$300 million to dam up a dry canyon? It could make sense for the Mid-Columbia

KENNEWICK – A bone-dry canyon south of Kennewick could hold the key to planting more wine grapes and other high value crops along the Columbia River.

Switzler Canyon, an ancient waterway above McNary Dam, could be dammed and turned into a reservoir.

With a capacity of 44,000 acre-feet – the water needed to produce 16.4 million gallons of wine – the reservoir would allow officials to issue new water rights and bolster supplies during dry times.

If built, Switzler Canyon Reservoir would bank water in the spring, when it’s plentiful, and release it in the summer, when it’s not.

Officials have been kicking the idea around for more than a decade.

Now, the Washington Department of Ecology, working with Benton and Klickitat counties, is about to launch a two-year, $1 million environmental impact study.

The public can shape the review by identifying economic and environmental issues now, before the process gets started.

Switzler Reservoir in theory would offer farmers more reliable access to water from the pools behind the John Day and McNary dams.

The reservoir would release water as needed to ensure the Columbia experienced no net loss of stream flow.

Farmland in southern Benton County and eastern Klickitat would benefit the most.

“It’s for new water rights in the Horse Heavens,” said Joye Redfield-Wilder, spokeswoman for the department of ecology.

Not the region’s first reservoir

A study is no guarantee Switzler Canyon will ever become a reservoir.

Funding the project will be difficult. A 2012 study by Aspect Consulting said the cost could be more than $300 million, adjusted for inflation.

At 44,000 acre-feet, the Switzler Canyon Reservoir is far smaller than Black Rock Dam, a 1.7 million acre-foot behemoth proposed for the Yakima Basin some 20 years ago.

Black Rock would have been filled with water pumped from the Columbia when water ran high and power rates were low.

Conceived to bank water for droughts, when junior water rights holders see their water curtailed, Black Rock would have been one of the largest dams of its kind.

Though advocates continue to push the project, its multi-billion dollar price tag has kept it from advancing.

A former Benton County official who worked on Black Rock said it is effectively dead.

Pros and cons

Darryl Olsen, executive director of the Kennewick-based Columbia-Snake River Irrigators Association, put the odds of Switzler Reservoir being built at “zero.”

The association’s board opposed Switzler last year, calling it financially unsound. Olsen said the board will review it again, but he doubts its position will change.

Irrigators feel the $1 million the state allocated to the EIS would be better spent on conservation measures in the Roza Irrigation District.

That would yield near-term water savings, Olsen said.

“We want to support things that are going to get built and that are going to deliver water,” he said, calling Switzler a “hydraulic fiction.”

Adam Fyall, Benton County’s sustainable development manager, said the idea is worth exploring.

As drought years arrive with greater frequency, it’s important to address summertime shortages that harm agriculture.

Storage is a critical piece of the picture. Switzler is the best of the options studied over the past decade.

“This is a mitigation reservoir to assist in drought years,” he said. “We are in a dry area that is always water stressed, with or without climate change.”

Fyall prefers to call Switzler a “concept” rather than “proposal.”

To move forward, it will need a champion, possibly a new utility district to develop, maintain and operate it.

It would have to offer water at a price irrigators are willing to pay, but it won’t be low-cost. High-value crops such as wine grapes could make sense.

Wheat would not.

A source of funds has not been identified, but could include a mix of state and federal dollars and revenue bonds backed by user fees.

The project

From above, Switzler Canyon has the jagged shape of a two-point antler, with one long prong and one shorter one.

The canyon narrows as it reaches the Columbia. It’s mouth is near a pump station operated by Easterday Farms, on the Washington side, east of Plymouth and across the water from Oregon’s Hat Rock State Park.

A 320-foot earthen dam would block the canyon at the the channel.

As with Black Rock, Columbia River water would be pumped via an 83-inch pipe to the reservoir when the river is high and power is cheap.

The reservoir is not intended to serve boaters or recreation since the property is privately owned by Easterday and its neighbors.

The owners have given preliminary approval to evaluate the concept, said Fyall.

It would affect habitat and attract water-oriented species to the area. There is no current plan to equip the dam with power generators.