A decision on replacing or fixing a riverside wall in Ystradgynlais that partially collapsed 18 months ago will be made by senior Powys councillor later this week.

On Friday, August 15, cabinet member for highways, transport and recycling, (HTR) Cllr Jackie Charlton (Liberal Democrat) will received four options and decide the “most appropriate” way forward that “best meets” Powys County Council’s legal obligations in respect of the Llys Tawel triver wall in the town.

The wall is located at the back of four homes at Llys Tawel on the west bank of the River Tawe as it flows through this part of the town.

The report explains that the wall is 100 metres in length, but 30 metres of the structure collapsed on February 1, 2024.

According to the report the remaining structure shows visible signs of “scour” – this means that its foundations could be affected by soil erosion.

There has been some legal wrangling over the ownership of the wall with Powys council eventually conceding that they own it.

Options for repair are estimated to cost from £382,000 to £1 million.

Option Four, which is also supported by residents, emerges as the best option in the report.

This would be the direct replacement of the retaining wall, providing riverbank protection which would cost £1 million.

However, the recommended preferred option from council officers is Option Three.

According to the report it would provide: “blockstone at a lower level with an embankment above it.

“This is a tried and tested form of erosion control offering bank protection but would not be reinstated to the original wall level.”

This would cost the council £850,000.

Funding for the repairs would come from the HTR department’s own capital budget.

Local Powys councillor Susan McNicholas (Ynyscedwyn – Labour) said:  “I am very grateful to Powys council for their decision to rebuild the river wall at Llys Tawel.

“It has taken a long time to get to the stage we are now at.

“The residents will rest a lot more easily once the work has been completed.”

Under the council’s protocol, the decision will come into force five full working days later - this is  to allow for it to be called-in by councillors for scrutiny should they wish to do so.

The wall was built by Brecknockshire County Council in 1912 and the report states that there is no evidence that the structure’s ownership has been passed on to another owner.

Following the last local government reorganisation in Wales during 1995/1996 the ownership of the wall fell to Powys council as a successor local authority.

But the council’s Highways Service refused to take responsibility for the wall and believed that either National Resources Wales (NRW), as the lead authority for main rivers, or the riverbank landowner was responsible for it.

After the wall’s partial collapse, the residents of Llys Tawel engaged lawyers that argued the council as owner of the wall is responsible for it and have a duty of care to: “take reasonable steps to prevent natural occurrences on its land from causing damage to neighbouring properties.”

After taking their own legal advice, Powys council “concluded” that it owns the wall.