The South African Academy of Engineering (SAAE) has urged government to focus on securing reliable hydrological information to manage South Africa’s scarce water resources.

In an advisory note to President Cyril Ramaphosa, the academy recommended that the Ministers responsible for water, sanitation and environmental affairs prioritise their respective hydrological and climate information systems and ensure adequate funding for the collection and maintenance of these data records.

The advisory note suggested that events such as floods, droughts or climate disasters are predictable and can be mitigated through the use of available hydrological information to enable early actions and address identified risks.

“The present danger is that the foundation of South Africa’s hydrological information system is being undermined. This is a long-term threat to the country’s water security that must urgently be addressed if we are to have a sustainable future under present or future climates,” says SAAE president Professor Elsabe Kearsley.

Hydrological data comprises data on water flows and the quality of the water in rivers, water storage in dams and rainfall and evaporation rates.

The raw data is processed and analysed to produce many kinds of hydrological information.

“That information could include warnings about tomorrow’s floods or predictions about the worst drought that may be experienced in the next 50 years. It is also essential for the planning and operation of our infrastructure, as well as to support a multitude of social and economic activities,” Kearsley points out.

There is a need for both real-time data, particularly for flood and drought management, as well as for very long-term data records, without which it is impossible to estimate climate variability or detect climate change trends to develop mitigation measures and implement them in a timely manner.

It is also critical to determine how much water can reliably be supplied from rivers and dams in order to plan and develop the water resource and allocate it between different users, including the natural environment; enable supply restrictions during dry periods in a predictable and timely manner; identify the risks posed by floods to life and property and prepare mitigation strategies, such as demarcating safe areas for housing development or identifying locations where flood warning systems are needed; and provide information about the likely size of extreme floods and the duration of extreme droughts to inform the design of transport, power and other infrastructure.