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The All-American Canal in southern Arizona delivers approximately 3.1 million acre-feet (382,379 ha m) of the Colorado River to nine cities and 500,000 acres (202,343 ha) of agricultural land. The 82 mile (132 km) long canal was originally constructed in the 1930s and 1940s. It begins at the Imperial Dam on the Colorado River, about 20 miles (32 km) northeast of Yuma, Arizona, and extends south and west, following the Mexican/American border.

The canal is currently unlined and substantial amounts of water are lost due to seepage, according to the Imperial Irrigation District, who operate and maintain the All-American Canal. They want to rebuild a section of the canal, with the new canal constructed parallel to the existing canal. The new concrete-lined canal will help minimize water lost because of seepage.

This project required three very specific and unique machines. The contractor turned to GOMACO to build an all new canal slipform paver, water stop machine and work bridge.

Read more on the All-American Canal project here.

This is a dual pass canal lining operation with finishing on one slope and half of the bottom of the canal. Concrete trucks have access on one side only and the canal spanning conveyor allows concrete to be placed on the opposite canal slope. Longitudinal and transverse joints are scored with attachments on the GOMACO SL-450 and the laborers on the Spanit® Work Bridge finish the joints.

More on the SL-450

This GOMACO CP-650 is lining this canal in a one pass operation. Grade and steering control is maintained by an automated sensoring system following stringline. To maintain high longitudinal production during the one pass operation, the CP-650 utilizes two separate finishing cylinders and carriages. The CP-650 is mounted on crawler tracks. The unit finishes the concrete lining with a minimum radius at the intersection point of the slope and bottom which reduces the possibility of a fracture point in this area of the lining. The Spanit® Work Bridge that matches the canal profile is part of the system and serves as both a finishing work bridge and crosswalk.

More on the CP-650

GOMACO's commitment to concrete canal lining involves participation in projects such as this underwater paving concept done on the Coachella Canal in the southwestern United States. In 1988, GOMACO Corporation built very specialized equipment for underwater concrete slipform paving of the Coachella Canal in southern California. The world's largest paver and trimmer were designed to span the canal's top width of 103 ft. (31.39 m) with a bottom width of 48 ft. (14.63 m) and slopes of 2.5 to 1. The GOMACO trimmer was used to trim the canal to a specific profile while directing water flow away from the trimming operation. The specialized GOMACO paving machine was then used to place a geotextile material along with PVC (polyvinyl chloride) and slipform a concrete lining in the bottom and sides of the canal.

More on the Coachella Canal project

GOMACO's GT-6300 continues to be the most versatile slipform paver in the industry, as its four-track paver also is capable of canal paving. A chain-type trimmer can be added to the mold for trimming the base to increase the concrete yield. Concrete is supplied to the GT-6300 four-track by means of an on-board belt-type charging auger system.

More on the GT-6300 and the canal application

GOMACO's line of canal pavers also includes the CP-650 in a slope configuration.