McNary Dam
title: "McNary Dam" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["dams-completed-in-1954", "energy-infrastructure-completed-in-1954", "energy-infrastructure-completed-in-1957", "buildings-and-structures-in-benton-county,-washington", "dams-on-the-columbia-river", "dams-in-oregon", "dams-in-washington-(state)", "hydroelectric-power-plants-in-washington-(state)", "hydroelectric-power-plants-in-oregon", "buildings-and-structures-in-umatilla-county,-oregon", "run-of-the-river-power-stations", "united-states-army-corps-of-engineers-dams", "1954-establishments-in-oregon", "1954-establishments-in-washington-(state)", "gravity-dams", "dams-with-fish-ladders"] topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/McNary_Dam" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::data[format=table title="Infobox dam"]
| Field | Value |
|---|---|
| name | McNary Dam |
| image | McNrDam1.jpg |
| image_caption | Spillway view from the southwest, Oregon side of the Columbia River |
| dam_crosses | Columbia River |
| res_name | Lake Wallula |
| location | Benton County, Washington / Umatilla County, Oregon, USA |
| dam_type | Concrete gravity, run-of-the-river |
| operator | U.S. Army Corps of Engineers (Operator) |
| dam_length | 7365 ft |
| dam_height | 183 ft |
| construction_began | 1947 |
| opening | 1954 |
| res_capacity_total | 1350000 acre feet |
| plant_commission | 1954-1957 |
| plant_turbines | 14 |
| plant_capacity | 1,127 MW |
| plant_annual_gen | 5,170 GWh |
| spillway_type | Service, gate-controlled |
| coordinates | |
| :: |
| name =McNary Dam | image =McNrDam1.jpg | image_caption =Spillway view from the southwest, Oregon side of the Columbia River | name_official = | dam_crosses =Columbia River | res_name =Lake Wallula | location = Benton County, Washington / Umatilla County, Oregon, USA | dam_type =Concrete gravity, run-of-the-river | operator =U.S. Army Corps of Engineers (Operator) | dam_length = 7365 ft | dam_height = 183 ft | dam_width_base = | construction_began =1947 | opening =1954 | demolished = | cost = | res_capacity_total =1350000 acre feet | res_catchment = | res_surface = | plant_commission =1954-1957 | plant_turbines = 14 | plant_capacity = 1,127 MW | plant_annual_gen = 5,170 GWh | spillway_type =Service, gate-controlled | coordinates = | extra = McNary Dam is a 1.4-mile (2.2-km) long concrete gravity run-of-the-river dam which spans the Columbia River. It joins Umatilla County, Oregon with Benton County, Washington, 292 miles (470 km) upriver from the mouth of the Columbia. It is operated by the U.S. Army Corps of Engineers' McNary Lock and Dam office. The dam is located a mile (2 km) east of the town of Umatilla, Oregon, and 8 miles (13 km) north of Hermiston, Oregon. The dam was originally planned to be named Umatilla Dam, but the Flood Control Act of 1945 renamed the dam in honor of Senator Charles L. McNary of Oregon, who had died in February 1944.
The dam provides for slackwater navigation, hydroelectric power generation, recreation, wildlife habitat, and incidental irrigation.
::figure[src="https://upload.wikimedia.org/wikipedia/commons/a/a7/McNary_Dam_-seen_from_Washington_side_of_Columbia_River-_July_2013.JPG" caption="Water spilling at McNary Dam, seen from the Washington shore in July 2013."] ::
Bills for the construction of a dam were introduced in the United States Congress as early as 1931. The United States House of Representatives rivers and harbors committee initially approved the project in April 1941; navigation, power generation, and national security were the major reasons cited for construction of the dam.{{cite news |title=Umatilla Rapids dam approved by House group |date=May 1, 1941 |work= The Hermiston Herald |url=http://www.ccrh.org/comm/umatilla/primary/approval.htm
As with some other dams, it has two additional turbines whose purpose is to power the dam itself. That is, this dam is entirely self-sustaining. In the event of a large-scale grid outage, McNary would provide the black start capability necessary to restart other generation facilities. These two "station service" turbines are only capable of providing about three MW, compared to the 70 MW each of the other 14 turbines produce. These two turbines alternate service duty to provide the dam with its energy requirements.
The dam is equipped with three large "fishway" pumps which provide water to supplement the mostly gravity-fed fish ladders. These units are constructed like smaller versions of the main turbines which run "in reverse."
McNary Dam is part of the Columbia River Basin system of dams and is one of fourteen hydropower facilities belonging to the Federal Columbia River Power System (FCRPS).
Stats:
- Altitude: 344 ft above sea level
- Height: 183 ft
- Length: 7365 ft
- Navigation lock:
- Single-lift
- 86 ft wide
- 683 ft long
- Powerhouse
- Fourteen 70,000-kilowatt units
- Total capacity: 980 megawatts
- Overload capacity: 1,127 MW
- Spillway
- Gates: 22
- Length: 1310 ft
References
References
- "Carbon Monitoring for Action {{!".
- "Carbon Monitoring for Action {{!".
- "The Columbia River System Inside Story". BPA.gov.
- [http://records.sos.state.or.us/ORSOSWebDrawer/RecordView/6777852 Julius Meier's Governor's Message], 1931
- "FCRPS Hydrosystem, CPN Region {{!}} Bureau of Reclamation".
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