Manx Utilities says it's spending half a million pounds replacing two and a half miles of water mains in the south of the Island.
The main runs from Ballaglonney Farm to Ballaquinney Farm and will take 30 weeks to replace.
The organisation says the existing main was originally laid in 1967 and delivers water to more than 3,800 people.
Manx Utilities says the work may occasionally affect some roads but residents will keep access to their properties.