Rock Lake Reservoir Report
Last Updated: December 5, 2025
Rock Lake is a privately owned irrigation reservoir located in Wheatland, Wyoming, along the North Wheatland Creek.
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Summary
Built in 1930, this Earth dam stands at 15 feet high and spans 660 feet in length, with a maximum storage capacity of 334 acre-feet and a normal storage level of 250 acre-feet. The dam's primary purpose is to support irrigation in the area, and it is regulated, inspected, and enforced by the Wyoming State Engineer's Office.
Despite its age, Rock Lake's dam is in fair condition with a low hazard potential, making it a relatively safe structure. The reservoir covers a surface area of 37 acres and is equipped with an uncontrolled spillway that is 4 feet wide. With a moderate risk assessment rating of 3, the dam has undergone regular inspections, with the last assessment conducted in May 2020. Overall, Rock Lake serves as a vital water resource for agricultural activities in the region, showcasing the importance of maintaining and monitoring such infrastructure in the face of changing climate conditions.
Year Completed |
1930 |
Dam Length |
660 |
Dam Height |
15 |
River Or Stream |
NORTH WHEATLAND CREEK |
Primary Dam Type |
Earth |
Surface Area |
37 |
Hydraulic Height |
11 |
Nid Storage |
334 |
Structural Height |
15 |
Outlet Gates |
Valve - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
15 |
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.
Rock Lake