Peterson Lake Reservoir Report

Last Updated: December 5, 2025

Peterson Lake, located in Boulder, Colorado, is a privately owned water supply reservoir with a capacity of 197 acre-feet.


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Summary

Built in 1961, this earth dam stands at 12 feet high and spans 88 feet in length, serving as a critical source of water for the surrounding area. Its primary purpose is water supply, with a normal storage capacity of 117 acre-feet and a surface area covering 18 acres.

Managed by the Colorado Department of Water Resources, Peterson Lake is regulated, permitted, inspected, and enforced to ensure its structural integrity and safe operation. The dam's spillway, with a width of 24 feet, is uncontrolled and designed to handle a maximum discharge of 345 cubic feet per second. Despite its low hazard potential, the dam received a satisfactory condition assessment during its last inspection in 2008, indicating a moderate risk level that requires ongoing risk management measures.

Situated along the Middle Boulder Creek, Peterson Lake is a vital component of the local water infrastructure, playing a crucial role in water supply management and supporting the surrounding ecosystem. With its historical significance and continued regulatory oversight, Peterson Lake stands as a testament to responsible water resource management in the face of changing climate conditions and evolving environmental challenges.

Years Modified

2002 - Hydraulic

Year Completed

1961

Dam Length

88

Dam Height

12

River Or Stream

MIDDLE BOULDER CREEK-TR

Primary Dam Type

Earth

Surface Area

18

Hydraulic Height

12

Drainage Area

1

Nid Storage

197

Structural Height

12

Outlet Gates

Slide (sluice gate) - 1

Hazard Potential

Low

Foundations

Rock, Soil

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.