CHINOOK, Wash. (KRT) — Six miles off shore and 210 feet below the surface of the ocean spreads the largest dumpsite ever proposed off the Pacific Northwest coast.
It’s a 14-square-mile patch that may eventually hold tens of millions of cubic yards of sediment dredged up from the mouth of the Columbia River in the annual effort to keep the river mouth clear for seagoing vessels.
Army Corps of Engineers officials say they are running out of places to dump and want to use at least some of this site in the decades ahead. But the deep-water plan would waste a precious resource: sand that could bolster a 70-mile stretch of eroding Washington beaches north of the river.
The Columbia River once played an extraordinary role in building up the southwest Washington beaches. The old free-flowing river — which drains 259,000 square miles of United States and Canada and is subject to intense seasonal flooding — washed down vast amounts of sediments, which then were flushed north by coastal currents. Studies indicate virtually all the sand on the southwest Washington coast came from the river.
But during the past half-century, much of the Columbia has been tamed by dams that created a network of slack-water pools. The sand flow has dropped by nearly 70 percent, and its movement north is impeded by a river-mouth jetty built to help large-vessel travel.
The prospect of chronic beach erosion has some people calling for a fundamental rethinking of yearly dredge disposal at the mouth of the Columbia. Rather than dump at sea, corps critics say, it’s time for a more aggressive — and more expensive — effort to get sand into the surf zone or directly up onto the shrinking beaches.
“We’re looking at some 20 years until we get to a critical point — but if we wait to do anything until then, it will probably be too late,” said George Kaminsky, a Washington Department of
Ecology geologist.
Even with less sand washing down from inland reaches, the river mouth still clogs with sediments. Most of the sand now moves in from the offshore seafloor, according to Kaminsky, who coordinates a long-term study of the southwest Washington coastline.
But the end result is the same shoals that create one of the most treacherous river-mouth passages in the nation. Dredging, which began more than a century ago, remains vital to the survival of upriver ports of Kalama, Longview, Vancouver and Portland.
Dredge ships stick 30-inch diameter pipes into the river bottom and vacuum clean a 6-mile-long channel to depths ranging from 48 to 55 feet. The work begins anew each June, and in a typical year it yields enough sediment to fill 450,000 dump trucks.
“Our primary mission is to maintain navigation for all the commerce coming into the river,” said Eric Braun, a corps official who oversees the river-mouth dredging. “And we feel we do a good job at that.”
In recent years, corps officials have recognized the value of river sands to Washington beaches. They’ve focused their dumping in a shallow “flush zone” that helps the movement of sand northward.
Known as Site E, the turbulent two-mile stretch of water has received the equivalent of 1.5 million dump-truck loads of sand in the past four years.
Corps officials say these sediments move north with currents to help replenish sands on an eroding submerged fan known as Peacock Spit. But no one knows how much sand eventually makes it to shore.
And in an area already infamous for perilous seas, commercial crabbers say Site E dumping has mounded up the bottom, creating navigational risks for them and recreational boaters.
“Protection of mariners’ lives has to take precedence over other obligations,” said Dale Beasley, of the Columbia River Crab Fishermen’s Associations.
Corps officials say they still plan to use Site E in the years ahead to help flush sands north, but the clash with the crabbers has increased pressure to open the new deep-water site.
The site still needs an official permit from the Environmental Protection Agency (EPA), though spokesman John Malek says the agency has decided to approve it. Corps officials hope the first load of sand will hit the bottom
this summer.
But the deep-water site also needs Washington permits. It faces a tough review by the state Department of Ecology, which is expected to rule on the permits later this year. State geologists say little if any of the sand dumped in deep water is likely to move north and wash up on Washington beaches.
The deep-water site also has drawn scrutiny from state biologists, who say the corps has not complied with state laws to mitigate the damage that dumping causes to crabbing grounds and other marine resources. That mitigation typically involves efforts to improve marine resources in areas outside the dump zone.
Even with such efforts, they say, the deep water site is a nutrient-rich area that should never be hit with dredge sands.
“This is essential fish habitat of the highest quality, and its conversion from a highly productive fine-grained bedlands rich in aquatic life to a disturbed mound of coarse sand would be a travesty to the environment and the fisheries it supports,” wrote Robert Burkle, a state Fish and Wildlife biologist, in a Feb. 6 letter to the state Department of Ecology.
While state officials review the deep-ocean permit, coastal communities are pressing the corps to switch directions and get more dredge sand up on the beach. No one expects this to halt the coastal erosion — but they hope to slow the pace and ease the damage.
Corps officials say their annual dredging budget — $4.6 million — leaves little room for expensive ventures in beach rescues.
But both downstream and upstream ports have embraced the idea, and their lobbying efforts yielded a $200,000 congressional appropriation for a pilot project. Another $300,000 in state money is expected.