Helping the Fish to Cross the Road
In recent years, efforts to restore fish habitat in the US have gained momentum. It has been recognized that barriers to fish passage have suppressed populations of salmonid fish species such as coho, Chinook, steelhead, and others. These fish are important for many reasons. According to the Wild Salmon Center (WSC), at least 137 different species, including grizzly bears and orca whales, depend on the marine-rich nutrients that wild salmon provide. Salmon, WSC says, are considered key to protecting the environment in the North Pacific: “Protect salmon and you protect forests, food, water, communities, and economies.” The Columbia River Inter-Tribal Fishing Commission, a consortium of native tribes involved in fishing rights on the Pacific Coast, says salmon are also central to the spiritual and cultural identity of tribal members, and for many, fishing is still the preferred livelihood.
Proponents of salmon habitat restoration have been very effective in focusing attention on removing or modifying massive structures that pose barriers to salmon habitat, such as hydroelectric dams and impoundments explicitly engineered to impede and redirect the flow of streams and rivers. But the US Fish and Wildlife Service says that throughout the US, more than six million barriers exist blocking waterways of all kinds, some of which have outlived their original intent. Among these barriers are a large number of structures that were not specifically designed to modify or significantly alter hydrology, but that nonetheless negatively affect fish passage and survival. Culverts at road and rail crossings rank high among the types of infrastructure causing these inadvertent problems for aquatic life.
According to the Federal Highway Administration (FHA), estimates of road and railroad crossings affecting Massachusetts streams are as high as 28,500. In the western states of Washington and Oregon, a survey of Bureau of Land Management (BLM) and US Forest Service land found 10,000 culvert crossings on fish-bearing streams, with more than half considered to be barriers to juvenile salmon passage.
Large woody debris, coir fiber blankets, and wattles combine
to stabilize Crystal Springs Creek.
While advocates for preserving migrating fish habitat have called vocal attention to dam removal projects and to promoting installations of fish ladders—structures designed to allow adult fish to migrate to spawning areas in upstream lakes and headwaters—the plight of their hatched spawn and juvenile fish inhabiting headwaters encumbered by any number of culverts has been largely overlooked. However, recent developments have shed light on the role of culverts in undermining fish habitat.
A Salmonic Nightmare
Immature fish lack ability to overcome even the most modest of the obstacles presented by culverts. Installed, for the most part, to strengthen society’s interconnectedness through transport and transit, culverts have had the opposite effect on salmon, fragmenting the ecosystems they inhabit, isolating populations, and eventually banishing them from streams in which they had thrived for eons.
According to the FHA, culverts can damage fish habitat through a variety of mechanisms. They “tend to reduce the sinuosity of a stream, which in turn increases the slope of the stream and ultimately stream velocity and erosion potential.” The longer the culvert, the greater this tendency. A stream subject to runaway erosion and consequent turbidity, sediment deposition, and disturbance is necessarily less hospitable to sensitive species such as salmon.
Other deleterious impacts include perching, or the tendency to develop a scour hole at the outfall of a culvert due to erosion of the stream channel, representing another major stumbling block to both mature salmon and juveniles, who rely on unimpeded access to headwater streams to complete their life cycle.
According to the FHA, many of the culverts that are currently in place “were designed and installed with hydraulic conveyance as the main criterion.” In its 2010 guidance on natural stream processes and aquatic organism passage, the FHA states that factors affecting animal habitat viability “were generally not considered in designing culverts that could pass a design flow without roadway overtopping.”
James Adams, project manager for a joint US Army Corps of Engineers project with the city of Portland to restore salmon habitat on Crystal Springs Creek in Oregon, explains the challenge young salmonids face. Adams notes that Crystal Springs Creek was formerly home to abundant salmon populations; however, a number of culverts installed in the 1930s and 1940s across the creek gradually depleted these stocks. “They were designed to convey water and prevent flooding. They didn’t consider the impact they would have on juvenile salmonids.”
