Groundwater Contractors in Yuma County, AZ

Groundwater Contractors in Yuma County, Arizona

Yuma County occupies Arizona’s southwestern corner, where the Colorado River completes its journey through the Grand Canyon and Basin and Range country before reaching (or formerly reaching) the Sea of Cortez. The county is defined by the Colorado River: its agricultural bounty, its water conflicts, and its groundwater resources all connect to this single overallocated river.

Groundwater in Yuma County

Yuma County is one of the most productive agricultural regions in North America. The Yuma area grows roughly 90% of the nation’s winter leafy greens, relying heavily on Colorado River water delivered through an elaborate canal system managed by the Bureau of Reclamation. Groundwater plays a secondary but important role — for domestic users outside the city’s water service area, for agricultural tailwater recovery, and for supplemental irrigation during peak demand periods.

Key Aquifer Characteristics

Colorado River Alluvial Aquifer: The primary aquifer beneath the Yuma valley is a sequence of sand and gravel deposits laid down by the Colorado River over millennia. This shallow alluvial aquifer is highly productive and generally has good yields. Well depths for domestic use typically run 150–400 feet.

Gila River Confluence Zone: The confluence of the Gila and Colorado rivers near Yuma sits above an especially thick alluvial sequence. This area has been heavily used for both irrigation and domestic water supply.

Wellton-Mohawk IDD: This agricultural irrigation district east of Yuma pumps substantial groundwater to supplement Colorado River deliveries. The district also operates a desalination facility to manage drainage water salinity — a reflection of the significant TDS issues in this region.

Water Quality in Yuma County

Total Dissolved Solids (TDS): Yuma has some of the highest TDS groundwater in Arizona. The Colorado River itself carries elevated salt loads from agricultural return flows and natural weathering upstream. Well water TDS can range from 800–3,000 mg/L in some areas. Reverse osmosis systems are common for drinking water.
Hardness: Very hard, often exceeding 500 mg/L as CaCO₃. Water softeners are standard.
Arsenic: Present in some areas; test all new wells.
Nitrates: Heavy agricultural use over decades has elevated nitrate levels in shallow aquifer zones in many areas.
Fluoride: Some wells exceed secondary MCLs for fluoride in this region.