Vergennes Plant No. 9 Spillway Reservoir Report
Last Updated: December 13, 2025
Vergennes Plant No.
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Summary
9 Spillway, located in Vergennes, Vermont, is a captivating hydroelectric facility with a rich history dating back to its completion in 1912. This concrete gravity dam stands at a height of 12 feet and spans a length of 162 feet, providing a storage capacity of 200 acre-feet and serving a drainage area of 866 square miles. The dam's maximum discharge capacity reaches an impressive 3459 cubic feet per second, making it a crucial component of the local water resource infrastructure.
Managed by a public utility, Vergennes Plant No. 9 Spillway falls under the regulatory oversight of the Federal Energy Regulatory Commission (FERC) and operates as an uncontrolled spillway with a width of 87 feet. Despite its age, the dam is rated with a low hazard potential and a moderate risk assessment. Regular inspections are conducted to ensure its structural integrity and safety, with the last inspection taking place in August 2017. The dam's Emergency Action Plan (EAP) was last revised in February 2014, highlighting the facility's commitment to emergency preparedness and risk management.
With its picturesque location on Otter Creek and its role in generating hydroelectric power, Vergennes Plant No. 9 Spillway is not only a historic landmark but also a vital piece of Vermont's water resource infrastructure. As climate enthusiasts and water resource advocates, understanding the significance of this dam in the context of energy production and water management is crucial for appreciating its contributions to the local community and the environment at large.
Year Completed |
1912 |
Dam Length |
162 |
Dam Height |
12 |
River Or Stream |
Otter Creek |
Primary Dam Type |
Concrete |
Surface Area |
133 |
Drainage Area |
866 |
Nid Storage |
200 |
Hazard Potential |
Low |
Foundations |
Rock |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Button Bay State Park
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Mt. Philo State Park
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DAR State Park
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D.A.R State Park
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Vergennes Plant No. 9 Spillway
Hawkins Road Ferrisburgh