Government has launched an urgent bid to contain the looming disaster posed by millions of litres of toxic and acid water to Johannesburg and surrounding towns.

Through the Department of Water Affairs, the government is calling for service providers to - in 18 months - come up with a solution to address acid mine water drainage in the Witwatersrand underground mine voids.

In March, The Times reported a warning by scientists and geologists that if efforts are not made to address the problem in the central basin, in just under two years water will start seeping up in downtown Johannesburg at a rate of up to 70 mega-litres a day - as much water as is in 1400 average-sized swimming pools.

Government's call for proposals contains a hard-hitting report on acid mine drainage, and reveals that acid water that reaches the surface in the Central Basin is likely to affect the foundations of buildings.

The report says if left unattended, "the matter could have far reaching environmental, social and economic consequences to the sub-region, and the Vaal-Orange River basin as a whole."

Despite these findings, Minister in the Presidency Trevor Manuel last month said the debate was being driven by "private sector interests".