Blanco Reservoir Dam Reservoir Report
Last Updated: December 27, 2025
Blanco Reservoir Dam, also known as El Paso Natural Gas Dam No.
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Summary
2, is a privately owned structure located in San Juan, New Mexico. Completed in 1957, this Earth-type dam stands at a height of 43 feet and has a length of 380 feet, providing a storage capacity of 198 acre-feet of water. The dam, situated on the San Juan River, serves a variety of purposes and is regulated by the Office of the State Engineer, with regular inspections and enforcement to ensure its safety and functionality.
With a high hazard potential but a satisfactory condition assessment as of December 2019, Blanco Reservoir Dam poses a moderate risk (3) that is managed through appropriate risk management measures. This uncontrolled spillway type dam features slide gates for outlet control and has a spillway width of 8 feet. The dam's emergency action plan status and inundation maps are currently under review, ensuring that adequate measures are in place for the safety of the surrounding area in case of emergencies.
Water resource and climate enthusiasts can appreciate Blanco Reservoir Dam as a vital structure in the management of water resources in the region, offering storage and flood control benefits. Its historical significance, efficient design by W. Carlos Powell, and ongoing regulatory oversight by the state of New Mexico make it a noteworthy example of infrastructure that plays a crucial role in maintaining water security and resilience in the face of changing climate conditions.
Year Completed |
1957 |
Dam Length |
380 |
Dam Height |
43 |
River Or Stream |
SAN JUAN RIVER - OS |
Primary Dam Type |
Earth |
Surface Area |
11 |
Drainage Area |
0.11 |
Nid Storage |
198 |
Outlet Gates |
Slide (sluice gate) - 0 |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
43 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Animas River Below Aztec
|
310cfs |
San Juan River Near Archuleta
|
276cfs |
Animas River At Farmington
|
297cfs |
San Juan River At Farmington
|
622cfs |
La Plata River Near Farmington
|
5cfs |
La Plata River At La Plata
|
3cfs |
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.
Blanco Reservoir Dam