With South Africa experiencing numerous devastating flood events in recent years, this has placed a spotlight on the challenges inherent in minimising flooding by undertaking accurate stormwater analysis and using this analysis to place infrastructure away from vulnerable flooding areas.
One of the key aspects of placing infrastructure is guided by estimating the flood levels and modelling where flood levels through hydrological and hydraulic modelling of stormwater volumes and flows, according to hydrologist Charmaine Thulo, a member of SRK Consulting's water team. A fundamental objective is to manage the risk to life and property but there are also stringent water regulations which must be observed.
"Regulations GN704 of the Water Act requires that clean water runoff that is not contaminated by mine infrastructure be separated from runoff water that comes into contact with mine infrastructure" said Thulo.
Sizing facilities
The analysis of stormwater patterns is therefore the subject of specialised computer modelling, to simulate storage in pollution control dams as well as assisting the sizing of drainage channels and pipes. This modelling helps minimise discharge from the pollution control dams, Such models utilise detailed rainfall data from one or more sources to establish baselines and predictions for 1 -in-50-year or 1-in-100-year floodlines.
