Harare City Council says it now requires 11 chemicals to treat its water to satisfactory levels because of heavy pollution in Lake Chivero, its source of water.
The pollution has been made worse by artisanal miners who have invaded Kintyre Estate and heavy farming near Lake Chivero.
According to the municipality's communications corporate manager Michael Chideme, the authority now needs 11 chemicals to treat water which is draining its budget and at the end affecting service.
"Council now requires up to 11 chemicals to treat the water to satisfactory levels and required standards of clean and safe drinking water," Chideme told NewZimbabwe.com Monday.
"The bill is RTGS20 million per month depending on the obtaining interbank rate... the city ends up using money for other service delivery on water chemical alone."
Chideme added, "Some of the water challenges we are facing as a city are man-made. Harare and Chitungwiza residents need to understand that water pollution is not done in Lake Chivero but from them.
"If we could use just three chemicals to treat our water, the municipality could be saving a lot of money.
"If we all understand this and change our behaviour, our water problems will not be as much as we are facing today.
"Residents are pouring large amounts of organic and inorganic waste down the drain such as plastics, glass bacteria rich faeces and these are polluting both surface and ground water."
Chedeme said if Harare water is declared a state of emergency, this will help to marshal resources for the construction of new sources such as the long awaited Kunzvi Musami and Mazowe dams.
Recently, the municipality introduced water rationing as some of its water sources have dried up with Prince Edward waterworks already decommissioned.
"Water pollution, dried up water sources have contributed to water shortages in Harare, but residents need to own up on water pollution and avoid dumping waste on undesignated areas as it is being easily washed into lake Chivero," he said.
"Industries are also discharging waste water into water bodies polluting the water and when rain comes the gaseous particles are deposited together with rain onto the ground and seep into the underground aquifers thereby polluting the ground water."