Towards applying a green infrastructure approach in the GCR

In recent weeks, the Gauteng City-Region (GCR) has experienced heatwaves, raising renewed concerns over water security, as well as heavy and persistent rains, leading to severe flooding in some areas. In this context of heightened climate variability, thinking about ways to redesign our urban areas with more sustainable infrastructure solutions is becoming more and more important. Green infrastructure (GI) is emerging as an alternative approach to traditional (‘grey’) infrastructure in urban planning and development. Its emergence can be understood in terms of the growing demand for infrastructure and services, increased concerns over natural resource constraints and climate change, and the negative impacts associated with traditional approaches to designing and building cities. It has been proposed that GI can provide the same services as traditional infrastructure at a similar capital cost, while also providing a range of additional benefits.

However, despite greater policy interest in green infrastructure in recent years, traditional infrastructure solutions to urban problems continue to dominate. This is partly due to the lack of a systematic evidence base to support GI implementation. There have been calls from decision-makers for more concrete examples of the benefits of successful urban GI applications, as well as for practical guidelines on their implementation.

Towards applying a green infrastructure approach in the Gauteng City-Region is the GCRO’s eleventh Research Report. This report builds on the findings of two previous green infrastructure reports, as well as a CityLab process run with academics and government officials between 2014 and 2016. These outputs and the CityLab discussions highlighted as critical the need to for a deeper evidence base in building support for, and enhancing investment in, the GI approach.

Unlike the earlier studies which were more theoretically grounded and policy oriented, this report comprises a number of technical investigations that more practically reflect on how a GI approach could be incorporated into urban planning in the GCR, and in other similar urban contexts.

The report consists of six chapters:

Chapter 1: Introduction and overview, by Christina Culwick, provides an overview and rationale for the report, situating it within the context of GCRO’s long standing Green Assets and Infrastructure Project.

Chapter 2: Mapping the inequity of green assets in Gauteng, by Samkelisiwe Khanyile, re-engages with the mapping of GI in the Gauteng City-Region that was a core feature of the first GCRO green infrastructure report in 2013. The mapping explores inequities in green assets and infrastructure through three different lenses, namely: (i) the distribution of green assets across the region; (ii) the proximity and accessibility of parks in Johannesburg; and (iii) the apparent degradation of Gauteng’s wetlands over time.

Chapter 3: Sustainable urban drainage systems for informal settlements, by Anne Fitchett, Lerato Monama and Jennifer van den Bussche, investigates the potential for sustainable urban drainage systems (SUDS) in addressing inadequate stormwater infrastructure in informal settlements. The chapter graphically illustrates a range of practical, low-cost GI solutions that could be applied in an informal settlement context.

Chapter 4: Green infrastructure stormwater solutions for Diepsloot, Johannesburg, by Anne Fitchett, Lerato Monama and Jennifer van den Bussche, focuses on these researchers’ experience in working with community organisations to apply a range of GI solutions in Diepsloot, an informal settlement in Johannesburg. The analysis draws out important learnings both in terms of the process of, and results from, implementing this local GI experiment.

Chapter 5: Atlas Spruit flood relief scheme: costs and benefits, by Stuart Dunsmore, Raishan Naidu and Marco Vieira, reflects on the results of the Atlas Spruit flood relief scheme, which saw the design of an artificial wetland to address stormwater challenges in a typical suburban setting in Ekurhuleni. The analysis weighs the costs and benefits of the GI approach actually taken, relative to the more conventional ‘grey infrastructure’ engineering solution that would have called for the construction of concrete drainage channels.

Chapter 6: Developing a ‘green asset registry’ to guide green infrastructure planning, by Gillian Sykes, investigates how GI could potentially be incorporated into traditional local government asset registries as an important way to see the value of GI recognised by municipal engineers and financial managers.