With no prospect of quick action on a multi-year Federal Aviation Administration bill, the House has approved another in a series of extensions for FAA programs, including the agency's Airport Improvement Program construction grants. The measure, which extends funding authority and aviation user fees through Sept. 30, was approved on March 18 by voice vote. The next step is action by the Senate. Enactment of the extension is needed by March 31, when the current FAA extension lapses.
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.