Urban Wetland Management In A South African Context
Urban wetlands are defined as wetlands that occur in and around urbanised areas and these wetlands can either be natural or artificially constructed. They are often referred to as the ‘city’s kidney’ or ‘biodiversity library’, due to their ability to purify water passing through the wetland ecosystem and being a habitat to a vast number of different plant and animal species. Natural or artificial wetlands can be permanently or temporarily flooded. They make up lakes, marshes, floodplains, peatland, estuaries, mangroves and coral reefs, and artificial/constructed wetlands are ponds, storm water treatment sites, drains, reservoirs and constructed canals. Some of the goods and services provided by urban wetlands include:
- Socio-economic benefits to the community, where grass-like plants from the sedge family (bulrushes or Typha capensis) are harvested for making mats, baskets or brooms. Fishing from wetlands can also provide communities with food.
- Recreational, leisure activities are monetized to increase job employment for the communities living in the vicinity of wetlands.
- Their microclimate allows wetlands to reduce overheating in urban areas.
- They reduce the occurrence of floods in urban areas by reducing the speed and power of the water that enters the wetland ecosystem, and release the water slowly out into the environment.
- Due to the hydrology, geomorphology and vegetation found in wetlands, the water that enters this ecosystem can be purified through sedimentation that allows particles to settle due to the reduced speed of the water. Also, certain heavy metals can be absorbed by specialised plants within wetlands making them unavailable in the water and making the water cleaner.
The total population of South Africans living in urban areas in 2021 was over 67%. By 2030 the numbers are expected to reach levels more than 71% and by 2050, eight out of ten people will be residing in urban areas. Due to urbanisation, more urban green/ blue infrastructure has been lost to compensate for the increasing population, and because wetlands are highly sensitive ecosystems, they have been hit the hardest. This has led to an alarming decline in the existence of wetlands and other challenges such as a decrease in wetland biodiversity; changes in the hydrological regime of wetlands; an increase in wastewater, pollution and pesticides that end up in the wetlands because of the change in the landscape and land uses within the catchment areas. There is also an increase in soil erosion within wetlands because of the increased development in catchment areas.
Urban wetland management is now crucial to alleviate the further loss of wetlands. It is important for any urban wetland management plan to make provision for sustainable development that can be beneficial to both humans and the environment. Urban wetland management strategies should include community projects to promote better management of wetlands; a centralised legal framework that helps protect wetlands; and buy-in from local government to ensure that the green/blue infrastructure is well protected by enforcing the law.
READ MORE: Learn more about stormwater management.
The management of urban wetlands has been presented with many challenges ranging from urbanisation to climate change, which highlights the amount of dedication still needed to preserve these sensitive ecosystems. More than 70% of wetland ecosystem types having no protection in South Africa, so it’s imperative to call for immediate action for wetland conservation, especially as this is a water scarce country. To make an impact on wetlands in your area, please visit the Water Wise website to see how you can get involved in wetlands conservation.
Always be Water Wise!