Caballo Arroyo Dam No. 1 Reservoir Report
Nearby: Percha Diversion Caballo
Last Updated: December 7, 2025
Caballo Arroyo Dam No.
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Summary
1, also known as Underwood Dam, is a vital flood risk reduction structure located in Sierra, New Mexico. Constructed in 1959 by the Natural Resources Conservation Service, this earth dam stands at a height of 36 feet and spans 800 feet along the Underwood Arroyo. With a storage capacity of 79 acre-feet, the dam plays a crucial role in mitigating flood hazards in the region.
Despite its importance, Caballo Arroyo Dam No. 1 is currently rated as having a high hazard potential and poor condition assessment, based on a 2015 inspection report. The dam's spillway type is uncontrolled, with a width of 100 feet, and its outlet gates are also uncontrolled. The structure is under the jurisdiction of the Office of the State Engineer in New Mexico, and it undergoes regular state inspections and enforcement to ensure its integrity and safety.
As water resource and climate enthusiasts, it is essential to monitor the ongoing maintenance and risk management measures for Caballo Arroyo Dam No. 1. With its moderate risk assessment rating and the potential for significant impact on the surrounding area in the event of a breach, it is crucial for local government authorities to prioritize the dam's upkeep and any necessary upgrades to enhance its resilience in the face of changing climate conditions.
Year Completed |
1959 |
Dam Length |
800 |
Dam Height |
28 |
River Or Stream |
UNDERWOOD ARROYO |
Primary Dam Type |
Earth |
Hydraulic Height |
28 |
Drainage Area |
1 |
Nid Storage |
79 |
Structural Height |
36 |
Outlet Gates |
Uncontrolled - 0 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
36 |
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.
Caballo Arroyo Dam No. 1
Caballo Reservoir