Durban – If South Africa doesn’t address the gap between water supply and demand now, the problem could worsen by 2035.

This was the warning by Dr Jakkie Cilliers, head of African Futures and Innovation at the Institute for Security Studies.

“South Africa is also experiencing the worst drought in 23 years, and demand for water is not slowing down,” he said.

In its updated forecast for the Water Research Commission, the Institute for Security Studies and the Frederick S Pardee Centre for International Futures found that the water demand in South Africa would outpace supply every year to 2035.

When asked what that meant, Cilliers explained that “we modelled South Africa’s water demand and supply from 2014 to 2035”.

“South Africa is currently over-exploiting its water resources at the national level. This means that national water withdrawals for municipal, industrial and agricultural sectors exceed levels of sustainable supply,” he said.

Cilliers said this was based on best estimates of current water withdrawals and current water supply.

“Over-exploitation occurs when more water is withdrawn from a water source than is sustainable. The amount of water that can be reliably or sustainably extracted from a resource is called the yield.”

Cilliers explained that this was determined using what was called “a level of assurance”.

For example, a river may have a yield of one cubic kilometre per year at a 98% assurance of supply. This means that one cubic kilometre can be extracted from this river for 98 out of 100 years.

“If there is above-average rainfall in a given year, more than one cubic kilometre of water may be extracted without immediate consequence.

“But when withdrawals exceed reliable supply, the system is being over-exploited and becomes more vulnerable, and this is especially a problem when there is below-average rainfall,” Cilliers said.

According to the most recent version of the National Water Resource Strategy, “as at 2012, South Africa has had 16 consecutive years of above-average rainfall in the majority of summer rainfall areas, and in these areas the last major drought was more than two decades ago”.

However, because of climate change and other external factors, this trend was unlikely to continue. Cilliers said that if the gap between water supply and demand was not closed by 2035, “every time there is below-average rainfall it will become a crisis” for the country.

He emphasised that the gap could be closed, but that to do so it was important for South Africans to find a balance between supply and demand.

“Additional measures are needed, which include groundwater extraction, wastewater treatment and better water conservation. Generally, we need a change in mindset,” he said.

“The gap we mention continues to exist even after we factor in all the plans that the government have committed to from now to 2035. This indicates that additional measures, above and beyond the interventions outlined in the large-scale reconciliation strategies undertaken by the government, will be required to close the gap by 2035.”

Cilliers had a strong message for South Africans.

“We need to maintain our existing infrastructure much better and change our mindset. Climate change will exacerbate the gap and make rainfall more unpredictable.”

ilanit.chernick@inl.co.za

THE MERCURY
Source: ‘Demand for water is not slowing down’ | IOL