infrahub.africa

Background

The City of Cape Town reached the height of a multi-year water crisis in early 2018, when dam levels dropped below 20% and the city prepared for “Day Zero” - the day when its taps would run dry. Many source water catchments feeding the Western Cape Water Supply System (WCWSS) were being heavily degraded by water-intensive invasive alien plants that alter soil ecology, increase the frequency and severity of wildfires, and significantly impact river flow and aquifer recharge worsened by drought. This reduced the amount of water reaching the rivers and dams feeding the region, resulting in an estimated loss of 55 billion litres of water a year. As part of a range of responses to the drought, a coalition of partners including The Nature Conservancy, National Departments of Water and Sanitation, and Environmental Affairs, Provincial Department of Environmental Affairs and Development Planning, City of Cape Town, SANBI, CapeNature, Coca-Cola Peninsula Beverages, AB Inbev, Nedbank, Remgro Ltd, and WWF, conducted a business case evaluation and implemented an ecological infrastructure restoration programme under the auspices of the Greater Cape Town Water Fund (GCTWF).

‍

Approach

The GCTWF commissioned studies to evaluate the impact of nature-based solutions on the water supply, and found that investing at scale in ecological infrastructure restoration was more cost effective than grey infrastructure solutions. The water fund then launched activities for targeted removal of invasive alien trees including acacia, pine and eucalyptus in rugged and hard to reach areas of the catchment. By 2023, GCTWF teams had cleared more than 46,000 hectares of invasive trees. The state of the cleared areas is captured monthly in an online interactive decision support system to track the progress of activities undertaken by the water fund and its partners. Today, the program involves multiple government departments, non-government organisations, and water user associations that are all using the decision support system tool to coordinate their actions.

‍

Environmental Impact

The GCTWF teams have cleared more than 46,000 hectares of invasive trees such as Australian acacias, pines and eucalyptus with some used for contour stocking to reduce erosion risk. This has led to the recovery of over 17 billion litres of water per year, significantly improving yields from the water catchment by October 2024. Clearing invasive species has also helped local biodiversity to thrive, and improved water health and habitat for endangered fish species such as the giant redfin and other freshwater species. In addition, invasive species removal improves soil ecology and reduces the frequency and severity of wildfires. The diversity of native plant life in the sensitive and rare Cape Floral Kingdom now thrives as invasive species that quickly replaces them are removed.

‍

Success Factors

Securing local government buy-in was key to the success of this program. Since July 2021, the City of Cape Town committed R125 million to continue clearing the catchments of other dams operated by the city. Also, the public-private partnerships secured through the GCTWF have helped to connect downstream users like businesses, utilities, and local governments to contribute to a common goal of upstream conservation initiatives aimed at improving water quality and quantity for the region.

‍

Evidence

Evolution

In April 2023, the GCTWF was registered as the Greater Cape Water Fund to transition to a fully independent entity and scale its activities beyond Cape Town to include other key catchments in the Western Cape Water Supply System.

‍