The Willamette Falls Hydroelectric Project (FERC #2233) is located at river mile 26.5 on the Willamette River between Oregon City and West Linn in Clackamas County in north-central Oregon. The Willamette River flows north to its confluence with the Columbia River at Portland and drains an area of approximately 11,250 sq mi. The Project is located in a highly populated, industrialized urban setting about 10 miles from downtown Portland. Willamette Falls is a horseshoe-shaped, 40-foot-high, natural waterfall that marks the head of the tidally influenced lower Willamette River. The obstruction of the river by volcanic bedrock causes the river to cascade over a Falls producing a hydraulic head of at least thirty feet. The Project is owned and operated by PGE.
|Project Name||Willamette Falls|
|LIHI Certificate Number||33|
|LIHI Effective and
|November 2, 2012
November 2, 2017
|Owner||Portland General Electric|
|Location||Located at river mile 26.5 on the Willamette River between Oregon City and West Linn in Clackamas County in north-central Oregon.|
|Installed Capacity||15.18 MW|
|Average Annual Generation||122,471 MWh|
The site has been home to hydroelectric generation for more than 100 years, beginning with PGE’s Station A in 1889 and continuing to this day with PGE’s T.W. Sullivan Powerhouse, built in 1895, and the now-shutdown Blue Heron Paper Company (BHPC) powerhouse, built in 1916. Paper mill operations have also been present at the Falls for more than a century. Historically the area was also home to flour, saw and pulp mill operations that no longer operate. A navigation canal and locks on the west bank of the river have been operated since 1873, providing 30 ft of lift for commercial barge transport and recreational boat traffic.
The project lies entirely within the city limits of Oregon City on the east shore of the Willamette River and the City of West Linn on the west shore. The project boundary of the Willamette Falls Project encompasses 97.23 acres and includes the project facilities described below. Most of the property within the project boundary is owned by PGE.
The pool upstream of Willamette Falls extends approximately 30 miles to RM 56. Given the Project’s highly developed and industrialized setting, the impoundment was not included within the project boundary by FERC. Computer modeling indicates that the pool without any Project structures would extend approximately to RM 54.
The horseshoe-shaped project dam is located along the crest of Willamette Falls and consists principally of a 600-foot spillway section, a 2,300-foot dam topped with flashboards, the T.W. Sullivan (TWS) Powerhouse, containing 13 units with a total generating capacity of 16 MW and the now-shutdown BHPC Powerhouse, containing 2 units with a total generating capacity of 1.5 MW. At the time that PGE applied for a new license for the Project, BHPC operated the BHPC Powerhouse and was co-licensee for the Project. As discussed in documents (attachment 3) provided by the Applicant as part of this filing, PGE purchased, shutdown, and is decommissioning the BHPC Powerhouse as part of the suite of fish protection measures agreed to in the Settlement Agreement and implemented in the FERC license.
The Project also includes the West Linn Paper Company’s (formerly Simpson Paper) grinder rooms number two and three at the north abutment of the dam. In 1996, FERC approved the decommissioning of the generating facilities of the project’s Simpson Development. However, because these structures and facilities were integral to the project’s dam, they remained in the project boundary and under license. A fish ladder, owned and operated by ODFW, is located on the west side of the Falls, and includes three entrances within the Falls and one at the TWS Powerhouse tailrace. A navigation lock at the Project is owned and operated by the U.S. Army Corps of Engineers.
Pursuant to the terms of the Settlement Agreement, as approved by the new license issued by FERC on December 8, 2005, PGE is implementing a number of measures and constructing new project facilities to improve fish passage at the Project. PGE has completed a number of modifications to the Project’s forebay, has installed a second fish bypass system (the North Fish Bypass or NFB), and is now completing a flow control structure at the apex of the Falls to improve downstream migrant passage over the Falls.
The Willamette River flows from southwest to northeast emptying into the Columbia River at Portland. The project operates in a run-of-river mode and does not provide useable water storage or flood control. Flashboards are added to the dam around the crest of the Falls during low flow periods of the year, typically summer through fall. The flashboards are allowed to washout as flows increase. Under the range of normal operations, the water surface at the dam varies from approximately 54 feet msl during low flow with the flashboards installed to about 58 feet during normal winter flows, when flashboards have washed out. Typical water surface elevations are in the range of 55 to 56 ft msl.
The Willamette Falls Dam diverts water into the T.W. Sullivan powerhouse forebay on the west side of the river. The water intakes for the turbines are located at the base of the powerhouse. Water diverted through the powerhouse rejoins the main river immediately below the Falls. Since the tidal effect of the Pacific Ocean is evident all the way to the base of Willamette Falls, the tidal influence on tailwater elevation also has a small effect on hydroelectric generation.
PGE terminated operation of the BHPC development in 2003. As discussed in greater detail in Attachment 3, the Settlement Agreement and the new license provided for PGE to permanently decommission the development. This process is scheduled to be completed in 2008.
December 5, 2012: The Low Impact Hydropower Institute has determined that the Willamette Falls Hydroelectric Project continues to meet the certification criteria. They have been re-certified for a second five year term of low impact certification, effective November 2, 2012 and expiring November 2, 2017.
February 29, 2008: The Willamette Falls Hydroelectric Project has been certified as low impact for a five year term, effective November 2, 2007 and expiring November 2, 2012.
November 2, 2007: Portland General Electric has submitted an application for certification of the Willamette Falls Project.