Administration officials have put the brakes on future oil and gas leasing development in certain areas of the Outer Continental Shelf through 2017, modifying a Dept. of Interior proposal for the OCS leasing program released in March. Interior Secretary Ken Salazar said on Dec. 1 that the updated strategy calls for agency officials to focus their efforts on planning areas that already have leases for potential future development. Consequently, the area in the Eastern Gulf of Mexico that remains under a congressional moratorium, as well as the Mid and South Atlantic planning areas, are no longer under consideration for further
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.