Managing climate risk in South Africa’s Western Cape

Predicting and balancing competing water needs

Involving all water users and authorities in decisions on water use helps to agree fair and sustainable ways to share scarce water resources. Integrating scientific analysis and modelling of climate change with policy planning helps planners to understand the effects of climate change.

Growing demand for water, and shrinking supplies

The Western Cape contributes almost a quarter of South Africa’s national gross farming income, and the Cape’s fruit and wine sector is a critical source of jobs and revenue. However, this sector depends on water – in a region struggling with competing demands from farmers, industry, tourism and a growing urban population. Climate change scenarios consistently predict reduced rainfall in this already dry region.

Recent land and water reforms aim to transfer at least 30 per cent of South Africa’s agricultural land and water to people defined as ‘previously disadvantaged’ under apartheid. The process has been slow, but some of the most successful land-reform projects have been in the fruit and wine industry. This sector, however, is extremely vulnerable to climate change. A diverse team of researchers, led by the University of the Free State, is working in the Western Cape to give planners and farmers access to improved climate information and a range of options to help them prepare for a water-scarce future.

Weather or climate? Too little water, either way

The climate of the Western Cape is Mediterranean – warm and sunny, with most rainfall during the winter months. In the last decade, the region has experienced some unusual droughts, leading to municipal water rationing. It is not clear yet whether these droughts reflect long-term climate change or short-term variability, but they are projected to occur more frequently in most climate-change scenarios.

Peter Johnston of the University of Cape Town’s Climate Systems Analysis Group sees the immediate challenge as balancing scarce water supply with rising demand: “This scarce resource needs to be equitably and efficiently divided between the ecological reserve in rivers… and domestic, industrial and agricultural use from rivers and dams.” And there is an added problem of know-how, he says: “Water resource managers currently do not have the skills and tools to do this.”

This project combines the hard science of predicting climate impacts with the delicate art of helping institutions apply that knowledge to water-resource policies and planning. It brings together a multidisciplinary team of scientists with farmers, community and industry groups, and a range of local planning authorities.

The idea: using integrated models to frame choices

With input from stakeholders, the research team is using an integrated modelling approach. This combines climate-change scenarios, a hydrological model, and an economic model to analyse and suggest the most practical and efficient ways of sharing water. The models clarify costs, benefits and risks associated with likely changes in climate, and different approaches to land and water use. The modelling tools aim to separate short-term variation in the region’s weather from the likely long-term, enduring changes that may result from climate change.

These models and the options they produce are shared with stakeholders so they can make better-informed decisions about investments and water use. For Jabavu Nkomo, a former CCAA senior programme specialist, the project’s value lies in what it will bring to water-resource users: “This project will build the capacity of water users and the political bodies trying to ensure adequate and equitably shared water supplies for the future. It will see the results and skills developed shared with those most affected by changes in water supply.”

Looking ahead: from conflict to collaboration

Better-informed planning will be crucial to prevent job losses in commercial farming and reduce risks for small and resource-poor farmers. By engaging in water-management issues, poor communities will learn more about water-supply mechanisms, and how to use water more efficiently. In bringing together disparate stakeholders, the research aims to build lasting relationships. Those involved will face hard choices on contentious issues such as water supply and pricing.

The lessons of this Western Cape project may extend to others across Africa facing similar conflicts over shared water resources under pressure from climate change. The team intends to create a centre of excellence for integrated modelling that will draw students from across the continent to study climate-change adaptation. For project leader, Daan Louw, the search for solutions to potentially crippling water shortages may yet reveal a silver lining: “Climate-change adaptation will add strength to the glue that binds us together as Africans in the decades to come.”