skip to the content of this page
AZ.gov Arizona's Official Website Arizona Department of Water Resources
Arizona Department of Water Resources AZ.gov Arizona's Official Web Site
Securing Arizona's Water Future
Groundwater Conditions in the Lower San Pedro Basin

Major aquifers, well yields, estimated natural recharge, estimated water in storage, number of index wells and date of last water-level sweep are shown in Table 3.8-6.  Figure 3.8-7 shows aquifer flow direction and water-level change between 1990-1991 and 2003-2004.  Figure 3.8-8 contains hydrographs for selected wells shown on Figure 3.8-7.  Figure 3.8-9 shows well yields in five yield categories.  A description of aquifer data sources and methods as well as well data sources and methods, including water-level changes and well yields are found in Volume 1, Appendix A.  For more information on groundwater in the basin see Lower San Pedro Basin Hydrology.

Major Aquifers

  • The major aquifers in the basin are basin fill and recent stream alluvium.

  • Artesian conditions exist about five miles north to ten miles south of Mammoth in wells drilled deeper than 500 feet.

  • Flow direction is generally from southeast to northwest.

  • There are two groundwater sub-basins; Camp Grant Wash and Mammoth.

Well Yields

  • As shown on Figure 3.8-9 well yields in this basin range from less than 100 gpm to more than 2,000 gpm.

  • One source of well yield information, based on 181 reported wells, indicates that the median well yield in this basin is 1,000 gpm.

Natural Recharge

  • Refer to Table 3.8-6.
  • Principal sources of recharge in this basin are mountain-front recharge and streambed infiltration.

  • Natural recharge estimates range from 24,000 acre-feet per year (AFA) to 29,000 AFA.

Water in Storage

  • Refer to Table 3.8-6
  • Storage estimates for this basin range from 11 million acre-feet (maf) to more than 27 maf to a depth of 1,200 feet. 

Water Level

  • Refer to Figure 3.8-7.  Water levels are shown for wells measured in 2003-2004.
  • The Department annually measures 19 index wells in this basin.  Hydrographs for six of these wells are shown in Figure 3.8-8.  More recent hydrographs of the index wells may be available through the Department's GWSI webpage.
  • Depth to water varies in this basin with the deepest recorded water level in 2003-2004 at 503 feet south of Mammoth and the shallowest at 17 feet north of Mammoth.

Click to view Table 3.8-6

Click to view Table 3.8-6 Groundwater Conditions in the Lower San Pedro Basin

Click to view Figure 3.8-7

Click to view Figure 3.8-7 Lower San Pedro Basin Groundwater Conditions

Click to view Figure 3.8-8

Click to view Figure 3.8-8 Lower San Pedro Basin Hydrographs Showing Depth to Water in Selected Wells

Click to view Figure 3.8-9

Click to view Figure 3.8-9 Lower San Pedro Basin

Well Yields

 

Arizona Water Atlas Home

Southeastern Arizona Planning Area Home

Download pdf of entire Southeastern Arizona Planning Area Download pdf of the Lower San Pedro Basin References and Supplemental Readings for the Lower San Pedro Basin
Colorado River Southeastern Arizona Planning Area

Download Southeastern Arizona Planning Area Atlas

Gila River San Pedro River