Typic aridic soil moisture regime. This is the Carrwash series. The Carrwash soil control section is dominated by 2 to 5 millimeter gravel. Carrizo soils are on flood plains, including arroyos and washes, and alluvial fans, fan aprons and fan terraces. Many areas have numerous shallow braided channels.
Some areas have surfaces covered with gravel, cobble and stones.
Slopes are 0 to 9 percent. The soils formed in stratified mixed alluvium. Elevations are near sea level to 2500 feet. The climate is arid with very hot dry summers and warm slightly moist winters. Rainfall occurs as gentle winter rains or as erratic high intensity summer storms.