Coliban Water will focus the cleaning on four towns west of Bendigo - Laanecoorie, Bealiba, Dunolly and Tarnagulla.

The works aim to remove sediment build up to ensure good disinfection levels and are part of the annual cleaning works program.

Coliban Water Manager Customer Operations Steve Dunlop said customers may notice a slight change in taste and odour of water.

"The cleaning will not impact the flow or pressure of supply and the drinking water will be safe to drink," he said.

"The taste and odour will return to normal following the cleaning.

"Customers in these towns have been notified by mail of the works."

The cleaning will use a method known as free chlorination.

"Chlorination is needed to ensure the water supply continues to be safe to drink and meets the Australian Drinking Water Guidelines," Mr Dunlop said.

"The water is also safe for your pets to drink. Customers should seek advice from their local pet shop with regard to aquariums. They may need to review their treatment process of the water due to this change."

Mr Dunlop said chlorine sensitivity can be a concern for a very small number of people.

"If customers believe they are sensitive to chlorine, they can fill a jug with water and place it in the fridge for at least one hour to allow the taste of chlorine to dissipate," Mr Dunlop said.