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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.

LATEST NEWS: Further progress report on the Tylorstown Landslip site activity (November 2023)

The Council has provided an update on Phase Four work to remediate the Tylorstown Landslip site. The majority of the colliery spoil has been moved to the receptor site, with good progress made to develop drainage infrastructure. Read more here


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

How the landslide initially appeared after it occurred in February 2020 (above) and the landslip area following Phase Three in autumn 2021 (below)

Tylorstown landslip area following Phase ThreeThe 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). An additional phase of work to stabilise the slope above the one remaining closed footpath was completed in autumn 2021.
  • Phase Four – Remediation of the remaining tip on the hillside. Planning permission was granted in October 2022 and works started on site in April 2023. It will enable future enhancements to the community route. Substantive work will be completed by winter 2023.
  • 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 three 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 A1 and A2 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 and bike use area, 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, subject to Welsh Government funding. This route would ‘pass through’ the riverside park scheme at Tylorstown.

The Council undertook a Pre Application Consultation with the community in January and February 2022, so residents could have their say on Phase Four – with the feedback received helping Officers to finalise the planning application. Officers organised a public exhibition at Rhondda Fach Sports Centre (May 19, 2022) for residents to attend for a further progress update.

Full planning permission was granted for Phase Four, by the Planning and Development Committee, in October 2022.

The planning application that was granted for Phase Four (ref. 2022/0600/08) covers a number of works, including relocating colliery material to a site adjacent to the tip, and reprofiling/stabilising the upper tip site. It also includes new drainage work, the formation of access tracks and paths, vegetation regeneration and ancillary works. Find more information on the Council’s planning portal here. Hard copies of documents can also be viewed at Porth, Ferndale and Pontypridd Libraries.

The appointed contractor Prichard’s Contracting, which is based in Llantrisant, started the main works for Phase Four during April 2023. The Council provided a progress update on the works in June 2023, following the good progress on site.

The Council also made two further planning submissions in December 2022, relating to proposed works at receptor sites within Phases Two/Three of the remediation plan. These include a proposed planting scheme of trees for Receptor Site A2 (ref. 22/1477/08) and proposed bench seating, small footbridges over drainage channels tying into the local path network, interpretation panels and a ‘stepping stone feature’ for Receptor Site B (ref. 22/1476/08). The links included above give more information on the Council’s planning portal.

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.

Proposed Community Route - 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.

Welsh Government's wider work relating to Coal Tips

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 – with a public consultation running from June to September in 2021. Details here.

Following on from this, Welsh Government launched a separate consultation on its Coal Tip Safety White Paper from May 12, 2022. Details here.

Wattstown 2
Wattstown 3
Monitoring equipment installed on the National Tip in Wattstown