Entec and FRM > Project experience: Midlands
|
Strategic flood risk assessment Client: Charnwood Borough Council In April 2007, Charnwood Borough Council commissioned Entec to undertake a Strategic Flood Risk Assessment (SFRA) to inform the Council’s emerging Local Development Framework (LDF). The SFRA was undertaken in line with the guidance set out in Planning Policy Statement 25 Development and Flood Risk and the accompanying PPS25 Practice Guide. Entec ensured the SFRA was tailored to the specific flooding and development issues facing Charnwood Borough, to ensure a SFRA relevant to the council’s needs. The SFRA alongside other technical studies will underpin decisions on the choice of locations for future development and in support of regeneration in the Borough. The Environment Agency flood zones and hydraulic models were used to assess the flood risks posed by the main rivers in the Borough. Hydraulic modelling was used to delineate the Flood Zone 3b (the Functional Floodplain) and potential future increases in the extent of Flood Zone 3a due to climate change. In addition, a large number of watercourses across the Borough have recently been enmained as these watercourses potentially pose a significant flood risk to nearby people and property. Two of these water courses, the Wood Brook and Burleigh Brook pass through Loughborough near the town centre, adjacent to key regeneration sites, flood risk being a significant constraint on their redevelopment. Recommendations were provided on flood risks issues specific to these areas to inform the planning and design process, and to inform more detailed Flood Risk Assessments (FRAs) of any sites selected for redevelopment. In addition to watercourses, other sources of flooding were also considered, including sewer flooding, overland flow, runoff control and groundwater. The SFRA provided a collated source of all flood risk information currently available. This included consideration of planning policy as well as catchment flood management plans and flood risk strategies relevant to the borough. During the development of the SFRA, all digital information was compiled into a GIS and detailed graphical outputs were included in the final report |
Integrated Urban Drainage (IUD) Pilot Project
Client: Telford & Wrekin Council
Entec was employed by Telford & Wrekin Council to assist in delivering their pilot IUD study for Defra, one of 15 funded by Defra around the country. One of the aims of the study was to provide strategic drainage information based on sub-catchments to inform planning of future development and assist developers.
Entec developed innovative techniques to enable relatively rapid production of data that would assist planners and developers in the initial stages of site design with regard to flood risk. In particular the study considered exceedance flows, whereby the conveyance capacity of the urban drainage system is exceeded and excess flow is conveyed on the ground by surface flood pathways.Initially a broad-scale Borough-wide analysis was conducted using 2D pluvial modelling whereby a design rainfall event was simulated over the Borough and the resulting runoff flowed according to the underlying digital terrain model. This gave strategicc information on indicative flow pathways and areas of ponding during extreme events.
A key development site in the town centre then formed the focus of more detailed studies in which the input and output data were verified on the ground and inflows to the model were modified in the form of FEH flow hydrographs. Additional detail was provided by modelling the piped surface water drainage networks. This formed the basis of designing strategic overland routes to convey excess flow from and through the site to established storage features.
Would you like to comment on this? Use our feedback form to let us know what you think.
