A team will be undertaking a project refreshing or cleaning some of the water pipes around the city.
The work - to take place between Sunday and Thursday from 11pm until 6am - involves the removal of naturally occurring mineral deposits which can build up over time.
Water will not need to be turned off in the houses, and residents should not notice the work being carried out as much will be done overnight.
However, some residents may find the tap water pressure temporarily reduces, or that after the work has taken place it may appear a little discoloured.
The 955 properties affected have been sent an information card in recent weeks explaining the process and what they should do if the water colour changes.
It is part of continued maintenance that takes place on the water network across the region.
A United Utilities spokesman said: “Work is taking place through the night in parts of Lancaster to improve water supplies. We will be refreshing pipes and carrying out cleaning work as part of an overnight programme.
“No customer will be without water at any point during the work, and households will be informed directly in advance by letter, card or email.”