Regular flooding has plagued the road near the entrance to Astley Park, and police had to close it for the second time in less than a week after last night's torrential rain.
The road remains closed this morning between Ackhurst Road and Glamis Drive, with the 109 Preston to Chorley bus service having to be diverted.
Last night, fire crews were called to the scene to try and pump out floodwater, but the road remains closed this morning after being deemed unsafe. Chorley Council workers have resumed efforts to pump out the water this morning, but the road is not expected to reopen today.
Pictures from the scene show the Grade-II listed Ackhurst Lodge nearly submerged by floodwater, prompting concerns from residents who fear the historic building is at risk of permanent damage.
But a solution to the flooding is now in the works, with Lancashire County Council confirming that plans are in place to fix the problem as soon as water levels subside.
After last week's flooding, Chorley Council said an investigation had revealed that the flooding is being caused by a blockage found in the culvert taking runoff water under the road from the swollen River Chor.
But it said it did not have the authority to make repairs because the culvert is owned by Lancashire County Council, who have responsibility for its upkeep and repairs.
Today, the county council has confirmed that the blockage is being caused by logs that have fallen into the river during tree felling along the River Chor, which is now restricting water flow through the culvert under Southport Road.
It said plans are being drawn up to remove the blockage as soon as the water levels subside and workers can gain safe access to the culvert.
John Davies, head of highways, said: "We received a report before Christmas that the culvert under Southport Road was being obstructed by a large number of logs and branches which had washed into the river following tree felling operations in the area while awaiting collection.
"We have worked closely with colleagues at Chorley Borough Council and highway teams have attended and removed as much of this debris as they could, however a large log had become firmly wedged in the culvert which unfortunately they have been unable to remove and is restricting the flow of water through the culvert.
"We now need to wait until the water levels have subsided enough to allow someone to safely enter the culvert and cut up the log, however in case this is not possible to do safely, we are also looking into other options to remove the log using remotely controlled equipment.
"We will continue to monitor the situation and take action as required to ensure that the area remains safe."
A Chorley Council spokesman said: "You’ll have seen again the rain has caused flooding on Southport Road by Ackhurst Lodge, which has led to some disruption on the road this evening (Tuesday, January 19) so please be careful if travelling in that direction.
"All we’ve wanted from day one when this became an issue is to see it resolved and the cabinet member at Lancashire County Council has tonight confirmed his team has been instructed to find a solution to the flooding to ensure the road is safe.
"We standby ready to help with whatever is necessary to fix the problem - all we want to do is get it sorted.
"We feared it may end up in this position with more and more rain forecast but we look forward to getting it resolved so we can move forward with the plans to restore the historic lodge and bring it back into use."
It follows a statement issued by Chorley Council on Friday, January 15, calling for "urgent action to be taken" by the county council to fix the problem. It said it had demanded a "comprehensive solution" and called for the installation of a new and larger culvert to accommodate the flood water.
You can read the full statement from Chorley Council here.