ALBUQUERQUE, N.M. - Bureau of Reclamation construction crews are working to realign a portion of the Rio Grande around a sediment plug that has formed within the Bosque del Apache National Wildlife Refuge. This construction work will ensure that water is effectively delivered to Elephant Butte Reservoir.
Large equipment will be working in the area for about two months as crews excavate a channel that formed naturally this year during high flows. While water levels were high, water continued to flow around the plugged area with minimal reductions in flow reaching Elephant Butte. The Bosque del Apache stretch of the river began to naturally dry last week due to reduced flows on the mainstem of the Rio Grande and continued high temperatures, allowing Reclamation construction crews improved access to the area.
“The Rio Grande used to migrate back and forth across the valley, choosing its own path," said Albuquerque Area Manager Jennifer Faler. “Whenever we have a lot of water like we had this summer, the river channel at this location fills with sediment and starts to seek a better flow path. This year, we had already completed the analysis and environmental compliance and were ready to start the work needed to allow the river to move to the lower, eastern side of the floodplain."
The Rio Grande is being rerouted in an area that has historically plugged with sediment during high flow years. Sediment plugs occur at this location because the river channel is perched above the adjacent floodplain. Most of the sediment in the river moves along the bottom of the channel. As water levels rise above the river banks during high flows, water leaves the main channel and inundates the overbank area. The water remaining in the channel becomes concentrated with sediment, which deposits rapidly and fills the main channel with sand. Channel plugging most recently occurred in 2017.
The realignment project aims to reduce plugging, improve downstream water delivery and direct water away from important riverside infrastructure. This pilot project within Reclamation’s River Maintenance Program will provide data and could lead to additional realignment work in the area.
Reclamation hydrologists continue to monitor and model river flows. Reclamation will also coordinate with the New Mexico Interstate Stream Commission to remove a separate sediment plug that has developed directly above the Elephant Butte Reservoir pool.
Source: Bureau of Reclamation
