CARSON CITY, Nev. (AP) - An environmental group is pushing the U.S. Fish and Wildlife Service to make a decision on whether four species of tiny snails found in isolated Nevada springs deserve protection under the Endangered Species Act.

The Center for Biological Diversity says a determination could foil plans by Southern Nevada Water Authority to pump billions of gallons of water from along the Nevada-Utah line to Las Vegas.

The group filed a lawsuit last week, asking a judge to compel the Fish and Wildlife Service to issue its conclusions after determining last year that protection for the springsnails may be warranted.

The water authority was granted approval in March to pump up to 84,000 acre-feet of groundwater a year from the rural valleys.

Environmentalists say the snails could perish as groundwater levels drop.

Copyright 2013 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.