United Utilities water bosses can’t rule out more Queens Drive flooding after grandparents' tragic death

Mark Garth, United Utilities waste water services director, told the fourth day of the inquest into the death of Elaine and Philip Marco measures were being put in place to reduce the frequency of floods but would not prevent it completely.

Mr and Mrs Marco died when their vehicle became submerged in torrential flash flooding. The couple, who were well-known in south Liverpool and in the city’s Jewish community, were just a few days away from their 54th wedding anniversary when the tragedy happened.

Mr Garth told the inquest at Gerard Majella Courthouse how around 2.7m litres of flood water were seen on the night the Marcos died. He added how the bowl-like nature of the road meant “if there was going to be flooding at any point, it would be here.”

The water company chief detailed how the sewage network beneath Queens Drive likely predates the construction of the road itself, which is 7.5m below ground level. As a result the nearest manhole cover is only 1m below ground, compared to others nearby, creating what he described as “an artificial basin” which retained water.

Mr Garth said the cost of a new sewer network to replace the Victorian-era infrastructure serving the city would cost United Utilities between £80 to £140bn. He said it was not feasible for the water company to undertake routine inspections of the network and a risk based approach was adopted.

The increase in population and urban development had put further strain on the sewage network, according to Mr Garth. He added how the increase in paved driveways had been a “key reason” as it reduced the number of areas rainwater could seep into.

Regarding flooding incidents in 2023, it was said around 20-30% of silt was recorded but this was not considered to be a cause for concern at the location. On the day the Marcos’ died, Mr Garth said the “intense rainfall” was compounded by the bowl-like nature of the road.

Further flooding was recorded in July 2024, less than a year after the Marcos died. Mr Garth said the fact this occurred so soon after the “tragic events of August 26 highlighted the need for a permanent solution. As a result, a water tank reaching 60ft deep is being installed at the Mystery in Wavertree.

The United Utilities official said this would include a flow control device at Penny Lane. The scheme has been criticised by residents for its impact on the park.

Mr Garth said the tanks would eventually feed back into the sewer system once the capacity had subsided in extreme events. However, he said he could not eliminate the possibility that further flooding would occur in future.

He said this would reduce the likelihood of flooding from once every four years to once a decade. The hearing continues.