Lower Basin States Sign MOU to Stave Off Shortage

Faced with the specter of a possible shortage in the Lower Basin, the Lower Basin States and the U.S. Bureau of Reclamation have developed a plan to put additional water into Lake Mead, thereby reducing the risks associated with the ongoing drought.

Under the 2007 Interim Guidelines, the first shortage is triggered in the Lower Basin when the August edition of Reclamation’s 24-Month Study projects that Lake Mead’s January 1 elevation will be at or below 1,075 feet.  Subsequent shortages with increasing cutbacks to Arizona and Nevada are triggered at 1,050 feet and 1,025 feet.  Even more, when the Interim Guidelines were established in 2007, there was only a 1% chance that Lake Mead’s elevation would fall to 1,000 feet to during the interim period, which ends in 2026.  Now there is a 5% chance that Lake Mead will fall to 1,000 feet by 2019.

To avoid the devastating impacts of a drop to 1,000 feet, participants signed a Memorandum of Understanding (MOU) that specifies a goal to put an additional 1.5 to 3 MAF into Lake Mead over the next five years—and lays out responsibilities and means to take initial steps toward that goal by storing an additional 740,000 AF over the next three years.

The participants who signed the MOU include the Bureau of Reclamation (Reclamation), Metropolitan Water District of Southern California (MWD), Southern Nevada Water Authority (SNWA), Central Arizona Water Conservation District (CAWCD), Colorado River Board of California (CRB), Colorado River Commission of Nevada (CRCN), and the Arizona Department of Water Resources (ADWR)—but only Reclamation, MWD, SNWA and CAWCD are directly taking on water saving activities:

Reclamation: 50,000 AF
Anticipated methods of creation include improving efficiency and operations and creating system water

MWD: 300,000 AF (for the dual purpose of preventing Lake Mead from reaching critical levels and providing drought relief in California)
Possible methods of creation include funding conservation projects to create or defer delivery of Intentionally Created Surplus (ICS)

SNWA: 45,000 AF
Possible methods of creation include delivering imported groundwater to Lake Mead, recovering banked groundwater in Arizona and Nevada, acquiring additional water or water rights in the Muddy or Virgin Rivers and reducing Colorado River off-stream storage.

CAWCD: 345,000 AF
Anticipated method of creation includes creation of Extraordinary Conservation ICS and may also include creation of system water.

The parties will reconsult in 2016 to determine what actions are needed to meet the goal in the remainder of the MOU’s active period.  They will also reconsult if Lake Mead falls below 1,060 feet.

The precipitous drop in Lake Mead’s elevation and increasing probability that shortage trigger levels and worse will be reached are heavily caused by over-allocation.  There is a structural deficit of 1.2 MAF per year in the Lower Basin that has caused Lake Mead to drop 12-15 feet each year that this imbalance has existed.  Additional stressors on the Colorado River include a relentless 15-year drought, which has produced the lowest inflows ever recorded over a 14-year period—and tree ring studies, the lowest show that it is actually the lowest inflows for any comparable period in over 900 years—growth, which is expected to increase population by 20 million people and water demands by 5 MAF per year by 2050 (not including growth in Mexico’s portion of the basin); and climate change, which could reduce runoff by 8.5% by 2050.

For more Lake Mead elevation, as well as Lake Powell elevation, see recent chart of Reclamation’s 24-Month Studies in Hydrologic Conditions.

Written by Marta Weismann