Page 9 - Waterfall_Issue 5_2022

STORMWATER The heavy rainfalls experienced
“When you have undeveloped land, in Gauteng this past season have
the flow of rainwater is moderated by certainly highlighted the importance
soil and vegetation. The water seeps of water management. According Because silt is not stable and cannot
into the ground and the vegetation to the latest figures, for 2021/2022 bind together, this could potentially
stops it from flooding or causing Gauteng recorded a seasonal rainfall cause the wall to collapse.
erosion. Once you start developing of 1176mm. During the previous The main dam was also getting
and creating hard surfaces, the result season, 2020/2021, the figure was shallow, having a negative impact
is a concentrated, fast runoff of 774mm of rain, an increase of on the ecology. “By using the silt to
rainwater that can cause significant more than 50% year-on-year. increase the size of the first island and
problems. With the Jukskei River form the two new islands, the dam
running through Waterfall, we DAM INNOVATION: A KEY was deepened to its original depth.
have seen how just 20mm of rain FOCUS This has been an ecologically-friendly
upstream from us can come down Waterfall has established a large way of treating the problem, even
like a flood,” Redelinghuys says. attenuation dam within the Waterfall though silt must be continuously
Country Village Estate, and eight managed. We aim to desilt the dams
A significant challenge, therefore, other smaller attenuation dams eventually,” explains Gaynor.
has been that of erosion control. across the development. “These dams
One of the ways in which Waterfall significantly reduce the risk of flooding In the main dam, the team has
has managed this is through the and form part of the development’s removed some of the reeds and
building of attenuation dams that have strategy to reduce soil erosion. focused on introducing indigenous
become part of its green belt. These However, the build-up of silt, especially plants. Furthermore, many distinct
carefully designed civil structures in the main dam due to rainfall and soil species of fish have been added to the
blend into the natural landscape of disturbance, remains a key challenge. dam to support the natural process
the nature areas and play a critical role Silt management across all the dams of keeping it healthy and creating a
in controlling the flow of rainwater is a vital part of our focus as we must thriving ecosystem. Residents can even
throughout the entire development. ensure the dam is safe for the bird and fish on a ‘catch and release’ basis.
aquatic life and that it can be used
“All of this comes down to managing for recreational non-motorised sports Waterfall has also reached out
stormwater as effectively as possible, by residents. To help manage silt in to some of the schools on the
in order to minimise the possibility the main dam, the existing island was development for pupils to come
of flooding and soil erosion. Slowing supplemented with the creation of and observe the wetlands, erosion,
down the water, managing it and two additional islands,” says Gaynor. and all the interventions that have
controlling it, is vital in our efforts to been implemented. This reinforces
mitigate the risk of soil erosion,” says Safety engineers further pointed the objective of teaching children
Kenneth Gaynor, CEO of Waterfall out that silt was starting to cause in the area how best to live in
Country and Village Estates. problems on the spillway wall. harmony with the environment.

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