Bosque projects address flooding, habitat

People, plants and animals all stand to benefit from upcoming projects in the local bosque.

Natalie Daniel, left, and Rachael Blodgett, both 3, walk on the Willow Creek trail Thursday. The girls were visiting the bosque with family. The U.S. Bureau of Reclamation is scheduled to dig side channels to the Rio Grande in the area this fall, but no trail closures are expected. Photo by Argen Marie Duncan.

To restore wildlife habitat and protect infrastructure by lessening erosion, the U.S. Bureau of Reclamation is rehabilitating and constructing side channels along the Rio Grande in southern Bernalillo and northern Rio Rancho. In Bernalillo, the bureau is partnering with the Southern Sandoval County Arroyo Flood Control Authority to connect the Venada Arroyo with one of those side channels to get storm water to the river.

The Bureau of Reclamation is scheduled to work near the Venada Arroyo starting the first week in March, and then a little farther south in the Willow Creek Trailhead area this fall, said Project Manager Ann Demint.

The federal government is paying for that work, which Demint estimated would cost between $500,000 and $1 million. She said she’d know more about the price once work started and she had a better look at the land.

Construction hours are 7 a.m. to 5:30 p.m. Monday through Thursday.

She said workers will bring in equipment over recreational trails, but no trails will be closed for the projects. The floodplain containing the side channels will be closed when it’s an active construction site.

In the Venada Arroyo area, the Bureau of Reclamation plans to rehabilitate three side channels built in 2008 so they’ll flow again, Demint said. The project also includes work on the lower portion of the point bar, the surface where the river has deposited sediment on the inside of a curve.

SSCAFCA is providing $281,000 from a bond voters approved in 2016 for the bureau to connect the arroyo with the side channel this spring, said authority Executive Engineer Charles Thomas.

He said the creation of Cochiti Lake led to the Rio Grande digging its main channel deeper and moving away from the point where the Venada Arroyo emptied into the river. That led to the sediment from the storm water creating a delta at the mouth of the arroyo.

This map shows the Venada Arroyo, in green in the bottom right quadrant, and the area where it will connect to a Rio Grande side channel, in the blue cross-hatching.

“So it started creating a situation where it wasn’t functioning properly,” Thomas said.

The delta slowed the storm water, causing it to dump sediment in the arroyo channel, filling it too much so that water backed up into the adjacent subdivision.

“It hasn’t gotten to the point of where it’s flooding,” he said.

However, the problem will get worse if something isn’t done, and the water running over the sediment is making the arroyo wider so that the erosion is threatening homes, Thomas said.

When the Bureau of Reclamation invited SSCAFCA to join its project, engineers had already designed the arroyo improvements to fix the problem and the bond money was available, Thomas said.

“It was pretty serendipitous at the point,” he said.

Once the arroyo is connected to the side channel with the proper slope for drainage, Thomas said, future storms will start carrying away the sediment upstream in the arroyo. He’s hoping the governor will approve $800,000 in capital outlay money from the legislature, so SSCAFCA can clear out more sediment faster.

Demint said the Venada Arroyo-area project is anticipated to take a little more than two months. Equipment will be kept on Corazon del Bosque private land when it’s not being used.

In the Willow Creek area, Demint said, the bureau will build two new side channels.

“Our approach these days is to try to do projects that work with the river,” Demint said.

If the bureau uses natural processes, projects are more successful, she said. Planners still have to work within the confines of existing infrastructure.

The side channels will draw water from the main part of the river, reducing pressure on the east bank to lessen erosion, thus protecting irrigation-system infrastructure there. The side channels installed in 2008 were meant to do the same thing, but the river meandered away from them, stopping the channels from flowing and doing their job.

The work will also make the channels better habitat for endangered silvery minnows, especially for their young in the spring, Demint continued.

Mary Carlson, spokeswoman for the bureau’s Albuquerque Area Office, said the minnows prefer water slower and shallower than the river’s main channel. Side channels also provide more protection from predators.

Demint said the channels would provide a variety of water depths and velocities, including the minnows’ favorite conditions.

Bringing water into the channels will encourage the growth of natural vegetation.

“We’ve had really good results in the past in this area, so we’re expecting the same occurrence,” Demint said of the vegetation.

For questions about the work, contact Carlson at [email protected] or 462-3576.