Flood Risk Assessments

Case Study

ESI, now part of Stantec, has undertaken work for both Developers and Local Authorities including extensive flood risk assessments and drainage plans during the rehabilitation of brownfield sites.
Work is undertaken on a range of scales to address the risks posed to individual sites. We have experience supporting the development of complex sites that have in some cases required Expert Witness level support to gain planning approval.


Tangier, Taunton:
Flood risk proposals put forward to permit redevelopment of a central brownfield area within a flood risk area. The assessment included on-site and off-site and compensatory storage and flood emergency plan and written expert witness support at planning inquiry. Planning permission granted and site currently under construction.


West Wick, Weston-super-Mare:
A flood risk and management strategy was developed suitable for areas comprising of residential units, Business Park and retail and leisure facilities.


Cambridgeshire County Council Surface Water Management Plan and PFRA:
Combined Surface Water Management and Preliminary Flood Risk Assessments for Cambridgeshire, including option assessment and mitigation design.


Other work undertaken has included the redevelopment of an industrial site within the flood plain of the Poyle Brook in Slough (April 2012). ESI liaised with the client and Environment Agency to agree a flood mitigation strategy that attenuated site run-off and enhanced the biodiversity of the river corridor. Run-off calculations were undertaken using the flood estimation handbook to derive the required storage of swale and attenuation pond features necessary to reduce site run-off. As a result of this work the site was granted Planning Permission.


To meet the requirements of the code for sustainable homes a complex and challenging drainage strategy was developed (November 2012) for 4 proposed dwellings using a combined system incorporating soakaways and surface attenuation ponds which helped the developer obtain the required credits from the code for sustainable homes necessary to obtain planning permission.


ESI has successfully undertaken a range of detailed flood risk assessments in support of a number of renewable energy schemes including a proposed new hydroelectric scheme on the River Severn in Shrewsbury (June 2012) and several Solar PV installations (December 2012). A series of swales were designed to compensate for the additional run-off created by areas of hard standing associated with the new plant rooms and transformers.


For further information on our range of flood risk assessments and sustainable drainage plans to support development contact us.