By Adam Lapierre
Hood River News
Since its completion in 1923, the Powerdale Hydroelectric Project has been a major obstacle for aquatic wildlife in the Hood River. The 200-foot-long concrete diversion dam is located just a few miles upstream from the Hood River’s confluence with the Columbia, meaning significantly restricted access to and from roughly 144 miles of upstream habitat for Hood River’s native fish population.
For the 60 or so people who attended a public meeting last week, plans to remove the dam in a few months was music to their ears. Representatives from PacifiCorp, Columbia Land Trust, Hood River Watershed Group, Oregon Department of Fish and Wildlife and Hood River Parks and Recreation District attended at the meeting to answer questions, take input and help explain their roles in the upcoming project.
The decommissioning and removal of the dam will start in April 2010 and is expected to be complete about seven months later. By this time next year, the diversion dam, fish trapping facility, intake structure, power canal, steel flume and sand-settling basin at the site know as “Copper Dam” should be a thing of the past; in its place a stretch of rapids at a natural grade, where fish and wildlife can once again pass freely up and downstream.
“Nothing is going to happen overnight,” Rod French, district fish biologist for the Oregon Department of Fish and Wildlife said about the affects of dam removal. “It took a long time for the fish population to degrade to where it is today, and once the dam is gone it’s going to take some time for it to rebound.
“This project will mean a lot for the health of the river, and we are expecting considerable returns over the long term.”
French noted that although the dam was a fairly large barrier for upstream fish movement, the larger problem has been for fish passing downstream through the dam. He said “substantial” numbers of fish trying to migrate downstream make it into the diversion pipeline, where they are almost certainly killed. For ocean-bound species, that has meant large numbers of the population are killed before they can live out their life cycle and eventually return to their home waters to spawn.
The diversion pipeline, which channeled water from “Copper Dam” to the powerhouse three miles downstream, took 500 cubic feet per second of water away from the river. During low-flow summer months, that amounted to up to 80 percent of the river flow diverted into the pipeline. With significantly reduced water levels, river temperatures in the three mile stretch between the dam and the powerhouse were at times elevated above accepted state standards.
“We are anxious to see the project completed,” said Steve Stampfli, Hood River Watershed Group coordinator. “This is going to eliminate the lowest, most significant barrier in the valley’s most significant watershed.
Also scheduled for removal in the same time period is the tall green water tower (which was a surge tank for the diversion pipeline) and a maintenance garage structure three miles downstream for the dam, at the site known as Powerdale.
A majority of the metal pipeline that stretches the about three miles from the diversion dam to the power house will have an uncertain fate; at least for the immediate future. Wood segments of the line that were damaged in 2006 will be removed with the project, but the remaining metal pipeline and concrete support structures are not included in the decommissioning agreement.
From the downstream (north) end, the pipeline is a fairly well-known walking, fishing and recreation path for the public, particularly in the summer months. The fate of the pipeline was discussed at the public meeting, and while some cited electated sections of the pipe as a danger and a liability, everyone seemed to agree that an access path of some kind is very important.
In addition to paying the $2,400,000 price tag for the removal project, PacifiCorp has also agreed to turn over about 400 acres land known as the Powerdale lands corridor, which runs on both sides of the Hood River between the diversion dam and the substation just outside of downtown Hood River.
Tentatively, three entitites have been chosed by a group called the Powerdale Lands Stakeholders to adopt the corridor property. A final recommendation by the stakeholders is scheduled to be made by Dec. 31 of this year, and as of now the plan is for Hood River County to take over 101 acres, Columbia Land Trust 263 acres and Oregon Dept of Fish and Wildlife 32 acres of the corridor.
If the agencies agree to adopt the land, they will be legally bound to manage it based on a draft management strategy drawn up by the Powerdale Lands Stakeholders. As stated in the draft, the following management guidelines must be followed, in order of priority from first to fourth: (1) Protection of existing fish and wildlife habitat while allowing for habitat restoration and enhancement; (2) Retention of existing recreational uses while allowing improvements commensurate with those uses, provided such uses and improvements are consistent with Goal 1; (3) Expanded recreational and educational opportunities consistent with Goal 1; (4) Acknowledgement and preservation of rights of Confederated Tribes of Warm Springs tribal members to exercise their treaty-secured off-reservation fishing rights on the subject lands.
“This is a project that we are very enthusiastic to be a part of,” said Brad Paymar, associate director for Columbia Land Trust. “Our goal is to follow the guidelines laid out in the settlement agreement. Habitat is the number one goal, and maintaining the existing recreation in the area will be second to that.
“One thing we’d like to see is the pipeline removed. It’s a significant liability, and we’d like to eventually replace it with some sort of trail that will maintain the existing recreational use.”
After working with several state, federal and local agencies, PacifiCorp initially planned to decommission the dam by 2012. After flooding in November 2006 destroyed a stretch of the dirversion pipeline, rendering the dam inoperable for the production of electricity, PacifiCorp decided to start the project early. The extent of the flood damage would have cost PacifiCorp about $4 million to repair. With a removal date of 2012, and with other facilities that could provide the 47,000 megawatt hours estimated to be lost at Powerdale, PacifiCorp decided it was not economically viable to pursue repairs.