LIHI Certificate #71 - Dalles Dam North Fishway Hydroelectric Project, Washington
The turbine is powered by about 800 cfs that, prior to the PUD turbine construction, plunged into a basin and then into the fish ladder as auxiliary water. The PUD diverted that flow into a screened intake structure that separates the fish from most of the flow. The fish free water powers the turbine and then supplements the flow in the north shore fishway entrance. The fish pass out the end of the intake structure and into a pipe that conveys them to the tailrace. Annual evaluation of passage conditions based on the condition of sampled fish has occurred every year, except 2007, since the unit went on line in 1991. This monitoring is stipulated in the Federal Energy Regulatory Commission issued operating permit. Annual Reports include sampling activities for that year and summaries of previous years’ data. The objective of this reporting is to summarize the results of the fish sampling, both in quantity and quality of fish, relate that to performance of the bypass system, and to suggest improvements.
Northern Wasco County PUD’s North Shore Hydroelectric project at The Dalles Dam produced its first commercial power on 28 May, 1991. The 5 megawatt generator has produced 630,293 Mwh of power since it started, which is enough to heat and light about 1000 average homes per year. Currently the power produced by The Dalles plant is being sold to Puget Sound Energy on a long term contract due to expire in 2011. When that contract expires, the PUD intends to market the power locally.
The PUD facility is located on the north shore of The Dalles Dam, technically in Washington State. The Dalles Dam is a 22 turbine federally owned “reregulating” hydroelectric facility that impounds Lake Celilo, a 25 mile reservoir/lake. It was built in 1957, long before the PUD facility.
Adult fish ladders at these large dams are long and need auxiliary water to maintain adequate attraction flows, especially at the entrances. Prior to the construction of the PUD’s hydro plant, the entrance of the north ladder at The Dalles Dam received about 800 cfs of auxiliary water from the forebay, through a rock channel. Water entering the system passed through a set of parallel bars spaced 7/8” apart called the “trash rack”. This bar assembly kept adult fish and large debris from entering the auxiliary water system. However, juvenile fish small enough to pass through these bars would end up in the auxiliary water system.
The PUD saw an opportunity to harness the power of this 800 cfs to generate electricity. One of the conditions for construction was a requirement to separate the fish from the water that would power the turbine. Consequently a dewatering structure was designed that consisted of a diagonal wall screen that would separate the fish from most of the water. The fish free water would then power the turbine and the fish would proceed toward the end of the dewatering structure.
|Project Name||Dalles Dam North Fishway|
|LIHI Certificate No.||71|
|LIHI Certificate Term||July 17, 2015 - July 17, 2020 Extended to December 31, 2020|
|Owner||Northern Wasco County People's Utility District|
|Location||Located at river mile 192 on the north shore of The Dalles Dam, technically in Washington State, on the Columbia River.|
|Installed Capacity||5 MW|
|Average Annual Generation||39,000 MWH|
|FERC No.||P-7076 issued 1987, expires 2037|
November 11, 2015: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has certified that the Dalles Dam North Fishway Hydroelectric Project (FERC No. P-7076) continues to satisfy the LIHI Certification Criteria. A Preliminary Decision was announced on November 12, 2015, and a 30-day appeal period was open through December 12, 2015. No requests for appeal were received. This Certification Decision includes one facility-specific condition, as follows:
- Although the special condition that was required in the previous LIHI certification at the Dalles Dam North Fishway facility was satisfied, management of migratory salmonids in the Columbia River remains an on-going challenge for all interests along the river. Therefore, the facility owner shall notify LIHI within 30 days of any changes in the NOAA Biological Opinion or related actions necessary to protect threatened or endangered species at the facility. LIHI reserves the right to modify the facility’s certification as needed to ensure consistency with migratory fish protection requirements of the resource agencies.
The effective certification date for the Dalles Dam North Fishway Project is July 17, 2015 for a five (5) year term, which will expire on July 17, 2020.
September 30, 2015: The Low Impact Hydropower Institute received a complete application for a new term of Low Impact Certification for the Northshore Fishway Hydroelectric project on September 1, 2015. The application materials can be found in the Files section below.
April 21, 2011: The North Shore Fishway Hydroelectric Project has been certified as low impact for a five year term, effective July 17, 2010 and expiring July 17, 2015.
September 17, 2010: The public comment period on the application for certification has been closed.
July 17, 2010: The Northern Wasco County PUD has submitted an application for the certification of the North Shore Fishway Project. The public comment period will remain open for 60 days.