Despite its dams being more than 90% full, the City of Cape Town will not be reducing its water tariffs.

A reduction in tariffs would be dependent on an increase in consumption, said mayoral committee member for water and waste Xanthea Limberg.

"Currently, the City is selling approximately 30% less water than before the drought, but is facing additional costs that come with increasing our resilience," she said in a statement.

"It is important that the City cover its costs to ensure that the maintenance and augmentation programmes can be carried out. Should the amount of water we are selling significantly increase, this will be factored into the tariffs, but given the uncertain impact of climate change, it may not be wise to actively encourage such an approach at this stage."

According to the most recent figures, dams supplying the metro were at a total capacity of 90.7%, up by 2.7% from the previous week.

Figures recorded for the week of 24 to 30 August, showed that consumption for the same period decreased by 28-million litres per day, from an average of 661-million litres per day the previous week, to 633-million litres per day.

Limberg said the fixed basic amount charged was introduced to "ensure financial sustainability irrespective of the level of consumption and to ensure a fairer payment of the costs by all customers".

"Prior to the drought, the tariff was based on a consumptive portion only. The drought revealed that if consumption dropped significantly (i.e. beyond levels we could have expected before the drought), it could also affect our long-term future by taking away resources for necessary maintenance," she said.

The City changed the tariff structure to allow a fixed portion of the revenue needed to "run the system responsibly" be guaranteed, no matter how much water residents consumed.

The City did not budget for a profit from the sale of water, Limberg said.

"When compiling the budget, the City looks at affordability, and attempts to set service tariffs based on the projected consumption trends, so that the income received covers the cost of providing the service," she explained.

"The current tariffs are for the projections and realities of the 2020/21 financial year. Costs of providing water to the City stay similar, even if residents drastically reduce consumption, and if maintenance is delayed, it can cause much more serious and costly problems down the line.

"This service includes maintaining a 11 500 km water network, 9 500 km sewer infrastructure, 5 600 km stormwater pipelines, 490 waste water pump stations and 23 waste water treatment works."

A year ago, dam levels were at 81.9%.

"Significant recent rainfall has pushed total rainfall for 2019/20 close to the long-term average and dams are close to full for the first time since 2013/2014. This will of course prompt serious consideration that current water restrictions be further eased following the end of the rainy season - 31 October," Limberg said.

"However, residents should please keep in mind that the impact of climate change in subsequent years is still uncertain and that this will also be factored into the eventual decision around restrictions."