For the most part, contractors have not yet been engaged in cleanup or remediation efforts to combat the flow of oil encroaching on the Gulf Coast. Photo: Courtesy of La. Dept. of Natural Resources Permits have been approved for closing two breaches opened by hurricanes at Elmers Island, La. HNTB Corporation, Kansas City, Mo. has contracts in place with both the State of Louisiana Office of Coastal Protection and Restoration and with the U.S. Army Corps of Engineers, New Orleans District, that would allow either the state or the Corps to hire HNTB immediately. However, HNTB is currently engaged only
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.