High level estimate of return on investment and priority interventions for the Greater Cape Town Water Fund
This study was commissioned by The Nature Conservancy to provide information to stakeholders and funders of the Greater Cape Town Water Fund on the context and rationale for clearing invasive alien plants in order to improve the security of Cape Town’s water supply, and to communicate a strategy for doing so in the most efficient possible way. The study focused on where clearing of invasive alien plants (IAPs) would have the greatest return on investment, and identified the priority areas for clearing. This was carried out by mapping IAP densities across the catchments, modelling their impacts on water supply and modelling the cost of removal in order to create a spatial return on investment layer (m3/R invested). This layer was used to prioritise where investment in clearing should be focused.Information about where major stakeholders are already clearing IAPs was also collated and mapped to help inform an integrated water resource management approach to IAP clearing within the catchment areas. In addition, this study also examined how catchment restoration in terms of IAP clearing compared to other alternative water supply interventions in terms of costs and co-benefits. The study was further extended to include a business case for wetland restoration and the removal of plantations in catchment areas.