Home » January 2011 Southwest Climate Outlook » Arizona Reservoir Levels
Recent Conditions
Published January 25, 2011

Arizona Reservoir Levels

 (through 12/31/10)
Data Source(s): USDA-NRCS, National Water and Climate Center

During the last month, combined storage in Lakes Mead and Powell decreased slightly. As of January 1, combined storage was at 49.1 percent of capacity, which is 1.7 percent less than a year ago (Figure 6). Storage in other reservoirs within Arizona’s borders increased slightly in December, including small increases in the Salt and Verde River basins that offset a slight decrease in San Carlos Reservoir storage. Reservoir storage in Arizona is up compared with one year ago, due in part to management actions that anticipate spring reservoir depleting that is historically characteristic of La Niña winters.

In water-related news, the Cocopah Tribe has received a grant to restore parts of the lower Colorado River along the U.S.-Mexico border (Yuma Sun, January 12). The region has been modified as a result of flood control and water diversion activities, which have altered wetlands, vegetation, and wildlife and effectively rendered stretches of the river inaccessible to the tribe.

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 Resource Conservation Service (NRCS). For additional information, contact Dino DeSimone, Dino.DeSimone@az.usda.gov.

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