A road in York city centre is closed now for four weeks.
High Ousegate is shut to traffic until Sunday 9 June to allow Yorkshire Water to divert a water main.
Parliament Street is also closed from its junction with Feasegate.
As YorkMix reported last month, work to install more anti-terror bollards uncovered the problem. The road closed yesterday.
A City of York Council spokesperson said at the time: “During an earlier survey of this site, we identified an unmapped Yorkshire Water valve which needs work doing to it.
“Trial holes to explore and install an additional valve will be dug together to minimise disruption.
“This means that High Ousegate from Parliament Street to Spurriergate will close to all vehicles for up to four weeks from mid May. Pedestrian access will be unaffected.”
The road is usually busy with vehicles making deliveries in the morning before it closes during footstreet hours. Diversions are in place.
Once the Yorkshire Water work is completed there will be a couple of months when High Ousegate reopens, before work to install the bollards begins.
That will start at the end of August “to avoid key events”, the council said.
