Municipalities must upgrade culverts and drainage infrastructure whenever necessary ( Image : SRK Consulting )
wetlands will act to slow down the flow of water and allow more of it to percolate into the ground .
Emergency Plans At the most basic level , however , municipalities must ensure that any new developments are outside the floodline and must also upgrade culverts and drainage infrastructure whenever necessary , as part of their emergency planning .
“ Other situations where a floodline is required include mining operations which might encroach on rivers or streams ,” said Adams . “ Holders of water use licences might also need to determine floodlines , as their work may potentially disturb the area within the floodline .”
It is likely that a floodline will be required by law if a developer or other entity are planning to build on a property that have a river or stream running across it , she said . It might also be a legal requirement if a river is within a few hundred meters of the property being developed . catchment scale is another relevant field of enquiry which can significantly reduce flooding so I wouldn ’ t be surprised to see more regulations focusing on catchment scale management of floods .”
Floodline studies remain a highly specialised task , and they need to be properly signed off before a local authority will accept the floodline determination . This sign off must be done by a professional engineer registered with the Engineering Council of South Africa .
Urbanisation is a significant factor in increasing the size of floodplains and the velocity of floods ( Image : City of Tshwane )
EIAS and Water Use Licences “ Companies who require a full environmental impact assessment ( EIA ) or even a basic environmental assessment may be required to furnish a floodline as part of the permitting process ,” she said . “ In fact , planning any activity in or near a river – such as building a bridge or installing a pump – my require a water use licence that includes a floodline .”
She noted that while the recent flooding seemed out of the ordinary , this would still have to be confirmed by detailed studies . It was also difficult to know the extent to which climate change contributed to the magnitude of these rainfall events , as there were many different global climate models – each with a range of predictions .
Protection Measures “ More important will be the country ’ s ability to develop flood protection measures alongside floodline studies , as it is likely to be impractical to move houses and infrastructure which today lie within floodplains ,” she said . “ Flood management on the
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