The Upper and Highline canals were originally built as two open unlined canals in the late 1800s. Over time, sandy soils, vegetation and even theft led to significant water loss. Estimates suggest that water intake of 10 cu ft per second at the inlet structure diminished 40% by the time it reached Highway 40, resulting in significant ditch loss to the water owners. The project is expected to improve water delivery efficiency while reducing salinity loading in the Colorado River Basin by 2,713 tons annually.

The project scope included replacing the unlined canals with an underground pressurized pipe. Part of the project’s challenges included the fact that the original inlet structure for the canals was built larger than what was needed. The project offered an opportunity to redesign and reconstruct the inlet structure with a simpler, more cost-effective solution. The replacement design originally called for a sand-settling structure that was 50 ft wide and 150 ft long, which became costly due to its size and the amount of concrete required. The team worked to develop an alternative that included a self-cleaning stormwater detention screen. This change provided substantial cost savings for the client while accommodating the size of the specified replacement pipe.

Additional project challenges came from the need to manage the multiple landowners whose properties abutted the original canal. The project team worked with each landowner to ensure activities progressed on schedule.