7th Street and Arizona Avenue | Site Hydrogeology

The site is located within the Tucson Basin, a northwest trending alluvial valley covering an area of about 750 square miles in the Santa Cruz River drainage basin of southeastern Arizona. The soil beneath the site consists predominantly of inter-bedded fine-grained sands and silts from ground surface to approximately 80 feet below ground surface (bgs). The interbedded material is underlain by a clay aquitard approximately 12 feet in thickness, forming a perched aquifer above.

Depth to perched ground water is approximately 65 feet bgs. The regional aquifer is encountered approximately 170 feet bgs. Flow direction in both the perched groundwater and the regional aquifer is predominantly to the northwest.