Thompson #2 Reservoir Report

Reservoir Report

Colorado

Nearby: Thompson No 1 Gardner Lake

Last Updated: December 5, 2025

Thompson #2 is a privately owned dam located in Mesa County, Colorado, near the city of Dewey.

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Summary

The dam was completed in 1953 by the USDA NRCS and serves the primary purpose of irrigation, with a maximum storage capacity of 393 acre-feet and a normal storage capacity of 243 acre-feet. The dam, which is an earth-fill structure with a height of 32 feet, is situated on the Trail Canyon Wash and covers a surface area of 30 acres.

Despite being categorized as having a low hazard potential, Thompson #2 is subject to state regulation and inspection by the Colorado Division of Water Resources. The dam features an uncontrolled spillway type and is equipped with slide and uncontrolled outlet gates. However, the last inspection of the dam was conducted in May 1994, highlighting the need for updated assessments of its condition and risk management measures. With a moderate risk assessment rating of 3, it is crucial for stakeholders to ensure that the necessary emergency preparedness protocols are in place to mitigate any potential hazards associated with the dam.

Water resource and climate enthusiasts will find Thompson #2 to be an intriguing case study of a privately owned irrigation dam in the western United States. The dam's location in a semi-arid region underscores the importance of efficient water management practices for agricultural purposes. As discussions around climate change and water scarcity continue to gain prominence, the responsible maintenance and operation of dams like Thompson #2 are essential for sustainable water resource management in the face of evolving environmental challenges.

Year Completed	1953
Dam Length	1220
Dam Height	32
River Or Stream	TRAIL CANYON WASH
Primary Dam Type	Earth
Surface Area	30
Hydraulic Height	34
Drainage Area	16
Nid Storage	393
Structural Height	34
Outlet Gates	Slide (sluice gate), Uncontrolled
Hazard Potential	Low
Foundations	Rock, Soil
Nid Height	34

Explore Interactive Map

THOMPSON #2

Reservoir Report • Water Levels • Weather Forecast

December 5, 2025

Year_Completed	1953
Dam_Length	1220
Dam_Height	32
River_Or_Stream	TRAIL CANYON WASH
Primary_Dam_Type	Earth
Surface_Area	30
Hydraulic_Height	34
Drainage_Area	16
Nid_Storage	393
Structural_Height	34
Outlet_Gates	Slide (sluice gate), Uncontrolled
Hazard_Potential	Low
Foundations	Rock, Soil
Nid_Height	34

Seasonal Comparison

Weather Forecast

Nearby Streamflow Levels

Colorado River Near Colorado-Utah State Line 2370.0cfs	2370cfs
Gunnison River Near Grand Junction 964.0cfs	964cfs
Colo River Blw Grd Valley Div Nr Palisade Co 1140.0cfs	1140cfs
Dolores River Near Gateway 100.0cfs	100cfs
Dolores River Near Cisco 112.0cfs	112cfs
Plateau Creek Near Cameo 55.8cfs	56cfs

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.