Antelope Dam Reservoir Report

Last Updated: December 5, 2025

Antelope Dam, located in Bonanza, Oregon, along the Antelope Creek, serves primarily for irrigation purposes.


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Summary

Completed in 1959, this earth dam stands at a height of 16 feet with a hydraulic height of 14 feet and a structural height of 17.5 feet. It has a storage capacity of 1400 acre-feet, with normal storage levels reaching 973 acre-feet. The dam spans 900 feet in length and covers a surface area of 205.4 acres, providing water resources for agricultural activities in the region.

Managed by a private owner, Antelope Dam is regulated by the state with permitting, inspection, and enforcement carried out by the Oregon Water Resources Department. Despite being classified as low hazard potential, the dam is considered to have a moderate risk level. The dam's spillway is uncontrolled, with a maximum discharge of 400 cubic feet per second, and features needle outlet gates. With a last inspection date in August 2015 and an inspection frequency of six years, the dam's condition assessment is currently not rated.

Overall, Antelope Dam plays a crucial role in sustaining water resources for irrigation in Klamath County, Oregon. Its strategic location along the Antelope Creek and efficient design ensure reliable water supply for agricultural activities in the region. As a key infrastructure for water management, the dam's operational and maintenance practices are essential to ensure its continued functionality and safety for water resource and climate enthusiasts alike.

Year Completed

1959

Dam Length

900

Dam Height

16

River Or Stream

ANTELOPE CREEK

Primary Dam Type

Earth

Surface Area

205.4

Hydraulic Height

14

Drainage Area

10.23

Nid Storage

1400

Structural Height

17.5

Outlet Gates

Needle

Hazard Potential

Low

Nid Height

18
       
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.