Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/85919
Applications & Innovations Fixing a Hole S A tiny Arkansas town gets ready for a flash flood mall towns can face the same big problems as big towns when it comes to stormwater infrastructure. This one faced an essential emergency culvert repair without a lot of reserve funding waiting at the bank. They didn't fund their way out it; they thought their way out of it. Three days before a flash flood. When a large sinkhole developed down the side of the main thoroughfare in the town of Garner (pop.284), in central Arkansas, some quick decisions had to be made, especially when it was discovered that the drainage pipes installed more than 30 years ago were completely rotted. "You could see down about 3 feet into that sinkhole," Arnold Sewell, the mayor of Garner, Ark., tells Better Roads. A patch was made over the two culverts where the hole was on this south main highway, Sewell says. "But once we got started, [we discovered] there was a bigger hole in the side [of the pipes] than anticipated. The road has four culverts about 50 yards apart. The second set of culverts, where the water main is, has a concrete bridge over them. "These were completely washed out inside," Sewell says. In fact, the pipes were so eroded they backed up water, always sending typical drainage into the overflow culvert that was supposed to be reserved for emergency stormwater. The "usual" solution may not be the best Completely replacing the pipes was going to be very difficult for the small community. The town could dig and replace the pipes, but money wasn't available. Plus, doing a complete replacement would mean closing down the road. There are a number of school buses that travel that road each day, and closure would mean rerouting them 10 to 12 miles out of the way, Sewell says. A secondary road could be used, but 18 wheelers can't use that road. But with an already-sinking roadbed, something needed to be done, and done quickly. That's when Sewell discovered an alternate solution – simply relining the pipes. 30 June 2012 Better Roads The culvert reline method cost-estimate was 40-percent less than the cost of digging and replacing the pipe – based on the initial quote. Overall, by relining the bad pipe instead of digging it up and replacing it, this saved money and did not have to shut down a main road. Sewell says it would have cost $68,000 to dig out the pipes. "That is for demolition of the culverts and replacing the galvanization," Sewell says. "The head bowl, which was about 4 feet tall and about 20 feet, need to be replaced. Plus, if you add in the engineering feel, it would have been around $75,000." Replacing only the liner pipe cost the cash-strapped town about $46,000. When engineering fees are figured in, Sewell says, the city saved about $27,000. "We've been asking for donations," he says. "You can fill out for a grant, but it could take a year. The road would be gone by then and it doesn't do you any good." The relining of the culverts was completed this spring. Snap-Tite/ISCO Industries supplied the high-density polyeth- ylene (HDPE) pipe liner, with Baldwin Construction serving as the contractor on the project. Just three days after the project was completed, flash floods slammed into Garner and its surrounding community. There was tremendous rainfall, but in addition to local floodwater,