As Adams explains, some culverts do more harm to fish than others. “The velocity through an undersize culvert is pretty high. The recommendations from the state of Oregon are that velocities of the water going through a culvert shouldn’t be any greater than 2 feet per second. If it’s greater than that, the juvenile salmonids can’t swim up against the current. What happens is the fish, which needs to stay up in the tributaries to hide and feed itself until it grows enough so it can defend itself in the big rivers, ends up getting flushed downstream. They get up to a culvert and they get flushed down through the culvert and they can’t get back up.” On Portland’s Crystal Springs Creek, he says, “successively, over these nine or 10 culverts, they get pushed all the way to the big river where they are easy prey for predator fish.”
The solution for many of these barriers, Adams says, is to make the culverts larger “so the velocities do not exceed 2 feet per second, which would allow the fish to go through the culvert one way and come back the other and not get flushed out into dangerous, predator-laden waters.”
While salmon have been all but permanently expelled from innumerable spawning areas across the region by dams and major infrastructure, such as hydroelectric facilities that are not likely to be taken down any time in the foreseeable future, Crystal Springs Creek presented a viable opportunity to revitalize salmonid populations through an activity as simple as replacing undersized culverts.
Dream Stream
Ronda Fast, Portland Bureau of Environmental Services (BES) environmental program coordinator, says, “This idea of salmon refuge is important to their survival in the Pacific Northwest.” She observes that Crystal Springs Creek had “numerous key characteristics that would make it ideal as a salmon refuge. Number one, they are there, so the seeds for restoration can be sown.” Furthermore, she says, “Crystal Springs Creek has no barriers between it and the ocean—there are no dams between Crystal Springs and the ocean,” (which is 100 miles distant). As an additional bonus, she notes, “It’s cold. It’s a spring-fed system. The water feeding it literally bubbles out of the ground at Reed College and around East Moreland Golf Course. That doesn’t mean it stays cold, but we hope some of the projects we do are improving stream temperatures, which is a huge issue for salmon.”
Fast says the restoration of salmon habitat is important not just for ecological reasons, but also because salmon have a strong constituency in the local community, particularly among native tribes. Over the past few years, she says, the tribes of the northwestern states have brought legal action against the neighboring state of Washington, resulting in a mandate directing Olympia to address fish passage issues and their impact on native fishing rights by various methods, including removal of impediments like culverts.
BES made a careful study of the 16 culverts crossing the Crystal Springs Creek channel as it coursed from the spring-fed headwaters at Reed Canyon on the campus of Reed College, to Johnson Creek, and eventually toward the Willamette and Columbia Rivers and the ocean beyond. BES set its sights on improving and replacing the culverts that presented the most serious threats to fish passage and salmonid recovery. It settled on removing or replacing nine of the most problematic existing culvert installations.
Fishing for Partners
Fast says BES cast a wide net for partners, ultimately enlisting groups as varied as US Army Corps of Engineers, Metro, NOAA-Fisheries, the East Multnomah Soil and Water Conservation District, Reed College, and TriMet, the regional light rail system, as well as community partners such as the Crystal Springs Partnership and others, in a quest to restore salmon habitat.
With $2 million on hand, BES targeted nine culverts that presented the most serious challenges for juvenile and migrating salmon. Acknowledging that the scant funding available “would not get us to the finish line,” says Fast, BES appealed to its diverse array of partners.
One of the key partnerships involved working with the US Army Corps of Engineers (USACE) to eliminate one obsolete culvert and replace three undersized culverts with properly sized conveyances designed and installed with the salmonids’ life cycle in mind.
To bring financial heft to its role in the partnership with Portland BES, USACE engaged its authority to perform ecosystem restoration projects under Section 1135 of the Water Resources Development Act. The program allows the agency to work with local partners to restore or remedy problems resulting from past USACE projects. According to Adams, at the time USACE entered into an agreement with BES, the program authorized USACE to provide 75% of the needed funding up to $5 million, with the local partner providing 25% of the funding to cover the balance of costs. Additional funds were brought to bear through engaging authorities under Section 206, which allows USACE to work on ecosystem restoration projects that have no association with prior USACE projects. Through these means, Portland BES was eligible to receive $5 million in funding from USACE, while cost sharing with a local contribution of 35% of the cost of the overall project.
