The Vaal Dam is only 29.1% full.
The department of water & sanitation has urged residents in Gauteng to use water sparingly as the Vaal Dam's levels continue to decline. Last week, its water levels sat at 30.1% but have dropped to 29.1% this week.
During the same week last year, the level was at 48.4%.
The department said people should report water leaks and prevent excessive water use as this can be detrimental to the system. It said while water conservation is important, the province is nowhere near implementing water restrictions.
“The iconic Vaal Dam declined to record lows this week, and is in stark contrast to last year's levels amid few chances of rainfall and sweltering weather conditions.
“Even as Vaal Dam levels drop weekly, it is not at a point where Gauteng faces the prospect of day zero,” the department said.
Should water levels in the Vaal Dam continue to drop, it will be replenished by the Sterkfontein and Grootdraai dams which make up the Integrated Vaal River System (IVRS). The system consists of 14 dams.
The Bloemhof Dam also decreased from last week's 86.2% to 82.0% this week.
The department said one of the system's “headaches” is the Mohale Dam in Lesotho, which is at 2.9% compared to 32.6% in the same week last year.
The water levels at the Katse Dam are at 21.7% for two subsequent weeks.
The reserve Sterkfontein Dam in the Free State has remained at 94.3% for two weeks in a row, from 91.5% this time last year.