Brandvlei Dam, also known as Lake Marais, is a large reservoir situated approximately 10 km from the town of Worcester in the Western Cape Province of South Africa. Fed by natural hot springs and positioned near the Breede River, the dam sits within the Breede River Catchment — a vast watershed of approximately 12,600 km² flanked by the Franschhoek and Du Toit's Mountains to the west and the Hex River Mountains to the east. Originally a natural wetland (vlei) of about 10 km in extent, the site was developed into a major water storage facility, with the Greater Brandvlei Dam completed in 1981. Today it serves as a critical water supplier for agricultural activities in the Robertson area and beyond, while also offering diverse and productive angling opportunities. The dam is notable for hosting one of the largest known populations of the indigenous Cape whitefish (Barbus andrewi), estimated at well over 100,000 adults, making it a landmark fishery for anglers interested in targeting native South African species alongside a healthy population of introduced sport fish.