Hydrogeologic units defined for the site are: upper fine-grained unit, coarse gravel unit and wedge unit. Many shallow wells on the Yuma Mesa are screened in the upper fine-grained unit, and water quality is variable due to the large volume of irrigation recharge. The primary regional aquifer is the coarse gravel unit that underlies the upper fine-grained unit.

The direction of groundwater flow beneath the site is from southeast to northwest. Water levels have declined 6 to 8 feet starting in the late 1990s, but began slowly increasing again beginning in 2017 and have increased approximately 3 to 5 feet since then.