Mitigating the environmental impacts of construction work requires careful planning and meticulous execution, particularly in areas such as the Karoo – where vegetation can be more sensitive to disruption and take longer to recover, says construction company Concor Construction.

The 140 MW Karreebosch Wind Farm, being developed by turnkey renewable-energy solution provider Cennergi Holdings and green energy supplier G7 Renewable Energies – located between Matjiesfontein and Sutherland – will supply power to a private offtaker. The project comprises 25 turbines, each 100-m tall with blades over 84-m long.

Environmental management has centred on protecting local watercourses and biodiversity, says Concor environmental officer Kevin Booth. While the rivers in this region are generally small and ephemeral or intermittent, they play a vital role as biodiversity hotspots.

“We design the layout of our working areas specifically to mitigate our environmental impact,” Booth says, adding that this is done in compliance with both the project’s environmental management plan and its water use licence (WUL).

The WUL permits construction work within 32 m of a watercourse, provided specific requirements outlined in the licence are met. All environmentally-high-risk activities – such as refuelling which carries the risk of spillage and contamination – must observe this buffer zone.

“Our onsite environmental care must always prioritise the soil, organisms, plants, animals and the riparian environment of the watercourses,” he explains, adding that Concor limits its construction footprint as far as possible, as a result.

The road network – to reach the sites where wind towers will be placed – is one of the main infrastructural elements of the project, with the roads occupying a width of 6 m to 9 m.

The environmental-impact assessment allowed a total laydown area of some 18 ha, but the Concor team strategically planned its laydown zones to reduce the area required, thereby minimising the footprint as far as possible.

Before any construction began, Concor’s surveyors demarcated the working area with surveying poles, ensuring that all activity would be conducted within these zones.

“Within these servitudes, we carry out a formal ‘search and rescue’ process to preserve diversity. This means identifying those plants that are sensitive and moving them out of harm’s way to where they can continue to thrive,” says Booth.

Each province issues a biodiversity permit that prescribes how the work is to be conducted. As the project traverses both the Western and Northern Cape provinces, the developer secured permits from both provincial authorities, with Concor responsible for executing the permit requirements.

“After removing the identified plants from the working areas, we place them in an onsite nursery to help them recuperate before they are transplanted back into the surrounding area. The sites for transplanting must be carefully selected as the new position must have comparable topography and geological conditions,” Booth says.

The search and rescue phase focuses on plants that need protection, as defined by ordinances from national and provincial environmental authorities. The Concor team – including botanical specialists – then prepares a detailed report on the plant relocations for the client and the authorities, so that the area can be effectively monitored over time.

After the removal of sensitive vegetation, a ‘clear-and-grub’ is done to remove topsoil. Once construction is completed; this material can be returned during rehabilitation, to ensure that indigenous vegetation can regrow.

Stormwater management is another critical element of preserving the environment, Booth explains, especially the separation of clean from ‘dirty’ water. While clean water refers to rainfall that lands on natural ground and flows off normally, there is also water that picks up sediment from the disturbed ground in the construction areas.

“Our priority is to limit the runoff from the construction areas – using strategies including silt traps and sandbags. This prevents muddy water from leaving the work areas and finding its way into natural drainage lines.”

The Concor site team follows a dedicated stormwater and erosion management plan, which aligns with the requirements of the WUL. The plan details exactly how the work will be carried out, specifying the drainage systems, cut-off berms and other infrastructure, as well as culverts, gabion baskets and rock packing.

With the movement of trucks, excavators and other vehicles on the site and road network, dust invariably becomes an environmental issue. Booth points out that this is mitigated through the application of a dust management plan – including the regular spraying of roads.

“To conserve water in a responsible manner, however, we carefully target our water spraying activity for optimal effect.”

He highlights that managing waste is also an ongoing concern for Concor and is governed by a dedicated waste management plan.

In addition to the main work site where the turbines will be located, the project also includes a 9-km powerline between the wind farm and the connection substation to the main grid. This too required the investment of considerable time and environmental expertise.

“While the distance of the powerline itself was less than 10 km, the specialist botanist and her team covered a distance of 150 km over ten days – searching for sensitive plants and removing them from the working area,” he says.

He notes that construction clients are increasingly conscious of onsite environmental obligations and value Concor’s proactive detail-driven approach to ensuring full compliance while safeguarding natural resources.