Visit this page often for regular updates about events, ongoing research and programs, and other topics of interest at our Clackamas hydroelectric project.
Oct. 22, 2020
Fire can make life difficult for fish in the short term. Stream temperatures rise, excessive debris can fall into the river, and bank erosion can increase the turbidity of once-clear water. But luckily for any adult salmon or steelhead seeking refuge in the North Fork Reservoir in the last few weeks, they had a new shady place to hide and rest: over a dozen log structures installed in the transition zone between the river and the North Fork Reservoir. The woody structures were placed earlier this summer by the Oregon Wildlife Foundation, with design from McBain Associates, construction by Aquatic Contracting and funding from PGE’s Clackamas Habitat Fund. These groups worked closely together throughout the project, from the concept phase through design and construction, all the way up until the last log was placed.
In fact, clear communication and shared problem-solving allowed the project to be completed both under budget and ahead of schedule – a fact that likely spared it from serious fire damage. (Had construction still been in progress during the fire, we might have lost equipment or logs on the riverbanks awaiting placement.) Unlike other habitat structures in the area primarily designed to enhance cover for young fish, these new features were built with both adult and juvenile salmon in mind. The log jams create complex dynamics in the reservoir, providing shallow areas with slow-moving water as well as deep pools and rocky riffles. Over 6,500 wild adult salmonids migrate through our hydropower project on the Clackamas each year, with many electing to spawn in this region. Recent use of the area has increased as well, thanks in part to the installation of other woody debris structures built by the Forest Service between 2015 and 2017.
Our biologists are hopeful that these improvements will compound the benefits for fish and wildlife in North Fork Reservoir, leading to an increase in spawning and juvenile numbers.
Sept. 17, 2020
The Riverside Fire that sparked around Labor Day has continued to grow within Clackamas County. We know customers, park visitors and environmental stakeholders are anxious to hear how PGE’s facilities in the area have fared. Here’s what we know so far:
In response to the growing wildfire danger, PGE preemptively turned off the Oak Grove, North Fork and River Mill powerhouses along the Clackamas River. Additionally, river flow is currently being passed over the spillways at Lake Harriet, North Fork, Faraday and River Mill Dams to reduce impact.
At this time, it appears that all our fish passage infrastructure has survived the fire. The surrounding area has been evacuated and field work has been placed on hold until PGE staff can safely return to the site.
Before evacuating, biologists placed our adult sorting facility into volitional passage mode, meaning fish could swim freely upstream without needing to be sorted or counted. We will not have fish counts for those days and can’t definitively confirm if we reached the historic 4,000 fish mark for this year's wild spring Chinook run (which was forecasted to occur).
It is unlikely that many hatchery fish made it into the wild fish sanctuary of the upper Clackamas.
Nearby fires led to the closure of all PGE parks located along the Clackamas River, including Timber Park, Faraday Lake, Promontory Park, Clackamas River access sites, Lake Harriet and Timothy Lake. PGE crews have confirmed that Promontory Park and Marina and the North Fork Lower Boat Launch are still standing and not currently at risk. The only structural damage sustained was to spare park amenities in storage. Level 3 evacuation orders are still in effect for the area.
June 17, 2020
Warm weather means Clackamas River Pacific lampreys are on the move. As part of our annual trap-and-haul program, our biologists are spending the summer collecting, tagging, transporting and releasing these unusual fish.
Lampreys are often feared or misunderstood, but they’re both ecologically and culturally significant to the Pacific Northwest. These eel-like fish play an important role in marine and freshwater food webs. Additionally, many Native American tribes have been harvesting lampreys for centuries for subsistence, ceremonial and medicinal purposes.
Once widely distributed throughout the West, lamprey populations have declined throughout the region. In the Clackamas River, the construction of River Mill and North Fork Dams created impediments to upstream passage for adults. Fish ladder infrastructure – designed for salmon and steelhead – caused problems for lampreys, which struggle to swim in swift currents and around sharp corners.
In 2006, we reconstructed the fish ladder at River Mill Dam to include lamprey passage features. Lampreys quickly responded to these improvements, returning to the stretch between River Mill Dam and Faraday Diversion Dam. However, passage through the North Fork fish ladder is still low, and we are trying to determine why.
Scientists suspect that adult Pacific lampreys are attracted to areas occupied by juvenile lampreys. Since very few of these fish make it upstream of North Fork Dam to spawn, there is likely a lack of juvenile pheromones to attract adults upstream. In 2017, PGE biologists began trapping hundreds of adult lampreys at River Mill Dam and releasing them above North Fork Reservoir. We’ve continued this work every summer since. By moving fish above North Fork Dam, we aim to increase spawning in the Upper Clackamas Basin.
