ESTUARIES IN SOUTH AFRICA

Useful links

Main Page	General Information	Land and Estuary Uses	Ecology	Water Quality
Threats	Hydrodynamics and mouth dynamics	Physical Features	Climate	References
BITTER RIVER ESTUARY: Catchment Characteristics

	Main Rivers and tributaries
	The total river length from Speelmanshoek near the national road, to the mouth of the Bitter is approximately 70km. Outeeprivier is a tributary of the Bitter river.
	Dams

	River run-off
	The topography and nature of the river suggests sporadic run-off. The mean annual rainfall ranges from 76 to 100mm at the mouth to 151 to 200mm in the upper reaches of the catchment. (Le Roux and Ramsey 1979; Heydorn and Tinley 1980) (Ref 1)
	Geomorphology

	Geology
	The basement rocks fall under the Namaqualand-Natal belt of metamorphism and granitization.
	Overlying the basement rocks are sedimetary deposits consisting of unconsolidated sands with fluvial and terrestrial gravels, shells, limestone and calcrete cappings. The sedimentary deposits are of Cenozoic age (era in geological time scale from 65 million years ago to 2 million years ago) and the basement rocks Precambrian (all geological time and the associated rocks before about 570-600 million years ago and extending back for more that 4000 million years) and approximately 1100 million years old. (Ref 1)
	The Bitter, as is the case with other Namaqualand rivers, has been incised into granite bedrock and can be seen as a small water course running down a shallow valley. Rounded granite boulders occur in places and in the lower reaches, the valley floor is filled with alluvium. Granite outcrops can be seen along much of the adjacent shoreline. (Ref 1)
	From observations made during the ECRU survey, calcrete occurs in small quantities in association with damp interdune slacks to the north of the Bitter mouth, indicating freshwater seepage. (Ref 1)