Cutler Hydroelectric Project, Bear River, Utah -- (FERC No. 2420)
Cutler Powerhouse and Dam
Portland, Maine - (October 22, 2010) At their Annual Meeting, the Low Impact Hydropower Institute’s Governing Board determined that the Cutler Hydroelectric Project meets the LIHI Certification Criteria. In reaching its decision to certify the Cutler Hydroelectric Project, the Low Impact Hydropower Institute’s Governing Board reviewed the application for certification, as well as the Application Reviewer’s report.
In reaching its decision to certify the Cutler Hydroelectric Project, the Low Impact Hydropower Institute’s Governing Board reviewed the application for certification, as well as the Application Reviewer’s report. The Board’s vote to certify the Cutler Hydroelectric Project was unanimous and the Board approves certification for the Cutler Hydroelectric Project for five-years with the following project specific condition :
This certification by LIHI is issued contingent upon PacifiCorp, submitting to LIHI a letter within 60 days of issuance of this certification authored by the Utah Division of Wildlife Resources in which the Utah Division of Wildlife Resources states that the flows released downstream of PacifiCorp's Cutler Project No. 2420, are adequately protective of fish, wildlife, and water quality, pursuant to LIHI’s application questionnaire criteria, question A.1. Such a letter is required by LIHI because no minimum flows have been established for the Cutler Project. In the event that this letter has not been submitted to LIHI within this 60-day time period, LIHI will suspend the certification until such a letter has been received.
The effective certification date for the Cutler Hydroelectric Project is December 31, 2009 and will expire on December 31, 2014.
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Portland, Maine (December 31, 2009) – The Low Impact Hydropower Institute (LIHI) announced today that PacifiCorp Energy ("PacifiCorp" or "Applicant") has submitted an application for certification of the Cutler Hydroelectric Project ("Project"). This application for Low Impact Hydropower Certification pertains only to the Cutler project on the Bear River in Utah.
Note: A separate LIHI Certification Application posted on the same date (December 31, 2009) deals with the Soda, Grace, and Oneida Developments that are operated under FERC license No. 20 and are all located on the Bear River in Idaho
The Bear River Basin is located in northeastern Utah, southeastern Idaho, and southwestern Wyoming. It comprises approximately 7,500 square miles of mountain and valley lands (2,700 in Idaho, 3,300 in Utah, and 1,500 in Wyoming). The Bear River begins in the Uinta Mountains in Utah and extends 500 miles, crossing state boundaries five times before ending in the Great Salt Lake. It is the largest tributary to the Great Salt Lake and the largest stream in the western hemisphere that does not empty into an ocean. The Bear River ranges in elevation from over 13,000 to 4,211 feet and is unique in that it is entirely enclosed by mountains, thus forming a huge basin with no external drainage outlets.
Cutler from the West Valley
PacifiCorp operates five hydroelectric developments in the Bear River Basin. Three of the upstream developments—Soda, Grace, and Oneida—are operated under the FERC license for the Bear River Hydroelectric project No. 20 in Idaho. The Last Chance development, also located upstream in Idaho and operates under a FERC Exemption issued in 1981. The Last Chance Development, is not part of PacifiCorp's LIHI certificate applications for either FERC Project No. 20 or 2420. The Cutler project is located 44 miles downstream of the Oneida development in Utah, near the confluence of several major tributaries.
The Cutler project includes a 545-foot-long, 109-foot-high concrete gravity arch dam built in 1927. The dam has a spillway containing four 30-foot-wide by 14-foot-high radial gates. A 7- foot-diameter low-level sluiceway is located near the base of the dam and controlled by a slide gate. Irrigation canal intake gates are located at each abutment of the dam and are an integral part of the structure. The project is operated seasonally and at full pool (4407.75 feet msl) the reservoir active storage capacity fluctuates from approximately 5,800 acre feet from March 1 through December 1 to about 7,800 acre feet from December 2 through February 28. Much of the reservoir has the characteristics of a shallow-water emergent marsh; the southern portion of the reservoir has a mean depth of 1.8 feet, while the deeper section of the reservoir to the north has a mean depth of 3.6 feet. The flowline intake is a concrete tower located in the reservoir approximately 60 feet upstream of the dam. It connects to an 18-foot-diameter steel-lined conduit that passes through the dam (Figure 2.2-2). A 1,160 foot-long, 18-foot-diameter steel penstock carriers water to an 81-foot-high, 45-foot-diameter steel surge tank. Two 112-foot-long steel penstocks bifurcate from the surge tank and lead to the powerhouse. The powerhouse is a 60-foot by 123-foot brick building containing appurtenant facilities and two vertical Francis generating units with a total installed capacity of 30 MW. The Cutler project has an average annual generation of 93,287 MWh.
Cutler Dam
The Cutler hydroelectric project operates seasonally in normal and low-water years, generally from fall through early summer, based on the availability of flows after irrigation commitments are met (during high-water years there may be additional available flow). During the normal operation period, the facility is operated as a daily peaking project. When inflows to the reservoir are too low to keep an efficient load level on the generating units, water is stored on a daily basis until it reaches a level appropriate for power generation, then the water is released. Typically, the project suspends normal operation during low summer flows (July through September), but the facility remains available to provide short-duration emergency generation (spinning reserve). During normal operation periods, the project is operated in a semi-automatic mode whereby the generators are started and synchronized to the system manually by the local operator. Once on- line, the units are controlled remotely by the System Dispatcher to control the load on the generators to meet system requirements and to stay within the reservoir elevation guidelines. Substations containing step-up transformers and circuit breakers are located adjacent to the Cutler powerhouse. The substation serves as the point of interconnection to the transmission grid system.