An improbable character is at the center of a debate between environmentalists and La Bajada farmers: the beaver.

The nonprofit group WildEarth Guardians, which began restoring the Santa Fe River environment in 1997 in cooperation with government agencies, says the beavers have caused measurable improvements. But to La Bajada Community Ditch Chairman Alonzo Gallegos and other farmers in La Bajada and La Cieneguilla areas, the buck-toothed rodents are a menace keeping already-scarce irrigation water from reaching their crops.

Photos taken in 1997 of the Santa Fe River below the city's Paseo Real Wastewater Treatment Plant show a bleak environment: brown water flanked by barren, treeless banks. The effects of restoration projects undertaken since then are dramatic. Cottonwoods and willows crowd the river, and animals abound—even the endangered leopard frog and southwestern willow flycatcher.

Gallegos and other La Bajada area farmers have been using the river water to irrigate their crops for their entire lives, in many cases following in the footsteps of generations before them. Things changed when the city built a wastewater-treatment plant in the 1960s: There was still water in the riverbed, but it was treatment plant effluent that left the banks covered with sludge.

Over the years, environmental standards increased, and so did effluent quality—so much so that the wastewater became a valuable commodity. The city began selling it to various customers—most significantly, The Club at Las Campanas—and the share of water that made it downstream to the farmers dwindled as restoration efforts began to have sweeping effects.

Gallegos says that, instead of releasing a relatively steady stream like it did in the past, the city now releases water it doesn't sell in sporadic spurts. That gives the beavers a chance to "dam up the river completely," Gallegos says, without a constant flow of water washing away some of their work.

The state Department of Game and Fish suggested installing water flow control devices—colloquially called "beaver deceivers," pipes through each dam with netting on the upstream ends to keep out debris—Santa Fe County Community Projects Division Director Paul Olafson says. The devices wouldn't necessarily deceive the beavers, but would let some water flow through their dams. But when NMDGF inspected the area, it determined the dams weren't suitable for that approach because of shallow water depth.

"You have to have a pond structure to back up a lot of water," Brandon Griffith, NMDGF northwest area depredation specialist, says. "If you don't, you put a flow device in and you drain the flow down to nothing; beavers will move up or downstream. Before long, you'd have a pipe going through the entire riparian habitat." Griffith also says that, when he inspected the dams, water was flowing over the top, suggesting they weren't causing significant obstruction to farmers. But he agrees habitat restoration attracted the beavers.
"When the habitat is there, the animals will come," he says.

Gallegos says beavers are thronging to the area—he estimates 40 or 50 inhabit a four-mile stretch.
"I think that's an extreme exaggeration…50 beavers would be insane," WildEarth Guardians Wild Places Program Director Bryan Bird counters.

Santa Fe River and Watershed Coordinator Brian Drypolcher says habitat limitations and predation by coyotes, bobcats and mountain lions naturally rein in beaver populations.

"[Beavers] are very territorial; they occupy a habitat to the extent that habitat can support the population," Drypolcher says. Gallegos has been farming on his land for 52 years, growing vegetables that he sells at the farmers market and to local restaurants and grocery stores. He believes the beavers were introduced to that particular part of the river and don't belong there. Although drought is the prevailing issue right now, a flood could also cause devastation if it swept the dams onto farmland, he says.

To Bird, though, drought is the problem—and beavers are part of the solution.

"To try to blame the beavers is just scapegoating…We've demonstrated with data that the beavers are having a beneficial effect on the river," Bird says.

Bird says beavers have caused the groundwater level to increase by slowing water flow. Beaver dams are so well engineered that they can withstand many flood events, he adds.

"Frankly, we need more beavers in this state," Bird says.