A view of Lake Shasta with 93 percent of total capacity, or 108 percent of historical capacity, on May 11th, 2016 near Redding, Calif. Lake Shasta is part of the Central Valley Project, operated by the U.S. Department of the Interior, Bureau of Reclamation.

(Kelly M. Grow/ California Department of Water Resources)

A $1.4 billion plan to revamp California's Shasta Dam, the state's largest reservoir, could be derailed by salamanders.

Plans to raise the dam are in jeopardy due to the recent reclassification of a single salamander species into three unique species. Environmental groups argue the project threatens the existence of those species.

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The Los Angeles Times that two environmental groups filed a federal lawsuit last month asking a judge to force the U.S. Fish and Wildlife Service to determine if Shasta salamanders should be protected under the Endangered Species Act.

One of the groups, the Center for Biological Diversity, asked the wildlife service in 2012 to declare the salamanders endangered or threatened, but the agency has not made a decision, said Jenny Loda, an attorney for the group.

Environmentalists say the project would destroy the amphibians' habitat and put them at risk of extinction.

The lawsuit was prompted in part by the federal government's sudden momentum in efforts to raise the Shasta Dam nearly two stories.

The California Wild and Scenic Rivers Act, passed in 1972, prohibits the 602-foot structure from getting any taller. But the Trump administration is moving forward with the plan.

Congress approved $20 million in March to jump start the heightening project and the Bureau of Reclamation, the Interior Department division overseeing the plan, expects to award initial construction contracts in late 2019.

The Shasta salamander was considered one species until April, when scientists split it into three species based on DNA analysis — the Shasta salamander, the Samwel Shasta salamander and the Wintu Shasta salamander, Loda said.