Leonards Mill dam
Leonards Mill
Leonards Mill, located in Penobscot, Maine, is a historic timber crib dam constructed in 1796 on the Blackman Stream. It serves multiple purposes, including hydroelectric power generation, flood risk reduction, and providing a habitat for fish and wildlife. The dam stands at 7 feet high and stretches 135 feet in length, with a storage capacity of 4200 acre-feet and a surface area of 1200 acres.
Managed by a private owner, Leonards Mill is regulated by the Maine Emergency Management Agency (MEMA) and undergoes regular inspections to ensure its structural integrity and compliance with state regulations. Despite its age, the dam has a low hazard potential and has not been rated in terms of its current condition. The surrounding area benefits from the dam's presence, offering recreational opportunities and contributing to the local ecosystem.
For water resource and climate enthusiasts, Leonards Mill represents a historic and functional piece of infrastructure that continues to play a vital role in managing water resources in the region. With its diverse purposes and longstanding presence, the dam serves as a reminder of the intersection between human development and environmental conservation, highlighting the importance of sustainable water management practices in the face of changing climate conditions.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Leonards Mill -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Kenduskeag Stream Near Bangor | 251 cfs | → |
| Penobscot River At West Enfield | 16,000 cfs | → |
| West Br Bear Brook Near Beddington | 1 cfs | → |
| East Br Bear Brook Near Beddington | 0 cfs | → |
| Piscataquis River At Medford | 2,470 cfs | → |
| Narraguagus River At Cherryfield | 338 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Leonards Mill.
Boat launches
- Fourth Street 22, Old Town
- Camp Roosevelt Road 18, Clifton
- Snowmobile Trail 7c Holden Holden
- Greenbush
- Craig Pond Trail 79, Orland
- Acadia Highway 1117, East Orland
Campgrounds
- Cold River Campground
- Star Rock Campsite
- Paul Bunyan Campground
- Great Pond Military
- Balsam Cove Campground
More reservoirs
Track Leonards Mill in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Leonards Mill
Where does the data for Leonards Mill come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Leonards Mill.