A dam designed to protect life and property by holding back ash and volcanic debris has exacted a high price for the wild salmon and elk herds of the Toutle River Valley, near Mount St. Helens.
Wildlife continues to struggle for survival in the harsh environment, prompting comparisons between the once-lush Toutle River area and the barren desert of California's Death Valley.
Saving a species from extinction is not easy, but one or two days each week Cowlitz Tribe biologist Shannon Wills dreams of bringing wild runs of salmon and steelhead back to the North Fork of the Toutle River.
The wild salmon that she and Washington Fisheries biologists handle each week are few in number. But they're "tough, resilient animals," descendants of the native salmon that survived Mount St. Helen's eruption nearly 30 years ago.
Three decades ago this May the volcano blew her top, shooting a giant wall of logs, mud and ash down the Toutle River system.
In an amazing engineering effort to protect life and property, the U.S. Army Corps of Engineers quickly built a dam on the N. Fork Toutle designed to hold back 250 cubic yards of debris.
The trouble was they didn’t build a fish ladder for salmon to pass around the dam. Since the 1980s, wild Toutle River salmon must first be caught in a trap, then removed by humans from the thick, slurry, ashen water.
It isn't easy for the fish, Wills said.
“It’s like sandpaper to the fish. Just think about it: they get that micro-abrasion from the ash and it’s so thick they can’t breathe," she said. "It’s a bit like us trying to breathe in a sandstorm - you can only last for so long.”
A glance upriver from the dam and another obstacle for the fish is visible: a massive debris flow that has backed up behind the Sediment Retention Structure completed by the Corps in 1983.
The snaking debris flow smothers everything in its path and is growing bigger each year.
Some call this area “Death Valley” because of the fish and wildlife habitat lost, covered by a growing mud-and-ash flow streaming down from Mount St. Helens.
Wills noted that it’s an area few tourists to the mountain ever see; an area kept "hush-hush" by the Corps.
“They’ve kept this really quiet ... Kind of ‘don’t ask -- don’t tell’ -- and so people don’t realize it’s here,” according to Wills.
But word about the vast sediment plain and what challenges it presents to fish and wildlife has gotten out. Locals aren't happy about what they call a "growing problem that's been ignored."
Biologist Bob Brown told KGW that a close look at the soil shows the problem.
"[The soil] is abrasive, like a thousand little knives, and it's also so pervasive that it's not very healthy for the fish," Brown said, adding the river itself is no longer a "fish friendly" part of the ecosystem. Salmon and steelhead runs that once numbered in the tens of thousands have dropped to the hundreds.
There’s no stability to the soil; there’s no shade across the plain here. But there is a braided, meandering river crossing a hot wasteland during summer months that during winter become a frozen, barren tundra.
Mark Smith remembers when the N. Fork Toutle was 150 yards across at its widest, prior to the 1980 eruption. Thirty years later the river is more than 2 miles wide, due largely to the ash, rock and debris that has backed up behind the dam.
The shallower river shifts in ribbons across the valley floor. In winter months it moves erratically with heavy waters flowing down the mountain, Smith said, killing trees and shifting tributary creek mouths - or consuming them entirely.
Sediment has gouged out critical elk habitat on a state-managed wildlife refuge that further erodes each winter as more and more of the ground falls away, he added.
“We came in and we made a super-unnatural environment and we are going to pay for it, either in more lost habitat or fewer wildlife species that can survive in this sacrifice zone,” Smith said.
Tim Kuhns, a biologist and manager with the Corps of Engineers, agreed that some fish do have problems with migrating parts of the flow. But had the ash and mud not been stopped by the dam, he argued, the Corps would still be dredging the Cowlitz and Columbia rivers 30 years later.
“It has done what it was designed to do ... store over a hundred million cubic yards of material that would have worked its way through the system. Overall, on it’s timeline and considering the amount of material, it’s done pretty well,” Kuhns said, adding that the flow of ash and mud will continue down Mount St. Helens via the N. Fork Toutle River.
Wills counters that the sediment flow is itself the "source" of all the ash. The dam itself, designed to hold back ash and debris, now creates the flow, too.
Meanwhile, the legacy for wild salmon remains unnavigable home waters filled with soot from the 1980 eruption. Instead, salmon take a truck ride and a 20-foot slide down a plastic pipe, into a "tributary" named Bear Creek. Against all odds, the fish survive in the volcano's own Death Valley, Wills said.
“People need to get down on their knees and thank the lucky stars that we still have salmon up here because if this was humans, we’d have been extinct a long time ago."