The two-year rebuild of Tacoma Power's salmon hatchery was designed so that the utility could produce fish in a smarter, more efficient way. The new hatchery contributes about 8 million fish a year to the Cowlitz River in Washington.
By Patrick D. McCarty
Tacoma Power once took great pride in producing fish in a big way, but now the utility is more interested in producing fish in a smart way. The newly reconstructed Cowlitz Salmon Hatchery is a shining example of this changing focus. When it was originally built in 1968, the hatchery was considered state-of-the art. Through the use of innovative design features, the Cowlitz Salmon Hatchery can once again make that claim.
Tacoma Power worked closely with resource agencies for years to plan the $30 million rebuild of the Cowlitz Salmon Hatchery. The result is a hatchery that is able to produce healthier fish, which, after spending years in the ocean, will hopefully return in greater numbers to the Cowlitz River.
Background on the hatchery
The 462-MW Cowlitz River Hydroelectric Project is Tacoma Power's largest electricity generating facility, producing enough energy to serve more than 135,000 homes. On the Cowlitz River in western Washington, this project includes two dams and powerhouses - 162-MW Mayfield and 300-MW Mossyrock. To mitigate the impact of the two dams on fish in the river, Tacoma Power constructed two fish hatcheries in 1967. The utility pays the Washington Department of Fish and Wildlife to operate these hatcheries to raise fish, release them into the river and manage them when they ultimately return to the hatchery.
When the original Cowlitz Salmon Hatchery was built, it was considered the largest in the world. The salmon hatchery and separate trout hatchery reared coho salmon, chinook salmon, steelhead and cutthroat trout.
One of the regulatory requirements included in the new 35-year Federal Energy Regulatory Commission operating license for the project, issued in 2003, was a rebuild of Tacoma Power's salmon hatchery. The 2003 FERC license was a result of a comprehensive settlement agreement reached in 2000. The parties involved in the agreement included Tacoma Power, Washington DFW, U.S. Fish & Wildlife Service, Washington State Department of Ecology, National Marine Fisheries Service, American Rivers, Trout Unlimited and Lewis County. These parties met over the course of several years to determine license terms, including major improvements to both the salmon and trout hatcheries. One of the primary needs identified was to determine how the utility could raise fish that more closely mimicked natural-origin fish.
The vision was that the hatchery fish would be healthier and more likely to return to the hatchery at the end of their life. Typically, natural-origin fish survive at a higher rate than hatchery fish, so Tacoma Power would need to design the salmon hatchery so that it would more closely mimic nature during the early life stages of the fish and hopefully boost the number of adults that return.
|At the new fish separator, technicians sort the mix of wild and returning hatchery salmon, check for identification devices, and load them into the proper channels to reach holding ponds. As many as 2,500 fish are handled a day during the busiest times.|
The settlement made it clear that the emphasis on fish production has changed from quantity to quality, which is a sea change for the hatchery. There will always be a place for hatcheries, but Tacoma Power had to figure out how to use them, improve them and work at protecting native fish.
And so, the focus changed.
The utility wanted to provide a healthy environment for its hatchery fish and use innovative rearing practices to more closely match the natural conditions that native fish experience. The goal became using those methods to increase survivability and also the likelihood of fish returning to their points of origin.
To maintain a healthy environment for fish, hatcheries - and those who engineer them - must be wary of diseases and plan for ways to prevent them. One way to do that is to keep adult fish away from juveniles. Thus, the utility needed to find a way to separate them, which was a significant element of the rebuild. Tacoma Power engineers designed a new set of ponds for adult fish that would be located downstream from the rest of the facility, so there would be no water sharing or possibility of contamination. The separation will aid tremendously in raising healthier, more robust fish.
To increase the survival of juvenile fish in the facility, the utility also opted to change the pattern of the raceways, where the young fish live until they leave the hatchery. This involved changing the 100-foot oval raceways, called Burrows Ponds, where water continually circulates, to 200-foot, one-directional raceways where water flows through just once and is discarded into the river. The latter setup greatly reduces the risk of disease for the fish and is considered state-of-the-art.
One of the primary tools used to enable the hatchery operators to better mimic the natural conditions of native fish is temperature control. Typically, hatchery water temperatures are warmer than those of the river water upstream of the dams due to the influence of the reservoirs. To match the river temperature as closely as possible, Tacoma Power installed a system that filters and recirculates some of the hatchery water, allowing it to be cooled more efficiently to the desired temperature.
The raceways also were rebuilt to accommodate "volitional release." In other words, when juvenile fish are ready to leave the hatchery, they can swim into the river through a pipeline. They no longer have to wait for hatchery staff to make the decision regarding which day they will head for the ocean. Allowing the fish to move out when their instincts tell them to is another way of ensuring hatchery life mimics life in the wild as closely as possible.
Netting was installed over the hatchery to protect the juvenile fish from birds, a simple but effective addition to the facility.
|In the adult handling facility, technicians separate fish by sex and harvest eggs and sperm for fertilization. Hatching takes place in the juvenile building, where fish are raised until large enough to return to the river.|
Adult fish come home
Lots of small fish leaving the hatchery equates to plenty of big fish coming back. The adult fish return up the river at the time that is natural for them, and in a typical year, about 100,000 adult salmon and steelhead return to the hatchery separator facility. Once there, a lot of work is done to ensure those fish are accurately accounted for and end up in the correct location. They must be processed, moved through a separation facility into the fish trucks and delivered to the appropriate tributary, all in the course of a few hours.
