Theewaterskloof dam spillway with overflow water released to control flooding

theewaterskloof dam spillway water scarcity western cape floods flooding dam wall flooding control water level capacity cascading overflow channel level controlled release villiersdorp reservoir western cape earth fill dam earthfill infrastructure sonderend river manmade dam water supply waterbody static no people cape town water supply south africa drought resistance weather rainfall concrete fresh overflow energy engineering flow architecture construction hydro outdoor barrier resource drain sluice rushing consumption structure downstream