Home » March 2012 Southwest Climate Outlook » Arizona Reservoir Levels
Recent Conditions
Published March 21, 2012

Arizona Reservoir Levels

 (data through 2/29/12)
Data Source(s): National Water and Climate Center

Combined storage in Lakes Mead and Powell decreased by 310,000 acre-feet in February, but combined storage is still about 12 percent greater than it was one year ago due to copious winter snow in 2010–2011. Storage fell more in Lake Powell because the interim guidelines on coordinated operations of both reservoirs dictate equalizing storage. In other reservoirs in Arizona, the Salt River Basin system, which supplies water to the Phoenix metropolitan area, increased by about 5,000 acre-feet in February and is 72 percent full and 12 percent above average for this time of year (Figure 6). However, Verde River Basin reservoirs declined by 8,000 acre-feet in February and are at 23 percent of capacity.

In water-related news, construction is underway at Lake Mead to build a third intake pipe, which will ensure that water can be directed to the Las Vegas valley even in times of severe storage decline (Las Vegas Review Journal, March 6). The intake pipe will be the deepest of the three. Completion of the $800 million project is slated for 2014.

Arizona Reservoir levels as a percent of capacity
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).

Related Links: