Holmes Mill dam
Holmes Mill
Holmes Mill, located in Waldo, Maine, is a historic masonry dam completed in 1870, with a primary purpose of hydroelectric power generation. Situated on the Passagassawak River, this dam stands at a height of 15 feet and has a length of 125 feet, providing a storage capacity of 60 acre-feet. With a low hazard potential and a condition assessment of "Not Rated," Holmes Mill remains a vital structure for water resource management in the area.
Owned privately, Holmes Mill is state-regulated by the Maine Emergency Management Agency (MEMA) with permitting, inspection, and enforcement processes in place. The dam serves multiple purposes including fire protection, stock, or small fish pond, in addition to its main function of hydroelectric power generation. Despite its age, Holmes Mill continues to play a significant role in water resource management and climate adaptation efforts in the region.
With its picturesque location and historical significance, Holmes Mill stands as a testament to the enduring impact of water resource infrastructure on the environment and local communities. As climate change threatens water resources worldwide, structures like Holmes Mill serve as critical components of sustainable water management practices, highlighting the importance of preserving and maintaining these vital assets for future generations.
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 Holmes Mill -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Ducktrap River Near Lincolnville | 31 cfs | → |
| Sheepscot River At North Whitefield | 349 cfs | → |
| Kennebec River At North Sidney | 12,700 cfs | → |
| Kenduskeag Stream Near Bangor | 206 cfs | → |
| Cobbosseecontee Stream At Gardiner | 767 cfs | → |
| Sandy River Near Mercer | 1,310 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Holmes Mill.
Boat launches
- Turnpike Drive Camden
- Water Street, Castine
- Megunticook Lake
- Pitchpole Trail Camden
- Prairie Road 21, Unity
- Acadia Highway 1117, East Orland
Campgrounds
- Lake St. George State Park
- Camden Hills State Park
- Mic Mac Ln, Llc
- Balsam Cove Campground
- Oceanfront Camping @ Reach Knolls
- Paul Bunyan Campground
More reservoirs
Track Holmes 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 Holmes Mill
Where does the data for Holmes 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 Holmes Mill.