News Release
| Release Number: | 99-088 |
| Dated: | 9/29/1999 |
| Contact: | Matt Rabe, 503-808-4510 |
Portland, Ore.--Water releases from Dexter Dam will be increased Monday, Oct. 4 to test recent work on the dam's lone generator, and the increases could impact downstream users of the Middle Fork Willamette River.
Engineers, powerhouse operators and reservoir regulators from the U.S. Army Corps of Engineers have coordinated efforts to increase water releases from the dam and powerhouse from 2,500 cubic feet per second to about 4,200 cfs beginning at 7 a.m. to 'tune' the unit. The actual test will begin at 10 a.m. and will last about one hour.
The Willamette River just below Dexter Dam will rise about one foot during the height of this test, then will recede as releases are decreased. The river will rise about 0.8 feet at Eugene. Following the test, water releases from the dam will be gradually decreased to 2,500 cfs.
Dexter water releases are maintained at 2,500 cfs during September and October to maintain river conditions for spawning fish and to help lower upstream reservoirs for the winter flood damage reduction season.
"During the testing we check the generator's response to a power system disturbance" said Judy Stromquist, assistant operations manager for the Corps' Willamette Valley projects.
"The new system will provide better voltage control and better response to system disturbances. The old system was very slow in response to disturbances," she added.
Dexter Dam's single power unit has a generating capacity of 15,000 kilowatts. Power generated at the dam is fed into the Northwest Federal Power System.
The Corps began replacing the excitation system - which controls the generator voltage - at Dexter on Aug. 1 to replace the original equipment that has been in operation since 1955, according to Stromquist.
Engineers were able to perform the majority of the work on the equipment without interrupting power production, though the generator has been off-line since Sept. 13 to complete the job.
Similar work was completed at Big Cliff Dam in August. New excitation systems are scheduled for installation at Lookout Point and Detroit dams beginning October 1999 and January 2000, respectively.
"Our goal is to improve system reliability," she said.