Flood protection is provided for nearly 250 square miles (647 km2) of land downstream from Canyon Dam. The canyons of the upper Guadalupe River have a capacity to carry 40,000 - 50,000 cubic feet per second (1,100 - 1,400 m³/s) ; however, the channel on the lower Guadalupe River, downstream from the Balcones Escarpment, can carry only 13,000-30,000 cubic feet per second (400 – 800 m³/s). This has led to serious flooding in the lower Guadalupe River Basin, including a major flood in New Braunfels in 1972 which was caused by heavy rains just downstream from Canyon Dam.