Communities and conservation areas safeguarded from erosion with crucial engineering works

Engineers are set to work on two crucial projects in the Upper Afan Valley to address issues including embankment failures.

One of Neath Port Talbot Council’s projects involves major maintenance work on the 1,200 foot long retaining wall supporting Norton Terrace in Glyncorrwg.

Severe challenges

The retaining wall has failed in several places and the ongoing work involves repointing and rebuilding the wall, repairing and reconstructing the drainage system associated with it plus replacing a failed ground beam and a substandard parapet.

The wall is being reconstructed in 50 ft sections to coincide with expansion joints and to minimise disruption to local residents. Currently around 150ft has been completed with temporary surfacing in place, and an additional 50ft section is 50% complete. 

The other important project involves workers addressing the severe challenges posed by the deteriorating Dyffryn Rhondda Colliery Tip. 

Situated around three miles west of Cymmer, the site’s embankment, a legacy of remediation efforts in the late 1970s, is facing significant erosion issues.

Collapsed areas

Due to high river flow caused by heavy rain in recent years, a gabion basket wall (wire cages filled with stone), protecting the toe of the embankment along the River Afan, has suffered major damage, leading to four main collapsed areas and the loss of approximately 5,000 cubic metres of tip material.

Among the consequences is a threat the local National Cycle Network stretch related to the embankment failures. While a temporary solution was implemented in 2020, the long-term viability of stretch remains uncertain. 

Other issues connected with possible embankment failures could mean the loss of ecologically significant habitats, including open meadows and reptile populations.

The Dyffryn Rhondda Colliery Tip is part of the Afan Valley Mineral Railway Site of Importance for Nature Conservation (SINC), hosting diverse flora and fauna. 

The remediation project aims not only to restore the structural integrity of the embankment but also to preserve these priority habitats. 

The Afan Environment Volunteers and Neath Port Talbot Council’s Countryside and Wildlife Team have played a crucial role in managing the site’s natural regeneration over the years.

To address the issues, the proposed remediation plan includes repairing the gabion baskets, realigning the river channel, and undertaking structural repairs on four long masonry arch culverts. 

The repair works are scheduled to start in the summer of 2024, starting with haul road construction in January 2024. The gabion basket repair and replacement works are set for the summers of 2025 and 2026, pending Welsh Government funding.

Neath Port Talbot Council’s Cabinet Member for Streetscene, Councillor Scott Jones said: “The council recognises the importance of these projects, not only for safeguarding infrastructure but also for preserving the environmental richness of the Afan Valley.”

He added: “The council will work closely with Natural Resources Wales and local communities to ensure the success of these vital remediation efforts.”