Home » April 2011 Southwest Climate Outlook » Arizona Reservoir Levels
Recent Conditions
Published April 27, 2011

Arizona Reservoir Levels

 (through 3/31/11)
Data Source(s): USDA-NRCS, National Water and Climate Ctr.

During the last month, combined storage in lakes Mead and Powell decreased by 361,000 acre-feet. As of April 1, 2011, combined storage in both lakes was 47.5 percent of capacity (Figure 6), which is 2.5 percent less than a year ago. Due to above-average winter snowpacks in the Upper Colorado River Basin, storage in Powell and Mead is expected to increase during the next several months. Storage in other Arizona reservoirs increased slightly in March, including small increases in the Salt and Verde river basins.  The San Carlos Reservoir on the Gila River experienced a decline of 18,600 acre-feet. Total storage in Arizona reservoirs is less than one year ago as a result of dry winter conditions caused in large part by the moderate-to-strong La Niña event.

In water-related news, the city of Payson, Arizona will use a portion of a $10.5 million federal stimulus grant to build a pipeline from Blue Ridge Reservoir near Pine, Arizona to a proposed water treatment plant (The Payson Roundup, April 12, 2011).  The 15-mile-long pipeline will ultimately carry 3,000 acre-feet of water to Payson each year, doubling the city’s long-term water supply.

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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