Urgent repairs are to be carried out by Anglian Water in Grantham town centre on Sunday.
Temporary traffic lights will be in place at the London Road junction with Wharf Road and St Peter’s Hill.
The signals will be manually controlled, and in place from 9am to 3.30pm.
A spokesman for Lincolnshire County Council said: “They will be cleared as soon as works are completed but delays can be expected.
“The works have been agreed for this date as it will avoid congestion during the busy half-term period.”