LIHI Certificate #25 - Pelton Round Butte Project, Jefferson County, Oregon
Pelton Round Butte Project Certified as Low Impact
At their March 28, 2007 Board Meeting the LIHI Governing Board certified the Pelton Round Butte Hydropower Project as Low Impact.
On October 30, 2006 the Portland General Electric Company (PGE) and the Confederated Tribes of the Warm Springs (Tribes), Licensees for the Pelton Round Butte Project (FERC No. 2030) filed an application to certify the project as Low Impact.
The Project is located on the Deschutes River in Jefferson County, Oregon. It is jointly owned by PGE and the Tribes. The application for LIHI certification is based on the new 50-year license that the Federal Energy Regulatory Commission (FERC) issued for the Project on June 21, 2005.
SUMMARY
Facility location: Deschutes, Crooked, and Metolius rivers, in central Oregon
Installed capacity: 366.82 Megawatts (MW)
Average annual generation: 1,591,000 megawatt hours (MWh)
FERC license: FERC No. 2030 recently relicensed for a 50-year term
Applicants Contacts:
Julie Keil, Hydro Licensing, Portland General Electric Company, 121 SW Salmon Street, 3-WTC BRHL, Portland, Oregon 97204, 503-464-8864
Jim Manion, General Manager, Warm Springs Power Enterprises, 5180 Jackson Trail Road, P.O. Box 960, Warm Springs, Oregon 97761, 541-553-1046
Date application posted to website: October 30, 2006
Date public comment period closes: December 30, 2006
Projected date for preliminary certification decision: March 2007
Project Description
The 366.82-MW Pelton Round Butte Project consists of three developments located on the Deschutes River, Crooked River, and Metolius River. The powerhouses for all three developments are integral with each of the three project dams.
The 247.12-MW Round Butte Development is the uppermost development and includes the 4,000-acre Lake Billy Chinook, the project's largest storage reservoir. Lake Billy Chinook is located on the Deschutes, Metolius, and Crooked Rivers.
The dam for the 100.8-MW Pelton Development is located on the Deschutes River about 7 miles downstream from the Round Butte Dam. The 540-acre Pelton reservoir, known as Lake Simtustus, begins at the base of the Round Butte Dam.
The 18.9-MW Reregulating Development is the most downstream development; its 190-acre reservoir on the Deschutes River extends from the tailwater of the Pelton Dam 2.5 miles downstream to the Reregulating Dam.
The principal features of the Round Butte Development are:
(1) a 1,382-foot-long, 440-foot-high compacted, rock-filled embankment dam;
(2) a 535,000-acre-foot reservoir (Lake Billy Chinook);
(3) a powerhouse containing three 82.35-MW turbine generating units and one 70-kilowatt generating unit with a total installed capacity of 247.12 MW;
(4) three 2,800-foot-long, 230-kilovolt (kV) transmission lines extending from the powerhouse to the Round Butte Switchyard;
(5) a fish hatchery (Round Butte Hatchery) located adjacent to the dam; and
(6) appurtenant facilities.
The principal features of the Pelton Development are:
(1) a 636-foot-long,204-foot-high concrete arch dam with a crest elevation of 1,585 feet mean sea level (msl);
(2) 7-mile-long, 540-acre reservoir (Lake Simtustus) with a gross storage capacity of 31,000 acre-feet at a normal maximum water surface elevation of 1,580 feet msl;
(3) a powerhouse with three turbine generating units with a total installed capacity of 100.8 MW;
(4) a 7.9-mile-long, 230-kV transmission line extending from the powerhouse to the Round Butte Switchyard; and
(5) other appurtenances. The principal features of the Reregulating Development are:
(1) a 1,067-foot-long, 88-foot-high rock-filled embankment dam with a spillway crest elevation of 1,402 feet msl;
(2) a 2.5-mile-long, 190-acre reservoir with a gross storage capacity of 3,500-acre-feet and a useable storage capacity of 3,270 acre-feet at a normal maximum water surface elevation of 1,435 feet msl;
(3) a non-operating 3-mile-long fishway extending from the tailrace upstream to the forebay of the Pelton Development;
(4) a powerhouse containing one 18.9-MW, bulb-type turbine generating unit;
(5) a 200-foot-long, 6.9 kV primary transmission line extending from the generator to a step-up transformer located adjacent to the powerhouse; and
(6) other appurtenances.
