Emergency drainage works are due to begin this week on Priory Street to fix a 19th-century plumbing mistake that has leaked untreated sewage into the River Monnow for years.

The repair targets an old long-forgotten mis-connection at St Mary's Priory Church, where foul waste was mistakenly routed into a Victorian roof-drainage pipe. Built originally to carry only rainwater under Priory Street to flush out the slaughterhouses below before emptying into the river, the forgotten pipeline eventually became an active pollution source.

Following investigations by Natural Resources Wales and Welsh Water, the discovery forced the emergency closure of toilets at Monmouth Priory, scuppering bookings from wedding rentals and private parties and although some groups relocated to other spaces like Bridges, some—such as yoga and coffee morning groups—were able to continue, but the venue lost a lot of potential revenue.

Monmouth's Priory has been impacted by the emergency
(Des Pugh)

Getting on with the job

After years of multi-agency talks involving local architects, solicitors, Monmouthshire County Council (MCC), and highways teams, a Communities Grant finally unlocked funding for the fix with South Wales-based Folly Contractors taking the lead to connect the rogue outflow into the main Welsh Water sewage network.

To allow the work to proceed safely, a traffic order will suspend all parking along Priory Street—including disabled bays—and implement a traffic contraflow, with the works scheduled to run through November 6.

Impact on traders and businesses

The changes will impact shops and businesses on Church Street. Chris Ryde, Director of the historic Savoy Theatre, warned that the disruption hits vulnerable patrons hardest.

"We can only hope that the timeline is realistic because we get a lot of audience members here who are not as mobile as they once were and who cannot walk far. We have quite a few shows in November which have large older audiences."

This is not the only unresolved sewage leak plaguing the area.

Local resident Richard Butcher raised the alarm in August 2024 over a separate, foul-smelling discharge near the old slaughterhouses close to the Market Hall. Despite passing details to MCC and Welsh Water, Butcher returned the following year with his children to find the spill still active, patched over with little more than two sandbags and a metal barrier.

Meanwhile, local landlord Churchill Al Temimi reported hitting a bureaucratic deadlock after Welsh Water claimed the localized leaks were the private financial responsibility of Priory Street property owners despite the utility billing for sewage disposal continued uninterrupted.

“We have been paying Welsh Water for the sewage system use for 25 years” he told the Beacon last year.

“If Welsh Water claims that the sewage system is not their responsibility, then Welsh Water will have to pay all the monies back to us that we have paid to Welsh Water with interest” and called on the water authority to make sure that the sewage system is working correctly for the health and safety of all the people living in the area.

He added that Welsh Water offered him backdated payments, “for only the last 5 years”,

St Mary’s Priory is holding a coffee morning on Saturday to help fund the church organ restoration fund between 10 and 12