Cape Town dams: Theewaterskloof deals a blow as water usage remains high

In its latest report published Tuesday, the City of Cape Town revealed that the combined level of its six largest reservoirs saw the first decrease in over a month.

Last week, the City reported a total capacity of 37.5%. This week, that figure is down by 0.1% (pdf).

That may sound like a small margin, but that signals a decrease of just over 1000-million litres of water.

Cape Town dam levels: September sees slow growth

The Theewaterskloof Dam experienced the most notable drop, shedding 0.4% over the week to 28.4%. More than three times the amount of water was stored within its banks in 2016.

Steenbras Lower was the other dam to see a drop, falling from 47.8% last week, to 46.3% this week.

The Voelvlei Dam and Steenbras Upper Dam remained steady at 26.7% and 99.9% capacity respectively.

(Click on image to zoom)

Other dams in the system however continued their positive trend.

The Berg River Dam saw a 1.2% rise in stored capacity, and is now just 8.2% off its 2016 storage level at the same point last year. The Wemmershoek Dam also saw a rise of 0.4%. It however remains more than 20% off its 2016 storage level.

Cape Town’s minor dams combined storage saw a drop of 7.5% over the past week.

Cape Town rainfall: 2017 well below average

The droop in capacity is largely due to the underwhelming rainfall figures experienced in September.

Areas monitored by the City of Cape Town failed to reach their long-term average, with the Theewaterskloof catchment receiving close to 20mm less rain this year. Wemmershoek and Voelvlei also received less than half of September’s long-term average rainfall.

Data from the University of Cape Town’s Climate System Analysis Group also suggests that 2017 is the driest year the city has seen this decade.

For the City of Cape Town, a lack of rainfall and high water consumption remains a headache.

It announced “a process to install approximately 2 000 water management devices per week on the properties of identified excessive users.” Said devices will be limited to 350-litres per day.

“This is in an effort to force consumption down among those who have shown a flagrant disregard for the water restrictions which stipulate that every single person is only allowed to use 87 litres of water per day,” it continued in a news release.

Notably, water usage remains 114-million litres per day above the City’s consumption target.

“We need the whole of society to stand with us and to help us to get through this drought, but also to start laying the building blocks for a more resilient city over our longer-term future,” concluded Xanthea Limberg, the City of Cape Town’s Mayco member for water and waste services.