John Day Dam

The John Day Dam is a concrete gravity run-of-the-river dam spanning the Columbia River in the northwestern United States.<ref>Template:Cite web</ref> The dam features a navigation lock plus fish ladders on both sides. The John Day Lock has the highest lift (at Template:Convert) of any U.S. lock.<ref>Template:Cite web</ref> The reservoir impounded by the dam is Lake Umatilla,<ref>Template:GNIS</ref> and it runs Template:Convert up the river channel to the foot of the McNary Dam. John Day Dam is part of the Columbia River Basin system of dams.

Location

John Day Dam is located Template:Convert east of the city of The Dalles, Oregon, and just below the mouth of the John Day River. The closest town on the Washington side is Goldendale, Template:Convert north. The closest town on the Oregon side is Rufus. The dam's crest elevation is approximately Template:Convert above sea level. It joins Sherman County, Oregon with Klickitat County, Washington, Template:Convert upriver from the mouth of the Columbia near Astoria, Oregon.

History

Construction of the dam began in 1958 and was completed in 1971,<ref name="oclc">Template:Cite web</ref> making it the newest dam on the lower Columbia, at a total cost of US$511 million. The pool was filled in 1968 and a dedication ceremony was held on September 28, 1968.<ref>Template:Cite web</ref> The first vessel through the new lock was the Coast Guard buoy tender USCGC Blueberry.<ref>Template:Cite news</ref> John Day Dam was built and is operated by the U.S. Army Corps of Engineers. The condemnation of land upstream of the dam led to the Supreme Court case United States v. Rands,<ref>Template:Cite web</ref> a well-known case regarding the constitutional doctrine of navigable servitude. The dam's power generation capacity is 2,480,000 kW (overload capacity). Skeleton units for eventual installation of four additional generators were fitted to the powerhouse during construction, allowing for a 20% increase in output should the decision be taken to complete them.<ref>https://usace.contentdm.oclc.org/digital/api/collection/p16021coll11/id/426/download Template:Bare URL inline</ref> The dam underwent a major repair to the upper lock gate in 2010, as documented in an episode of the National Geographic Channel program World's Toughest Fixes.<ref name="TheFutonCritic airdates">Template:Cite web</ref>

As of 2007, the 76-mile-long reservoir formed the deadliest stretch of the Columbia River for migrating young salmon. The reservoir is the longest lake on the Columbia that young salmon must swim on their way to the ocean.<ref>Template:Cite news</ref>

Specifications

• Altitude: 266 feet (81 m) above sea level
• Height: 183 feet (56 m)
• Length: 7,365 feet (2,327 m)
• Navigation lock:
  • Single-lift
  • 86 feet (26 m) wide
  • 675 feet (206 m) long
• Powerhouse
  • Sixteen 140,000 kW units (4 additional incomplete skeleton units installed in powerhouse during construction)
  • Total capacity: 2,240 MW (2700 MW if all twenty generators installed)
  • Overload capacity: 2,485 MW
• Spillway
  • Gates: 20
  • Length: 1,228 feet (374 m)

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Images

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See also

• Hydroelectric dams on the Columbia River
• List of power stations in the United States
• List of hydroelectric power stations
• List of dams in the Columbia River watershed
• List of largest hydroelectric power stations in the United States
• Blalock, Oregon

Sources

• Template:Cite web
• Template:Cite web

External links

• John Day Dam US Army Corps Engineers