South Africa is struggling to provide services to the millions of poor people migrating to the major centres and living in informal settlements (shanty towns). Whilst the local authorities are generally able to provide potable water from the municipal network to communal taps scattered around the settlements, there is usually inadequate provision of sanitation and little or no provision for the drainage of either stormwater or greywater. This paper describes an investigation into ways of engaging with community structures in the settlements with a view to encouraging "self-help" solutions to greywater management requiring minimal capital investment as an interim "crisis" solution until such time that local and national government is able to provide formal services to everyone. The work was carried out in three settlements encompassing a range of different conditions. Only two are described here. It has become clear that the management of greywater has a low priority amongst the residents of informal settlements. The lack of effective political structures and the breakdown in communication with Ward Councillors and local government officials have contributed to the lack of progress. As the project progressed it became evident that greywater cannot be considered separately from stormwater, sanitation and refuse removal.

This paper discusses the potential use of ‘managed aquifer recharge’ (MAR) in Cape Town to provide additional water supplies to the city that are fit-for-purpose. The paper investigates the feasibility of implementing MAR by simulating the artificial recharge of winter stormwater into the Cape Flats Aquifer (CFA), an extensive sandy, unconfined aquifer that covers most of metropolitan Cape Town’s urban landscape. The objective is to assess the storage capacity and supply potential of two MAR sites by modelling various scenarios in order to determine the feasibility of MAR as a viable strategy for achieving improved water security by augmenting groundwater water supply. The selected scenarios demonstrated that MAR could be used to minimise the risk of seawater intrusion and maximise the amount of water available for abstraction from the CFA. Six MAR scenarios provided strong evidence to suggest that there is sufficient storage capacity within the CFA for using stormwater to improve the wellfield yield in two regions of the CFA and which can sustainably yield approximately 18 Mm3 per year. The study concluded that the use of stormwater or treated wastewater could be deliberately used to recharge the CFA and as a viable option in support of the City of Cape Town’s intention to establish a water-resilient city by 2030.

High-quality water-related data are fundamental to water-resource planning, water and sanitation infrastructure design, and scientific research. However, high-resolution smart water-monitoring equipment can be extremely costly and vulnerable to vandalism and theft. Consequently, developing countries struggle to acquire and maintain high-quality monitoring instruments. Thus, water data in those countries remain fragmented, inaccurate, and largely based on isolated measurements. This article describes a smart low-cost remote-monitoring flow sensor designed for the developing country context. The sensor uses low-cost off-the-shelf sonar devices to gauge river height as a proxy for flow rates and operates via an Internet-of-Things (IoT) node based on the Global System for Mobile Communications (GSM) standard. The sensor transmits logging data to a centralized server to provide realtime data analytics.

Biofiltration holds one of the most promising options for removing environmental pollutants from water by reducing inorganic matter, and nutrient concentrations and removing pathogens. This study evaluates the performance of six large field-scale biofiltration cells and assesses the risk of reusing this treated water for irrigating food gardens. The study took place at an abandoned wastewater treatment work (WWTW) in Franschhoek, South Africa. A batch operation was used to measure physical water properties and nutrient concentrations. Large stone cells performed best in reducing ammonia nitrogen (NH3) and orthophosphate () by 98 and 95%, respectively, however, an overall increase in nitrate () and nitrites () was also observed in these and other cells. Phytoremediation made a marginal contribution to reducing contamination. The extent to which biofiltration can be used to clean and reuse contaminated surface water runoff from an informal settlement to safely reuse the water for irrigation purposes is poorly understood. Laboratory analyses revealed that the water quality from four successive harvests broadly met South African guidelines for irrigation and compared favourably with the quality of vegetables from local supermarkets.

The management of greywater in the non-sewered areas of South Africa has been identified as a key area of research owing to the fact that very little, if any, provision has been made for it. Without water-borne sanitation, the disposal of greywater becomes a problem that has the potential to create a host of environmental and health problems, and this is particularly evident in the high density informal settlements that surround the major South African cities. The main aim of this study was to understand the use and disposal of greywater in the non-sewered areas in South Africa, determine typical quantities and qualities, and develop a preliminary guide for its management, both in terms of reducing health and environmental risks as well as possibly providing benefits through controlled reuse.

This paper describes a collaborative process of identifying and prioritising current and future water research questions from a wide range of water specialists within South Africa. Over 1 600 questions were collected, reduced in number and prioritised by specialists working in water research and practice. A total of 59 questions were finally proposed as an outcome of the study and are categorised under the themes of change, data, ecosystems, governance, innovation and resources. The questions range in scale, challenge and urgency, and are also aligned with prevailing paradigms in water research. The majority of the questions dealt with relatively short- to medium-term research requirements and most focused on immediate issues such as water supply, service delivery and technical solutions. Formulations of long-term research questions were sparse, partly because some of the principles and methods used in this study were difficult to apply in the South African context, and also because researchers are influenced by addressing what are believed to be the more immediate, short-term water-related challenges in South Africa. This is the first initiative of its kind to produce a comprehensive and inclusive list of research priorities for water in South Africa. Keywords: research, questions, collaboration, prioritisation, South Africa