Satellite Images Aid South Africa In Monitoring Dam Levels and Water Availability

Citizens of South Africa, and residents of Cape Town, in particular, are breathing a much-needed sigh of relief as dam levels recover from previously low points, following recent rains. Cape Town’s dam levels are now up to 71.2%, according to statistical figures provided on 26 July 2019. This is a positive departure from figures in 2017 when dam levels stood at a meagre 27.2%.

Even with the gradual rise in dam levels, South Africans have been warned to use water sparingly in their homes and their farms. The signs of an impending drought are important reminders that freshwater is a precious commodity and needs to be looked after. It doesn’t take much for things to change, and for dams to become depleted. In 2014, about three years before the Day Zero crisis hit Cape Town, dam levels were at 100%.
“South Africa is a naturally water-scarce country, with only 490mm annual rainfall on average which is less than half the global average,” said Christine Colvin, Head of WWF South Africa’s Freshwater Programme.

“Only 10% of the land in South Africa generates half of the freshwater run-off into our rivers. The need to secure these areas should be a national priority – not only for households and the well being of our citizens but for the economy as a whole”, Colvin added.

Other dams across the country actually look to be drying up. According to the Department of Water and Sanitation’s Drought Status and Management information system, many provinces are still touted to be in danger of severe drought.
With an impending cold front on the cards, dam levels are expected to experience a marginal increase, bringing rain, strong winds and light snowfall over parts of the Western Cape and Northern Cape, according to predictions from the South African Weather Service. The dam is the source of drinking water for most of Cape Town and is crucial to irrigation for farming in the area.

Gariep, located in the Free State Province, had its dam levels at 46.3% in early 2017. The primary purpose of the dam in the area is for irrigation, domestic and industrial use as well as power generation. The Department of Water and Sanitation has predicted that there would be little rain during the winter and to this end, issued a notice for Gauteng water consumers to save water.

The water from the Vaal Dam is distributed across provinces in terms of borders and in particular, Gauteng and Mpumalanga as well as the Free State province. The Vaal Dam is officially South Africa’s 2nd biggest dam in terms of surface area, and the 4th largest dam in terms of volume.

Pongolapoort Dam’s level reached 85% five years ago but hasn’t attained anything close to that level since then. Since 2016, levels have hardly made it past the 40% mark. The dam was originally built to supply water to local farmers for the cultivation of cash crops, and it is also surrounded by private game reserves.

These reports and dam level figures would not be possible without the functionality of satellite data, which is an integral part of space technology. Residents of Cape Town and other parts of South Africa are able to keep tabs on water levels, and ultimately make decisions pertaining to water consumption, because of data and information provided by satellite services. This goes to show how space technology is invaluable in preventing avoidable crises, and to this end, there is a need for stakeholders to elaborate on the advantages of space science, in order to encourage increased investment in the African space industry.