Signal Butte Frs Reservoir Report

Last Updated: December 5, 2025

Signal Butte Flood Retention Structure (FRS) is a critical water management asset located in Maricopa County, Arizona, near the city of Apache Junction.


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Summary

Built in 1988 by the USDA NRCS, this earth dam serves the primary purpose of flood risk reduction along unnamed washes in the area. With a dam height of 22.4 feet and a structural height of 45 feet, Signal Butte FRS has a storage capacity of 2,822 acre-feet, a surface area of 140 acres, and can discharge a maximum of 2,450 cubic feet per second.

Managed by the Arizona Department of Water Resources, Signal Butte FRS is regulated, inspected, and enforced to ensure its structural integrity and operational effectiveness. The dam's spillway type is uncontrolled, with a width of 152 feet, and it poses a high hazard potential but is currently assessed to be in satisfactory condition. Despite being a man-made structure, the dam blends seamlessly with its surroundings, utilizing stone core types and rock and soil foundations to support its functions.

As part of flood risk management measures, Signal Butte FRS has an established inspection frequency and a moderate risk assessment level. While the dam has not been modified in recent years, its emergency action plan (EAP) status and inundation maps preparedness are not disclosed. Overall, this water resource infrastructure stands as a crucial component of the region's water management system, highlighting the importance of proactive monitoring and maintenance in safeguarding against potential hazards and ensuring water security for the surrounding community.

Year Completed

1988

Dam Length

7038

Dam Height

22.4

River Or Stream

UNNAMED WASHES

Primary Dam Type

Earth

Surface Area

140

Hydraulic Height

21

Drainage Area

106

Nid Storage

2822

Structural Height

45

Outlet Gates

Uncontrolled

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

45
       
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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.