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Salt River Catchment Soil
4.2.2 Soils
The soils within the catchment are classified as soils with a diagnostic ferrihumic horizon (Ga). These deeper, sandy, calcareous soils dominate the low-lying areas of the Cape Flats. They tend to be less acidic and slightly higher nutrient content than the surrounding red and yellow Capedal soil types. These soils are often subject to waterlogging during the winter months and have a subsurface accumulation of organic matter typical of wetland areas.
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Salt River Catchment
Waterbodies
4.2.3 Types of waterbodies
The rivers in the catchment are mainly transformed, especially in the flatter areas, where development took place. Most of the rivers are canalized, only the streams on the high slopes of Table Mountain and the Tygerberg Hills flow in their natural river bed.
The two Waste Water Treatment Works (WWTW) in the catchment are releasing treated effluent into the Kalsteinfontein and Vygekraal rivers, which changes the flow regime from an ephemeral to a steady flow. Water quality is also influenced negatively by the discharge from the WWTW’s, which can be observed, by the vigorous growth of alien water plants. The 5m contour forming the bound- ary for the estuary goes as far inland as Pinelands and Athlone. This area simulates a flood risk for a future sea level rise.
Salt River Catchment Subcatchments
4.2.4 Subcatchments
The Salt River catchment extents 250km² into the central metropolitan area. The catchment drains from the Tygerberg Mountains and Table Mountain into Elsieskraal, Vygekraal, Blomvlei, Bokmakierie, Black and Liesbeek through the Salt River canal river into the Table Bay. The system receives additional flow from the two Wastwater treatment works, Borchards query and Athlone. This continuous discharge into the system made it a permanent flow from the natural ephemeral flow pattern. Ephemeral flow pattern was influenced by the winter rainfall, the very hot windy and dry summer and the porous soil conditions, that discharge water quickly, especially in summer, when the water table is low.
The Salt River catchment is divided into 12 sub-catchments, see diagram 61.