Another important piece of the hatchery remodel was to modify the fish separation facility so it was capable of processing all returning adult fish in a given day - which could be up to 2,500 a day at peak times of the year. Tacoma Power designed and installed larger holding tanks, a new split-level sorting table and an electro-anesthesia system to double the number of fish that could be processed each day.
Rebuild helps staff, too
Fish were not the only ones on the minds of engineers during the design of the hatchery rebuild. The work of handling each fish is grueling, and hatchery employees needed some help.
Previously, regulations did not require the utility to handle and examine each adult fish returning to the facility. There has always been a fish separation component to the hatchery, but it was much less hands-on than what is required today. Fish entered the facility through a flume, and an operator performed a quick visual examination to determine species and gender before separating them by opening the appropriate gate. Today, regulations are more stringent, requiring physical handling of every fish to identify species and other characteristics, such as tags and markings.
At the fish separator, longtime Tacoma Power Fisheries Technician Gary Gilhuly adeptly operates the new controls at the separator, where the mix of wild and returning hatchery salmon are pushed through a holding tank after climbing the fish ladder into the hatchery. (Editor's note: Gilhuly recently retired with more than 43 years of service, mostly at the Cowlitz Salmon Hatchery.)
After they're electro-shocked into submission for sorting purposes, it's easy to see their bright red stomachs filled with eggs or sperm and ready for spawning. Jamie Murphy, environmental technician, handily lifts dozens of the 20- to 30-pound fish over the course of just a few minutes, running a wand over them to detect any identification devices and loading them into the proper channels, which lead to different pipes and holding ponds. Despite being shocked, they're sometimes still flailing, giving all of their energy to their biological mission of getting home to spawn.
|Design of the raceways was changed to a one-directional setup where water flows through just once and is discarded into the river. Juvenile fish live in the raceways until they are ready to leave the hatchery.|
Murphy says he used to go home "wiped out at the end of the day" when handling 2,500 fish at the hatchery's busiest times. The new setup, which brings the separation table nearly to chest height, makes his job a lot easier.
Hatchery runs during rebuild
While shutting down the facility could have cut the two-year construction period almost in half, it was important that the utility live up to the high standard it set of having fish returning to the hatchery every week of the year. Even if the hatchery was not operated for a period of time, the fish would still return, leaving Tacoma Power to handle collection in some manner or another. So, the utility set and met the goal of remaining fully operational during the rebuild and celebrated the completion of the $30 million project in May 2010.
An extremely detailed and rigorous phased construction schedule was designed to maintain fish production and timed to work with the hatchery schedule for fish spawning, egg incubation, juvenile rearing, demand for water, space for holding fish, release of smolts and return of adults. Each phase of work had a specific window of time in which it had to be accomplished, or the construction schedule could have been delayed by a year. In addition, each phase of work was dependent on the previous phase in order to maintain the complex staging of construction around fish cycles.
The lead engineer, Chad Druffel, worked with up to 20 other Tacoma Power engineers, technicians, electricians and mechanics from design through the construction, with the majority of the design work being done in-house.
It is unique to see a project of this magnitude and scope executed with primarily in-house resources from concept, to design, to construction management, to construction support and into operations. So why did Tacoma Power opt to take on this massive project? It came down to leadership, ownership and staying connected.
The utility knows its projects, facilities and needs better than anyone else. The ability to manage these projects in-house gives it a great advantage in building reliable infrastructure that meets specific needs. The team that designed the project from concept and saw it through construction is now directly involved in supporting maintenance and operation. Tacoma Power is accountable in that it is the owner of the final product, and as such has great interest in the quality and success of the project.
Tacoma Power completed the work on the hatchery in 2010 and has since worked with the Washington Department of Fish and Wildlife to reduce operating costs. Several operations previously performed at both the salmon and trout hatcheries have been consolidated at the salmon hatchery. All salmon and steelhead adult collection, holding, spawning, incubation and early rearing now occurs at just one hatchery.
A state-of-the-art visitor center was recently completed to help inform the public about the life history of salmon. The five H's - hatcheries, habitat, high seas, harvest and hydropower - so prominent in salmonid life history are featured in unique interactive displays that make learning about salmon fun for all ages.
Hatchery wins award from NHA
The Cowlitz Salmon Hatchery Visitor Center received an Outstanding Stewards of America's Waters award from the National Hydropower Association in 2012. The award, given in the public education category, recognizes companies for including "extraordinary" recreational, historical, environmental and educational values as part of their normal operations.
The center allows visitors to the hatchery to explore the connection between salmon and what it calls the "Five H's," hatcheries, habitat, high seas, harvest and hydropower. The center features a number of custom-built exhibits.
Special features of the hatchery
The Cowlitz Salmon Hatchery was conceived and designed with unique features that help mimic the life of wild salmon and protect both juvenile and adult fish. These include:
- Recirculating water treatment systems that allow incubation and early-rearing water to be heated or cooled. Recirculation maximizes valuable well-water resources;
- Reconfigured juvenile raceways so water runs through only once in order to prevent disease; previously, the water entered and exited in a circular matter;
- Overhead netting to protect fish from predatory birds;
- Automatic feeding system;
- Separate adult handling facility, including holding and handling features that are more comfortable for the fish and operators;
- Five fish crowding machines designed in-house to move fish into desired locations;
- 48-inch pipeline for out-migrating juvenile fish;
- State-of-the-art hatchery control and monitoring system; and
- Improved electro-anesthesia that provides a more fish-friendly means of handling adult fish.
Pat McCarty is generation manager for Tacoma Power. He is responsible for Tacoma Power's seven hydroelectric plants and the associated fish, wildlife and recreational activities.
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