Lake Kachess during the 2015 drought.

The Bureau of Reclamation has approved further study of a floating pumping plant option in Lake Kachess in years of severe drought.

The pumping barge — expected to be 80 feet wide, 90 feet long and 7 feet deep and to cost at least $252 million — would be a permanent feature that would float on the surface of Kachess.

Officially, the project is called the Kachess Drought Relief Pumping Plant, or KDRPP, and is part of the larger Yakima Basin integrated water plan. The 30-year plan aims to secure the future water supply for the Yakima River basin while also enhancing and conserving fish and wildlife species and habitats.

The pumping plant would make an additional 200,000 acre-feet of water in Lake Kachess available to irrigators in times of drought. The option includes some fish passage improvements to help the lake’s bull trout and other fish. Roza Irrigation District would be responsible for covering the costs and construction of the pumping plant.

Pacific Northwest Regional Director Lorri Gray signed Reclamation’s record of decision approving the floating pumping plant as the chosen alternative on April 26.

“Getting to this point represents a tremendous effort from a great team of partners and stakeholders in the Yakima basin,” Gray said in a news release. “Reclamation looks forward to working with our partners as we move forward with further site-specific analysis.”

The next step is a tiered study evaluating site-specific effects of the floating pumping plant. The effort will include additional opportunities for public comment. The review could take a year or more.

The first review evaluated five options for the pumping plant before deciding the floating pumping plant would have the least adverse impact while also yielding increased benefits for area irrigators.

The upcoming review must be completed before Reclamation can make any final decision about whether to approve and implement the floating pumping plant.

The review will evaluate in more depth the site-specific impacts of the floating pumping plant, including the impact on the lake’s endangered bull trout population, critical fish habitat, the groundwater wells potentially affected by Kachess drawdown, homeowner property values, and cultural resources should the drawdown uncover tribal artifacts. The review also will aim to address specific issues raised during the public scoping and comment periods.

Funding for the additional review will be covered by the Roza Irrigation district, with no federal funding needed or anticipated.

Reclamation received more than 2,300 public comments about the Kachess project prior to the release of the final environmental impact study in March.

The agency received an additional 31 letters following that final study’s release. Also added to the project’s record was a petition from Change.org, including thousands of signatures and comments from those opposing the project.

Reclamation noted that drawdown of Kachess — of up to 80 feet — would be “less visually attractive” and also would result in a temporary loss of Kachess’s surface area for boaters, fishers, and other recreationists.

The drawdown, however, would not have a foreseeable significant economic impact on the region, Reclamation said. Rather, the agency projected that the improved water supply and agricultural output would increase by at least 1 percent the regional economic activity during drought years — an amount that “more than offsets” the loss to those who visit Kachess for recreational purposes.

The additional public comments note a variety of ongoing concerns: that the final study did not take into consideration water conservation efforts, identify who would carry out mitigation efforts for possible groundwater well depletion, describe how the bull trout passage improvements would benefit the fish, or address increased fire risk or reservoir refill should the surrounding watershed not replenish following drought years.

Reclamation, in response, said that the Yakima Basin integrated water plan, of which KDRPP is a part, did consider water conservation, efficiency, and marketing in the project. Further review of groundwater wells near Kachess is planned.

The fish passage improvements consisted of a roughened channel that would connect Big Kachess and Little Kachess, when water levels dropped enough to create the two separated pools, Reclamation said.

Reclamation said the total water supply available will not be reduced in years following drought years, regardless of whether the pumping plant project is implemented, and that the reservoir drawdown will be able to be refilled within two to five years, as noted in the final study.

Regarding fires, Reclamation said the agency had spoken with Kittitas Fire District No. 8 and the state Department of Natural Resources to gather information regarding fire hazards and suppression capability and found no cause for concern but will continue to coordinate with the fire districts.

Those interested in viewing the Record of Decision or Final Environmental Impact Statement can do so online at http://www.usbr.gov/pn/programs/eis/kdrpp/index.html and https://www.usbr.gov/pn/programs/eis/kkc/index.html.

Reach Lex Talamo at ltalamo@yakimaherald.com or on Twitter: @LexTalamo.