Home » November 2010 Southwest Climate Outlook » Arizona Reservoir Levels
Recent Conditions
Published November 23, 2010

Arizona Reservoir Levels

 (through 10/31/10)
Data Source(s): Salt River Project, U.S. Bureau of Reclamation, U.S. Geological Survey, and AZ Game and Fish

The Natural Resources Conservation Service had not reported reservoir levels before publication of this issue. The data were assembled from a variety of other sources, including the Bureau of Reclamation and the U.S. Geological Survey.

During October, combined storage in Lakes Mead and Powell decreased by 73,200 acre-feet, which was less than expected due to significant local precipitation in the region around Lake Powell. As of November 1 combined storage in the lakes was at 50 percent of capacity (Figure 6), which is 1.7 percent, or 862,000 acre-feet, less than a year ago. Overall reservoir storage in the Colorado River Basin is around 55 percent of capacity. Storage in reservoirs not on the main stem of the Colorado River decreased in October by around 49,500 acre-feet. Storage in the Salt and Verde river basins is greater than average and greater than last year.

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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