FLAGSTAFF, Ariz.— The Center for Biological Diversity filed motions with the Federal Energy Regulatory Commission today urging denial of preliminary permits for two proposed dams on the Little Colorado River near Grand Canyon National Park. The motions include a new analysis showing the projects would destroy or harm all of the river’s critical habitat for the endangered humpback chub.

“These short-sighted projects would destroy the cradle for humpback chub recovery throughout the entire Colorado River Basin,” said Taylor McKinnon, a senior campaigner at the Center. “Construction of either project would fast-track the humpback chub toward extinction while wasting the millions of dollars and years of work invested in the recovery of these endangered fish.”

The Center’s analysis shows that the proposed Little Colorado River and Salt Trail Canyon pumped storage projects would destroy or adversely modify all 7.9 river miles of the chub’s designated critical habitat in the Little Colorado River. By itself, the Salt Trail Canyon project would destroy or harm the entire critical habitat. The Little Colorado River project would destroy or adversely modify 87 percent of it.

The planned dams and reservoirs upstream from the confluence with the Colorado River in Grand Canyon National Park would flood river habitat, dewater sections of river and alter flows essential for the fish’s survival. Changes to the temperature, hydrology, and sediment loads in the river would harm humpback chub survival and reproduction while creating conditions favorable for non-native fish that compete with and prey on the chub. The dams would fragment chub populations and restrict their movement from the Colorado to the Little Colorado to spawn.

Each project includes a dam and reservoir on the Little Colorado River and a dam and reservoir on the adjacent canyon rim. They would pump water uphill to the rim when electricity prices are low to generate electricity and revenue from downhill return flows when prices are higher.

In today’s filing the Center urged the commission to deny preliminary permit applications for both projects because they could threaten the existence of the fish throughout its range, violating the Endangered Species Act.

Separate filings from the Interior Department and Arizona Game and Fish Department have echoed these concerns, stating that the projects would result in “a major decline and possible extirpation of the only remaining population of humpback chub in the lower Colorado River basin.”

American Indian tribes, including the Hopi and Hualapai Tribes, have lodged opposition because of potential harm to cultural values in the area.

Thousands of people have submitted comments in opposition to the project.