Pelton Round Butte Hydroelectric Project

Pelton Round Butte Hydroelectric Project
Name	Pelton Round Butte Hydroelectric Project
Country	United States
Location	Deschutes County, Oregon, Jefferson County, Oregon
Coordinates	44.4811°N 121.0386°W
Status	Operational
Construction began	1958
Opening	1964
Owner	Portland General Electric
Reservoir	Lake Billy Chinook, Lake Simtustus
Plant capacity	362 MW
Plant commission	1964–1966

Pelton Round Butte Hydroelectric Project is a hydroelectric complex on the Deschutes River in central Oregon. Located near Madras, Oregon and Warm Springs Indian Reservation, it comprises two dams and associated powerplants forming significant infrastructure for regional Portland General Electric, Bonneville Power Administration interconnections and Columbia Basin power systems. The project is notable for its role in river regulation, irrigation, indigenous relations, and salmonid mitigation efforts involving federal and tribal entities.

Overview

The project consists of Pelton Dam and Round Butte Dam on the Deschutes River, creating Lake Simtustus and Lake Billy Chinook respectively, and an intermediate diversion and powerhouse complex. Developed during the postwar expansion of Pacific Northwest hydroelectric resources, it integrates with transmission networks tied to Bonneville Power Administration and serves municipal, industrial, and agricultural users in the Willamette Valley, Central Oregon and beyond. Stakeholders include Portland General Electric, the Confederated Tribes of Warm Springs, the U.S. Bureau of Reclamation, and the Federal Energy Regulatory Commission, with oversight influenced by regional entities such as Oregon Department of Fish and Wildlife and the U.S. Fish and Wildlife Service.

History and Development

Planning began in the 1950s amid rapid growth in demand for electrical power across Oregon and the broader Pacific Northwest. The project was authorized and developed by Portland General Electric with construction of Pelton Dam starting in 1958 and Round Butte Dam completed in 1964–1966, contemporaneous with other major works like John Day Dam and The Dalles Dam. Development intersected with issues involving the Warm Springs Indian Reservation, treaty rights affirmed in cases such as United States v. Winans and broader tribal water and fishery claims that later involved the Confederated Tribes of the Warm Springs Reservation of Oregon. Throughout its history the project has been subject to licensing and relicensing under the Federal Power Act and adjudication with agencies including the Federal Energy Regulatory Commission.

Dams and Reservoirs

Pelton Dam is a concrete arch-gravity structure forming Lake Simtustus; Round Butte Dam is a concrete rockfill dam creating Lake Billy Chinook, a reservoir that inundated portions of the confluence of the Crooked River (Oregon), the Metolius River, and the Deschutes River. The reservoirs altered flow regimes affecting tributaries that include the Metolius River and the Crooked River (Oregon), and required coordination with projects such as the Deschutes Project and Columbia Basin water management. Engineering features mirror contemporaneous structures like Bonneville Dam in scale and required design work by firms and agencies that had roles in projects such as Grand Coulee Dam and Chief Joseph Dam.

Power Generation Facilities

The generation complex includes Pelton and Round Butte powerhouses equipped with Francis and Pelton turbines sized to a combined installed capacity around 362 MW, supplying energy into the grid via transmission corridors linked to substations in The Dalles, Oregon and connected into systems serving Portland, Oregon and Salem, Oregon. The project's operational profile complements federal reservoirs on the Columbia River operated by the U.S. Army Corps of Engineers and Bureau of Reclamation projects, participating in ancillary services, peak power production and voltage support for utilities like PacifiCorp and regional balancing authorities. Maintenance and upgrades over decades have paralleled technological advances described in engineering literature from institutions such as Oregon State University.

Environmental and Fishery Impacts

Impoundment at Round Butte and Pelton disrupted historic runs of anadromous fish including Chinook salmon, Coho salmon, steelhead trout, and Pacific lamprey, affecting tribal fisheries for the Confederated Tribes of Warm Springs and neighboring tribes such as the Confederated Tribes of the Umatilla Indian Reservation and the Nez Perce Tribe. Mitigation has involved fish passage studies, construction of a downstream fish collection and transport program, and implementation of the Round Butte Fish Passage Project in partnership with federal agencies and tribes. Environmental review under the National Environmental Policy Act and compliance with the Endangered Species Act has guided measures addressing water temperature, dissolved oxygen, and habitat restoration involving organizations such as the National Marine Fisheries Service and the Oregon Department of Environmental Quality.

Operations and Management

Operations are managed by Portland General Electric under FERC licensing, with long-term agreements and collaborative governance including the Confederated Tribes of Warm Springs and federal partners. Licensing processes have required coordination with the Federal Energy Regulatory Commission and coordination with regional planning bodies such as the Northwest Power and Conservation Council and the Columbia River Inter-Tribal Fish Commission. Management includes flow scheduling, sediment management, and adaptive mitigation programs implemented with partners like the U.S. Fish and Wildlife Service and academic institutions including University of Oregon researchers.

Recreation and Public Access

Lake Billy Chinook and Lake Simtustus support boating, angling, camping and wildlife viewing, attracting visitors from Bend, Oregon, Redmond, Oregon, and Prineville, Oregon, with facilities managed by local parks departments and private marinas. Recreational use interfaces with cultural resources of the Warm Springs Reservation and requires coordination with the Oregon State Parks system and county authorities in Deschutes County, Oregon and Jefferson County, Oregon. Interpretive programs discuss hydroelectric history alongside regional subjects like the Oregon Trail corridor, regional geology of the Cascade Range and native cultural sites.

Category:Hydroelectric power stations in Oregon Category:Dams in Oregon Category:Buildings and structures in Deschutes County, Oregon Category:Buildings and structures in Jefferson County, Oregon