Temporary traffic lights on one of the busiest routes on the Fylde coast led to jams for motorists.
The lights were put up to allow for engineers to dig a hole in Bispham Road, Bispham - around 100 yards from the busy junction with Warbreck Hill Road, Plymouth Road, and Holyoake Avenue - and fix a burst pipe. That work is expected to last all week.
One resident said: "There was water flowing down the street right down to the traffic lights. It was a river."
The leak is understood to have been fixed at around dawn on Saturday, though the hole had still not been filled in last night and workers were not at the scene.
The close proximity of the temporary lights to the busy four-way junction as well as the sheer volume of cars on the road, which links Blackpool to Bispham and Cleveleys, led to lengthy tailbacks over the weekend.
Blackpool Council said water repair firm Morrisons, a subcontractor for water company United Utilities, carried out the work without a permit on Saturday morning, as is usual and "vital" in emergency cases.
The authority was told at 8.15am today, and was expected to visit the site to "make sure all signs, procedures, and works meet safety standards".
A spokesman said: "We expect the work to be completed on Friday. It is not just a hole that will be filled. The work consists of assessments, safety checks, water pipe repairs, and then repairing the road, followed by further inspections as it is of utmost priority that the work must be safe."
Roadworks were also underway in nearby Devonshire Road, another arterial route, though no temporary lights were being used and there was no impact on traffic.
United Utilities said it was notified of the leak just before midnight, on Friday. "Our team of engineers worked through the night to repair the leak and make sure residents had their water back on for the morning," it said.
When asked why no other work was done over the weekend, the firm added: "Once the repair is complete we usually allow a little bit of time to make sure that the pipe is working again properly before we reinstate the road.
"We’ll be filling in the hole and getting out of everyone’s way as quickly as we can this week and apologise for any inconvenience caused.”