The history
Built on the extraction of timber and gold , Knysna developed as a rough-and-ready town with an industrialised waterfront . The gold was short-lived but , even after the town evolved into a major tourism destination , the timber industry continued to dominate and , from the 1920s , Thesen Island was the centre of the timber processing industry . The power station , which was built on the island in 1939 , was fuelled by the sawdust and wood chips generated by the sawmills . Not only did it provide jobs for the local community and power to Knysna and Plettenberg Bay , it also fed into the Eskom national grid . By the late 1990s this island was 96 hectares of underutilised and somewhat degraded land – but in a prime location in the biodiverse Knysna Estuary .
This presented any potential developers with a range of challenges , and Dr Chris Mulder , a modern-day pioneer who has embraced the adventurous spirit of this seaside town , rose to the challenge , and achieved the triple bottom line of social , economic and ecological integration and sustainability in the design and development of the Thesen Islands project . The design work commenced in 1991 when the then owners , Barlows , asked CMAI what could best be done with the island . Seven years and 26 design concepts later , approval of this environmentally sensitive project was obtained in 1998 . Construction started in September 2000 , and eight years later the entire project of 605 residential units and the commercial area with two hotels and five restaurants was completed and sold out . No wonder CMAI claims this project as their flagship after 15 years of constant design and construction implementation .
Decontamination
As a result of decades of industrial activity , the low-lying island was polluted by chrome , arsenic , creosote and copper . This highly contaminated soil was encapsulated and sealed with sodium bentonite cut-off walls and blankets , and capped with topsoil and replanted . The area was rehabilitated by creating wetlands and planting trees , shrubs and grasses along the 11 kilometres of canal bank .
Ecological rehabilitation and conservation
The Knysna Estuary is an important and diverse one , with mudflats , sandy areas , rocky sections , deep water , extensive saltmarsh areas , and subtidal sea-grass beds . The island harbours endangered bird , plant and marine life including the Knysna seahorse ( Hippocampus capensis ).
The solutions to the ecological issues were pure genius . Before any construction was done , a complete assessment of the status quo of the lagoon was done . This baseline assessment gave the developers something against which all construction activities could be assessed and measured . Only then was the system of canals dug , based on the approved CMAI design . The excavated soil was used to raise the level of the newly created islands by 1.8 metres to a height of 2.8 metres above sea level .
The canals were constructed using rock mattresses and gabions to establish the canal edges and bottom lining . Fortuitously , this created an ideal habitat for the seahorses , whose population has subsequently increased . The water flowing through the marina is open to the estuary so it moves with the tides , thus ensuring constantly changing clean canal water , providing an ideal habitat for a host of marine creatures . This habitat and biodiversity creation contributed immensely towards CMAI Architects ’ s winning the IFLA award but – even more importantly – it has also resulted in Thesen Islands ’ s ever-increasing and enduring property values .
www . estate-living . co . za | 5