Understanding risks to human health from water pollution and declining water security under climate change

AWARD is undertaking work on the links between water quality and human health in the Inkomati Basin. The work is funded by the Water Research Commission (WRC) and the Inkomati-Usuthu Catchment Management Agency (IUCMA). The aim of the work is to capacitate water resource and public health managers to understand and manage biotic and human health risks arising from poor water quality and changes in flow in the Inkomati Catchment, particularly under climate change. This phase focuses on the Crocodile River Catchment of the Inkomati-Usuthu Water Management Area. Ultimately, maintaining river flows with good water quality is intended to support societal well-being, one aspect of which relates to human health. However declining water quality and flow, such as that seen in some rivers of the Lowveld, has clear implications for human health since an unhealthy ecosystem – such as a river or wetland – cannot support a healthy community. In South Africa, many people – particularly those living in the densely-populated former apartheid bantustans – still rely on untreated water (“run-of-river”) for domestic purposes as well as for crop irrigation, livestock watering, cultural, spiritual and recreational purposes. This highlights issues of socio-environmental justice since past inequities often persist today. In the Lowveld, even communities with access to treated drinking water may still suffer detrimental health effects of water pollution through bioaccumulation in crops irrigated from polluted water. These impacts will be exacerbated under declining river flows due to increased abstraction and climate change (see for example Predicted Impacts of Climate Change on Water Olifants Catchment 2020). However, assessing these risks in the complex work of water resources management is challenging and currently not readily possible. Water resources staff have to make complex decisions regarding the licencing of water and regulating water use. They also need early-warning systems for floods, droughts and temperature extremes as part of disaster management. For this, they need easy-to-use, systems that allow them to integrate not only biophysical but also social data in order to assess risks and implications. For example, in our work with CMA and DWS staff, answers to the following questions are regularly sought: If this water-use licence is approved, what are the potential risks downstream and for which communities? Approving a water-use licence without understanding what the downstream or cumulative impacts might be, is proving exceedingly difficult. Access to information that supports this in a format that is easy to understand and use, is vital. Ultimately, the outputs need to have meaning for water resource managers and stakeholders. Currently, water resource managers – and water users – are often provided with standards to comply with, which are developed by specialists and captured in reports. Since not everyone is a water quality specialist, these standards have little meaning or value unless they are rendered in a form that is readily understandable, and are used in conjunction with the potential risks associated with non-compliance.  With universal applicability, we propose to use human health as an entry point for understanding risk. Our work in the rivers of the Lowveld where declining water quality and flows threaten biotic and human health has highlighted the need for such a system.  The use of our INWARDS Decision-support system can quickly and partially contribute to an integrated understanding of risks for biotic and human health (see Integrated Water Resources Decision Support Olifants Catchment 2020). The project started in July 2021 and runs to February 2023. We will adopt a collaborative, systemic approach and work closely with key stakeholders including the IUCMA, SANParks, DWS and the City of Mbombela amongst others. We aim to build the capacity of key IUCMA staff through inclusion in the project.