Editor's Note: This was written by our partners in the Bureau of Reclamation. The Albuquerque District is one of the partnering agencies in this effort to help the Rio Grande silvery minnow.
ALBUQUERQUE, N.M. - Flows on the Rio Grande from Albuquerque to Elephant Butte Reservoir will increase this week in a coordinated effort aimed at triggering a spawn of the endangered Rio Grande silvery minnow. This pioneering effort by federal and non-federal water managers will create conditions that haven’t naturally occurred over the last four years due to drought.
The April forecast data released by the Natural Resources Conservation Service shows snowpack volumes well below average throughout southern Colorado and northern New Mexico. The inflow at El Vado Reservoir is expected to be about 64,000 acre-feet of water or about 28 percent of average. This type of coordinated effort is needed to attempt to cue a spawn, as minnow numbers in the critical habitat from Cochiti Dam to just above Elephant Butte Reservoir are at their lowest since populations have been monitored.
The release out of Abiquiu Reservoir increased to about 1,500 cubic-feet-per-second today to begin moving water toward the Middle Rio Grande. The flow out of Cochiti Reservoir will increase to as high as 2,000 cfs, doubling the current release. It will continue for a week, and then be stepped down to the current release. The goal of this flow is to mimic a natural spring runoff peak to encourage the Rio Grande silvery minnow to spawn while still meeting the irrigation needs of the middle valley. The water for this action is being released from reservoirs and will not diminish the available water supply for Middle Rio Grande Conservancy District irrigators.
“This release is the result of focused planning and coordination among water management agencies and the Fish and Wildlife Service,” said Albuquerque Area Manager Mike Hamman. “It was a tremendous effort by all involved to use what limited water that is available to help create an artificial pulse flow that we hope will trigger a substantial spawn, which hasn’t happened naturally in the last few years due to the severe drought conditions in New Mexico.”
This multi-agency effort was between Reclamation, the Albuquerque Bernalillo County Water Utility Authority, who agreed to an exchange that provided the largest portion of the water, the New Mexico Interstate Stream Commission, the city of Albuquerque, the Middle Rio Grande Conservancy District, the Fish and Wildlife Service and the Army Corps of Engineers. The Middle Rio Grande Pueblos Coalition is also working closely with Reclamation to assist in this effort.
“Creating a successful spawn of silvery minnow while still meeting the needs of our farmers and cities is a remarkable accomplishment,” said Estevan Lopez, Director of the New Mexico Interstate Stream Commission. “We are proud of this innovative effort and the hard work of all the people involved. This success was only possible through collaboration in the middle Rio Grande valley and demonstrates New Mexico’s ability to work through another summer of drought.”
The approximately 18,000 acre-feet of water to be used for the peak flow came from two sources. About 12,000 acre-feet came from an exchange whereby water held in storage last year on behalf of the six Middle Rio Grande Pueblos that went unused and would have been released last fall was exchanged at Elephant Butte with the Water Authority for San Juan-Chama water. Updated sediment studies at Abiquiu Reservoir led to the discovery of an additional 6,000 acre feet of water which must now move down to Elephant Butte.
Water managers and biologists have been preparing for this since the beginning of the year. A similar effort was underway in 2013, but could not be attempted due to extremely low river flows. Conditions are now more favorable and recent meetings have focused on the logistics of the release for the best possible timing. It is important that river temperatures are warm enough to allow for minnow spawning and that there is enough natural flow in the river to allow the majority of this water to reach Elephant Butte. Crews will be in the river to gather some of the minnow eggs as part of the FWS’s Southwestern Native Aquatic Resources & Recovery Center propagation program and for the city of Albuquerque BioPark. Other eggs will hopefully hatch in the river to help maintain the wild population. MRGCD is coordinating with egg collection crews and adjusting its intake structures as necessary to avoid accidental entrainment of eggs it in its system.
A similar high flow was released from El Vado on April 25-28 for overall ecosystem improvement on the Rio Chama. In that case, the Middle Rio Grande Conservancy District agreed to allow its water to be moved down and held at Abiquiu Reservoir for use in the Middle Rio Grande in the coming months. ABCWUA allowed MRGCD to use some of its storage space in Abiquiu. The flow reached 2,000 cfs for about 24 hours before being gradually reduced.