Saving our water

"Too much, too little, or too dirty." These are the problems that plague South Africa's water resources.

South Africa faces three major water challenges: flooding, drought, and pollution, explains Peter Shepherd, principal hydrologist and partner, SRK Consulting.

Drought has been at the forefront recently as many towns face water shortages and Cape Town nears Day Zero. Drought planning is one of the most important aspects of South African water resource management. Much of the planning and implementation of water management lies with the Department of Water and Sanitation (DWS), which is assisted by municipalities in minimising water wastage and understanding growth and demand. This focuses largely on management of surface and groundwater in various catchments, understanding source and demand through surface water, rainfall and groundwater modelling as well as yield analysis.

The variability of the climate means drought planning will always be an ongoing process. However, the planning of where water is transferred to and where and how much water is needed is well understood within the DWS, and there are various plans in place that should be implemented to reduce the risk of running out of water, explains Shepherd.

He argues that South Africa's dry climate has resulted in a great deal of understanding around water resources and although Cape Town in facing a crisis, its drought planning is done in line with the standard of a 1:100 event. What is currently being experienced is a 1:300 drought event. Shepherd, therefore, believes Cape Town is doing fairly well insofar as it has maintained supply to this point.

"I still believe that because we are a dry country, our planning of water resources has been good. But implementation of those plans and the continual updating of water resource modelling is paramount," says Shepherd.

"The implementation of water transfer schemes takes a long time, so strong leadership and management of the implementation is required. We have a great team of water resource planners in the country but we need to implement he plans at a more urgent pace than what is happening at the moment. If we do not, we are bound to find ourselves in a situation where water rationing will be more prevalent. There are many places in South Africa where growth could occur if more water was available and we, as South Africans, need growth as much as possible."

Measure to manage

With climate change and variability, Shepherd believes South Africa is not collecting enough data on rainfall to look at its potential impact on resources. Many weather stations have closed down and that should change – we need more rainfall stations not less, he says.

Similarly, it is vital to know how much water is coming into and being abstracted from all dams and water sources.

"All our monitoring facilities need to be upgraded to ensure that we understand the changes," he stresses.

"In South Africa, we do have a very good water resource model but it needs to be continuously updated. The more data available, the better the simulation will be," Data is mainly collected by the DWS and municipalities, but Shepherd believes it is time for farmers, mines and industries to collect data that can be reported on, "We really need to work together as a team," he adds.

"For too longwater has been cheap and relatively accessible in the larger towns. The growth of our population and changes in demands in the urban environment mean we need to spend more effort understanding where we can reduce demand.
 

60%

Agriculture, which accounts for approximately 60% of water use in South Africa, will have to adopt better methods of irrigation, such as drip issigation, which can reduce water consumption by 30%

Tackling pollution

Planning aside, it is vital that South Africa protect its water resources if long-term water security is to be achieved. When it comes to the "too dirty". South Africa's poorly performing wastewater treatment works pose a serious concern, as untreated effluent damages the ecology of dams and rivers as well as downstream water resources.

"It is going to take a lot of money, planning and implementation to get those sewage works up to standard, but we need to do that. We can't have a situation where we are destroying rivers because we don't have the money to treat our sewage correctly," says Shepherd.

"The longer we leave it, the more capital we will have to spend to get it back to where we want. It is vitally important and a lot of the DWS budget should be spent to try to rectify the situation."

Future water resources

Dams form the primary source of South Africa's water, and remain the cheapest way to collect water. Shepherd believes dams will continue to be the primary source of the Country's water supply going forward, but South Africa's water supply needs to diversify. Sustainable abstraction of groundwater is likely to become an important contributor, but Shepherd predicts this will become unsustainable in the next 100 years and South Africa may have to look outside its borders. There are several large rivers to the north and although this is a lengthy distance, it may be a sustainable option to boost water supply. Desalination also has potential, and although the price is currently prohibitive, it will likely be required in most if not all coastal towns in the future.

Driving down demand

"For too long water has been cheap and relatively accessible in the larger towns. The growth of our population and changes in demands in the urban environment mean we need to spend more effort understanding where we can reduce demand," says Shepherd.

Agriculture, which accounts for approximately 60% of water use in South Africa, will have to adopt better methods of irrigation, such as drip irrigation, which can reduce water consumption by 30%. Similarly, industries like mines are working to minimise the water they use by better utilising what they have on-site and reducing losses from tailings dams via seepage and evaporation. South Africa also urgently needs to address its bleeding reticulation infrastructure, where unnecessary water losses can add up to 30%.

Positively, many people have realised the importance of reducing water consumption to ensure access to water for all citizens. "There has been a big attitude change; there are a lot of technologies available to minimise the amount of water used and I think this will only improve going forward," concludes Shepherd.

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