Mccall Reservoir Report

Last Updated: December 5, 2025

McCall is a significant dam located in Boulder, Colorado, primarily owned by the local government for water supply purposes.


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Summary

Built in 1909, this earth-type dam stands at a height of 14 feet and spans 1900 feet in length, with a storage capacity of 722 acre-feet. The dam's primary purpose is water supply, but it also serves for recreational activities.

Situated on the St. Vrain Creek, McCall Dam is regulated by the Colorado Department of Water Resources (DWR) and undergoes regular inspections to ensure its structural integrity. With a high hazard potential but a satisfactory condition assessment, the dam poses a moderate risk (rated 3 out of 5). In case of emergencies, the dam's emergency action plan is set to be reviewed periodically to meet safety guidelines, although specific dates for updates are not provided in the data.

Despite its age, McCall Dam continues to play a crucial role in water resource management and recreational opportunities in the region. Its presence and operation are vital for ensuring a stable water supply and mitigating potential risks associated with its high hazard potential.

Year Completed

1909

Dam Length

1900

Dam Height

14

River Or Stream

ST. VRAIN CREEK-OS

Primary Dam Type

Earth

Surface Area

51

Hydraulic Height

14

Nid Storage

722

Structural Height

14

Hazard Potential

High

Nid Height

14
       
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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.