A family from Albuquerque moored their boat after a day of boating on Lake Abiquiu, Tuesday, September 14, 2021. Signs around the lake warn of blue-green algae in the water. (Eddie Moore / Albuquerque)
Copyright © 2021
Major repairs to the El Vado Dam next year will force New Mexico to look elsewhere to store irrigation water for the Middle Rio Grande Valley.
Page Pegram, the New Mexico Interstate Stream Commission’s Rio Grande Basin manager, said repairs should begin in spring 2022.
“This makes the El Vado Reservoir quite unusable (for storage) for at least a year, if not a few years,” Pegram said.
The reservoir has a total storage capacity of approximately 60 billion gallons.
A recent study by the US Bureau of Reclamation states that the current dam, built on Rio Chama in Rio Arriba County’s 1935, poses risks to the public.
“The infiltration of the dam, both through cracks in the steel face plate and through the foundation of the dam, has led to high infiltration losses,” says the study. “The steel liner of the service overflow has similarly deteriorated and is no longer operationally safe.”
The federal agency will fill holes in the dam and install a new liner. This first phase could limit the reservoir’s storage capacity to approximately 782 million gallons for a year.
The crews will then replace the overflow with concrete and build a new inlet structure and control gate, which could limit storage to approximately 26 billion gallons by the time the project is complete.
Pegram said the Abiquiu Reservoir is the most likely alternative to storing water while it is being rebuilt.
The Cochiti and Heron reservoirs are not permitted to store native Rio Grande water for irrigation.
Abiquiu was recently granted this permit, with a provision in the 2020 Federal Water Rights Development Act.
El Vado’s storage water can be used to supplement river irrigation for the six pueblos of the central Rio Grande: Cochiti, Isleta, Sandia, San Felipe, Santa Ana and Santo Domingo.
But federal law prevents the Heron Reservoir from “satisfying the (water) rights of Indian tribes,” so the reservoir would not be an adequate replacement.
The limited options for storing water for next year’s irrigation season stem from the ongoing drought in New Mexico and the possibility of a warm, dry La Niña winter.
“The water supply conditions for the Central Rio Grande in 2022 are expected to be severely impacted,” Pegram said. “We expect the drainage in the basin to remain below average.”
Theresa Davis is a member of the Report for America Corps, a water and environmental researcher for the .