Sites and Policies Plan Consultation Draft

Document Section Sites and Policies Plan Consultation Draft Major Development Sites in Weston-super-Mare WSM12 [View all comments on this section]
Comment ID 1020673//19
Respondent Environment Agency [View all comments by this respondent]
Response Date 19 Apr 2013
Current Status Accepted
Comment

Policy WSM12-Birnbeck Pier and environs

 

Birnbeck island/pier is located some distance away from the mainland and is not located within Weston Bay so it is more vulnerable from a combined risk of high tides/surges and large waves being sourced within the Severn Estuary. WSM has experienced extensive tidal flooding in the past, most notably in1981 when a significant tidal storm overtopped and damaged large sections of the tidal defences.

 

Joint tide and wave flood risk is a significant constraint for this development and a robust FRA must be undertaken to ensure that the flood risks are fully understood for now and in the future, feasible mitigation measures are identified to determine if the development can be safe in accordance with the NPPF. We would strongly advise that a modelling exercise forms part of the FRA to investigate the flood risks at the earliest possibility so that the principle of this development can be considered by us and NSC in more detail.

 

At face value when considering the existing ground levels of the island and pier (approx.11mAOD) the island is higher than today’s 1in 200 year still water tide level i.e. Flood Zone 1 in planning terms. However, this may not be the case when considering high tides under surge conditions, combined with a large wave and with climate change over the lifetime of the development. It’s highly probable that the island experiences flood volumes from spray created by waves impacting on the island foreshore. Safe access and egress is a critical issue that needs to be considered in full to ensure the appropriate measures are incorporated so that the island can be evacuated when required.

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