Norumbega Reservoir Dam No. 1 Reservoir Report
Last Updated: December 19, 2025
Norumbega Reservoir Dam No.
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Summary
1, located in Weston, Massachusetts, is a state-regulated earth dam with a primary purpose of water supply. Completed in 1940, this dam stands at a height of 42 feet and has a hydraulic height of 34 feet, providing a storage capacity of 500 acre-feet. The dam, situated on Seaverns Brook, covers a surface area of 0.06 square miles and has a drainage area of 0.13 square miles.
Despite being classified as having a high hazard potential, Norumbega Reservoir Dam No. 1 is in fair condition, as per the last inspection conducted in September 2016. The dam is equipped with an uncontrolled spillway and has an inspection frequency of every two years. The risk assessment for this dam is rated as moderate, with no specific risk management measures listed. Overall, this dam serves as a critical water resource infrastructure in Middlesex County, Massachusetts, under the oversight of the Department of Conservation and Recreation.
Year Completed |
1940 |
Dam Length |
1100 |
Dam Height |
42 |
River Or Stream |
SEAVERNS BROOK |
Primary Dam Type |
Earth |
Surface Area |
0.06 |
Hydraulic Height |
34 |
Drainage Area |
0.13 |
Nid Storage |
500 |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
42 |
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.
Norumbega Reservoir Dam No. 1
College Road Wellesley