Capital Press - With a boom, John C. Boyle Dam drawdown begins on Klamath River

This article was published on: 01/18/24 9:42 AM

JOHN C. BOYLE DAM — The blast rocked the room.

In a warehouse just steps away from the John C. Boyle Dam, more than 50 people watched Tuesday as, seconds later, a livestream video — captured by a drone hovering over the dam — showed water bursting through the 10-by-10-foot hole the blast had opened.

The group soon gathered on the walkway above the dam as water released from the upstream Boyle Reservoir surged downstream toward the Copco 1 Dam. The process, called “drawdown,” is the slow draining of water from reservoirs behind the dams.

Another step in removing four dams — the largest dam-removal project in U.S. history — along the Klamath River was successfully completed.

‘It went well’

“It went well,” understated Mark Bransom, CEO of the Klamath River Renewal Corp., the company overseeing the removal of the Klamath River’s four hydroelectric dams.

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A group watches outside events unfold Tuesday on a large screen inside the maintenance shop near the J.C. Boyle Dam.

Located about eight miles downstream from Keno, the Boyle Dam is the uppermost of the dams. Late last year, the smallest of the four, Copco 2, was removed. The three remaining dams — Boyle, Copco 1 and Iron Gate — are scheduled to be removed later this year, possibly by September or October, to allow that stretch of the Klamath to become a free-flowing river once again.

Before the dams are taken out, a series of drawdowns are planned to drain the reservoirs.

The Boyle Reservoir was drained, as expected, over 17 hours.

“The river channel has emerged, of course, and sediment will continue to move through in the coming days,” he said. “Spencer Creek and other tributary streams are reconnecting to the river channel at their historic deltas. The system remains highly dynamic and will continue to be in a state of flux for many months to come.”

Tuesday’s explosion opened one of the two culverts in the dam. The second culvert was scheduled to be blasted out Thursday.

Drawdown at Copco 2

The drawdown at Copco 2, downstream from Boyle, is scheduled for Jan. 23. The drawdown at Iron Gate, the most downriver dam, began last week when the gate on a 16-foot-wide bypass tunnel at the base of the dam was opened from a crack to 36 inches, then lowered.

Along with releasing water from the Boyle Reservoir, Bransom said that opening the Boyle’s culverts will allow nontoxic sediments to be moved downstream and eventually out of the river.

“We’re going to move a lot of sediment,” he said, noting that it includes such fine-grained materials as sand, salt, silt, gravel and dead algae.

According to a KRRC statement, people along the Klamath River “can expect to see a significant amount of sediment moving through the river in the next two months during this operation.”

“Extensive testing done by the U.S. Environmental Protection Agency and our consultants has determined the sediment to be nontoxic, mostly consisting of dead algae, gravels and fine clay particulates,” the corporation continued. “Water quality is expected to improve in March, but it will likely take up to 24 months for water to return to the usual clarity, following the successful establishment of vegetation in the former reservoir footprint areas.”

As the dams are removed and the reservoirs drained, restoration work — including the planting of billions of native seedlings — and monitoring will continue over a multiyear period. “We’ll be carefully watching to see what happens,” Bransom said.

Efforts to remove the dams began decades ago.

‘The water helps us’

Native American tribes along the river — including the Klamath, Yurok, Hoopa, Karuk and Shasta — have lived, worked and depended on such fish as coho and chinook, salmon, steelhead and lamprey for thousands of years. Leaders and representatives from the Klamath and Modoc tribes attended Tuesday’s drawdown at the Boyle Dam, while members from the Karuk and Yurok tribes were among those at the Iron Gate bypass tunnel opening.

Watching water from the Boyle Reservoir pour though the opening in the Boyle dam from its walkway, Jeff Mitchell, a former Klamath Tribes chairman, began a chant in the Klamath language that he said translates to, “The water helps us, the water heals us.”

“It’s a healing ingredient that’s what we’re doing here,” Mitchell explained.

Since they began to be built in the early 1900s, the dams have blocked fish from going upstream, some as far as Upper Klamath Lake, and contributed to worsening water quality. Ongoing studies are aimed at trying to determine if fish migrations up and down the river will resume after the dams’ removal.

Bransom said it is planned and hoped that the three remaining dams can be removed by late summer or early fall to “give the river the opportunity to clear up” before the fall salmon run.

After the successful culvert removal, between hugs with KRRC staff and others, a pleased Bransom said, “It’s another step in a careful process.”