Rhondda Cynon Taf Council says Phase Four drainage works at the Tylorstown Landslip site are nearing completion, with recent activity largely focused on drainage.
The landslip on the Llanwonno hillside in February 2020 was triggered by rainfall in Storm Dennis. It blocked the river valley, broke a foul sewer, covered a water main with several metres of debris, and covered a shared footpath. A four-phase Remediation Plan has been implemented.
The first three phases included emergency clearance in the weeks after the landslip, embankment scour repairs, removal of material from the valley floor to receptor sites and reinstatement of paths, plus additional work to stabilise the slope. Phase Four covers remediation of the remaining tip on the hillside. The original drainage programme and overall scope of this phase have been extended and work is ongoing by contractor Prichard’s.
The main spine drains that collect water from the reprofiled tip have been completed, while attenuation work to slow water flows before discharge to existing streams is being progressed on site. The receptor site to the rear of the tip near Old Smokey, where a large amount of colliery spoil from the upper tip was transported, has been regenerated. Ecologists have surveyed the area, and information on revegetation is being awaited by the project team.
Specialist plant has been brought in to repair and maintain the channel outfall below a new cascade, to future-proof water run-off past the southern edge of the lower tip. Soil nailing work represents the last major work at the bottom of the site before the contractor works out and up the hill towards establishing a maintenance track and reinstating the Public Right of Way.
Officers have recently visited to review walking routes through the site, including the permanent Right of Way that has needed to be temporarily closed during the remediation work. That review is ongoing, as is monitoring of the long-term management of the hillside.
The council said people illegally accessing the site with off-road vehicles remain a problem, damaging drainage channels. The contractor is reporting each incident to South Wales Police. The overall completion date for Phase Four will depend on weather in the weeks and months ahead.
Councillor Andrew Morgan OBE, Rhondda Cynon Taf Council’s Cabinet Member for Environment and Capital Infrastructure, said: “The Tylorstown Landslip Remediation represents a huge operation, to firstly rectify the slip that occurred during Storm Dennis, and then to make safe the large remaining tip on the hillside. Central to the recent activity has been understanding the water movement on the site, and ensuring flows are channelled through and away in a safe manner. Drainage work in Phase Four has been significantly extended over the past two years, and is now entering its final stages.
“Inspecting, maintaining and repairing our former coal tip sites in Rhondda Cynon Taf remains a Council priority. We secured £13.7 million from Welsh Government’s Coal Tip Safety Grant this year, through which the Tylorstown Landslip Remediation continues to be funded. Our dedicated Coal Tip Safety Team administers a programme of work all year round using this funding. This does not include the £4.8 million funding commitment from the Coal Tip Safety Multi-year Grant Scheme, through which significant stabilisation work at Graigddu Tip in Dinas is taking place, having started on site this summer.
“At Tylorstown, alongside the hillside drainage activity, key work and consideration has progressed relating to the receptor sites, the temporarily closed Public Right of Way, and the future maintenance and monitoring of the area. Officers are also working with the police in relation to off-road vehicles that continue to access the site and cause damage to drainage infrastructure. As Phase Four nears completion, the Council will inform residents about the contractor’s concluding work, and the Council’s future activity beyond this.”
