Northern Wasco Public Utility District files application for North Shore fishway Hydroelectric Project at Dalles Dam

Portland, Maine (July 17, 2010) – The Low Impact Hydropower Institute (LIHI) announced today that the Northern Wasco County Public Utility District (“PUD” or “Applicant”) has submitted an application for certification of the North Shore Fishway Hydroelectric Project (“Project”).  The Project is located on the north shore of the US Army Corps of Engineers Dalles Dam. The PUD facility is located on the north shore of The Dalles Dam, technically in Washington State.

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’s of power since it began operation---enough electricity 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 Dalles Dam is a 22 turbine federally owned “reregulating” hydro electric 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.

Public Comments

We encourage public comments on this application. Specifically, we are interested in knowing whether you think this Project meets our LIHI criteria. Review the program and criteria in greater detail and then review the Project’s application. Comments that are directly tied to specific LIHI 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 at info@lowimpacthydro.org  with " North Shore Fishway 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 Eastern time on September 17, 2010 to be considered. All comments will be posted to the web site and the applicant will have an opportunity to respond. Any response will also be posted.