Adams says that since the time Portland applied for funding, the two civil works and ecosystem restoration programs have been updated to provide a maximum of $10 million in federal funding each. However, he concedes that with a $50 million Congressional allocation for each program, the competition for funds has been fierce.
A Multifaceted Effort
One section of the creek came into focus early as the source of multiple adverse impacts. The portion of the creek that flowed through Westmoreland Park had been converted into a swimming hole during the 1930s. That impoundment persisted as a duck pond, which, until recent times, remained somewhat popular among area residents. “But that pond served as a heat sink,” says Adams. “It would warm the water up and then send it down the creek. When adult salmon were coming up the creek to spawn, they’d sense that hot water and turn around and go back. A few made it up there, but generally not many.”
He says, “The adults didn’t have any problem getting through the velocity barrier of the culverts, but they were repelled from going up the channels due to higher temperatures.” Unless something could be done about the heat, it would cancel out the positive effects of clearing the physical obstacles from the spawning run.
Linda Scronce-Johnson, a spokesperson for Hamilton Construction, the general contractor on the project, says restoring the pond to a fish-friendly meandering stream required a multifaceted effort. “The base of the pond was concrete, and the duck population had increased significantly. Because of the decreased water flow, the water warmed up, it bred algae, and the water became very stagnant so it was uninhabitable by fish as well as being unpleasant in a park. It wasn’t really a pretty little pond anymore.”
An undersized culvert slated for replacement
Once the ducks had been relocated to an animal rescue farm, the pond could be reduced to rubble. The process began with the installation of cofferdams and silt fences, followed by the installation of pumps and piping to direct the entire creek flow away from and around the in-stream work site.
“We have a whole erosion control manual from the city of Portland. We follow all the measures that the manual prescribes, whether it be silt fences or biobags or whatever is appropriate for the specific activity involved to protect the waterway. We’re always working around waterways, so the goal is to control turbidity and control erosion from getting into the stream,” says Fast.
Complicating an already complex project, says Fast, the Oregon Department of Fish and Wildlife (ODFW) requires all in-stream work be completed within the confines of the “in-water work window.”
“It’s a period of time usually in the summer—for Crystal Springs Creek it was a six-week period from July through August where salmon and other protected species are least likely to be in the stream,” she says. “We have to do all this work in that in-water work window. It can be hectic. It’s never easy to divert a stream into a pipe. It never goes as planned, it seems.”
Adams attests to how challenging dewatering operations in a brief in-water work window can be. Although it took some time to become evident, several hours after the bypass pumps were started on Crystal Springs Creek, water began backing up upstream of the prospective work site, threatening to flood a neighborhood resident’s backyard. Adams recalls, “When we originally did the design work, we felt it would be sufficient to convey the water. But when it was put in, it didn’t go in exactly as planned. There was a little too much bending of the bypass channel, so it created a resistance to the flow. That resistance caused water to back up, and at the lowest point, on Mr. Brown’s property, he started seeing the channel slowly rising.”
The water continued to rise into the evening. “We got a call at 12 o’clock at night. We had the contractor go out and pull the cofferdams and allow the water to flow back into the channel again. We spent the next week and a half redesigning and analyzing what the contractor had placed there.” He says the problem arose from a combination of circumstances in the “capacity, design, and alignment of the pipe. We made a few changes, put the pipe back in, started the pumps, and waited 12 or 16 hours, and it worked beautifully.” However, he says, the work stoppage put the project two weeks behind schedule. With only a six-week window to complete the work in the channel, “that put a lot of pressure on the contractor.” USACE requested an extension from ODFW and the Department of Environmental Quality. The project was granted an extra two weeks for in-stream construction, “and we got it done in that time,” says Adams.
A meandering creek and scenic boardwalk replaced the
concrete-lined duck pond.
Scronce-Johnson says USACE had to first fix the water flow by replacing three culverts serving the pond. “As a part of replacing those culverts, they did streambed restoration,” improving the conditions along the waterway by allowing for a natural gravel streambed.
