Petry Reservoir Report

Last Updated: December 4, 2025

Petry, also known as Lindsay Lake, is a private water resource located in Cowdrey, Colorado within the Big Grizzly-Tr river/stream system.


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Summary

This recreational dam, completed in 1964, stands at a height of 26 feet with a length of 463 feet, providing a storage capacity of 132 acre-feet. While primarily serving purposes such as flood risk reduction, irrigation, and recreation, Petry is regulated and inspected by the Colorado Division of Water Resources to ensure its safety and functionality.

Despite its low hazard potential, Petry poses a high risk due to lacking a condition assessment and updated emergency action plan. The dam's last inspection dates back to 1994, raising concerns about its current state and potential risks it may pose. With no inundation maps prepared and limited risk management measures in place, enthusiasts in water resource and climate fields may find Petry an intriguing case study for examining the importance of regular inspection and maintenance practices to prevent potential disasters and ensure the safety of surrounding communities.

As a privately owned structure with limited federal involvement, Petry's risk assessment of high magnitude underscores the significance of proactive risk management strategies and emergency preparedness measures. The dam's location in a remote area of Jackson County, Colorado, highlights the importance of continued monitoring and evaluation to mitigate any potential threats to the local ecosystem and downstream communities. For water resource and climate enthusiasts, Petry serves as a compelling example of the complexities involved in managing and maintaining aging infrastructure to safeguard water resources and surrounding environments.

Year Completed

1964

Dam Length

463

Dam Height

26

River Or Stream

BIG GRIZZLY-TR

Primary Dam Type

Earth

Surface Area

10

Hydraulic Height

26

Nid Storage

132

Structural Height

29

Hazard Potential

Low

Nid Height

29
       
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.