Environmentalists on Wednesday accused the U.S. government of not doing enough to ensure the survival of the Rio Grande silvery minnow as drought tightens its grip on one of the longest rivers in the West.

In a lawsuit filed in federal court, the group WildEarth Guardians asked a judge to force the Bureau of Reclamation and the Fish and Wildlife Service to reassess the effects of water management activities on the endangered fish.

They also want federal officials to develop enforceable measures to keep dams and diversions along the river’s stretch through New Mexico’s most populated region from jeopardizing the minnow.

The tiny fish was declared endangered nearly 30 years ago and has been the subject of much litigation over the decades.

The challenges have only mounted in recent years as demands on the Rio Grande have escalated due to climate change, with snowpack melting sooner and strong winds further drying thirsty soil and limiting the amount of spring runoff that reaches the river. Like the Colorado River and other western waterways, record-low flows are becoming normal for the Rio Grande.

© Copyright LaPresse