The narrow culvert was replaced with a widened arched culvert. This reduced velocity and improved the flow. “With the restored natural streambed, fish could travel up the channel for spawning,” says Scronce-Johnson.
To complete the work at Westmoreland Park, Adams says, USACE removed concrete along the streambanks. “We have an overflow area there, which is kind of a wetland area. We planted all that a couple of years ago, and that is still growing. It’s mostly grasses, but we also planted some trees and we’re still waiting for that portion of the project to mature and provide the over-cover canopy and shading to the creek that will really help with the temperature issues.”
Describing the outcome of the stream restoration, Fast says, “This is coming closer to natural hydrology with the wider culverts. It’s not a flashy system; it’s spring-fed, so erosion is not a problem with the more natural hydrology.” However, she says, “With the old culverts there were huge erosion issues because of the artificially accelerated flows.”
The restoration and culvert replacement projects also removed many of the concrete streambanks that had been installed in a previous era “with the thinking that it was the right thing to do,” when, in fact, the effect was “to cut off the floodplain habitat,” she says.
Westmoreland Park during construction
Coir fabric replaced the hardscaping on slopes and streambanks. “We hydroseeded riparian seed mix underneath, and then we planted small seedlings and plants through the coir. We’ve had good erosion control with that method on slopes and streambanks,” says Fast.
“We do a lot of monitoring for the Corps on how the elements that we installed are holding out over time. We care a lot about pools and riffles that we install, and at the culverts we monitor for things like incision related to the culverts themselves. A lot of the monitoring is focused on making sure the cobble stays in place as well as fish presence or absence. So far, so good,” she says.
Westmoreland Park after work was completed
A Bright Future for Salmon
In implementing infrastructure improvement projects for salmon recovery, Fast believes persistence is the key to success. “These projects can take a long time to develop.
We had a very supportive community with an understanding that they had a resource in their front yards—and backyards, and side yards. Salmon recovery is something most people support; it’s a good place to start from when you’re talking about a loud intrusive project in someone’s backyard. Salmon recovery is a good overall purpose to keep in mind.”
She adds, “From my sense, we’re proactively working on replacing culverts, and more cities are going to have to do this in the future, especially cities that are lucky enough to have salmon present to the degree they are here. Portland is right on the superhighway of many species that are threatened or endangered, and we’re taking what I think are proactive approaches to prevent further listings.”
Relocating the wildlife
While, for Fast, endangered species recovery is a major driver for culvert replacement, she believes, “The same thing is going to happen in Washington, where there is litigation going on that’s going to require more culvert replacement projects for exactly the same kinds of purposes.”
The Westmoreland Park restoration received an American Planning Association award as a sustainable park project. Scronce-Johnson says the neighbors were happy, both with the process and the outcome. Throughout the project, which took place in a moderately urbanized community, representatives of the firm and leadership of the project employed a personal touch in interacting with the community.
Culvert placed on a natural streambed
Adams agrees, saying that although there were many times when work may have inconvenienced local residents, everyone involved, from project leaders such as Fast, to the construction laborers, kept the channels of communication open with partners in the community to ensure cooperation and success.
It was a very urbanized neighborhood—between a suburban neighborhood and an urban neighborhood. Peoples’ backyards are literally right on the creek. We had a very successful coordination with the neighbors—they were all in favor of doing the project, but the construction impacts, and the road closures, and the excavators, and the cranes literally 100 feet from the person’s bedroom or kitchen window required a very good rapport with them. Periodically, Ronda would knock on doors and ask, ‘How it was going? Was the noise bothersome?’ With all the heavy equipment running, we had strict limits on when we could be working. We ran a very close coordination with the neighborhood while the construction was going on and it was highly successful.”
At the conclusion of the project an even brighter goal came into sight as it became apparent that salmon had begun returning to the formerly impeded reaches of Crystal Springs Creek. Adams notes, “The tribes were very happy. We had a dedication ceremony and the tribes came out and celebrated, and they smoked some salmon there the old traditional way, and that was really neat.”
