New Mexico gets over $140 million to re-align a section of the Rio Grande

With $143 million from the federal government, the Bureau of Reclamation will realign 15 miles of the Rio Grande in the Middle Rio Grande Valley to help more water travel downriver.

The Biden-Harris administration announced almost $850 million for water infrastructure and drought resilience on Tuesday, including more than $180 million for six projects in New Mexico. The $143 million Lower San Acacia Reach improvement project in Socorro County is the most expensive to get funded in New Mexico.

“It was really a once-in-a-lifetime opportunity to get the level of funding needed to do a major project like this,” said Sharon Wirth, assistant area manager with the Albuquerque Area Office of the Bureau of Reclamation.

The $143 million will fund about half the project, Wirth said. The agency is planning and doing an environmental assessment, which should be completed by mid-2025. Construction will likely begin near the end of 2025 or early 2026, according to Wirth.

Before the levee and dam systems were built in the 1900s to manage the Rio Grande, the river meandered broadly, naturally shifting its path year to year. The realignment will mimic that natural process by giving the river more space to “better choose its own course and to move as much as it can,” Wirth said.

The Rio Grande is a sediment-heavy river, and big rains bring in more sediment. Over time, that sediment builds up, and the river becomes less efficient at moving water.

“The large sediment loads can create plugs in the river that can completely prevent water from moving, and it can create flooding as the water tries to find its way around these sediment plugs,” Wirth said.

The Rio Grande is sitting high in the Lower San Acacia Reach, so Reclamation wants to move the river to the lowest part of the valley. That would enable the water to move more efficiently, getting more water to Elephant Butte and beyond to Texas, which could help New Mexico meet its legal obligations under the Rio Grande Compact to deliver water to Texas.

When the river floods in its current channel, water sometimes gets stranded beyond the river. If the river floods when it is at the lowest point in the valley, the water will more easily be able to return. Because the river is at such a high location in this area, water seeping into the ground is unable to enter the water table, according to a project overview. Realigning the river should also fix that problem.

“We’re also dealing with a situation in that area of the river where, because of the way that it’s confined, the water only makes it to one small part of that whole flood plain,” Wirth said. That means there is less habitat for wildlife like migratory birds such as sandhill cranes that visit the Middle Rio Grande Valley en masse in fall and winter.

The realignment should reduce drying, which is good for the local wildlife. The endangered silvery minnow and imperiled birds like the willow flycatcher and yellow-billed cuckoo benefit when there is some water in the river all year.

The Lower San Acacia Reach project will be on federally owned land and thus should not affect private landowners. A similar project in the upper San Acacia Reach that received $10 million in federal funding in May is bounded by some private land, and Reclamation is working with the landowners, Wirth said.