Ruff Detention Dam Reservoir Report

Last Updated: December 5, 2025

Ruff Detention Dam, also known as Three Falls Reservoir, is a federal-owned structure located in Cody, Wyoming.


°F

°F

mph

Wind

%

Humidity

Summary

The dam was completed in 2003 by the Bureau of Land Management and serves primarily as a gravity dam with a height of 46 feet and a length of 325 feet. It has a storage capacity of 74.62 acre-feet and is designed to manage the flow of the Sand Coulee river/stream.

Despite being categorized with a low hazard potential, the condition assessment of Ruff Detention Dam is marked as unsatisfactory. The dam is inspected every five years, with the last inspection conducted in August 2016. The risk assessment for the dam is moderate (3), indicating a level of vulnerability that requires attention and potential risk management measures. The dam does not have an Emergency Action Plan (EAP) prepared, and there is no information provided on whether the EAP meets guidelines or if inundation maps have been prepared.

In summary, Ruff Detention Dam plays a crucial role in water resource management in the region, but its current condition raises concerns about its long-term stability. With an unsatisfactory condition assessment and a moderate risk rating, it is important for the Bureau of Land Management to prioritize maintenance and potential risk management measures to ensure the safety and functionality of the dam. The lack of an EAP and updated emergency contacts further highlight the need for proactive measures to address any potential safety issues related to the dam.

Year Completed

2003

Dam Length

325

Dam Height

46

River Or Stream

SAND COULEE

Primary Dam Type

Gravity

Surface Area

9.23

Hydraulic Height

44

Drainage Area

2

Nid Storage

74.62

Structural Height

46

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

46
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.