Engineers prioritise environmental designs for the Renishaw Development
Situated within the ecologically-diverse Mpambanyoni Conservation Development on the KwaZulu-Natal South Coast, the mature lifestyle village of Renishaw Hills is being constructed with a focus on promotion of the natural environment. One such aspect is the intricate Mandawe Wetland crossing.
“The responsible bridging of the wetland to allow access to Renishaw has been a challenge,” explained Phillip Barker, managing director of Renishaw Property Developments, a subsidiary of the Crookes Brothers group. “However, the essence of our development has always been to enhance the natural area and, with that in mind, we discussed and debated proposed solutions with reputable environmental consultants. Thereafter, we appointed environmentally-conscious engineers to design a crossing, to replace the existing dirt road, which would allow the wetland to function as intended.”
Renishaw Hills forms part of a long-term project undertaken by Renishaw Property Developments to develop parts of the Crookes Brothers Renishaw sugar cane estate, for residential and commercial purposes. Of the 1 800 hectares that make up the Renishaw farm, 266 hectares have approval from the KwaZulu-Natal Department of Economic Development, Tourism & Environmental Affairs (EDTEA) for mixed-use development. All the approved development plans have made provision for a number of watercourse and wetland crossings, including the upgrade of the main road leading to Renishaw.
“For the past 150 years, the Mandawe River Valley has been cultivated for sugar cane but we have some of the area’s best conservationists working on returning this area to its original coastal forest, grasslands and wetlands state,” continued Barker.
This restoration, which started in 2016, is being led by experienced team members Elsa Pooley (landscaper and botanist), Geoff Nichols (leading KwaZulu-Natal expert in rehabilitation), Gareth Hampson (project manager) and horticulturist, Amanda Maphumulo.
“The restoration of the Mandawe Wetland is a major project that will be worked on for the next five to 10 years,” said Barker. “The Mandawe River Valley, between the N2 and Mpambanyoni River, was originally a wetland adjoining the Mpambanyoni river estuary, but has not functioned as such for years, exacerbated by cultivation and the construction of the N2 across the water course.”
In June 2016, developers received approval from EDTEA for the development of the first phase of Renishaw Hills which included the main access road and wetland crossing. Construction began late last year and is nearing completion.
The approved Mandawe Wetland crossing structure includes a solid base of dump rock, fully wrapped in a high-strength, composite geotextile, specifically designed to allow water percolation, as well as a battery of 450mm diameter piped culverts.
Upon commencement of construction, however, it was discovered that the original box culvert was largely still intact, although the inlet had somewhat collapsed. This inlet was reinstated and extended to the full width of the approved road which crosses the wetland, thereby significantly improving the hydraulic capacity of the storm water controls associated with this road. This assisted in returning drainage of the Mandawe Wetland to a significantly more natural state.
“We are seeing some amazing progress with the environmental rehabilitation as the development continues, with natural fauna returning to the area,” said Barker. “This is evidence that we are on the right track and will maintain this meticulous approach to ecological sustainability.”