Featured Stories

Other Pamplin Media Group sites

Journey through the Clackamas


ESTACADA NEWS PHOTO: JOSH KULLA - Ackerman works at the River Mill Dam's jueveile fish sampling facility.

It’s been a good year for Spring chinook salmon in the Clackamas River.

Officials from Portland General Electric, who operate a variety of fish passage programs at the river, report that counts for returning Spring chinook, the river’s most populous fish, were almost double their normal numbers.

This year, 3,500 adult spring chinook successfully swam through the Clackamas River from the Pacific Ocean. Typically, this number is about 1,800.

“We’re excited about that, and hope to see it continue,” said Nick Ackerman, a fish biologist at PGE.

Most of these fish swam through the Clackamas, Willamette and Columbia Rivers and reached the Pacific Ocean near Astoria in the Spring of 2013 or 2014. In this journey, chinook are joined by other fish, such as coho salmon and steelhead.

Ackerman estimated that of this group, approximately 130 thousand chinook smolt initially made the journey from the Clackamas River to the Pacific Ocean. Often, many fish do not return from the ocean to spawn.

Ackerman attributed the chinook’s successful year to recently-created facilities for fish passage. The energy company has installed an additional surface collector at North Fork Reservoir, a fish ladder at River Mill Dam, sorting facilities for both juvenile and adult fish and extended a fish pipeline.

The company’s licence with the FERC (Federal Energy Regulatory Commission), which allows them to operate hydroelectric projects on the river, requires a 97 percent survival rate for fish. The license was most recently renewed in 2010 and lasts for approximately 40 years.

“It ensures that if we’re going to generate energy from this power source, we do things to ensure that there’s little impact for fish populations,” Ackerman said, also noting that the most recent license has included recreation projects, such as the updated Promontory Park.

Fish passage was a significant element of the 2010 relicensing.

“(The old license) emphasized hatchery fish,” Ackerman said. “Before, there was less of an emphasis on wild fish passage. It’s why there’s been so much construction lately.”

When swimming in the Clackamas River, fish stay anywhere from several days to several months.

“Chinook often stay for awhile because the river provides a natural spawning habitat,” Ackerman said.

There are a variety of PGE-operated facilities along the river to ensure that the fish pass safely around the River Mill, Faraday and North FoESTACADA NEWS PHOTO: JOSH JULLA - Ackerman examines a juvenile fish at the River Mill Dam's sampling facility.rk Dams, all designed to divert the fish away from turbines, where the survival rate is 70 percent.

While swimming to the mouth of the Clackamas River at Gladstone, juvenile fish go through a surface collector to bypass the River Mill Dam. The surface collector allows the fish to safely bypass the dam by using pumps to swiftly suck water that simulates a river flow, which draws the fish in.

Next, juvenile fish go to a sampling facility and are briefly studied by biologists, who spend anywhere from 15 minutes to an hour at the facility each day.

“We want to balance getting good information with minimizing the impact on the fish population,” Ackerman said.

Juvenile fish then continue their journey downstream through a seven mile pipeline that runs below one of Estacada’s sidewalks.

To bypass the dams, adult fish travel on a series of rising pools, known as a fish ladder.

First built in 1911, the fish ladder on the Clackamas River was the first of its kind west of the Mississippi River.

“Fish passage was included on the Clackamas from the start,” Ackerman said. “That was a big deal.”

Today, the fish ladder is around 8 miles long and the longest functional fish ladder in the world.

At the adult sorting facility at the North Fork Dam, wild and hatchery fish are sent their separate ways. Completed in 2011, the facility is one of the first-of-its kind and does not require the use of nets or anesthesia. Using the sorting facilities’ observation tank, a biologist presses a button to open the pathway for a wild fish or a hatchery fish. The hatchery fish are marked with a tail punch and returned downstream to Barton Park, and wild fish are released above the North Fork Dam.ESTACADA NEWS PHOTO: JOSH KULLA - A series of pools known as a fish ladder aids fish in their journey through the Clackamas River.

Biologists typically spend 45 minutes a day at the sorting facility, and a computer keeps track of the numbers and types of fish.

The sorting process takes five to eight seconds. At the previous facility, the process took up to an hour and required biologist to sort fish by hand.

“It’s a less stressful experience (at the new sorting facility),” Ackerman said. “It’s pretty short lived. Our objective is to get the fish through the process as fast as possible.”

At the North Fork Dam, there are several facilities in place to ensure that fish continue safely on their journey, including two additional surface collectors and a 50 foot net to prevent fish from going into the dam’s spillway, where excess water from the dam goes.

With two surface collectors at North Fork, the majority of the fish find their way through one.

One surface collector was built in 1958, and another was completed in 2015.

The surface collectors operate similarly to the one located at River Mill. Juvenile fish are naturally attracted to the simulated downstream flow, and once they enter the collector, the water velocity will be too fast for them to turn around.

Next, the fish are directed into a pipeline that will drop them downstream of the River Mill dam in just several hours.

After spending time exploring the ocean, chinook return to the same parts of the river where they were hatched to reproduce.

Biologists at PGE are eager to continue aiding fish in this process.

“We have a good record (with fish passage), and we’re taking steps to have the premiere fish passage (system) in the United States,” Ackerman said. “The improvements translate to getting more fish back from the ocean.”

This email address is being protected from spambots. You need JavaScript enabled to view it.