Over time, we hope the offspring of adult lampreys transported upstream will entice adults to move above North Fork Dam on their own. In addition to these trap-and-haul efforts, we also microchip up to 200 individuals each year, allowing us to track their movements through the North Fork fish ladder and identify any areas of concern.
Despite changes in operation caused by Covid-19, these essential efforts will continue in 2020. This year, we began trapping for lampreys at the River Mill ladder in mid-May. Throughout the summer, we will trap and haul up to 400 individuals and tag another 100-200 to help evaluate passage.
March 19, 2020
This spring, PGE will use a unique tracking method to study the movements of juvenile Chinook in North Fork Reservoir. This process, known as acoustic telemetry, will help us better understand the safety and effectiveness of our downstream passage facilities.
An acoustic telemetry study involves using acoustic tags and receivers to remotely track fish movement in multiple dimensions with a high degree of accuracy. Acoustic tags implanted into fish transmit sounds underwater that are “heard” by a network of hydrophones. By determining the sounds’ arrival time at multiple receiving locations, the 3D position of fish can be accurately estimated. Each tag emits a slightly different sound, which means that the location of many individual fish can be recorded simultaneously.
We’re trying to gain a better understanding of how juvenile Chinook behave in North Fork Reservoir, helping us refine our estimates of fish collection efficiency at North Fork Dam. Fish collection efficiency is a metric biologists use to gauge how well a fish collector is performing, and refers to the percentage of passage-seeking smolts that are captured and passed safely downstream. The higher the collection efficiency, the better the passage system is working.
PGE biologists have been developing detailed plans and securing equipment since last fall. The hydrophone array will be set up in North Fork Reservoir in mid-March. Releases of tagged fish will occur from mid-April through mid-May, with tracking occurring through late June. Final results of the study should be available in the first quarter of 2021.
Starting in mid-April, juvenile Chinook will be captured in our bypass facilities, tagged and then hauled to North Fork Reservoir for release. This process will take place five days per week. Acoustic tags are tiny – three millimeters wide and 15 millimeters long – and emit a sound pulse every three seconds.
During the monitoring period, it is critical to visit each of the 26 hydrophones in our array at least once a week to download data and check that the hydrophones are working properly.
Once all of the tagged fish have left the reservoir, the data will be analyzed, using sophisticated software to determine fish positions every few seconds over the entire duration of the study. Those positions are used to create “fish tracks” that can show us exactly when and where individual fish were in the reservoir.
Feb. 6, 2020
Winter on the Clackamas River is prime time for steelhead fishing. With an early run of hatchery fish spawning below River Mill Dam in January and February and a later run of wild fish typically peaking in March, there are plenty of steelhead to see, celebrate and attempt to catch. This year, we want to see the best photos from your steelhead fishing experience.
Snap a photo of your steelhead catch or views from the boat between now and April 17 for a chance to win our Steelhead Ahead Sweepstakes.
Here’s how to enter the competition:
Join us on Facebook .
Post your photo to the Facebook group, using the hashtag #ClackOnTrack
Like and comment on the other great photos you find.
Prizes include gift cards to Sportsman’s Warehouse, free camping at Promontory Park and PGE outdoor gear perfect for a day on the water.
P.S. When taking your photo, please handle fish with care, especially if practicing catch-and-release. Keep fish in the water, avoid poking the gills, and fully support the fish’s body weight by holding it horizontally.
Dec. 23, 2019
Warm-weather seasons busy with field work come and go. But here at West Side Hydro, we also appreciate fall and winter for the opportunity they provide to analyze all of that data we gathered. This year, we’re especially interested in the presence of fresh spring Chinook redds on new gravel distributed downstream.
Despite an average return of fish, we counted more spring Chinook redds downstream of River Mill Dam than ever before, thanks in large part to our gravel augmentation program. You might remember that we placed 20,000 cubic yards of gravel alongside the river last year to help restore rocky material for macroinvertebrates and spawning fish. (See our Spring 2019 newsletter for a refresher). In April, the Clackamas received heavy rainfall, and the high flow carried almost the entire gravel pile downstream.
During the two spawning surveys we completed in 2019, we found a total of 156 spring Chinook redds and 254 live fish. That’s more than three times the number of redds found in 2013 or 2018, and five times the number of redds found in 2012!
While the total number of spring Chinook at North Fork Dam has remained static or declined over the study period, the number of redds and spawning fish increased substantially in 2019.
Additionally, redds were observed in areas where the proper material for building fish nests was largely absent prior to the gravel augmentation program. While normal variation in environmental conditions could be influencing spawning distribution, the data strongly suggest that this year’s impressive movement of gravel played a large part in attracting spawning fish.
Oct. 30, 2019
This summer, PGE selected six organizations to receive $1.84 million in funding for Clackamas Basin habitat projects. Recipients will begin their work in 2020, contributing efforts toward fish passage, habitat restoration, and improving water quality.
