Guanella Reservoir Report

Last Updated: December 4, 2025

Guanella is a captivating water supply dam located in Clear Creek, Colorado, in the city of Empire.


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Summary

Completed in 2004, this earth-type dam stands at a height of 34 feet and boasts a hydraulic height of 33 feet, with a structural height of 40 feet. With a maximum storage capacity of 1660 acre-feet and a normal storage capacity of 1340 acre-feet, Guanella serves as a crucial source of water for the region. The dam spans 1950 feet in length and covers a surface area of 52 acres, regulating the flow of the West Fork of Clear Creek-OS.

Managed by the local government and regulated by the Colorado Division of Water Resources, Guanella has been assessed as having a high hazard potential but remains in satisfactory condition. The dam features an uncontrolled spillway with a width of 5 feet and a maximum discharge capacity of 237 cubic feet per second. Despite its moderate risk rating, the dam meets regulatory guidelines and undergoes regular inspections to ensure its safety and reliability for water resource management in the area. With its strategic location and vital role in water supply, Guanella stands as a testament to effective dam design and management in the face of changing climate conditions.

Year Completed

2004

Dam Length

1950

Dam Height

34

River Or Stream

WEST FORK OF CLEAR CREEK-OS

Primary Dam Type

Earth

Surface Area

52

Hydraulic Height

33

Nid Storage

1660

Structural Height

40

Hazard Potential

High

Foundations

Soil

Nid Height

40
       
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.