A LEGAL CASE
It might seem to be a stretch to envision that a civil engineering problem as mundane sounding as undersized culverts could rise to a serious violation of a US government treaty. But that is what happened in the state of Washington.
During the mid-1800s, after a period of violent conflict between newcomers to the region, who were eyeing settlement, farming, and mining opportunities, and the indigenous Native American communities, treaty negotiations between the US government and Native American tribes of the Pacific Northwest were concluded. In 1855, the US and the tribes penned a treaty that, in brief, called for the tribes to cede certain territory, with the tribes, in turn, being guaranteed in perpetuity fishing rights and respect for cultural traditions centered around fishing. While the terms related to ceding native lands were strictly enforced, the tribes noted, over more than a century later, that implementation of the terms obliging the US government to honor their fishing rights seemed lacking. Numerous practices that depleted fish stocks upon which the tribes depended had been allowed to proceed almost unabated—among them the installation of impediments to migration.
In a case that took more than a decade and a half to wend its way through the judicial process, the impediments to fish passage introduced by culverts were ruled a violation of a federal treaty obligation. In June 2016, a three-judge panel of the court of appeals voted unanimously to order the state of Washington to remove, replace, or modify 1,000 culverts located within its borders to permit fish passage. With a court-ordered deadline of 17 years to complete the entire task, the potential cost has been projected to range from $1.4 to $2.4 billion.
Ronda Fast says that although Oregon was not a party to the litigation in which the tribes prevailed in Washington, her agency has chosen to heed the handwriting on the wall. “Many more projects are planned,” she says.
CITIZENS MUSSEL IN FOR SCIENCE
Salmon are not the only aquatic organisms that need help crossing the road. Freshwater mussels can also find themselves stranded in the face of an insurmountable culvert. With a single foot made for burrowing into the sediment and not for walking, a mussel cannot move very far on its own. In fact, in their adult phase, mussels live a very static life, securely dug in between the pebbles on the streambed. However, mobility is a key part of their life cycle in their youth. To survive to reproductive age, they must hitch a ride with a cooperating salmon and go with the flow.
Attached to their host fish, mussels ride in to colonize additional stream reaches. Once they’ve matured, they detach from the fish, give up their wanderlust, and dig in permanently to live a more sedentary lifestyle. That is, at least as long as they remain undisturbed—and little could be more disturbing to a freshwater mussel colony than dewatering the creek where it had come to abide.
When the Xerces Society, a scientific organization dedicated to the study and conservation of invertebrate organisms worldwide, received word that part of the installation process for the new fish-friendly culverts in Crystal Springs Creek would require complete dewatering at locations where freshwater mussels had been reported, it sprung into action. The society had been working on freshwater mussel conservation for several years downstream at Johnson Creek. Hearing reports from citizen scientists of the presence of mussel colonies farther up in the headwaters, it turned its attention toward Crystal Springs Creek.
Michele Blackburn, endangered species conservation biologist with the Xerces Society, says getting buy-in for preservation of less-photogenic species such as freshwater mussels can be “difficult and challenging. A lot of people just aren’t aware they exist in the watershed,” she says. Furthermore, freshwater mussels in the western states lack the federal protection they enjoy in the eastern states. However, as filter feeders, they perform valuable ecosystem services and are indispensable to successful salmon habitat restorations. “They remove a lot of the particles from the water so salmon can see their prey, they become food for otters and raccoons, and the beds they create make habitat for caddisflies and other organisms that the salmon like to eat,” she says.
Xerces located an upstream reach with suitable habitat for mussels, and, with the help of volunteers, waded into the stream on the eve of restoration work at the Westmoreland Park project to rescue and relocate 3,400 mussels.
Fast is impressed by the diversity present in Crystal Springs Creek and the diversity of the partnerships helping make salmon recovery possible in the stream. She says that thanks to the Xerces Society’s involvement in the project, more people in the community are becoming aware of the important species, besides the salmon, that depend on the creek. Although she admits that perhaps compared to salmon “native mussels are not as iconic, they are an important part of the habitat that’s really incredible.”