 29, 1973
- 14.67 ft — December 19, 2023
- 14.3 ft — September 29, 1909
Recent crests: 14.67 ft (December 19, 2023) · 11.22 ft (October 19, 2022) · 10.7 ft (April 14, 2020) · 12.5 ft (April 28, 2019) · 12.22 ft (April 27, 2018)
Highest flow on record
37,000 cubic feet per second — April 30, 1923. From the USGS's yearly peaks since 1903.
Up and down the river, and nearby
- DownstreamPenobscot River at West Enfield, ME
- Wytopitlock Stream near Reed Plantation, ME
- Mattawamkeag River at Mattawamkeag, ME
- Seboeis River near Shin Pond, ME
- E. Branch of Penobscot Below Grand Lake Matagamon, ME
- Piscataquis River at Medford, ME
- Sebec River at Sebec, ME
- Meduxnekeag River above South Branch near Houlton, ME
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (GRNM1); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.