Sustainable Asset Valuation of Nature-Based Flood Mitigation Infrastructure in Drakenstein, South Africa

This report by the Nature-Based Infrastructure Global Resource Centre evaluates the cost-benefit ratio of implementing nature-based infrastructure (NBI) to mitigate flood risks in the Drakenstein Municipality of South Africa, specifically focusing on river restoration in the Berg River catchment.

• Implementing nature-based infrastructure (NBI) in Drakenstein can reduce flood damages by up to USD 36 million, which significantly exceeds the estimated costs of USD 8.65 million over a 25-year period. The value of NBI increases in climate scenarios characterized by intense and frequent flooding.
• The investment in NBI offers a high return on investment, with potential benefits ranging from ZAR 1 to ZAR 5 for every ZAR 1 invested over 25 years. This results in net benefits of up to ZAR 600 million (USD 34.2 million), driven by avoided flood damages, job creation, improved mental health, and the value of recreational areas.
• Flooding in Drakenstein Municipality, caused by the Berg River and its tributaries, is driven by a mix of degraded river and wetland systems, human encroachment on floodplains, and climate-related extreme rainfall. Currently, only 10% of rivers in the Western Cape are ecologically healthy.
• The proposed NBI scenario covers 214 hectares and includes the creation of urban green spaces, constructed wetlands, and the restoration of riverbanks and floodplains to increase water retention and flood resilience.

APA

Guzzetti,, H. C. B. (2025). Sustainable Asset Valuation of Nature-Based Flood Mitigation Infrastructure in Drakenstein, South Africa. International Institute for Sustainable Development. https://www.iisd.org/publications/report/flood-mitigation-infrastructure-drakenstein-south-africa

Chicago

Guzzetti,, Henri Contor,Ronja Bechauf,Marco. Sustainable Asset Valuation of Nature-Based Flood Mitigation Infrastructure in Drakenstein, South Africa. International Institute for Sustainable Development, 2025. https://www.iisd.org/publications/report/flood-mitigation-infrastructure-drakenstein-south-africa.

Wikipedia

{{cite report |last1=Guzzetti, |first1=Henri Contor,Ronja Bechauf,Marco |title=Sustainable Asset Valuation of Nature-Based Flood Mitigation Infrastructure in Drakenstein, South Africa |publisher=International Institute for Sustainable Development |date=12 February 2025 |url=https://www.iisd.org/publications/report/flood-mitigation-infrastructure-drakenstein-south-africa |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{guzzetti2025sustainable, author = {Guzzetti,, Henri Contor,Ronja Bechauf,Marco}, title = {{Sustainable Asset Valuation of Nature-Based Flood Mitigation Infrastructure in Drakenstein, South Africa}}, institution = {International Institute for Sustainable Development}, year = {2025}, month = feb, url = {https://www.iisd.org/publications/report/flood-mitigation-infrastructure-drakenstein-south-africa}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }