StormCast — Weather & Emergency Alerts

Penobscot River above Grindstone
Maine — Water Level & Flood Stage

Located in Penobscot County, Maine on the Penobscot River. Live water level data from USGS gauge 01029500, updated every 15 minutes.

Current Water Level

Gage Height

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Streamflow

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Last Reading

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Flood Stages

Major Flood

17 ft

39,580 cfs

Moderate Flood

16 ft

34,270 cfs

Minor Flood

14 ft

24,776 cfs

Action Stage

11.5 ft

17,965 cfs

Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.

What Floods at Each Level

17 ft

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 ft

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 ft

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.

14 ft

State 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 ft

Minor flooding of the flood plain through Penobscot River Trails cutting some trails off from access.

12 ft

River rising nearing bankfull with minor floodplain flooding along the Penobscot River Trails.

Impact statements from the National Weather Service, describing what typically happens at each water level.

7-Day Water Level Chart

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View Official NWS Hydrograph →

Historic Crests

Date Stage Flow
Apr 29, 192316.9 ft37,000 cfs
Apr 29, 192316.9 ft37,000 cfs
Apr 30, 200815.02 ft34,300 cfs
Apr 30, 200815.02 ft34,300 cfs
Apr 28, 197314.71 ft30,600 cfs

About This Gauge

USGS Site

01029500

NWS LID

GRNM1

River

Penobscot River

County

Penobscot, ME

Coordinates

45.7313°N, 68.5893°W

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StormCast monitors this gauge and sends a push notification to your phone when the water level crosses into a new flood category — even at 3 AM.

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Frequently Asked Questions

What is the current water level of Penobscot River above Grindstone?

The Penobscot River above Grindstone gauge is maintained by USGS (site 01029500) and reports water levels every 15 minutes. Visit this page to see the latest reading updated live, or download StormCast to get push alerts when levels rise.

What is flood stage for Penobscot River above Grindstone?

The NWS-defined flood stage for Penobscot River above Grindstone is 14 feet. Action stage begins at 11.5 feet. Moderate flooding starts at 16 feet, and major flooding at 17 feet.

How do I get alerts when Penobscot River rises?

Download StormCast free on Google Play, go to River Gauges, and add Penobscot River above Grindstone to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category — even when your screen is off.

Where is the Penobscot River above Grindstone gauge located?

The gauge is located in Penobscot County, Maine at coordinates 45.7313°N, 68.5893°W. USGS site number: 01029500. Data is provided by the U.S. Geological Survey and the National Weather Service.

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Source & Notes

Data provided by: US Geological Survey, Observations courtesy of U.S. Geological Survey