Upper Gila Valley Site No. 10 Dam Reservoir Report

Last Updated: December 5, 2025

Upper Gila Valley Site No.


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Summary

10 Dam, also known as Winn Canyon Floodwater Retarding Structure, is a key flood risk reduction infrastructure located in Grant, New Mexico. Constructed in 1963 by the USDA NRCS, this earth-type dam stands at a height of 47 feet and spans a length of 650 feet along the Winn Canyon river. With a storage capacity of 982 acre-feet, the dam plays a crucial role in debris control and flood risk reduction within its 13.5 square mile drainage area.

Managed by the local government and regulated by the Office of the State Engineer, Upper Gila Valley Site No. 10 Dam has a high hazard potential and is currently in poor condition, last assessed in May 2018. Despite its risk level, the dam's emergency action plan and inundation maps are yet to be updated, highlighting a need for improved risk management measures to ensure the safety of surrounding communities. With a moderate risk assessment score of 3, there is a call for increased inspection frequency and maintenance to mitigate potential hazards and enhance the dam's resilience in the face of climate variability and extreme weather events.

Year Completed

1963

Dam Length

650

Dam Height

47

River Or Stream

WINN CANYON

Primary Dam Type

Earth

Drainage Area

13.5

Nid Storage

982

Structural Height

50

Outlet Gates

Uncontrolled - 0

Hazard Potential

High

Foundations

Soil

Nid Height

50
       
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.