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June 14, 1999

Tire Dam Story

Don't know what to do with those old used tires?

University of Arizona professor emeritus Stuart Hoenig does.

Build tire dams and conserve water!

Retired from electrical and computer engineering, Hoenig was invited by agricultural engineering professors to solve an erosion dilemma at the Brawley Wash about six years ago. It is located near the Arizona-Sonora, Mexico border, 50 miles west of Tucson.

Hoenig teamed up with geological engineer Joshua H. Minyard, who was also interested in the use of tires to prevent erosion.

A wagon road in the 1920's, Brawley had gradually evolved into a wash. When flooded, it would scatter debris across Arizona 86 and close the remote highway connecting the towns of Sells and Ajo. Rancher John King asked Hoenig for help in reducing erosion.

"We built the first tire dam on one of the tributaries leading into the Brawley to stop the sand," Hoenig said. "After every rain he'd have to get out there with his bulldozer and put dirt in it.

"All the sand is inside the tires and the water trickles through slowly, so a lot of the water enters the ground and now there's vegetation where there wasn't any. It's certainly worked effectively," he said.

Tire dams build up soil by trapping the silt carried by the water in the wash. This silt forms a barrier, causing the water from later storms to spread out, move slowly and soak into the wash.

The silt produces a lush riparian oasis upstream that provides excellent wildlife habitat. Currently 5 acres of grass-covered silt lies upstream.

The UA has an installation of split tires made on campus by the College of Agriculture underneath the grass. This has cut water use by two-thirds.

The UA is in the process of installing tire bales at the UA fish farms near Maricopa.

"The problem is the sides have been eroding, so they're putting in the bales right now to protect the sides," Hoenig said.

Generally, tires are broken up and recycled as floor mats.

"The trouble is you can only use 40 percent of the tire, the rest of it has to go to a landfill," he said. "It's very expensive to take a tire apart because it has high strength steel in it, but in this case you use the whole tire."

Tires can be utilized in a variety of ways. They can provide sound barriers along highways, be used as impact barriers racetracks, or as hurricane walls. In addition, they can be used for fencing, retaining walls or used in mudslide control.

Hoenig said he hopes state and local governments will make use of tires, as they are extremely valuable in dealing with the dwindling water supply.