Safe as houses - Weholite technology ensures residential site remains watertight

With flooding events hitting the headlines seemingly on a monthly basis, there has never been more pressure on housing developers to ensure that the homes they are building are protected from flood waters. And that’s why water management specialists Asset International were chosen to provide the flood defence solutions for a new housing development in Carmarthen..

The new social housing development at Job’s Well Road near Carmarthen town centre consists of 27 new homes, built in a collaborative partnership between Gwalia part of the Pobl Group, and Carmarthenshire County Council. The development is part of a Welsh Government pilot scheme to test out the suitability of the co-operative model as a solution to the lack of affordable housing in Wales. It is one of three similar Welsh Government pilot projects in Wales.

Following initial meetings with site contractors Morganstone, Asset were briefed that the flood defences required were to be suitable for a ‘one in thirty year storm event’, however more generally an effective drainage system would be required to minimise flood risk to the new housing development during periods of heavy rainfall. Speed and ease of installation were also vital components to consider when meeting the projects strict schedule.

To meet the specific project requirements Asset also worked alongside C D Gray Consultants who put the drainage plan together to finalise the design of the two online surface water drainage systems required. Asset provided one 1800mm diameter Weholite system and one 900mm diameter Weholite system, which were prefabricated at Asset’s state-of-the-art factory in Newport, before being delivered complete to the West Wales site ready for their subterranean installation.

The 1800mm Weholite system also featured a dry weather flow channel. The dry weather flow channel is uniquely designed to improve the hydraulic efficiency of the tank in low flow conditions, helping to avoid silting.

The manholes and control chambers were also pre-fabricated at Asset’s factory and fitted with plastic benching, connecting stubs and weir-walls for flow control device fitting. As part of their extensive customer service offering, Asset also provided support on-site in an advisory role, to ensure a smooth and safe installation.

Rob Monkley of C D Gray, said: “It should be applauded that the staff at Weholite took the time to fully understand the difficulties of the site and work with ourselves to come up with a design and product that delivered on all levels. Any queries or assistance that was required during the design stage, Weholite was quick to respond and actioned quickly. Finally we are very impressed with the durability and flexibility of the products on offer.”

Carl Morris of Morganstone, said: “Our decision to include the Weholite system into this scheme was an easy one for us. It has proved beneficial in mitigating the risks associated with the challenging logistics of an installation of this type, with its easier, quicker and safer means of installation, all backed up with great technical support.

“We now consider Weholite to be one of our systems of choice for all flood reduction and SUDs requirements on our projects and we are already discussing several future schemes with them.”

One of the Weholite drainage systems has already been installed under the new road infrastructure, which has been laid to provide access to the site, while the other is due to be positioned at a later date in the developments schedule.

Weholite pipes of up to 3.5m diameter are now acceptable under highways on a project by project basis by Dwr Cymru Welsh Water. The Carmarthen project represents one of the first underground flood alleviation road projects accepted by the utility company.

Speaking about the project, Asset International technical sales engineer Jonny Johnson commented: “Previously on a project of this nature concrete would have likely been used for the large diameter drainage system, however, following the recent confirmation from Welsh Water regarding the adoption of Weholite pipe under roads, we were able to put forward a proposal which outlined the added benefits of a quicker and simpler installation thanks to Weholite’s lightweight quality and pre-fabricated components. The result is a success for all concerned.”