By David Hanson
The drawdown has already begun. We have to drag our kayaks across forty feet of sticky, fine-grained gray sediment recently exposed around Lake Mills, the upper reservoir of the Olympic Peninsula's Elwha River to even get to the water. On September 15th, 2011, the 210-foot-tall Glines Canyon Dam just below us will officially become the largest dam removal project in the country.
7.5-foot notches will be cut out of alternating sides of the concrete dam to drain the lake in measured increments. The second largest dam removal project will happen simultaneously, a few miles downstream at the 108-foot tall Elwha Dam. Over a three-year process the Elwha River will return to its free-flowing state, a 45-mile corridor that begins in the core of the Olympic Mountains and flows through temperate old-growth forests to the Strait of Juan de Fuca. On a larger scale, the much-watched removals will educate the country on how to rehabilitate a dammed river.
So a few Seattle-based friends and I went to paddle the middle section between the two dams as a way to understand what's in store for boaters on the new/old Elwha. The middle section begins a few hundred yards below the Glines Canyon Dam, where the pour-over looks like the next great waterfall drop for Tyler Bradt-- a perfect sloping boof ledge and a thick, even curtain of water twenty yards across--only, it's a dam and drops onto solid bedrock in a bowl the size of a hotel room. It's a mesmerizing sight, and it speaks to the engineering marvel of a turn-of-the-century dam and the mystery of what kind of river is buried underneath the twenty million cubic yards of sediment behind the dam (four more million cubic yards are in the lower reservoir, Lake Aldwell).
I asked Tim Randle, Manager of Sedimentation and River Hydraulics for the Bureau of Reclamation, to rephrase that amount of sediment: "If you were to place that volume of sediment in the river valley between the lower dam and the Strait - five miles of 200-foot-wide river channel - the sediment would stack up 123 feet high."
Much of the Elwha dams-removal story revolves around social justice issues of the Lower Elwha Klallam Tribe who occupy parts of the lower watershed, and the fisheries situation with five species of Pacific salmon clamoring to return to their native spawning grounds. But there's also the recreation aspect. The same reasons that make the Elwha a uniquely diverse salmon habitat also make it one of the most beautiful river runs in the country. Tom O'Keefe of American Whitewater knows the river as well as anyone, having paddled and studied it for decades.
"Most rivers on the Olympic Peninsula stay within one geologic strata, running parallel to it. The Elwha penetrates the center and cuts through all the layers. That's why you have distinct big canyons and then alluvial valleys. It's also why you have so many salmon species. Geologic diversity lends itself to diverse habitats." And a diverse kayak run. It starts eight miles above Lake Mills with the classic four-mile Class V wilderness run of the Grand Canyon of the Elwha, then the two-mile alluvial Geiser Valley section, followed by two miles of the Class IV+ Rica Canyon.
For now, the middle section that we're paddling, offers the best indication for boaters of what lies below the two reservoirs. It begins after a hundred yards of boulder sieves and log jams below the Glines Canyon Dam. The Elwha then opens and calms through a wide, shallow section before constricting into the fastest and steepest section of the middle run. The one Class IV move lurks there after a sharp bend to the left. A thin wave train piles up on river left and drops through a few small holes toward a Volkswagon-sized boulder where the flow pillows right, sending boaters to the calm of the river-center pool. From there, the canyon sides ease down and the river takes on a more wide, gravel-shallow, riffled character for five miles until it hits the Lake Aldwell delta.
So the question is, what will this free-flowing run look like in its entirety? What lies below the reservoirs and sediment? O'Keefe has studied historic photos preceding the dams, and he's read accounts from the 1889 Press Expedition that traversed the Olympics in 19th Century epic style. O'Keefe guesses that the section beneath Lake Mills will be a mild, Class II alluvial valley, much like the Geiser Valley upstream. He sees Glines Canyon, where the dam now sits, as becoming a Class V section of complex moves and massive boulders, a final leg to the expanded Grand Canyon of the Elwha segment. The middle section will likely remain the same, and Lake Aldwell's draining will reveal Class II and III whitewater with well-defined rapids.
But Randle warns not to get too excited. The whole flushing process of the river will take three years and no one really knows what the changes will reveal. "The width of the Glines Canyon Dam is only about 50' at bottom," says Randle. "The last little bit will have to be blasted out. You'll see the river become really turbid and chaotic. It will only be a few days of heavy movement and shifting, but it won't be real natural. And it'll be dangerous, especially since everyone wants to be the first to paddle the new river."