Improving the Safety of Our Dam Infrastructure—RCC Makes the Grade

Maintaining the safe operation of thousands of aging dams in North America is a daunting task for dam owners. Whether it is the need to increase spillway capacity, solve erosion problems at outlet structures, or improve stability for seismic, sliding, and/or overturning, finding a solution that protects the public and is economical can be difficult. Of the more than 76,000 dams on the national inventory in the United States many have either exceeded their design life or will over the next decade. In addition, many dams once classified as low hazard are now being reclassified as high hazard due to development downstream of the dams necessitating a reevaluation of the dam's overall safety. Roller compacted concrete (RCC) has now been in use in rehabilitating dams for over 22 years with over 200 projects completed in North America. The economics of using RCC for rehabilitating dams is well documented and its performance proven under some of the most severe climatic and hydraulic loading conditions. Seventy four embankment dams have had overtopping protection provided with RCC to provide the safe passage of extreme flood events, aging concrete and masonry dams have used RCC as a buttress material to provide additional stability particularity during the design seismic event, and RCC has been used to extend or reinforce stilling basins subjected to high velocity and turbulent flows.