Copyright © 2022 Albuquerque Journal
New Mexico water agencies are slowly piecing together a regulatory puzzle in order to store Rio Grande water in Abiquiú Reservoir for middle valley irrigation this summer as El Vado Dam is repaired.
But an objection from Texas water managers could interfere with the reservoir’s use for non-pueblo irrigators.
The U.S. Army Corps of Engineers operates the northern New Mexico reservoir on the Rio Chama.
Nabil Shafike, the Army Corps Albuquerque District’s water management chief, said Abiquiu was once authorized only to store Colorado River Basin water that is diverted into the Rio Grande Basin with a series of tunnels and dams for the San Juan-Chama Project.
“All the Corps reservoirs – Abiquiú, Cochiti, Galisteo and Jemez Canyon – work as one unit to protect the middle valley from flood,” Shafike said. “Any storing of native (Rio Grande) water would require a deviation from the current operation.”
The agency is weighing two potential changes at Abiquiu:
• A request from the New Mexico Interstate Stream Commission to store up to 45,000 acre-feet, or 14.6 billion gallons, of Rio Grande water in Abiquiú each year for release later in the season to meet middle Rio Grande irrigation demand.
• A request from the U.S. Bureau of Reclamation to store up to 20,000 acre-feet, or 6.5 billion gallons, of Rio Grande water in Abiquiú each year to meet direct flow right for the six middle Rio Grande pueblos of Isleta, Sandia, Santa Ana, San Felipe, Santo Domingo and Cochiti.
The Army Corps could approve both storage plans or may choose only one.
The agency’s environmental assessment found the proposals would not significantly impact regional wildlife or water resources.
Federal legislation in 2020 paved the way for Abiquiu as the only option besides El Vado Reservoir that can store native Rio Grande flows for pueblo and non-pueblo irrigation in central New Mexico.
Changing storage of Rio Grande water requires unanimous approval from the Rio Grande Compact commissioners of Colorado, New Mexico and Texas.
The Interstate Stream Commission sees the change as urgent to protect water supply for regional farmers and ranchers.
The Texas letter
A Feb. 21 letter from Texas Commissioner Robert Skov to the Army Corps said the Lone Star State doesn’t object to storing water for pueblo use.
But Skov said New Mexico’s large water debt to Texas should prohibit the release of Rio Grande water from Abiquiú for nontribal irrigators.
New Mexico had accrued a water debt of about 127,000 acre-feet, or 41 billion gallons, at the end of 2021.
“Simply stated, storing native Rio Grande water for use in New Mexico for (non-pueblo) water uses before the debit water owed to Texas is replaced violates the 1938 Rio Grande Compact,” Skov said.
The Texas commissioner also recalled when his state approved New Mexico’s emergency request in the dry 2020 summer to release 12 billion gallons from El Vado for middle valley irrigators.
That water would have been stored as “debt assurance” and released to Elephant Butte Reservoir for downstream users after the irrigation season ended.
Instead, the water was added to New Mexico’s debt column under the Rio Grande Compact.
Despite two consecutive short irrigation seasons for central New Mexico farmers, the state has yet to make a significant dent in the water debt.
NM’s water debt
Colorado commissioner Kevin Rein agreed to the pueblo water storage at Abiquiú.
Rein didn’t take a specific opinion on whether New Mexico could store for non-pueblo use.
But he noted that Texas’s denial on its own would prevent a unanimous compact decision.
The Army Corps is aiming to finalize the changes by mid-May, after which it would likely be too late to store significant amounts of runoff.
Shafike said the states may ultimately agree on a solution, but it’s unclear how they will resolve conflicting sections of the interstate water compact.
“New Mexico is in a debit situation but also has the right to store relinquishment credit,” he said. “Texas also has a right under the compact to hold any native water stored upstream equal to the amount of New Mexico’s debit.”
Potential storage restrictions have prompted the regional irrigation district to pay farmers not to water some fields this season and warn that water supplies could be unpredictable.
Reclamation’s Albuquerque-area water operations supervisor Carolyn Donnelly said the six pueblos have “prior and paramount” water rights of any users within the regional irrigation district.
A prior and paramount “call” to ensure irrigation for pueblo lands would come from the Bureau of Indian Affairs.
“That water is only released when things get really tough,” Donnelly said. “In the spring, probably through at least early June, there will be enough natural flow on the main stem of the Rio Grande to allow all the irrigators within the MRGCD to irrigate. I would expect the call for prior and paramount irrigation to come in July or later.”
Reclamation would move the Rio Grande water from El Vado to Abiquiu as soon as they receive Army Corps approval, which could be as early as mid-May.
The approval would be good for three years.
El Vado reconstruction is expected to begin this April or May after the spring snow runoff ends.
“The first thing crews are going to do is grout selected places under the faceplate where they suspect there’s voids,” Donnelly said.
The crew will then put a new membrane liner over the dam. That phase will last until late 2023.
Once spillway repairs begin in 2024, storage operations will likely revert back to normal.
Theresa Davis is a Report for America corps member covering water and the environment for the Albuquerque Journal.