Jun. 1—The Rio Grande has been reshaped by nature and humans, and now a portion flowing through the middle valley is about to be altered again.

A four-mile stretch of the river running past the Bosque del Apache will be shifted eastward to lower ground to help gravity propel it more briskly and prevent it from getting clogged with sediment, as it does now.

The U.S. Bureau of Reclamation will use $10.7 million in federal infrastructure money it recently received to do the bulk of the work, which is expected to begin this year.

Keeping the Rio Grande flowing freely and efficiently through New Mexico is a challenge water managers have grappled with for decades. In the past, they tried too hard to bend the river to their will through engineering and sometimes traded one snag for another in the effort to irrigate the valley’s 60,000 acres of farmland while delivering water owed to Texas.

Federal and state officials, and even some conservationists, believe shifting this stretch of the Rio Grande will naturally accelerate its flow through the San Acacia reach, a historic choke point, enhancing both water delivery and wildlife habitat.

“I would say it’s critical, and it’s a start,” Interstate Stream Commission Director Hannah Riseley-White said. “We’re encouraged that Reclamation is taking the lead in this effort. We’re fully supportive of this initiative.”

This is the Bureau of Reclamation’s second river realignment near the Bosque del Apache. A pilot project completed three years ago redirected a three-mile stretch of the river within levees on federal lands. It was done as an emergency response to this section becoming plugged with sediment in 2019.

The agency also plans to shift a 15-mile southern section of the river so it more tightly aligns or merges with the low flow conveyance channel just north of Elephant Butte Reservoir. It is awaiting infrastructure money for that project, which it hopes to start by 2026.

Aside from improving the water flow, lowering the Rio Grande to the valley floor will better connect the river to groundwater, Riseley-White added.

The objectives are to augment water conveyance and habitat, particularly for endangered species, she said.

The irrigation district’s chief said the realignment projects are needed to prevent water, a limited resource, from being lost in areas where sediment buildup on higher ground impedes flow.

“The science behind them needing to do these realignments is sound,” said Jason Casuga, CEO of the Middle Rio Grande Conservancy District. “That will have positive consequences over the longer term because that will move the river to a lower section of the flood plain.”

Casuga and other water technicians have said that, historically, this section of river running through the Bosque del Apache and San Acacia has jammed up and requires human intervention to keep it flowing.

In a PowerPoint presentation, the Bureau of Reclamation notes when the river is elevated above the valley floor, it seeps water wastefully into dirt rather than replenishing the aquifer. It also pools in spots where sediment blocks it, leaving fish stranded.

Both Casuga and Riseley-White say even if the river is made to flow freely through this troublesome stretch, restoring the low flow conveyance channel would be helpful and probably necessary.

The old canal was built alongside the Rio Grande in the mid-20th century to divert and funnel water to Elephant Butte when muddy, swampy areas blocked the river from flowing to that destination and caused New Mexico to amass an immense water debt with Texas.

The channel sliced through and bypassed the impediments, enabling New Mexico to pay off its water debt to Texas by the early 1970s. It was discontinued in the 1980s, and now with the state falling in heavy debt again to the Lone Star State, water manager are looking to revive it.

New Mexico owes Texas about 128,000 acre-feet of water. An acre-foot is roughly 326,000 gallons, enough to submerge a football field in a foot of water and supply two to three U.S. households for a year.

The debt has proved difficult to whittle down, despite the recent wetter years.

Still, the prospect of reactivating the old channel has stirred controversy. Some environmentalists view it as turning back the clock to serve commercial agriculture at the expense of ecosystems and wildlife.

But one conservationist expressed support for the river’s realignment, saying it will direct water to the flood plain where it can run deeper and be the most beneficial.

“Any kind of funding that is going towards these nature-based solutions … you can benefit conveyance as well as improving wildlife habitat,” said Joanna Zhang, WildEarth Guardians’ wild rivers advocate. “The more we can invest in those solutions, the better.”

At the same time, Zhang stood by her criticisms of the conveyance channel, arguing it was an antiquated piece of infrastructure that would have the reverse objective — diverting water from the flood plain and wildlife habitat.

Water managers insist they would be more moderate in how they use the channel compared to 50 years ago, when officials diverted the river into the canal for the entire growing season. Their assurances have not dispelled Zhang and other critics’ concerns about possible unintended consequences.

Riseley-White described this 178-mile stretch of the Rio Grande as being turned into an artificial waterway over the decades. Fixing all the problems and making the river fully function for the benefit of people, wildlife and ecosystems will take a long time and cost a great deal of money, she said.

The current realignment project will be the first of many steps, she added.

“The entire river channel from Cochiti to Elephant Butte was re-engineered and constructed in the 1950s. And there have been ongoing realignment projects ever since,” Riseley-White said. “I think the channel work that was done in the 1950s was very much focused on getting water from Point A to Point B. Since then, our objectives have broadened.”