Sidney Sewage Lagoon Reservoir Report
Nearby: Holly Sugar, Lower Sturgis
Last Updated: December 13, 2025
The Sidney Sewage Lagoon, located in Richland County, Montana, plays a crucial role in wastewater management for the city of Sidney.
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Summary
This local government-owned facility, regulated by the Montana Department of Natural Resources and Conservation, has been in operation since 1960 and serves as an essential component of the community's infrastructure. With a dam height of 9 feet and a storage capacity of 340 acre-feet, the lagoon helps to safely contain and treat sewage before it is discharged into the Yellowstone River.
Despite being classified as a low hazard potential structure, the Sidney Sewage Lagoon is subject to regular inspections and enforcement by state regulatory agencies to ensure its safe operation and compliance with environmental standards. The facility's primary purpose is categorized as "Other," reflecting its importance in water resource management within the region. As climate change continues to impact water availability and quality, facilities like the Sidney Sewage Lagoon play a critical role in safeguarding public health and the environment by effectively managing wastewater and protecting water resources.
Year Completed |
1960 |
Dam Length |
4000 |
Dam Height |
9 |
River Or Stream |
TR-YELLOWSTONE RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
6 |
Nid Storage |
340 |
Hazard Potential |
Low |
Nid Height |
9 |
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.
Sidney Sewage Lagoon