Ecological resilience and the interaction between the freshwater ecosystem services and built environment in the City of Tshwane, South Africa

Abstract

Nature and humans are intrinsic parts of the same system, called a social-ecological system (SES), wherein freshwater ecosystems form one of the important bases of the survival of all life. Human activities, such as land use and overconsumption, impact on freshwater systems; and freshwater systems also impact on the urban systems through which they flow. Changes in one part of the system, be it human or ecological, will impact on the other. If a freshwater ecosystem’s resilience is negatively affected and fails to retain its functional integrity, it will increase the vulnerability of the SES. Disregarding this connection can have a significant impact on the quality of an urban system.

Throughout its history since 1855, the City of Tshwane SES has moved through different eras of change, which have altered the quality of the connection between the Apies River and the urban infrastructure through which it flows. These eras have been identified as: a) First era (1855–1909) Apies River as a natural system; b) Second era (1910–1970) Apies River becoming a hidden, polluted and disconnected freshwater system; and c) Third era (1971–2016), the era of attempts at beautification and to regenerate the Apies River freshwater system.

The main goal of this study is to understand how changes in the connection between the built infrastructure in the City of Tshwane and the Apies River have affected the resilience of the Apies River’s system as an integral part of the Tshwane SES. The study achieved this by identifying the different changes, the drivers of change, and the effects that these changes have had on the resilience of the Apies River. This was carried out using the method of a historical narrative.

It was concluded that the Apies River gained specific resilience but lost its general resilience and therefore its adaptive capacity. The main drivers behind the loss of general resilience of the Apies River system were: a) the lack of a local government structure to supply proper infrastructure and service delivery to the people of Pretoria, followed by an inflexible and largely unresponsive local government system lacking tightness of feedback and therefore not detecting the signals of crossing a threshold in time; and b) a lack of ecological awareness or the necessary understanding of how freshwater ecosystems function, in order to integrate natural freshwater ecosystems as a functional part of the urban infrastructure.