Cape Town water report: usage spikes, dam levels drop & aquifer project begins

Dam levels or both major and minor reservoirs across Cape Town have once again taken a hit, this according to the City’s latest water report (pdf).

Last week, dam levels fell below the 37% mark, to 36.8%. This week sees the third consecutive drop, with levels now just above the 36% mark.

The Berg River Dam lost 1.4% of its storage capacity this week, shedding around 1.82-billion litres. The other two large dams in the system — the Theewaterskloof and the Voëlvlei — followed suit, dropping 0.9% and 0.4% respectively.

The remaining three reservoirs however bucked the trend.

Wemmershoek Dam saw small gains of 0.2% over the previous week, now sitting just below 50%.

The Steenbras duo gained water this week, due to more than 12mm of rain recorded in the catchment area last week. The Upper dam is now at 100.4% while Steenbras Lower is currently at 54.4% capacity.

In terms of November’s average rainfall, a number of areas across Cape Town has received close to or more than half the long-term average figures.

Voëlvlei Dam has received just below 15mm this month, from a usual figure of 25.4mm. Theewaterskloof received 18.5mm from a usual average of 36.8mm. And the Steenbras catchment area has received 31.7mm of rain this month, this from a usual 46mm.

Rain is also forecast on Tuesday and Wednesday across Cape Town.

Cape Town’s daily water consumption is also up again this week, spiking to 602-million litres per day from the 582-million litres recorded the previous week. This also remains 102-million litres per day above the City of Cape Town’s target.

But city mayor Patricia de Lille is adamant that a combination of factors will see the city through the water crisis.

With day-zero pushed back to mid-May 2018, the City has this week began accessing water from the Table Mountain Group aquifer.

“The City is currently drilling test abstraction boreholes in the Steenbras catchment area, which will inform the design of a full-scale wellfield and support a water use licence application for full-scale production,” de Lille explained in a statement issued Monday.

“The yield from the other areas of the TMG aquifers such as the Helderberg, South Peninsula and Wemmershoek will be approximately 50 to 60 million litres per day.”

Visiting the Steenbras catchment area where we will be drilling into the TMGA aquifers to increase water supply by approximately 10 million litres a day at this site. Other parts of these Aquifers will yield between 50 and 60 million litres per day. pic.twitter.com/VbdMXi6LYX

— Patricia de Lille (@PatriciaDeLille) November 19, 2017

Initially, the first phase of the project will yield 10-million litres per day, and will be pumped into the Steenbras system.

“This project is part of the City’s commitment to do everything it can to bring additional water online as we face the worst drought in our recorded history,” she concluded.

There have been no further updates on the City’s desalination efforts.

All images: City of Cape Town