Tonto Creek Bridge

Ames constructed a 1,982-foot-long, 40-foot-wide, precast concrete girder bridge to provide a safe, year-round, all-weather crossing of Tonto Creek in Arizona.

Residents of Tonto Basin were previously dependent on dirt crossings to traverse the creek bed. The community would be split in half whenever heavy rains caused the creek to flood. On average, the at-grade crossings were closed to vehicles 25 days each year, cutting off residents living east of the creek from food, medical supplies, emergency services, work, and school on the west side of the creek. Eight people died trying to cross the swollen creek on foot or in vehicles in the last 25 years, including three children in 2019.

Ames crews overcame several challenges to deliver the bridge on schedule, including limited construction easement, groundwater, and environmental clearance. The project site is home to several endangered species, including the northern Mexican garter snake, the southwestern willow flycatcher, and the western yellow-billed cuckoo. Clearing activities at the site were restricted to the period of October 1-April 15 to ensure that construction would not disturb breeding attempts of the birds.

Because the bridge is in Tonto National Forest, aesthetics played a role in its design. Gabion baskets using rock gathered from the jobsite provide scour protection at each abutment.