Water Department: Lourens River Flood Study

The Institute for Water and Environmental Engineering, Department of Civil Engineering, of the University of Stellenbosch was appointed to carry out an investigation on the flood hydrology and river hydraulics of the Lourens River.

This study followed on a number of floods in recent years which caused flood damage in Somerset West and Strand.

The main outcomes of the study were:

  • Deterministic and probabilistic hydrological methods were used to determine the flood recurrence intervals for both the 28 August and 15 November 2013 flood events.
  • The floodplain behaviour (numerical 2D model) considering bed level changes due to erosion and sedimentation was modelled. The current flood lines were revised as an outcome of this task.
  • Short term emergency measures, as well as long term mitigation options were analysed and priced.