Lachapelle Enl. Of Ben Res. Reservoir Report

Last Updated: December 5, 2025

Located in Uinta, Wyoming, the Lachapelle Enlargement of Ben Reservoir is a private irrigation dam designed by M.


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Summary

Malner and completed in 1997. This earth dam stands at a height of 34 feet with a hydraulic height of 29 feet and a length of 1020 feet. It serves the primary purpose of irrigation and has a storage capacity of 303 acre-feet, providing water for agricultural use in the region.

The dam is situated on the East Branch of Lachapelle Creek and is regulated by the State of Wyoming with inspection, permitting, and enforcement processes in place. Despite its poor condition assessment in 2018, the hazard potential is considered low with a moderate risk level assigned. The spillway is uncontrolled with a width of 20 feet, and the outlet gates consist of a valve system.

With Liz Cheney (R) representing Congressional District 00, Wyoming, the Lachapelle Enlargement of Ben Reservoir plays a vital role in water resource management in the area. Its strategic location in Evanston and contribution to irrigation make it a crucial infrastructure for sustaining agricultural activities in the region. Despite its condition, the dam continues to serve as a key component of the local water supply system.

Year Completed

1997

Dam Length

1020

Dam Height

34

River Or Stream

EAST BRANCH LACHAPELLE CREEK

Primary Dam Type

Earth

Surface Area

30

Hydraulic Height

29

Nid Storage

303

Structural Height

34

Outlet Gates

Valve - 0

Hazard Potential

Low

Foundations

Soil

Nid Height

34
       
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.