Spring runoff pumped up by water released from El Vado Reservoir today will push flows on the Rio Chama and Rio Grande up to as much as 4,000 cubic feet per second, the swiftest rate in recent memory, in a multiagency effort to benefit the environment and boost silvery minnow spawning.
“Today will be our high-flow day,” said Carolyn Donnelly, water operations supervisor for the Albuquerque office of the U.S. Bureau of Reclamation. “We are going up to 4,000 cfs out of El Vado for the first time since I don’t know when.”
In 2014, the spring peak flow was only 1,500 cfs, and last year, the best flow year since 2010, the rate at Albuquerque’s Central Avenue bridge was measured at just under 3,000 cfs.
Donnelly said this week’s fast-moving water on the Rio Chama between El Vado, 80 miles northwest of Santa Fe, and Abiquiu Dam, 60 miles northwest of Santa Fe, will break up channel vegetation that is harmful to the ecology.
“When the channel is static, native species, small invertebrates such as snails, for example, don’t do well,” she said.
The one-two punch of spring runoff and released storage water will provide the robust flow that cues the spawning of the endangered silvery minnow, found in the Rio Grande from Cochiti Dam, 50 miles north of Albuquerque, to Elephant Butte Reservoir, five miles north of Truth or Consequences.
Donnelly said the release from Cochiti Dam will be about 3,300 cfs for about two weeks. That rate will benefit the entire ecosystem as well as the minnow.
“The timing of the release is important to the minnow,” Donnelly said. “Conditions are looking really good. We had more snow in April in the Rio Chama watershed and also up in Colorado on the Rio Grande. We are going to start seeing high water from Colorado real soon. And since it’s late May, the water is warmer and the fish (minnow) like that.”
Agencies collaborating with Reclamation in the project are the Office of the State Engineer and the Interstate Stream Commission, the U.S. Army Corps of Engineers, the Middle Rio Grande Conservancy District, the Rio Chama Watershed Partnership and the Rio Grande Compact Commission, which represent the compact states of New Mexico, Texas and Colorado.
A resolution approved in March by the Compact Commission made this week’s high-flow push possible by allowing the storage of about 40,000 acre-feet of water in El Vado between May 2 and May 20. An acre foot is the amount of water necessary to cover an acre to a depth of one foot.
Donnelly said the flow from El Vado to Abiquiu Dam, 60 miles northwest of Santa Fe, will decrease to about 2,000 cfs by Friday and remain at that level for about two weeks. The release from Abiquiu Reservoir will rise to about 1,800 cubic feet today and continue at that rate for two weeks.
Donnelly said the slower rate out of Abiquiu is necessary because a network of small acequias along that stretch cannot handle high flows.