Recipients include partners PGE has worked with for many years, like the Clackamas River Basin Council, as well as organizations that are newer to the PGE family, like the Oregon Wildlife Foundation. “There’s a great deal of collaboration taking place in this basin,” says Lindsay Smith, the License Manager for Westside Hydro. “We’re happy to work with all of our Clackamas Basin partners, and know that the work of one organization will benefit all of the others as well.”
This year’s selection process was the third cycle for the Clackamas Habitat Fund, which also granted funding in 2012 and 2015. PGE will complete two more rounds of funding in 2023 and 2029, reaching a total investment of $8 million in our Clackamas Basin community.
The selection process involved site visits, a thorough review of application materials, and consideration of potential impact. “It’s more than just a license requirement for us,” says Smith. “We take the time to ensure we’re doing our homework and funding meaningful projects.”
The recipients of this funding cycle are:
Clackamas River Basin Council
Eagle Creek Large Wood Enhancement
Kingfisher Side Channel Project
Shade our Streams
Suter Creek Fish Habitat Restoration
Clackamas Soil & Water Conservation District
Clackamas River Invasive Species Partnership
Oregon Wildlife Foundation
Clackamas River Fish Habitat Enhancement Project, Upstream of North Fork Reservoir
Sept. 12, 2019
This August, PGE biologists once again donned their snorkel suits to brave the waters below Timothy Lake Dam in search of a special fish: the spectacular cutthroat trout. This study, which takes place every five years, helps us assess the status of cutthroat and other trout populations, including rainbow, brown and brook trout. Through these evaluations, we hope to learn more about the potential impact of our new flow regime below Timothy Lake Dam.
In 2013, flows were enhanced downstream of Timothy Lake Dam to help improve conditions for fish in the Oak Grove Fork. To determine the effect of these new flows, we capture, mark and count cutthroat and other salmonid species, allowing us to calculate population estimates and collect data on the size and abundance of fish. We hope that the studies will eventually show whether or not the new flow regime has changed the population structure or assemblage of fish.
Biologists angle for fish, which they mark with a small notch in one fin and then release. Then our scientists suit up and snorkel, observing and counting both marked and unmarked fish. This mark-recapture method allows for a population estimate to be calculated by comparing the ratio of marked to unmarked fish. We use the same methods every time we conduct the study so we can compare results from year-to-year.
Between 2009 and 2014, cutthroat trout populations appear to have increased in three of the four sites surveyed. However, the median length of all fish caught decreased over that same period. Until this year, 2014 was our only survey conducted since the flow regime changed, so further studies are still needed in order to observe any statistically significant trends. We will continue to repeat this evaluation every five years for the remainder of our hydropower license on the Clackamas River.
June 10, 2019
Pacific lamprey were once widely distributed along the Pacific rim, from central Baja Mexico to the Bering Sea and along the coast of Japan. But over time, lamprey distribution shrank and populations declined, mostly due to human impact. While these creatures are often feared or misunderstood, they’re both ecologically and culturally significant. Lamprey serve an important role in marine and freshwater food webs. Furthermore, they are cherished by Pacific Northwest Native American tribes who have harvested the fish for subsistence, ceremonial and medicinal purposes for centuries.
Lamprey have had a bumpy history in the Clackamas as well. The construction of River Mill Dam in 1911 created a serious impediment to upstream passage for adults. Fish ladder infrastructure, highly successful at passing salmon and steelhead, caused problems for lamprey, who struggle to swim in swift currents around sharp corners. In 2006, the River Mill fish ladder was reconstructed to include lamprey passage features. Lamprey quickly responded to these improvements, recolonizing the stretch from River Mill Dam to Faraday Diversion Dam. However, evaluations indicated that passage through the North Fork fish ladder, constructed in 1958, was still low. To better understand migration obstacles, we released lamprey within the North Fork Ladder and studied their responses. Some fish swam downstream, exiting the ladder into the Faraday Diversion Dam tailrace. Others continued upstream, swimming into North Fork forebay. Many lamprey either disappeared after release or over-wintered in the ladder. Based on these results, it is hard to identify a single cause of poor lamprey passage, but one possibility is a lack of motivation. Adult lamprey do not return to their natal stream like adult salmon. Rather, they are drawn to areas where juvenile lamprey reside. Since very few lamprey successfully reach upstream of North Fork Dam, there is likely a lack of juvenile pheromones to attract adults upstream. In 2017, PGE biologists started a lamprey trap and haul program to provide passage above North Fork Dam and help resolve some of these issues. We also continue to tag fish and evaluate their movement through the Clackamas Project.
