El Vado Dam and Reservoir

GENERAL

• Purpose: El Vado Reservoir stores water for irrigation and incidental flood control. The reservoir also provides recreational opportunities and allots space for sediment control.
• The Bureau of Relamation (Reclamation) owns El Vado Dam and Reservoir. Reclamation operates El Vado Dam under agreement with the Middle Rio Grande Conservancy District (MRGCD).
• Below El Vado Dam sits a Federal Energy Regulatory Commission-regulated hydroelectric plant that is owned and operated by Los Alamos County.
• The total maximum storage of El Vado Reservoir is about 180,000 acre-feet that is used to store native Rio Grande water for MRGCD and for the six Middle Rio Grande Pueblos, and, by agreement only, San Juan-Chama (SJC) contractors’ water for MRGCD and other SJC contractors.
• Storage and release of native Rio Grande water for MRGCD is subject to provisions of the Rio Grande Compact.
• SJC water and water stored for the Six Middle Rio Grande Pueblos are not subject to the provisions of the Rio Grande Compact that limit storage and release of water under certain conditions.
• Reclamation regularly performs exams of El Vado Dam as part of the Safety of Dams Program.
• Reclamation maintains an Emergency Action Plan for El Vado Dam and Reservoir and conducts periodic exercises of emergency operations with local government agencies to decrease agency response times and protect public safety in the event of a disaster.
• Storage restrictions limit the water surface elevation to 6896.20 feet from June 1 through September 30 and 6,900.0 feet from October through May; however, the restrictions have been relaxed in the past in an attempt to conserve water during years with expected below normal runoff.
• Channel capacity below El Vado Dam is approximately 4,000 cubic feet per second (cfs).
• Reclamation contracts with New Mexico State Parks to manage recreational opportunities at El Vado Reservoir.

STORAGE

• The plan for filling El Vado Reservoir is to store all flows into the reservoir that are in excess of downstream requirements, such as those for Rio Chama water rights holders. In general, water is stored during the spring run off for release later in the year when flows are lower.
• MRGCD allows other SJC contractors to store about 40,000 acre-feet in El Vado Reservoir; the amount available for SJC storage is re-evaluated by MRGCD every year. Storage of large volumes of SJC water may take place for extended periods of time.
• The Secretary of the Interior designates space in El Vado Reservoir to store some water for prior and paramount lands of the six Middle Rio Grande Pueblos. The Six Middle Rio Grande Pueblos are: Cochiti, Santo Domingo, San Felipe, Santa Ana, Sandia and Isleta. While not a storage right for these pueblos, this water can be released if native flows are insufficient to meet irrigation demand for prior and paramount lands.
• The following Rio Grande Compact (Compact) provisions exist on storage of native Rio Grande Basin water:
  • Under Article VII of the Compact, no storage can occur in reservoirs constructed after 1929 upstream of Elephant Butte Reservoir, including El Vado Reservoir, when total useable Rio Grande Project water in storage at Elephant Butte and Caballo reservoirs is less than 400,000 acre-feet. Useable water is defined in the Rio Grande Compact.
  • Under Article VI of the Compact, if there is an accrued debit in New Mexico’s Compact deliveries to Texas, a like amount of native water stored in El Vado Reservoir must be held in storage until the Texas Commissioner of the Rio Grande Compact Commission calls for its release.

RELEASES

• Water is released from El Vado Reservoir when natural flow of the Rio Grande is not sufficient to meet demands of the MRGCD and the Six Middle Rio Grande Pueblos.
• SJC water released from Heron Reservoir for immediate use downstream of El Vado Reservoir is simply passed through El Vado Dam.
• When El Vado Reservoir spills, MRGCD has the option to spill SJC water belonging to other contractors or to spill native water not held under terms of the Rio Grande Compact.
• Releases from El Vado Reservoir occur in a manner that is consistent with the following operational requirements and/or considerations:
• Native Rio Grande water flows into El Vado Reservoir up to 100 cfs are bypassed to meet demands of Rio Chama water rights holders.
• Reclamation targets a release of 150-185 cfs for fisheries below El Vado from November to March.
• Reclamation targets 400-600 cfs for rafting during the weekends during July, August and September when possible, given the needs of downstream water users.
• Releases from El Vado Reservoir flow through the hydroelectric plant within the maximum and minimum capacities of the plant. The plant operates as a “run of the river” facility; releases are not made for the sole purpose of generating power, but power is a byproduct of releases made for project purposes.

**** All data are provisional and subject to revision as final data are collected and analyzed. ****

Contact
Please contact the Operations Group via e-mail at ResourceMgr@usbr.gov for additional information.