Sullivan Reservoir Report

Last Updated: December 5, 2025

Sullivan Reservoir #3, also known as Wheeler Lake, is a private water resource located in Weld County, Colorado.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1905 for irrigation purposes, this earth dam stands at a height of 11 feet and has a storage capacity of 190 acre-feet. With a surface area of 18 acres, it is situated along the South Platte River and is regulated by the Colorado Division of Water Resources.

Despite its age, Sullivan Reservoir #3 is considered to have a low hazard potential and is in a satisfactory condition as of its last inspection in September 2013. The dam features an uncontrolled spillway and has a maximum discharge capacity of 120 cubic feet per second. With a moderate risk assessment rating, the reservoir is monitored regularly for any potential risks or hazards.

Managed by a private entity, Sullivan Reservoir #3 serves as an essential water source for agricultural irrigation in the area. It plays a vital role in supporting local farming activities and ensuring the availability of water resources for the community. As a key component of the water infrastructure in Weld County, this reservoir stands as a testament to the importance of sustainable water management in the face of changing climate conditions.

Year Completed

1905

Dam Length

1650

Dam Height

11

River Or Stream

SOUTH PLATTE RIVER-OS

Primary Dam Type

Earth

Surface Area

18

Hydraulic Height

11

Nid Storage

190

Structural Height

11

Hazard Potential

Low

Nid Height

11
       
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.