Evans Reservoir Report
Nearby: Flat Milford Colony Thompson, Frank
Last Updated: December 5, 2025
Evans, L.
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Summary
is a privately owned earth dam located in Cascade, Montana, specifically in Lewis and Clark County. Built in 1961 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock, and small fish pond management. With a height of 20 feet and a storage capacity of 155 acre-feet, Evans, L. plays a crucial role in water resource management in the area.
Situated on Black Rock Creek, Evans, L. has a low hazard potential and is currently not rated for its condition assessment. Despite this, the dam is regulated by the Montana Department of Natural Resources and Conservation and undergoes regular inspections, enforcement, and permitting processes to ensure its safety and functionality. The dam's spillway type is uncontrolled, with a width of 30 feet, and it has a moderate risk assessment rating.
In the event of an emergency, the dam does not have an Emergency Action Plan in place, but it meets regulatory guidelines. Overall, Evans, L. is a valuable water resource structure in the region, contributing to fire protection, livestock management, and recreational fishing opportunities while being carefully monitored and managed to mitigate any potential risks.
Year Completed |
1961 |
Dam Length |
240 |
Dam Height |
20 |
River Or Stream |
BLACK ROCK CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Drainage Area |
7.54 |
Nid Storage |
155 |
Hazard Potential |
Low |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dearborn River Near Craig Mt
|
36cfs |
Sun River At Simms Mt
|
1620cfs |
Sun River Bl Willow Cr Nr Augusta Mt
|
116cfs |
Little Prickly Pear Cr At Wolf Cr Mt
|
35cfs |
Missouri River At Cascade Mt
|
3090cfs |
Missouri River Bl Holter Dam Nr Wolf Cr Mt
|
2730cfs |
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.
Evans, L.