Six-month project planned to stabilise quarry after landslip

A quarry which suffered a major landslip following heavy rain could undergo stabilisation work aimed at preventing a repeat.

The slip at Hendre Quarry in Flintshire in February 2024 forced the emergency closure of a road bordering the site after land gave way at the limestone quarry, which lies on a geological fault line.

Owner Tarmac carried out emergency repairs following the incident and is now seeking planning permission from Flintshire County Council for a longer-term solution designed to reduce the risk of further landslips.

According to sustainability consultants SLR, who are working on behalf of Tarmac, following the completion of emergency works to make the road safe for vehicles remediation work is now required to stabilise the quarry face.

“Phase 2 of the remediation works involves the construction of engineered earthwork to stabilise the failure area and the protect the public highway to the north of the quarry over the long term,” said SLR Technical Director Morag Eaton in her covering letter to the Planning Department.

“This involves construction of a permanent engineered earthwork to stabilise the failure area and protect the public highway over the long term. The remediation design has been prepared by Coffey Geotechnics Limited, a specialist geotechnical and mining engineering firm.”

The works would include the installation of a wall of piles embedded three-six metres into the strongest areas of limestone, placement of large quarry boulders or gabion baskets, construction of a regraded rockfill embankment behind the piles and supporting structure, the creation of new drainage pathways at the base of the rockfill and reinstatement of a screening bund, fencing and planting.

The works may require closures or restrictions on the road between Fron Farm and Hendre Farm.

If granted approval the project is expected to take almost six months and will be subject to the same dust, noise and operating hours restrictions the quarry currently works under. Wherever possible materials used to stabilise the fault would come from Hendre Quarry itself so as to maintain the protected visual aspects of the Dee Valley and Clwydian Range National Landscape.

Flintshire County Council is expected to make a decision by 23 September.