Estate Living Magazine Estate Living Issue 29 May | Page 36

Tapping
rainwater the
natural way
Floods in urban areas are also largely as a result of
the geography of the urban built environment.
Towards the end of last year, while Cape Town felt the sharp further decreases the ability of the ground to absorb
end of the continuing drought, Durban and Johannesburg were rainwater. It’s a vicious circle, resulting in unsustainable
subject to destructive and deadly floods that left motorists cycles of low water levels in urban streams interspersed
stranded, roads flooded, trees uprooted, houses ruined, and with episodes of dramatic and destructive flooding
led to a number of deaths. – both because the rivers have lost their ability to
While both these disasters – floods and drought – can be
blamed on global climate change, floods in urban areas are
also largely as a result of the geography of the urban built
environment, specifically the preponderance of impermeable
surfaces like tarred roads, paved courtyards city squares and,
of course, roofs.
Unlike in nature, where rainwater is absorbed by vegetation,
and finds its circuitous way into sinuous rivers with permeable
beds and vast amounts of riparian vegetation, in the cities,
rainwater just pours over roofs, down drain pipes, across and
along roads and into hard-surface storm water drains.
absorb rain, and because it is delivered too rapidly
through hard-surface run-off.
Urban flooding - the Servest approach
That’s the bad news. The good news is that the solutions are
actually relatively simple, and are most effectively done by
emulating nature, and trying to ameliorate the more destructive
elements of urban design.
The Landscaping & Turf division of Servest does just that. Their
integrated approach to addressing the issues surrounding urban
flooding involves natural, and/or bio-engineered solutions that
are implemented in the short, medium, and long term, and that
Ultimately, the rainwater ends up in urban rivers, many of which are ultimately aimed at creating resilient and regenerative urban
have been canalised or otherwise radically changed from their landscapes that can support the complex hydrological cycle
natural state. Thus the problem is the rain is not soaking into the associated with urban systems.
ground, into rivers or wetlands, recharging aquifers and feeding
plants. In short, there is too much water where we don’t want
it, and not enough where we need it. This imbalance negatively
impacts the whole urban hydrological cycle.
This, along with the “harvesting” of water from urban rivers and/
or boreholes, results in a lowering of the water table, which
36 | www.estate-living.com
This is achieved by promoting and restoring resilience,
biodiversity and ecological integrity, by re-establishing natural
physical processes like flow and sediment size, natural physical
features like gradient and river shape, and biodiversity and
natural habitats.