The A158 in Skegness is closed in both directions after a water main burst.
Lincolnshire Police are advising drivers to avoid the area near to Southview Leisure Park while the main is repaired.
Bus services in the town are affected with Stagecoach not serving Southview Park until the water main is fixed.
Traffic is also building up on the approach to Skegness as motorists attempt to find alternative routes.
A spokesperson for Anglian Water said: “Engineers are on site and temporary traffic lights have been set-up.
“Customers’ water supplies should be unaffected but if any residents are experiencing low water pressure or no water at all they should contact us.
“We will be working to repair this and get things back to normal as soon as possible.”