Now tons of dirt and rock have been excavated at the site of the collapse, and motorists in both east and westbound lanes drive over the worksite on bailey bridges.
The highway is one of the nation’s most important roadways.
The Consejo Nacional de Vialidad plans to put in 52 meters (about 173 feet) of a concrete spillway with concrete sections 6.4 meters (21 feet) high and 7.5 meters wide (about 25 feet).
The department’s engineers estimate that the job will last 100 years, the agency said. The spillway is designed to handle 130 cubic meters of water per second, about 180 cubic yards.
Each of the 18 concrete sections weighs 20 tons, and they already have been constructed off the site, the agency said.
Agency officials say they hope to have the job done by December. It is about 60 percent along, they estimated Thursday. The construction firm Castro & De la Torre is doing the work.
When the roadway collapsed the so-called crater that formed became the topic of many cartoons and Internet jokes. It was a running embarrassment for the Laura Chinchilla administration which has