A big fight over a small, endangered fish that lives in the Rio Grande has come to a resolution, as a federal judge in New Mexico OK’d a settlement Tuesday proposed by the parties.

U.S. District of New Mexico Magistrate Judge Gregory Fouratt approved an agreement between WildEarth Guardians, an environmental and conservation nonprofit based in Santa Fe, the U.S. Fish and Wildlife Service and a middle Rio Grande irrigation district.

The deal ends a 2022 lawsuit brought by WildEarth Guardians alleging the federal government mismanaged the Rio Grande and promoted unsustainable water uses, which violated provisions of the Endangered Species Act to restore habitats for the silvery minnow and two other species.

Feds, irrigation district say keep your wheels off of the silvery minnow

The dual strains of climate change and human diversions for irrigation are contributing to the Rio Grande drying more frequently, especially the crucial stretch of river between Cochiti Dam and Elephant Butte, where silvery minnow live.

The 4-inch long minnow, is unlike most freshwater fish. Silvery minnow directly spawn into the water in the spring, and the fertilized eggs slip downstream, a method more common to marine fish. When the river was slower and shallower, the minnow was prolific along Rio Grande from Española to Gulf of Mexico. Federal and local irrigation projects straightened the river, making it deeper and faster, and built dams that prevented fish from moving freely in the river. Now, the short-lived fish is limited to one reach,which dries almost completely each year. After years of population decline, the fish was named an endangered species in 1994.

The minnow holds an important role as an indicator of the Rio Grande’s health, said Daniel Timmons, the wild rivers program director for Wild Earth Guardians.

“The Rio Grande through Albuquerque used to support sturgeon and catfish that were 200 pounds. And today, the river is barely able to support a 4-inch minnow,” he said. “If it’s not able to support a minnow, it’s not able to support the entire web of life.”

The settlement makes some immediate changes, such as outlining specific provisions of the the Middle Rio Grande Water Conservancy District to fallow 2,500-3,500 acres farmland for the next four years or offer imported Colorado River water to keep in the riverbed.

Other provisions, such as the agreement to start the process for new federal conservation measures – called a Biological Opinion – will take four years.

While the U.S. Fish and Wildlife Service will be “driving the bus” to produce a new Biological Opinion; there will be more opportunities for public comment as part of the agreement.

That’s unusual, he said, adding that Biological Opinions are often made behind closed doors.

“I’m hopeful the agencies will be more transparent throughout the process and will be engaging the public to make sure it’s more of a participatory process than it has been in the past,” Timmons said.

The federal government also agreed to pay $41,000 for WildEarth Guardian’s legal fees.

Currently, federal wildlife officials are going to continue using conservation measures from the 2016 Biological Opinion in the interim, said Debra Hill, a supervisory biologist for the U.S. Fish and Wildlife Service Rio Grande Basin.

One of the goals is to make the 87 conservation measures from the 2016 opinion less vague and more focused, she said.

The settlement shows that government agencies will have to work together to address creative solutions as the Rio Grande is expected to shrink further from climate change, she said.

“We are really going to have to figure out how to work with what is limited, and so it’s going to take working together as much as we can,” Hill said.

Hill called the minnow a “canary in a coal mine,” for life on the river.

“If we’re starting to see that a fish doesn’t have what it needs to survive in the Middle Rio Grande, we need to, as a society, realize that water is the same water that we rely on,” Hill said.