Community income generation through cultivation of high value plants in degraded urban wetlands.

The majority of rivers and stormwater canals in the Cape Metropolitan Area suffer from visible pollution, poor water quality and severe canalisation. This has led to a loss of recreational amenity value and a degraded urban environment in the vicinity of these streams. The natural drainage patterns prior to urbanisation on the Cape Flats consisted of seasonal wetlands; many of these have been filled in, and those that remain have lost much of their seasonal nature. The ecological characteristics of the wetlands have been lost or compromised, even where canalisation has not taken place. In this paper, we will show how degraded urban wetlands might function for the cultivation of high-value aquatic or hydrophilic plants. Wetlands used in this fashion would provide jobs and income to surrounding communities and would improve the aesthetic of the surrounding environment. In addition, a degree of nutrient scrubbing would be maintained by the crops planted, and infiltration of surface water in the wetlands would be enhanced. As the wetlands in question are severely degraded, negative environmental impact (if any) will be negligible. As an example, we will present a generic design for the cultivation of Zantedeschia aethiopica (Arum or Calla Lily) in stormwater detention ponds on the Cape Flats. Zantedeschia aethiopica, which is indigenous to the area, is a popular pot plant and several cultivars have considerable value as cut flowers on the international market. The detention ponds are highly disturbed systems that might easily be modified for lily cultivation. Given the low input and maintenance costs and high value of the flowers, the project has the potential to be profitable within a few years