The question of floodlines is in the spotlight following serious flooding in parts
of South Africa declared a national disaster by the National Disaster
Management Centre (NDMC).
Heavy rains in February, mainly in the Eastern Cape, KwaZulu-Natal, the Free
State, and North West provinces, destroyed property and infrastructure and
claimed over 80 lives.
While the national disaster declaration allowed more direct intervention in
recovery by national government and organs of state, the NDMC noted that
“these threatening conditions call for an all-society and government approach to
promote risk reduction”.
Among the standard measures in place to protect communities, businesses, and
infrastructure from flooding, is the regulated floodline alongside rivers in urban
areas – below which any building or development is not permitted.
According to Xanthe Adams, principal engineer at SRK Consulting, a floodline is
an imaginary line on the ground that denotes the edge of the water during a
flood. “The floodplain is the area alongside a river that will be expected to be
underwater during a flood, with the upper edge of this floodplain being
designated as the floodline”.
The National Water Act requires these floodlines to be shown on plans for
housing and other developments, which show the highest level that a flood
could reach every 100 years – the most common stipulated time-frame. All
buildings need to be above this floodline to avoid the danger of flooding.
Adams highlights that municipalities are responsible for enforcing compliance
with floodlines as part of reducing flood risks to communities and
infrastructure. Their planning must mitigate and manage the effect of
urbanisation, which generally means more rainfall run-off and greater risk of
flooding.
Read the full article in Property Wheel
