Previously I posted the response from EdF about the public consultation about the Emergency Response Centre (see Sizewell B Emergency Response Centre public consultation). I noticed in their documents that the 1953 completely cut off the area where Sizewell A & B stands from the mainland. Taking their 1 in 10,000 flood risk of 4.18m I had a look at an OS map and saw the the highest route to the stations was less than 3m AOD if you ignore the shingle on the beach – I assumed the worse case would be a 1953 type event with a sea surge and high waves.

Sent via email

18 July

Dear Mr Lux

Re: Sizewell B Emergency Response Centre public consultation

Thank you for your further comments with regard to the public consultation on the Sizewell B Emergency Response Centre (ERC).

Following your last email on the 9 July 2012 please find an answer to your additional question;

Would your vehicles be able to travel through at least 2m of water since there seems to be no other route between the ERC and the Sizewell B site at a higher level?

As part of the enhanced emergency response at Sizewell B, it has been assumed that the access route to the station will be blocked, flooded or compromised in some way. The vehicles to be stored in the ERC have therefore been chosen based on their ability to travel over difficult terrain or to help clear the route to allow access for further vehicles. These include for example JCBs, Land Rovers and large trucks, which will be fitted with additional modifications such as debris removal equipment and snorkels for driving through deep water. If the water is significantly deeper than one metre over a significant stretch of land, and continues to remain at this depth for a prolonged period of time (i.e. the water doesn’t dissipate), additional support may be called in through other emergency services and civil responders such as the military to support our response.

A range of alternative routes (both on-road and off-road) will be identified and considered over the next year prior to the opening of the ERC. These will be continually reviewed during the life of the station to ensure options are available in the case of vehicles needing to be deployed.

Once again thank you for taking the time to comment on our proposals for the Sizewell B Emergency Response Centre.

Yours sincerely

Jim Crawford

Station Director

EDF Energy

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My email response:

Thank you for sending this information. I am not sure if you were at the consultation that we attended. Anyway I would like to explain why I requested this information.

Our concerns were not about the flooding of the ERC since, as made clear in the report, it has an elevation of 15m and is a considerable distance from the sea. Our concerns were about how emergency vehicles would be able to access the Sizewell Site.

Your report states that the maximum 1:10,000 surge height would be 4.18AOD. This would increase to 4.918m by 2010 under the UKCP09 95% confidence level or 5.9565m* under H++.

The road access at the junction with Sandlings Walk is marked on the OS map as 3m and the road down to the site entrance and along the access road is lower than this. Would your vehicles be able to travel through at least 2m of water since there seems to be no other route between the ERC and the site at a higher level?

With a surge height of 4.18AOD it is also likely that waves would overtop Sizewell Gap (<5m AOD). Not only would this increase local flooding in this area but the wave energy would not be fully dissipated – i.e. they would continue down to the access road.

Therefore the ERC would not be able to provide any assistance in the event of conceivable extreme flooding from the sea.

Pete

* I am assuming you have applied the H++ sea level rise from 2011 to 2100. I also note that since H++ is given as a countrywide scale I doubt if it contains the isostatic sea level change for this region.