The Federal Energy Regulatory Commission (FERC) issued a new 50-year project license to PGE and the Tribes on June 21, 2005. The commitments stated in the multiparty settlement agreement, as modified by FERC, become the conditions of the new license.
The Pelton Round Butte project owners and a wide variety of government and non-government organizations representing the various interests chose to take a collaborative approach and reached agreement on the future operating conditions and long-term resource protection, mitigation, and enhancement measures.
Project Operation
The Round Butte and Pelton developments are operated as peaking facilities, typically generating between the hours of 6 a.m. and 11 p.m. daily. Lake Billy Chinook provides seasonal storage and is currently drawn down as much as 85 feet, to elevation 1,860 feet msl, in the winter, although typically the lake is only drawn down about 10 feet, to elevation 1,935 feet. The lake is typically refilled during the months of April and May. During the summer, the reservoir is held at the highest practicable level with a relatively stable pool elevation that usually does not fluctuate more than 1.0 feet below the normal maximum pool elevation of 1,945 feet msl. The surface elevation of Lake Simtustus usually fluctuates less than 0.75 feet per day but exceeds 3.5 feet per day about 25 percent of the time due to flow fluctuations produced by Round Butte.
The Reregulating Development is operated to attenuate high and low peak flows produced by the upstream developments. Flow releases are controlled to maintain an average daily flow in the Deschutes River downstream of the Reregulating Dam that approximates the average daily inflow to the project. The Reregulating Reservoir surface elevation fluctuates as much as 27 feet (between 1,435 feet msl and 1,408 feet msl) daily; however, typical fluctuations are about 15 feet daily. The turbine and spillway gates automatically respond to river stage measurements recorded at a United States Geological Survey (USGS) gage (No. 14092500) located at the dam.
Under the original license, flows downstream of the Reregulating Dam are kept at or above a minimum flow of: (1) 3,000 cfs or inflow, if less, from July 1 through February 28; and (2) 3,500 cfs or inflow, if less, from March 1 through June 30. Ramping rates below Reregulating Dam are limited to 0.1 feet per hour and 0.4 feet per day, except from May 15 to October 15, when ramping rates are limited to 0.1 feet per hour and 0.2 feet per day.
Project Vital Statistics
* Pelton Round Butte is the largest hydroelectric project completely within Oregon's boundaries.
* The Project area is approximately 19,300 acres, with about 4,700 acres of that occupied by the reservoirs.
* The Project length is about 20 river miles of the Deschutes River Canyon. The project also extends into two tributaries, the lower seven miles of the Crooked River and the lower 13 miles of the Metolius River.
* The total annual power production (1.5 billion kilowatt-hours) is enough to supply more than 137,000 average homes in PGE's service territory or a city about the size of Salem, Oregon's capital.
Note: (December 22, 2006) Based on a request from American Rivers the LIHI Board has granted an extension of time for Public Comments to January 19, 2007.
EXTENDED PUBLIC COMMENT PERIOD FOR THE PELTON ROUND BUTTE HYDROELECTRIC PROJECT RUNS TO JANUARY 19, 2007
We encourage public comments on this application. Specifically, we are interested in knowing whether you think the Pelton Round Butte Hydroelectric Project meets our Low Impact criteria. Review our program and criteria (click on the "Low Impact Certification Program" to the left), and then review the Pelton Round Butte Hydroelectric Project information.
Comments that are directly tied to specific Low Impact criteria (flows, water quality, fish passage, etc) will be most helpful, but all comments will be considered. Comments may be submitted to the Institute by e-mail (preferred) at info@lowimpacthydro.org with " Pelton Round Butte Hydroelectric Project " in the subject line; by fax at (206) 984-3086; or by mail addressed to LIHI, 34 Providence Street, Portland, ME 04103.
Comments must be received at the Institute on or before 5 pm pacific time on January 19, 2007 to be considered. All comments will be posted to the web site and Portland General Electric Company and the Warm Springs Power Enterprises will have an opportunity to respond. Any response will also be posted.