Twin Lakes Reservoir Report

Last Updated: December 5, 2025

Twin Lakes, also known as West Lake, is a state-owned water resource located in Larimer County, Colorado.


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Summary

This picturesque lake, with a surface area of 23 acres, was completed in 1904 primarily for recreational purposes, including fishing and wildlife habitat. The dam at Twin Lakes is an earth structure, standing at 15 feet high and 330 feet in length, with a storage capacity of 247 acre-feet and a maximum discharge of 100 cubic feet per second.

Managed by the Colorado Department of Water Resources, Twin Lakes is regulated, permitted, inspected, and enforced to ensure its safety and functionality. The dam has a low hazard potential and a satisfactory condition assessment as of its last inspection in 2013. Despite being uncontrolled, the spillway at Twin Lakes is 4 feet wide to manage excess water flow. With its serene location and recreational opportunities, Twin Lakes is a valuable water resource for both locals and visitors to enjoy in the Fort Collins area.

Year Completed

1904

Dam Length

330

Dam Height

15

River Or Stream

S LONE PINE CR

Primary Dam Type

Earth

Surface Area

23

Hydraulic Height

15

Nid Storage

247

Structural Height

15

Hazard Potential

Low

Nid Height

15
       
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.