Cape Town Reports 15% Decline in Wetland Areas Over Nine Years
Spatial data reveals significant loss of potential wetlands due to urban expansion and climate factors.
1Significant Wetland Area Reduction
Cape Town experienced a notable decline in potential wetland coverage between 2016 and 2025. Data from the 2025/26 Spatial Trends and Implementation Tracking report indicates a drop from 33,106 hectares to 28,002 hectares. This represents a net loss of approximately 5,104 hectares, marking a 15% reduction in the city's total wetland area.
2Methodology Behind Spatial Estimates
The reported figures rely on wetland probability mapping rather than physical counts of destroyed sites. The city utilized a machine-learning classification method to identify potential wetland areas across the metropolitan region. These estimates reflect broader land use patterns and hydrological changes observed throughout the city’s diverse landscape over the nine-year study period.
3Impact of Urban Expansion
Urban growth and land invasions are primary drivers of the observed degradation. Areas such as the Driftsands Nature Reserve faced significant pressure from land invasions during the Covid-19 pandemic. Furthermore, the expansion of informal settlements from Masiphumelele has directly impacted the Noordhoek vlei, highlighting the tension between housing needs and environmental conservation efforts.
4Affected Floodplains and Reserves
Multiple ecological zones across the city show signs of transformation and degradation. Affected sites include the Diep River and Kleine Stink River floodplains, alongside seasonal vleis in the Slangetjiebos section of the False Bay Nature Reserve. Additionally, the lower Kuils and Eerste rivers have experienced measurable changes in their natural hydrological systems.
5Role of Drought Cycles
Rainfall fluctuations significantly influenced the annual estimates of wetland extent. The severe drought period between 2015 and 2018, followed by subsequent wetter years, caused notable variations in surface water availability. Reduced hydrological connections during the drier years contributed to lower estimates, though modest recoveries were observed when rainfall levels increased later.
6Drivers of Long-term Loss
Beyond immediate weather patterns, persistent pressures are driving the long-term decline of these ecosystems. The report identifies urban expansion, land transformation, pollution, and hydrological modification as critical factors. These systemic challenges continue to threaten the integrity of Cape Town's remaining wetlands, despite the temporary relief provided by periods of higher rainfall.
7Informal Settlement Growth Correlation
The report highlights a parallel trend involving the rapid increase of informal structures within the metropolitan area. Over the same nine-year period, informal housing units in Cape Town grew by 67%. This substantial rise in residential density places additional strain on land use planning and complicates efforts to protect sensitive ecological floodplains.
8Future Environmental Outlook
The persistent downward trend in wetland area suggests that climate change and human activity remain dominant threats. While the city monitors these spatial patterns, the data underscores the difficulty of balancing rapid urban development with environmental preservation. Future management strategies must address these complex pressures to prevent further loss of vital natural infrastructure.
Original article: The South African — Cape Town Reports 15% Decline in Wetland Areas Over Nine Years