Overholser Reservoir Report

Last Updated: December 10, 2025

Overholser is a significant earth dam in Oklahoma City, Oklahoma, built in 1919 across the N.


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Summary

Canadian River for water supply purposes. The dam stands at an impressive 61 feet in height and spans 17,100 feet in length, with a storage capacity of 31,100 acre-feet and a normal storage level of 15,000 acre-feet. The reservoir created by Overholser covers an area of 1,500 acres and serves as a vital water resource for the region, with a drainage area of 738 square miles.

Despite its age, Overholser remains a key component of the local water supply infrastructure, with a controlled spillway and a maximum discharge capacity of 193,013 cubic feet per second. However, the dam is classified as having a high hazard potential and poor condition assessment, indicating the need for ongoing maintenance and potential upgrades to ensure its structural integrity. The risk assessment for Overholser is rated as very high, highlighting the importance of proactive risk management measures to safeguard the surrounding communities and water resources in the event of an emergency.

Year Completed

1919

Dam Length

17100

Dam Height

61

River Or Stream

N. CANADIAN RIVER

Primary Dam Type

Earth

Surface Area

1500

Hydraulic Height

61

Drainage Area

738

Nid Storage

31100

Structural Height

61

Outlet Gates

Slide (sluice gate) - 4, Tainter (radial) - 24, Uncontrolled - 1

Hazard Potential

High

Foundations

Soil

Nid Height

61
       
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.