Skip to main content

Tylorstown landslip – remediation process

This webpage contains information about the significant ongoing remediation process following the Tylorstown landslip.

It also shares details about the future vision for the site, to be developed as part of a wider Community Active Travel Route – providing a dedicated pedestrian and cycle route between Maerdy and Pontygwaith.

Update on current works activity at the Tylorstown Landslip site (October 2021) 

The Council is making good progress with an initial phase of work to stabilise the slope above the closed path at the Tylorstown Landslip site – with this activity on course to be completed by the end of October. Full details here

Tylorstown Phase 3A

On February 16, 2020, the landslip occurred on the Llanwonno hillside at Tylorstown, as Rhondda Cynon Taf was hit by three storms in quick succession. The landslip was triggered by Storm Dennis – a one in 200-year storm event that saw Maerdy at the top of the Rhondda Fach record the highest volume of rainfall in Wales. The site is a Category D tip and was being inspected every three months against a set of monitoring criteria prior to the storm, and inspections have subsequently increased in frequency since.

tylorstown FEB 2020

The landslip blocked the river valley, broke a foul sewer, covered a strategic water main with several metres of debris, and covered a footpath and cycle path. The area was closed to members of the public to ensure safety with immediate effect.

The Council is working towards a four-phase remediation plan, as outlined below:

  • Phase One – Emergency drainage and vegetation clearance (completed in the weeks following the landslip).
  • Phase Two – Embankment scour repairs (commenced in late June 2020, and was completed in June 2021).
  • Phase Three – Moving of material to receptor sites and temporary reinstatement of paths (commenced in late June 2020, and was completed in June 2021).
  • Phase Four – Remediation of the remaining tip on the hillside and undertake community enhancements such as the community route and riverside park enhancements (a planning application is likely to be submitted in summer 2021, with a view to starting works in 2022).
  • Cycle routes and receptor sites – Improvement works to several structures along the proposed Community Route in the future. The route will be resurfaced and works to the receptor sites completed.

Phases Two and Three

On June 10, 2020, the Council made an announcement outlining its intention to commence the second and third phases of work – starting by the end of June and ending later this year in accordance with Natural Resources Wales’ restrictions about working in the river from the end of October onwards. The announcement also confirmed that the Council is working closely with the Welsh and UK Governments over the funding options to cover the costs of Phases Two and Three, which are estimated to be around £2.5m. Here is Council Leader, Councillor Andrew Morgan, speaking before the start of Phases Two and Three in June 2020.

The Council made an Urgent Delegated decision on June 11, 2020, to progress the work, and to appoint a contractor. The decision noted that while these works will be initiated ‘at risk’ to the Local Authority in the absence of funding confirmation, there is a firm expectation that government support will be provided to the Council to carry out this essential scheme.

Works to deliver Phases Two and Three got underway on Monday, June 29, 2020 - after the Council appointed Walters as the contractor responsible for carrying out the scheme. Walters, which also undertook Phase One, is an experienced local contractor which has been involved in tips schemes such as this one in the past.

Phases Two and Three were completed on June 25, 2021. This followed a number of landmarks being achieved on site – such as removal of the slipped material from the valley floor, the reinstatement of the river to its correct line and level and a series of drainage works.

Completion of this work has allowed the two walking and cycling routes on the Leisure Centre side of the river to reopen – connecting to the local network of paths running through the area. The path to the rear of the leisure centre which has been part of the contractor’s site compound – and the riverside path which was completely covered by the slip – have both been reinstated and can now safely reopen.


The third route running through the area, on the opposite side of the river, has been repaired but will remain closed as there are future phases of work to stabilise the hillside above.

While the closure area for this path is around 1.5km, the wider route it forms a part of is open and can be accessed from Station Road in Ferndale. When walkers and cyclists reach the downriver closure point, they will be able to change to one of the recently-reopened paths via an existing footbridge, which cyclists must dismount to cross. The Council intends to reopen all routes in the future.

Ecological impact

In terms of the ecological impact, a number of surveys have been carried out by consultant ecologists in liaison with the Council’s ecologist and Natural Resources Wales (in relation to the clearance of undergrowth and trees from the receptor sites – together with the impact on flora and fauna).

All parties continue to work together to ensure the impact on the environment is minimised where possible. Consideration is being given to the final receptor sites and how this will benefit the ecology of the river valley.

Receptor sites

The two receptor sites are owned by Rhondda Cynon Taf Council, and are located to the north of the landslip site, alongside the former railway line. Receptor Site B (nearest the landslip site) formed part of the old railway sidings, and receptor Site A was a former colliery site footprint.

Planning permission for the receptor sites (temporary) for the slip material was subsequently applied for retrospectively, and it was granted by the Planning and Development Committee on Thursday, January 21, 2021. The agenda for that meeting can be found here.

Placing the spoil material on these sites has significantly reduced the amount of material which would have otherwise be moved along the public highway. The receptor sites have also ensured that the wider works are self-contained – and therefore the carbon footprint of the works is greatly reduced. For instance, there have been virtually no vehicles on the public highway from the site, which would otherwise cause noise, vibrations, air pollution, dust and damage to the carriageway. It is estimated that the process of moving 60,000 tonnes of material would have required 6,000 lorry movements – which was avoided by utilising the receptor sites.

Consultation on future vision

The Council will keep the local community informed about the proposed end use of the scheme, to be delivered in the future. There will also be a significant opportunity for residents to have their say in the final end use through a future consultation process. At present, the Council is considering the location to be converted into a riverside walkway, similar to the existing sites at Barry Sidings Country Park and Mountain Ash Riverside Park.

Phase Four

The Council’s future vision for the wider area includes more than £10m investment to remediate the remaining tip on the hillside. Upon completion of the remediation works, the commitment for an Active Travel Community Route for pedestrians and cyclists between Maerdy and Pontygwaith can then be delivered. This route would ‘pass through’ the riverside park scheme at Tylorstown. The Council envisages the remediation works to the remaining tip will begin in 2022, and upon completion it will be followed by the delivery of the Active Travel Community Route

Full planning permission will be sought for this wider development. As with the riverside park plans, the community will be kept fully up-to-date and given the chance to take part in a consultation to inform the final project.

Cycle routes

This future activity will tie into the overall completed works undertaken in Phases Two, Three and Four – and carry out significant schemes to repair or replace (and ultimately future-proof) a number of bridge structures along the new Active Travel Community Route.

The document below highlights the initial plans for the Community Route. The Community Route is highlighted in pink, with proposed links to the route in blue and the structures being considered for improvement also labelled.

Tylorstown Landslide Presentation - PDF (2.27mb)

Further information about the individual schemes to future-proof bridges along this route will be communicated by the Council in due course.

Law Commission Consultation

Rhondda Cynon Taf Council has welcomed the work the Welsh Government has undertaken since the landslide at Tylorstown. This work has included asking the Law Commission to evaluate current legislation for managing coal tips safety in Wales. The Law Commission has recently published a consultation paper and are asking for comments and feedback on this paper. More information and a link to the consultation can be found here.