The Eerste River, located in the
Western Cape,
South Africa, rises on Dwarsberg 60 km east of
Cape Town at the head of
Jonkershoek valley. The Eerste River catchment covers the eastern part of the
Cape Flats lying to the west of the
Hottentots Holland Mountains and south of the
Tygerberg where the
Kuils River tributary rises east of
Kanonkop. The Eerste River is a short river; its length has been given as 40 km. The major tributary, Kuils River, is approximately 30 km long to its point of confluence with the Eerste River.[1]
For a significant part of its course, the river flows through the
City of Cape Town.[1]
The estuary is at the eastern end of a large calcrete dune, and is part of the boundary of the
Helderberg Marine Protected Area. In its natural state the estuary was a small temporarily open system with little tidal flow. The state of the mouth was controlled by river flow, and under natural conditions, seawater intrusion would maintain an estuarine ecology. When the mouth closed, the river would back up past the Kramat to Zandvliet farm.[1]