Each year, starting in 2017 and continuing through 2025, PGE biologists trap hundreds of adult lamprey and release them above North Fork Reservoir. By moving fish to the upper basin, we hope to increase juvenile production and entice adults to swim upstream. In 2017 and 2018, several collected fish were given radio tags, allowing us to study their migration throughout the year. We learned that lamprey actively moved upstream following their release and dispersed throughout their historic range. Additionally, up to 200 individuals are implanted with PIT tags annually and are used to evaluate passage through the North Fork ladder. Motivation appears to be increasing, but overall passage rates are still low.
This year, we began collecting lamprey at the River Mill ladder in mid-May. Throughout the summer, up to 400 individuals total will be trapped and hauled upstream of North Fork Reservoir and another 100 to 200 will be PIT-tagged and released within our project to help evaluate passage. We are also evaluating the efficacy of future studies that involve changing operations or repeating passage tests to help us better understand what we can do to aid Pacific lamprey in the Clackamas Basin.
March 6, 2019
For 88 years, spring Chinook were absent from the lower Oak Grove Fork – extremely low flows in the summer caused by historic dam diversions meant that fish couldn’t enter this Clackamas tributary.
In 2013, that all changed. Thanks to several major habitat and flow projects, spring Chinook are now returning to Oak Grove Fork, where PGE biologists monitor their populations.
Every other year, biologists snorkel the lower Oak Grove Fork, swimming upstream to observe and record numbers of spring Chinook. This survey provides information on the various life stages of fish present in the stream.
A rotary screw trap is installed each year in the same location. The trap collects a sample of out-migrating juvenile fish; this data is compared to samples from previous years, allowing us to evaluate the effect of recent changes.
Improvements to the lower Oak Grove Fork include habitat alterations (large wood installation, gravel augmentation, and restoration of side channels) as well as enhanced flows from Lake Harriet Dam.
Early indications suggest that fish populations have responded quickly and positively to the habitat changes in the lower Oak Grove Fork.
ODFW spawning data obtained in 2018 suggest that this area is responsible for 7.5 percent of all spring Chinook redds in the Clackamas basin.
Collection of fry, smolts and other juveniles at the screw trap indicates that successful spawning is taking place in the area.
Despite their extended absence from 1924 to 2012, spring Chinook now represent the second most abundant fish species produced in the lower Oak Grove Fork.
Spring outmigrant sampling will continue for three more seasons, followed by a five year break, then another five years of sampling.
Dec. 7, 2018
In 2013, PGE began a multi-year evaluation of upstream fish passage through the Clackamas Hydroproject and into the upper basin. This ongoing study allows our biologists to monitor the migration of winter steelhead, spring Chinook, coho, and Pacific lamprey, helping us understand how our facilities and dams may be affecting fish behavior.
Each year, biologists collect a small percentage of adult fish at the North Fork Sorting Facility and carefully implant radio transmitters into the animals’ throats. The fish are released below the Project so that their movement can be monitored through our facilities and beyond.
Radio tags emit continuous signals which are detected when fish pass by a receiver. We have 29 receivers in fixed locations throughout the hydroproject and the upper basin, and we also track fish manually by foot, vehicle, and even helicopter. Using multiple tracking methods allows our biologists to access remote locations and gather a more complete picture of where, when, and how fish move throughout the river.
The study has helped us understand how long it takes fish to navigate various stretches of the river and our fish ladders. Additionally, the study has shown that our improvements to fish passage infrastructure have shortened the amount of time fish spend traveling through our project, enabling them to reach historic spawning grounds in the upper river earlier.
Fish also have a higher chance of survival, likely caused by a reduction in stress during their migration through our sorting facility. In fact, we’ve seen an 80 percent reduction in pre-spawning mortality for Chinook!
Nov. 2, 2018
30 miles of streamside habitat in the Clackamas basin have been restored thanks to the Shade our Streams program, powered by a partnership between PGE and the Clackamas River Basin Council (CRBC).
Staff from PGE, CRBC, and the Oregon Department of Environmental Quality (DEQ) recently toured several of these sites, witnessing their amazing transformation.
At each site, invasive species like Japanese knotweed and reed canarygrass were removed, beneficial native plants were installed, and in some areas, logs and boulders were placed instream to enhance aquatic habitat. Healthy riparian areas like these reduce erosion, enhance water quality, and support fish and wildlife.
During the tour, a pair of coho salmon even showed up to express their gratitude!
Aug. 14, 2018
It’s raining gravel at Oak Grove Fork!
Every year, PGE deposits 500 tons of gravel into Oak Grove Fork, allowing the rocks to slowly move downstream and improve the ecosystem below Lake Harriet dam. Gravel provides necessary habitat for macroinvertebrates as well as spawning grounds for the salmon that eat them.
When dams on the Clackamas were constructed decades ago, they cut off the flow of gravel, logs, and other debris, resulting in a river that lacked necessary components of habitat for fish and insects. Today, the annual gravel augmentation restores this essential biological process that was interrupted for so long.