Big Cliff Dam is a concrete gravity dam on the North Santiam River in the western part of the U.S. state of Oregon.[3] The dam spans the Linn CountyMarion County border in the Oregon Cascades.

Big Cliff Dam
Big Cliff Dam on the North Santiam River
Big Cliff Dam is located in Oregon
Big Cliff Dam
Location of Big Cliff Dam in Oregon
CountryUnited States
LocationLinn CountyMarion County, Oregon
Coordinates44°45′3.6″N 122°16′59.16″W / 44.751000°N 122.2831000°W / 44.751000; -122.2831000
PurposePower
StatusOperational
Construction began1949
Opening date1953; 71 years ago (1953)
Owner(s)U.S. Army Corps of Engineers
Dam and spillways
Type of damConcrete gravity
ImpoundsNorth Santiam River
Height191 ft (58 m)
Length280 ft (85 m)
Elevation at crest1,212 ft (369 m)
Reservoir
CreatesBig Cliff Lake
Total capacity6,450 acre⋅ft (7,960,000 m3)
Surface area128 acres (0.52 km2)[1]
Maximum length2.8 mi (4.5 km)
Commission date1953
Turbines1 x 18 MW Kaplan-type[2]
Installed capacity18 MW

The dam's primary functions are flood control, power generation, irrigation, fish habitat, water quality improvement, and recreation. It is one of 13 dams created by the U.S. Army Corps of Engineers under the Willamette Valley Project which was authorized by the Flood Control Act of 1938.[4]

It was constructed between March 1949 and May 1953[5] at the same time as Detroit Dam. Big Cliff is 2.7 miles (4.3 km) river distance below Detroit Dam at river mile 47 of the North Santiam River.

Big Cliff smooths river flow resulting from power generation fluctuations of Detroit Dam, a practice known as river re-regulation. Big Cliff Reservoir, primarily known as Big Cliff Lake, has daily depth variations of up to 24 feet (7.3 m).[3]

Big Cliff can generate up to 18 megawatts of power.[3]

The dams' operators try to keep the water temperature in the 50 to 59 °F (10 to 15 °C) range for ideal fish habitat by mixing water from the top of Detroit Lake with water from the bottom.[6]

References

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  1. ^ "Detroit Lake Temperature and Suspended Sediment Model". U.S. Geological Survey. Retrieved 10 January 2015.
  2. ^ "Appendix A - Portland District - U.S. Army" (PDF). U.S. Army Corps of Engineers - Portland District. p. A-6. Retrieved 10 January 2015.[permanent dead link]
  3. ^ a b c "Big Cliff". U.S. Army Corps of Engineers. Retrieved 2013-08-27.
  4. ^ "Willamette BiOp". Federal Caucus. Retrieved 2013-08-27.
  5. ^ Jamie Wyant (2012-06-12). "The Detroit and Big Cliff dams". North Santiam Watershed Council. Retrieved 2013-08-27.
  6. ^ Alex Paul (2009-08-04). "Corps of Engineers making repairs on Big Cliff Dam gates". Albany Democrat-Herald. Retrieved 2013-08-27. Echols said, "For a while, the water temperature got to about 68 degrees and we would like it to be in the 50s. We were able to mitigate that by running water from the power house, which is very cold, and mixing it in Big Cliff reservoir. That helped balance the temperature."
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