Within the Greater Los Angeles County Basin, the Los Angeles County Flood Control District (LACFCD) and U.S. Army Corps of Engineers share a joint responsibility in managing flood risk. The LACFCD is the main regional agency able to address large regional drainage needs and uses available funds to operate and maintain the existing flood control facilities and systems that transect the various cities. During years of heavy rainfall, the existing flood control system has largely prevented serious flooding that once plagued the Los Angeles area many years ago. The District's municipal flood protection and water conservation system is one of the largest in the world and includes 14 major dams and reservoirs, 487 miles of open channels, 162 debris dams, 2,919 miles of underground storm drain and more that 80,000 catch basins. The District boundaries encompass 2,752 square miles, 6 major watersheds and 85 cities. Planning efforts to rehabilitate flood control facilities also considers other potential beneficial uses of those facilities which include environmental ecosystem restoration, enhancement of water quality, and recreation amenities.