Big Aso Reservoir Report
Nearby: Number 10 Tank Masonry #2
Last Updated: December 5, 2025
Big Aso, also known as Big Aso Tank, is a privately-owned water resource located in Coconino, Arizona.
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Summary
This reservoir serves multiple purposes including fire protection, stock, and small fish pond usage. Managed by the Arizona Department of Water Resources, Big Aso is regulated, permitted, inspected, and enforced to ensure its safety and compliance with state water laws.
Constructed as an earth dam with a height of 16.4 feet and a length of 374 feet, Big Aso has a storage capacity of 95.3 acre-feet and covers a surface area of 17.43 acres. The reservoir is equipped with an uncontrolled spillway and has a low hazard potential, rated as moderate in terms of risk assessment. Although last inspected in 2012, with a scheduled inspection frequency of 5 years, the condition assessment of Big Aso is currently not rated.
Water resource and climate enthusiasts interested in the management and operation of dams will find Big Aso an intriguing case study. With its unique purpose and design features, this reservoir in Arizona offers insights into the regulatory processes, risk assessments, and safety measures involved in maintaining water infrastructure for multiple uses.
Dam Length |
374 |
Dam Height |
16.4 |
River Or Stream |
PARTRIDGE CREEK - TR |
Primary Dam Type |
Earth |
Surface Area |
17.43 |
Hydraulic Height |
16.4 |
Nid Storage |
95.3 |
Hazard Potential |
Low |
Foundations |
Unlisted/Unknown |
Nid Height |
16 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Big Aso