Report No: 1054/1/02

August 2003



Wetlands in urban environments are under great pressure due to competition for land resulting from poverty, inadequate infrastructure and services and particularly a lack of housing. An important function of urban catchment management is to preserve and restore urban wetlands where possible. However, under South African conditions, the pressing needs of people for jobs and housing often take precedence over environmental considerations. Hence projects which can provide tangible benefits from wetlands to the local community are set to become an important focus for responsible urban catchment management. Urban wetland conservation and restoration would be encouraged if wetlands could be turned into sustainable economic assets, by the cultivation of economically valuable plants in wetlands.

As a result of these considerations the Water Research Commission (WRC) initiated this project on the cultivation of aquatic plants in restored urban wetlands for income generation in local communities.

The original vision for the project was to carry out a more detailed monitoring of actual wetland projects, and in particular to examine any such projects being carried out within the urban stormwater systems of South African cities. The project proposal accepted by the Water Research Commission did not include the development of a database of wetland plants. Within the first year of project research, however, the following constraints emerged:

  1. There were no suitable wetland projects being undertaken in the South African stormwater systems examined, such as there are in cities in Holland and Australia, for instance;
  2. Existing wetland projects in South Africa tended to be small and based in rural areas;
  3. The establishment of the Cape Town wetland pilot project (Inyibiba) which was linked to this project was slow, and the prognosis for the success of the project was poor, given the unsuitable site location and the low level of funding. Furthermore the project was not located within the stormwater system.

In order to compensate for these drawbacks, the proposal was made to the WRC to develop the database of wetland plants with potential economic value as an additional deliverable from the project.

The aims of the project were therefore:

  1. To create a stand-alone database with information on economically valuable plants appropriate for cultivation in urban wetlands;
  2. To evaluate projects and to develop guidelines to select wetlands and optimise their design for urban agricultural activities and wetland rehabilitation;
  3. To develop methods to turn urban wetlands into economic assets though the cultivation of high-value plants;
  4. To evaluate the improvement in water quality in terms of litter control and microbial and nutrient loading as a result of urban wetland horticulture;
  5. To assess the ecological benefits of urban wetland horticulture schemes;
  6. To assess the economic benefits of urban wetland horticulture schemes to communities and to local authorities, and to evaluate the sustainability of such schemes;
  7. To develop training procedures to assist communities and local authorities in setting up and maintaining wetland horticulture schemes.

Accordingly, this project has resulted in the following outputs:

  1. Part A, which consists of the Project Guidelines and Decision Support for selecting wetlands for cultivation.
  2. Part B, which reports on the results of the lnyibiba pilot project which was implemented to test the feasibility and effects of cultivation in an urban wetland.
  3. The new green database of wetland plants with economic potential. Part C of this report is the User Manual for the new green database. new green itself is a stand-alone Microsoft Access database.