Banana Tip, Rhondda Valley

Flood Prevention

SDS delivers underground stormwater storage to support Welsh Water wastewater network capacity improvements

Overview

The ‘Banana Tip’ stormwater storage scheme – so called due to the tip’s shape – forms part of Welsh Water’s investment in improving wastewater network resilience across the Rhondda Valley. Located on the site of a former coal waste tip that has since been transformed into Greenwood Park, the scheme was designed to increase stormwater storage capacity while ensuring the land could continue to serve the local community.

SDS was appointed by JN Bentley to provide a value-engineered underground storage solution that would reduce construction time and deliver significant advantages over a previously proposed precast concrete design.

What We Did

The scheme required a high-capacity stormwater storage system capable of improving network performance while allowing the site to be fully reinstated for community use, including the construction of a new football pitch above the storage infrastructure.

SDS designed and supplied a bespoke 10-leg Weholite attenuation tank system incorporating multiple manifold connections and an integrated internal weir chamber for controlled flow management. Constructed from 2.5m diameter Weholite HDPE pipes, the system delivers 1,341m³ of underground storage capacity. The lightweight, modular nature of the system enabled phased installation and reduced the need for extensive heavy lifting equipment, making it particularly well suited to the challenging ground conditions associated with the former colliery site.

Results

The completed storage system significantly enhances the resilience of the local wastewater network by providing additional capacity during peak rainfall events and reducing pressure on existing infrastructure. Compared with the original precast concrete proposal, the Weholite solution delivered an estimated programme saving of three months, while reducing labour requirements, plant usage and overall construction costs.

The project demonstrates the benefits of a modular, value-engineered approach to stormwater management, delivering long-term operational performance while successfully reinstating the site for continued recreational use by the local community.

Working closely with MMB and Welsh Water, we were able to demonstrate a practical and efficient alternative to the original design. Our Weholite solution not only met the technical requirements of the project but also delivered significant programme and cost benefits, while accommodating the complexities of the site.

– Andrew Macdonnell, National Sales Manager – AMP, SDS Infrastructure