Lanes inspect a large underground chamber at Walton Hall

Saving and recycling is all the rage now – but we can still learn from our forebears, as Lanes for Drains discovered when asked to empty a hidden chamber at a Grade 2 Listed country house.

Engineers based at the Lanes for Drains Chester depot were called in to pump out and inspect the large underground chamber at Walton Hall, in Higher Walton, Warrington, Cheshire, after it was uncovered during a refurbishment programme.

The brick-lined chamber had been built in the 1830s under the courtyard of the hall’s stable block to collect rainwater delivered by downpipes from the stable block’s roofs.

But it had lain unused, and all but forgotten, for decades as the drains leading to the chamber had collapsed and become blocked over the years. Until, that is, the hall commissioned the refurbishments.

Ian Clapham, Lanes for Drains’ Area Development Manager for Manchester, who oversaw the project, said: “We spend most of our time working on unblocking drains, drainage repairs and sewer renewal with more modern systems.

“This was a bit out of the ordinary. Until we opened the manhole leading to the chamber, which was found under the cobbles of the courtyard, we didn’t know what we would find.

“The chamber was about 8m long, 4m wide and up to 2.8m deep, so it was a substantial structure. It was about a metre under the courtyard and covered with a lid made of concrete and steelwork.

“We found that the chamber was full of water and silt, but the overflow system, linked to a nearby brook still obviously worked. We then set about emptying the chamber. Given what we found, it was probably the first time it had been cleaned out since it was built 180 years ago.”

The specialist drainage support provided by Lanes for Drains Chester had three main elements – pumping, cleaning and surveying.

A JHL recycling jetter was used to pump out the water and silt. A van pack jetting team was deployed to provide additional cleaning support and survey gullies using its ‘look and see’ camera.

Also, a CCTV team used its mainline ROVVER pan and tilt robot camera and push-rod camera to provide HD quality images from inside the chamber and adjoining drain lines. An engineer was winched down into the chamber for a final inspection.

The drainage survey helped Lanes for Drains’ client, the leading Warrington-based construction and facilities management company Clovemead, carry out a structural assessment of the chamber.

The water from the chamber was over pumped on-site. An estimated 10 tonnes of silt was pumped out, which was taken for safe disposal at a registered waste site.

Walton Hall is an Elizabethan style Victorian mansion, built in the late 1830s for Sir Gilbert Greenall, the grandson of the founder of the Greenall brewery, MP for Warrington for 38 years, and a baronet to boot.

The house and gardens are now owned and administered by Warrington Borough Council and are a popular venue for weddings and other special events.

Ian Clapham said: “The chamber was an early form of green architecture. It’s an attenuation tank to collect rainwater, which was then pumped out each day for the horses to drink and for cleaning.

“In the early days it would have been pumped by hand. By the 1900s, they would have been using a mechanical pump powered with paraffin.”

Despite being ahead of its time as a green initiative to recycle rainwater, the hidden chamber has had its day. It has now been filled in as part of the refurbishment programme to bring the stable block into modern use.