Lacosta Reservoir Report
Nearby: Big Railroad Reservoir Tom #2
Last Updated: December 6, 2025
Lacosta is a privately owned irrigation dam located in Garfield, Montana, along the Sand Creek river.
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Summary
Built in 1968, this earth dam stands at a height of 28 feet and has a storage capacity of 1676 acre-feet, with a normal storage level of 707 acre-feet. The dam serves the primary purpose of irrigation, providing vital water resources to the surrounding agricultural lands in the area.
Managed by the Montana Department of Natural Resources and Conservation (DNRC), Lacosta is subject to state regulation, inspection, and enforcement to ensure its safety and compliance with standards. Despite being classified as having a low hazard potential, the dam's condition is currently not rated, indicating a need for further assessment and monitoring. With its location in a remote area and limited information on emergency preparedness, there may be opportunities for improvement in risk management and emergency response protocols for this essential water infrastructure.
While Lacosta plays a crucial role in supporting local agriculture through irrigation, there is a need for ongoing maintenance, assessment of its structural integrity, and the development of emergency action plans to ensure the safety and reliability of this water resource infrastructure. As climate change impacts water availability and usage patterns, the proper management and upkeep of dams like Lacosta are increasingly important for sustainable water resource management in the region.
Year Completed |
1968 |
Dam Length |
2640 |
Dam Height |
28 |
River Or Stream |
SAND CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
28 |
Nid Storage |
1676 |
Hazard Potential |
Low |
Nid Height |
28 |
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.
Lacosta