Some households in the PR2 postcode, which includes Fulwood and Ashton-on-Ribble, received text messages and emails from United Utilities this morning.
The water company advised customers to "avoid doing any clothes washing" and "do not give the water to bottled fed children until clear."
The water company is carrying out maintenance work in the area, which they said could lead to brown water coming out of taps.
United Utilities released a further statement clarifying the situation this afternoon.
A spokesman for United Utilities said: "The advice was purely precautionary due to the chance that our work could have caused discoloured water.
"If this happens it is due to naturally occurring sediment stirred up in the pipes which is unlikely to be harmful, but it is good practice to avoid giving discoloured water to babies.
"However, we have not had any reports of discoloured water so far and customers can continue to use the water as normal if it doesn’t appear discoloured.”
United Utilities said it has not received any complaints from customers regarding discoloured water.
Households were also told that they may experience poor pressure in their water supply.
If your tap water is brown, you should run the cold taps slowly until the discoloured water becomes clear.
Areas that may be affected include:
- Haighton Green