The roadworks on Summer Lane began in April, to repair a burst water main, and were expected to last a few weeks.
However, the works have caused long delays to drivers trying to enter and leave the town centre, and have led to traffic tailbacks during rush hour.
The works are not expected to be complete any time soon, after workmen damaged a culvert of the centuries-old Sough Dyke, which runs under the town centre and once supplied the town and its mills with drinking water.
As the damaged section is part of a main watercourse, the Environment Agency must approve a specialist contractor to repair the culvert.
Coun Chris Lamb, cabinet spokesperson for environment and transportation, denied any dispute of responsibility of the culvert.
Coun Lamb added: “Unfortunately, in the process of repairing the burst water main, Yorkshire Water inadvertently damaged a culverted section of Sough Dyke, the main watercourse flowing through the centre of town.
“This watercourse is classified as a main river and is therefore under the administration of the Environment Agency.
“As a result, the repair work now needs to be carried out by a specialist contractor and approved by the Environment Agency.
“Having now clarified the legal position, the cost liability clearly falls with Yorkshire Water however responsibility to carry out the work now falls to us to agree with the Environment Agency. At no point has there been a dispute with Yorkshire Water or their sub-contractor.
“We have been liaising closely with the Environment Agency on the scope of the repairs and their internal approval processes and will be looking to expedite the repairs as swiftly as we can.”