Pelton Regulating Reservoir Report

Last Updated: December 6, 2025

Pelton Regulating, also known as Pelton Reregulating Reservoir, is a privately owned structure located in Warm Springs, Oregon, along the Deschutes River.


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Summary

Built in 1958, this gravity dam stands at 40 feet tall and has a storage capacity of 3,500 acre-feet. With a maximum discharge of 30,000 cubic feet per second, the reservoir covers a surface area of 210 acres and serves multiple purposes including hydroelectric power generation.

Managed by the Federal Energy Regulatory Commission, Pelton Regulating plays a crucial role in regulating water flow and ensuring a stable water supply for the surrounding area. Despite its high hazard potential, its risk assessment is rated very high, emphasizing the importance of effective risk management measures. The dam features a controlled spillway with a width of 80 feet and four slide gates for water control.

The structure has not been inspected since September 2020, highlighting the need for regular monitoring and maintenance to ensure its structural integrity and safety. With its significant impact on water resources and climate in the region, Pelton Regulating remains a vital component of the local ecosystem and energy infrastructure.

Year Completed

1958

Dam Length

1067

Dam Height

40

River Or Stream

Deschutes River

Primary Dam Type

Gravity

Surface Area

210

Hydraulic Height

25

Drainage Area

7636

Nid Storage

3500

Structural Height

40

Outlet Gates

Slide (sluice gate) - 4

Hazard Potential

High

Nid Height

40
       
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.