Related Links: Interior Dept. fact sheet on proposal The Interior Dept. has proposed 15 lease sales for offshore oil and gas drilling over the 2012-17 period, including 12 potential leases at locations in the Gulf of Mexico and three off the coast of Alaska.Expanded energy exploration could provide opportunities for engineering and construction companies, both at offshore sites and at nearby, on-shore locations.The proposal, which Interior Secretary Ken Salazar announced on Nov. 8, drew criticism from advocates and opponents of expanded oil and gas development.Drilling advocates, such as House Natural Resources Committee Chairman Doc Hastings (R-Wash.), faulted the Interior for
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.