Every couple of months, when non-Iraqi representatives of the design team, mostly from the U.S., visit the site of the $100-million Al-Menaa Sports Complex in a suburb of Basra, they move in and out of the war-torn nation with as much secrecy as possible. All travel plans and meeting locations are kept confidential. They alert only one construction executive to the trip. While there, they have armed guards escorting them at all times. Instead of a construction fence, a precast-concrete security wall surrounds the site."We even have to be careful about how we send e-mails about travel to the site,"
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.