Self Closing Flood Barrier - UK Flood Barriers

Smart design: intelligent solutions

UK Flood Barriers recently working with a firm of architects have assisted them in gaining planning permission to build a development on a grade ‘A’ flood plain. Their solution, utilising the flood resilient design of the SCFB™ enabled the application to proceed. The plan included an undercroft flood storage of 3500 cubic metres controlled by the SCFB™ which dropped automatically to divert impending flood water into the storage area.

Through the application of smart design and an intelligent flood mitigation system the site redevelopment has maintained a focus on sustainability.

SMART DESIGN – INTELLIGENT PLANNING

Excerpts from planning 2008/01383/FUL T The site of the former Royal British Legion Club, Cowbridge

Flooding

The application site lies within Zone C2 (i.e. areas of the floodplain without significant flood defence infrastructure) as indicated by the Development Advice Maps under TAN 15: ‘Development and Flood Risk’ (2004). Within this zone highly vulnerable development, including residential development, should not be considered.

The applicant has entered lengthy negotiations with the Environment Agency to try to overcome their initial objection to the proposal, which led to the submission of an amended Flood Consequence Assessment (FCA) and amended plans on 5 August 2009. The amended plans have deleted any enclosures separating the rear garden areas and potential blocking flood waters, and include the provision of a void beneath the proposed dwellings with a barrier system which allows the void to flood in the event of any severe flooding. A Section 106 undertaking has been submitted which includes planning obligations to ensure the future maintenance of this system and to restrict occupiers from using the void for storage.

The Environment Agency has confirmed they are satisfied with the amended proposals, subject to conditions and the necessary Legal Agreement.

Justification

The site meets the requirements of previously developed land. The proposed redevelopment of the dilapidated former Royal British Legion Club building will provide much needed residential accommodation in the centre of Cowbridge, while the construction stage will boost the economic activity of the area. Owing to the mitigation measures being adopted, including rainwater harvesting and onsite runoff control, the development will not cause any material additional impact on downstream areas. The proposed development will indeed provide a betterment of runoff reduction and management compared with existing conditions as result of the smart design with undercroft flood storage and flood mitigation system. Therefore, the proposed redevelopment of the site will not pose a flood risk to other areas in the catchment. The development is thus justified as per the requirements of TAN15.

Flood Resilience Design and Mitigation

The plans show the flood resilience and mitigation design which includes an undercroft flood storage of 3500 cubic metres controlled by a specialist UK Flood Barriers control system that will drop automatically to divert flood water into storage in the event of a flood (overtopping of the upstream flood defence embankment). For this system to be most effective, its automation will be linked to the existing Environment Agency’s telemetry monitoring station near the site.

It was agreed with the EA that to ensure that the mitigation measures adopted prevail throughout the service life of the proposed dwellings, a Section 106 Agreement had to be part of the submission for planning consent and the acceptance of the flood mitigation measures presented to the EA. The agreement provides unrestricted access to the Environment Agency for maintenance purposes. The agreed development design allows for this with specified access and provision of open “grassed” space between the terraces of the houses and the banks of the River Thaw. The proposed residential town houses design has been carried out with a sustainability focus. The mitigation and design measures adopted for the proposed development will ensure that the challenges usually encountered with stilted developments are not realised for the site

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