Albuquerque Area Office
Water Operations Group
Operations Fact Sheet
Abiquiu Dam and Reservoir
- Purpose: Flood, sediment control, and water supply storage. Owned by the U.S. Army Corps of Engineers.
- The county of Los Alamos owns and operates the powerplant below the dam. The plant is run-of the river, and has no impact on reservoir storage or releases.
- Used to store San Juan-Chama (SJC) contractor water, all natural (native) water inflow is bypassed up to channel capacity. SJC water storage is allowed up to elevation 6220.0 feet. Although the project is authorized to store native Rio Grande water, institutional requirements are not in place to allow native storage at this time.
- If storage space was needed because of a forecasted large snowmelt runoff or a large flood event, the Corps could release the SJC water in storage. The Corps MOA with the city of Albuquerque and other entities allows the Corps to release the SJC if needed. The SJC water could also be released for maintenance of the structure.
- General plan for operating is to pass the entire natural inflow up to a channel capacity of 1,800 cfs below the dam.
- Rate of release, whether increasing or decreasing in stage, is generally held to a range of 0.25 to 0.50 feet at the downstream gage. The limitation on the increase in stage at the downstream gage is based on public safety. The limitation on the decrease in stage in the downstream gage is based on preventing bank sloughing.
- Release changes are not made in less than one-hour intervals when possible. Generally flow changes are limited to two per day.
- Release rates are adjusted to evacuate flood storage within a short period of time, usually within a 24-hour period after the peak inflow of a thunderstorm event. Duration of the evacuation depends on the volume. Release rates are also adjusted based on tributary inflow below the dam from a thunderstorm event. These measures are taken to protect downstream structures from flood damage and to save water during a drought.
- SJC water released from upstream reservoirs destined for Abiquiu is stored. All other SJC water is passed through. Release of SJC water from storage is at the request of the entities that own the water.
- SJC water storage serves to increase trap efficiency and enhance recreation.
- A "borrow/payback scheme" is used in which Middle Rio Grande Conservancy District (MRGCD) borrows water from the city of Albuquerque pool in Abiquiu. MRGCD then pays back the water at a later date with water from upstream reservoirs (El Vado or Heron).
- Rule of thumb minimum flow below Abiquiu is 70 cfs from November 1 through March 31. Cochiti Lake and Jemez Canyon Reservoir evaporation replacement water is released from storage at Abiquiu or reservoirs upstream during this time frame to maintain the minimum flow.
**** All data are provisional and subject to revision as final data are collected and analyzed. ****
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