Drew Lake South Weir Reservoir Report

Last Updated: December 15, 2025

Drew Lake South Weir is a concrete dam located in Weare, New Hampshire, designed for flood risk reduction along the Choate Brook.


°F

°F

mph

Wind

%

Humidity

Summary

The dam stands at a height of 12 feet and spans 385 feet in length, with a storage capacity of 1560 acre-feet. With a low hazard potential and a moderate risk assessment rating, the dam is state-regulated and inspected by the NHDES Dam Bureau to ensure its structural integrity and safety measures are up to standard.

The Drew Lake South Weir is owned by a federal agency and serves as a crucial infrastructure for managing water resources in the Hillsborough County area. The dam's uncontrolled spillway has a width of 210 feet, providing a means for managing excess water flow during periods of heavy rainfall. While the dam's condition assessment is currently not rated, it undergoes inspections every 6 years to assess its overall functionality and safety measures.

With its primary purpose being flood risk reduction, Drew Lake South Weir plays a vital role in protecting the surrounding community from potential water-related disasters. The dam's location, design, and operational features contribute to its effectiveness in managing water levels and minimizing the risk of flooding in the area. As a key component of the water resource management infrastructure in New Hampshire, the dam continues to be a significant asset in mitigating the impact of climate-related events on the local ecosystem and community.

Dam Length

385

Dam Height

12

River Or Stream

CHOATE BROOK

Primary Dam Type

Concrete

Surface Area

130

Drainage Area

426

Nid Storage

1560

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

12
       
Seasonal Comparison

Weather Forecast

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. 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

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, 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.