Abstract

The Salt River Canal discharges storm runoff from a 214 km2 catchment into Table Bay just north of Cape Town’s city centre. The catchment includes a number of the northern and central suburbs of Cape Town as well as the eastern slopes of Table Mountain.

Concerns about the effects of urbanisation within the catchment in terms of increased stormwater runoff and decreased water quality led the city’s Catchment, Stormwater and River Management Branch to appoint engineering and environmental consultants to assist in formulating a Catchment Management Plan for the Salt River Catchment. During the course of Phase 1 of the Management Plan formulation, the need for undertaking several specialist studies was identified (Sigma Beta, 2000). One of these was a detailed hydrological study that was necessary to evaluate the extent and risk of flooding of residential, commercial and industrial areas located in close proximity to the rivers of the catchment.

This chapter concentrates on Phase II of the hydrological study which included evaluation of storm runoff from the various sub-catchments forming the greater Salt River Catchment and the determination of 1:50 and 1:100 y floodlines for certain of the watercourses within the catchment. The chapter outlines the methodology used, presents the results of the study and includes comments on some of the difficulties experienced and lessons learned during the course of the project.

A requirement of the study was that the hydrological modeling be undertaken using the Visual SWMM analysis software

This paper is only available in PDF Format:

  View full text PDF