Keepmoat Regeneration goes large as Polypipe’s Ridgistorm-XL delivers benefits for multimillion pound Hull project

Polypipe has provided a complete water conveyance and attenuation solution for a new Keepmoat Regeneration residential development in Hull. Polypipe delivered a system that demonstrates how large diameter pipes can meet strict Sewers for Adoption guidelines, while managing the traffic load from the road system.

The Portobello Street development is located approximately three miles away from Hull city centre and will provide 142 new homes for Homegroup and Hull City Council as part of the regeneration of this area of the city.

Polypipe was approached to assist with the design and manufacture of a solution that met the requirements of Yorkshire Water and Hull City Council. Polypipe advised the use of large diameter plastic piping and modular manholes, and worked closely with Hull City Council and Yorkshire Water to present the benefits that their Ridgistorm-XL large diameter plastic pipe system could deliver over a traditional concrete system.

Working with the project Consulting Engineer, Polypipe assisted the design and manufacture of a solution that fulfilled all Sewers for Adoption criteria, as well as achieving the conveyance and attenuation needs of the site. The engineered system design gained full section 104 approval for the adoption of surface water run-off into their watercourse, and section 38 approval for the installation of the system on the development site.

The final design used over 231m of Polypipe’s 1,200mm Ridgistorm-XL large diameter plastic pipework. The adaptability of the thermoplastic system meant that the Polypipe pre-fabrication team could manufacture the pipework in a stiffness class tailored to the specific ground conditions at the location, without sacrificing overall strength and resilience.

The Ridgistorm-XL pipes were used to form four tanks to attenuate and convey surface water run-off from the development. Each tank was linked to a flow control chamber featuring a flow control unit and penstock, to manage the subsequent release of surface water run-off into the approved watercourse. A pre-installed weirwall in each of the chambers also provided a stable end connection to Yorkshire Water’s existing drainage system.

Furthermore, Polypipe was able to manufacture and supply pipes and chambers with spigot and socket jointing, once again reducing installation time, and also enabling easy separation in future, if required. With the thermoplastic structured wall system being up to 94% lighter in weight than concrete, it is easier to handle and quicker to install, which ensured efficient installation on the Portobello Street site.

The design also included 12 pre-fabricated Ridgistorm-XL Manholes, 10 of which were supplied in a diameter of 2,100mm, together with one 2,400mm and one 1,800mm in diameter. Polypipe’s pre-fabricated manholes are modular, ready-to-install access points that can be integrated at any part of a network system. The manholes were installed at strategic points throughout the pipe network, and were benched and channelled in accordance with Sewers for Adoption guidelines, once again demonstrating the adaptability of a large diameter plastic system to meet exacting project requirements.

These manholes, which can be installed efficiently straight from delivery, will ensure ease of access for future inspection and maintenance.

Trevor Smallman, Project Manager at Keepmoat Regeneration, said, “Polypipe provided a value engineered solution using Ridgistorm-XL tanks, with pipes manufactured to the perfect stiffness classification to meet our needs, together with convenient pre-fabricated pipework and manholes.

“The resulting solution met the requirements of Yorkshire Water and Hull County Council, while also providing a robust and efficient system ideally suited to the development’s challenging conditions.

“In addition, as the system is much lighter than concrete, it provides numerous benefits from a health and safety point of view during the installation.”

David Marsden, Residential Development Specialist, North at Polypipe, said, “We were delighted to provide a tailored solution for this multimillion pound residential development. We design and manufacture a range of trusted and approved water management systems that are robust and reliable, safer and quicker to install for ground workers, and adaptable enough to meet the specific requirements of each individual project. We were pleased to be able to work closely with Yorkshire Water and Hull County Council to achieve approval for installation under the local highway and demonstrate the multiple benefits that a plastic solution can offer over a traditional concrete system.”