Tonier Gulch Reservoir Report

Last Updated: December 5, 2025

Tonier Gulch, located in McCoy, Colorado, is a private earth dam built in 1946 for irrigation purposes on Toponas Creek.


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Summary

The dam stands at a height of 32 feet with a length of 325 feet, providing a storage capacity of 124 acre-feet. With a spillway type classified as 'Uncontrolled' and a hazard potential rated as 'Low', Tonier Gulch is deemed to be in fair condition according to a 2018 assessment. The dam's inspection frequency is every 6 years, with the last inspection conducted in July 2018.

Despite its moderate risk assessment, Tonier Gulch remains a vital water resource in Routt County, serving the agricultural community in the region. The dam's stone core and rock-soil foundation contribute to its structural integrity, ensuring its reliability in water storage and distribution. With a maximum discharge capacity of 390 cubic feet per second and an associated slide gate outlet, Tonier Gulch plays a crucial role in managing water flow for irrigation activities along Toponas Creek. As climate change continues to impact water resources, the maintenance and enforcement of regulations for dams like Tonier Gulch are essential to sustainably manage water availability in the area.

Year Completed

1946

Dam Length

325

Dam Height

32

River Or Stream

TOPONAS CREEK-TR

Primary Dam Type

Earth

Surface Area

10

Hydraulic Height

32

Drainage Area

1

Nid Storage

124

Structural Height

32

Outlet Gates

Slide (sluice gate) - 1

Hazard Potential

Low

Foundations

Rock, Soil

Nid Height

32
       
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.