Cape Town interventions see drop in water consumption

Thursday, March 1, 2018

Cape Town Deputy Mayor Ian Neilson says the city’s interventions, along with the water savings efforts of residents, have seen the consumption drop to just over 500 million litres a day (MLD) this year.

Giving an update on Cape Town’s water crisis on Thursday, Neilson said the increased roll-out of pressure management interventions alone has resulted in savings of 50 MLD over the past two months.

Neilson said in order to successfully navigate the drought and ensure that the water supply system do not run out of water, the city has to implement various demand management measures to manage the water drawn down from the dams, and to add additional water to the system through its water augmentation programme.

“At the same time, we must continuously assess the risk of uncontrolled and unknown variables, such as rainfall. Regardless of rainfall or water supply augmentation, Cape Town needs to continue striving to reduce average daily consumption to 450 MLD.

“This must be done not only to stretch our supplies as far as possible, but also because the National Department of Water and Sanitation has imposed a 45% restriction on the city’s water use for the current hydrological year (1 November 2017 – 31 October 2018).

“If we do not adhere to this restriction, there is a chance that the National Department may impose even more stringent restrictions on Cape Town in November 2018,” Neilson said.

The city’s water consumption over the past week was at the average of 516 MLD, with dam levels dropping 0.4% to 24%.

Neilson said the city needs to continue reducing consumption in line with Level 6B water restrictions, if “we are to avoid Day Zero”.

“Our latest Day Zero projections take into account the continuing drop in urban consumption over the past weeks, the Groenland water transfer, and the discontinuation of the agricultural releases for this hydrological year.

“We are now also in a position to exercise greater control on the consumption side with the implementation of Level 6B restrictions, the increasing roll-out of pressure management across the city and the installation of water management devices to limit the consumption of high water users,” he said.

Water augmentation programme update

Neilson said various projects currently under construction and those already completed will augment the city’s water supply by around 180 MLD.

He said approximately 150 MLD is sourced from groundwater; 16 MLD from temporary desalination; 10 MLD from water re-use; and 4 MLD from the city’s springs.

The city’s three small-scale emergency desalination plants, he said, will add approximately 16 million litres of water a day into the system by May 2018.

According to Neilson, the Strandfontein plant is on track to supply its first water in March 2018, and will supply 7 million litres of water a day when fully operational. 

“The plant at Monwabisi will also add 7 MLD, and will reach full production in May 2018. The plant at the V&A Waterfront will add 2 million litres of water a day, and is anticipated to go online during the second half of March, all seven containers have been delivered to the site, and construction on the water tanks has started,” Neilson said.

He added that the three ground water abstraction projects will at their peak supply almost 150 million litres of water a day to the city.

These include, the Cape Flats aquifer, which he said it is on track with drilling progressing well in all areas. –