Crow Lane No. 1 Reservoir Report

Last Updated: December 4, 2025

Crow Lane No.


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Summary

1 is a key water supply structure located in Lyons, Colorado, designed by McLaughlin Water Engineers, Ltd. Completed in 2008, this Earth-type dam stands at a height of 40 feet and has a hydraulic height of 35 feet, with a total structural height of 74 feet. It serves the primary purpose of water supply and has a storage capacity of 52 acre-feet, with a maximum discharge rate of 6052 cubic feet per second.

With a spillway width of 229 feet and a high hazard potential, Crow Lane No. 1 is regulated by the Colorado Department of Water Resources and undergoes regular inspections to ensure its satisfactory condition. The surrounding area includes an unnamed tributary of the Thompson-Os river, making this dam a crucial asset for water management in the region. Despite its moderate risk assessment, the structure meets guidelines for emergency action plans and risk management measures.

Crow Lane No. 1 represents a vital piece of water infrastructure in Larimer County, serving as a reliable source for water supply in the area. Its strategic location and design make it an essential component in the sustainable management of water resources amidst evolving climate conditions. As climate enthusiasts and water resource experts, monitoring and maintaining structures like Crow Lane No. 1 are crucial for ensuring the resilience and safety of our water supply systems in the face of changing environmental challenges.

Year Completed

2008

Dam Length

330

Dam Height

40

River Or Stream

UNAMED TRIB LT THOMPSON-OS

Primary Dam Type

Earth

Surface Area

4

Hydraulic Height

35

Nid Storage

52

Structural Height

74

Hazard Potential

High

Foundations

Rock

Nid Height

74
       
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.