Urban wetland management is now crucial

Substantial urban green/blue infrastructure has been lost due to urbanisation. Within this class, wetlands have been hit the hardest, as they are highly sensitive ecosystems. Urban wetland management is therefore needed to alleviate the further loss of wetlands.

The total population of South Africans living in urban areas in 2021 was over 67%. By 2030, the numbers are expected to reach levels of more than 71% and by 2050, eight out of ten people will be residing in urban areas. Due to this rate of urbanisation, there has been an alarming decline in the existence of wetlands. The increased development in catchment areas has led to the increase in wastewater, pollution and pesticides that end up in the wetlands, as well as changes in the landscape and an increase in soil erosion.

Urban wetlands are defined as wetlands that occur in and around urbanised areas; they can be either natural or artificial/ constructed. Whether natural or artificial, they may be permanently or temporarily flooded. Natural wetlands make up lakes, marshes, floodplains, peatland, estuaries, mangroves and coral reefs, while artificial/ constructed wetlands entail ponds, storm water treatment sites, drains, reservoirs and constructed canals.

Urban wetlands 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.

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 monetised to increase job employment for the communities living in the vicinity of wetlands.

• Their microclimate allows wetlands to reduce overheating in urban areas.

• Wetlands reduce the occurrence of floods in urban areas by reducing the speed/ power of water that enters the wetland ecosystem, and releasing the water slowly 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 water. Also, certain heavy metals can be absorbed by specialised plants within wetlands making them unavailable in the water.

Urban wetland management

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.

With more than 70% of wetland ecosystem types having no protection in South Africa, this calls for immediate action for wetland conservation, especially as this is a waterscarce 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.