Twine Mill Reservoir Report
Nearby: Dane Perkins Kesslen
Last Updated: December 21, 2025
Twine Mill, located in Kennebunk, Maine, is a hydroelectric dam on the Mousam River, completed in 1980 with a primary purpose of hydroelectric power generation.
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Summary
The dam is constructed of concrete and stands at a height of 18 feet, with a length of 223 feet. It has a storage capacity of 104 acre-feet and a maximum discharge of 2400 cubic feet per second. The dam is classified as low hazard potential with a very high risk assessment rating.
Owned and operated by the local government, Twine Mill is not regulated by the state and falls under the jurisdiction of the Federal Energy Regulatory Commission (FERC). The dam also serves recreational purposes, with a surface area of 12 acres for outdoor activities. The spillway, with a controlled design and a width of 108 feet, ensures safe water release during high flow events. The dam has one slide (sluice gate) outlet gate for water control.
Although the condition assessment of Twine Mill is currently not available, regular inspections are conducted every three years to ensure the safety and integrity of the structure. The dam has not been modified since its completion and is equipped with emergency action plans and contacts. With its strategic location and efficient operation, Twine Mill plays a crucial role in providing clean energy and recreational opportunities while minimizing environmental impact on the surrounding area.
Year Completed |
1980 |
Dam Length |
223 |
Dam Height |
18 |
River Or Stream |
Mousam River |
Primary Dam Type |
Concrete |
Surface Area |
12 |
Drainage Area |
125 |
Nid Storage |
104 |
Outlet Gates |
Slide (sluice gate) - 1 |
Hazard Potential |
Low |
Nid Height |
18 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Mousam River Near West Kennebunk
|
72cfs |
Cocheco River Near Rochester
|
66cfs |
Isinglass R At Rochester Neck Rd
|
70cfs |
Presumpscot River At Westbrook
|
-999999cfs |
Oyster River Near Durham
|
18cfs |
Lamprey River Near Newmarket
|
74cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams 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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Twine Mill
Pier Road 81, Kennebunkport