Halfway Detention Dam Reservoir Report

Last Updated: December 5, 2025

Halfway Detention Dam, located in Solomon, Arizona, is a vital federal structure managed by the Bureau of Land Management to mitigate flood risks along the San Simon River.


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Summary

This gravity dam, with a hydraulic height of 15 feet and a structural height of 18 feet, was completed in 1940 and spans 1680 feet in length. While its primary purpose is flood risk reduction, the dam also serves as a key component in the water resource management infrastructure of Graham County.

With a storage capacity of 247 acre-feet and a surface area of 16 acres, Halfway Detention Dam plays a crucial role in safeguarding the surrounding communities from potential inundation. Despite its low hazard potential and fair condition assessment, the dam undergoes regular inspections every five years to ensure its structural integrity and functionality. Its location within the Los Angeles District underscores the interconnectedness of water resource management efforts across different regions, highlighting the collaborative nature of climate resilience initiatives in the face of changing environmental conditions.

Year Completed

1940

Dam Length

1680

River Or Stream

SAN SIMON RIVER

Primary Dam Type

Gravity

Surface Area

16

Hydraulic Height

15

Nid Storage

247

Structural Height

18

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

18
       
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.