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Recent Conditions
Published November 21, 2012

Arizona Reservoir Levels

 (data through 10/31/12)
Data Source(s): National Water and Climate Center

Combined storage in Lakes Mead and Powell is at 53.4 percent of capacity, a slight decrease from last month (Figure 6), and 7.4 percent lower than one year ago. Declines in reservoir storage during the last year were primarily due to a La Niña event, which sent storms north of the Upper Colorado River Basin. San Carlos Reservoir and the Salt River Basin reservoir system continued to decrease, which is normal for this time of year.
In water-related news, the International Boundary and Water Commission confirmed that officials from the United States and Mexico have made a commitment to sign a new agreement on Colorado River water management (Associated Press, November 17). The addendum to the 1944 U.S.-Mexico water treaty would allow Mexico to store water in Lake Mead, provide for a pilot program of water releases to replenish Colorado River wetlands in Mexico, and allow U.S. water agencies to purchase water from Mexico.

Arizona Reservoir Levels
Notes:

The map gives a representation of current storage levels for reservoirs in Arizona. Reservoir locations are numbered within the blue circles on the map, corresponding to the reservoirs listed in the table. The cup next to each reservoir shows the current storage level (blue fill) as a percent of total capacity. Note that while the size of each cup varies with the size of the reservoir, these are representational and not to scale. Each cup also represents last year’s storage level (dotted line) and the 1971–2000 reservoir average (red line).

The table details more exactly the current capacity level (listed as a percent of maximum storage). Current and maximum storage levels are given in thousands of acre-feet for each reservoir. One acre-foot is the volume of water sufficient to cover an acre of land to a depth of 1 foot (approximately 325,851 gallons). On average, 1 acre-foot of water is enough to meet the demands of 4 people for a year. The last column of the table list an increase or decrease in storage since last month. A line indicates no change.

These data are based on reservoir reports updated monthly by the National Water and Climate Center of the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS).

 

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