Until recently, more than 40% of the water moving through the unlined Florence-Case Grande canal was lost to infiltration, evaporation and plant transpiration. San Carlos Irrigation and Drainage District sought to remediate this occurrence and improve service to the Gila River Indian Community lands and other territories. By lining the canal, the district could conserve water and reduce operational and maintenance costs. Knowing the canal is critical to irrigation of local cotton farms, it needed rehabilitation quickly. We installed a temporary bypass around the China Wash siphon, which allowed the district to put the canal into service while we completed the structures. This meant nearly four miles of the canal were returned to service almost one year ahead of schedule.

Irrigation canals like this one are typically lined using specialized canal trimming and lining equipment. However, soil conditions at a portion of the canal required a different approach. We trimmed the canal with a GPS-control-enabled excavator and lined with a standard cast-in-place invert and shotcrete slopes. The GPS-controlled earthmoving equipment sped production, reduced errors and virtually eliminated slope staking.

In another area of the project, we developed a proof-of-concept to demonstrate that it’s feasible to place waterstop, a substance embedded in concrete that prevents fluids escaping through joints. The trial succeeded and achieved a degree of smoothness that met or exceeded the traditional lining process.

The canal-lining program is eliminating water losses to allow more efficient transport of irrigation water from the Coolidge Dam to one of Arizona’s major cotton-growing areas. The San Carlos Irrigation and Drainage District now offers improved service to farmers who rely on the canal, including members of the Gila River Indian Community.

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