Flood and Storm Surge
In order to protect the proposed new nuclear power station site at Kirksanton from extreme flooding events over the 60 year working life of the reactors, and 100 year decommissioning period, a perimeter wall would be required varying in height according to the lie of the land.
Arup’s report for RWE Npower states that 4m (13′) high defences would be needed near to Kirksanton village, where the land is lowest, although their diagram hints that they may be even higher – perhaps up to 6m (20′).
A proportion of the nominated site is unavailable for building because it is below the 8.8m (29′) limit. This figure has been set by calculating anticipated flood levels and taking climate change into account.
The lowest ground on the farm land is around 5 to 6m (16′ to 20′). To meet the
“wave topping height protection” of 11.8m (39′) the defences need to be nearer
6m (20′) high. Residents on the south-west side of Kirksanton would face onto a huge concrete “Berlin Wall” type structure. They are just 200 yards away (183m) and presently look out over green fields grazed by sheep and cattle.
The coastal wall bordering the sand dunes section of the proposed site may be lower, (2m/6′). Channelling of rain water here would have detrimental effects on the dunes and shoreline, which are internationally protected.
To counteract rainwater run-off within the proposed site, Arup indicate that holding tanks would be utilized with excess water released into Kirksanton Pool, (the beck) at appropriate times.
Such a scheme poses major concerns. The above facts and figures compounded with the severity of the November 2009 floods (see photos section), may result in:
- interference with the existing natural drainage
- damage to Kirksanton Moss – a protected ecological area
- threat of flooding to properties in Kirksanton
- increased flood risk to farm land and dwellings along the beck to Haverigg
Site Access and Infrastructure Changes
Access to the site is a serious problem for RWE. One route might enter from the northern Silecroft boundary, near the Limestone Hall railway crossing, passing next to the Giant’s Grave, a scheduled ancient monument. To negotiate the flood plain and new flood wall a massive, concrete flyover on pillars would need to be constructed to elevate the road onto the nuclear site.
A second route via Haverigg is an alternative option. However, it is likely that BOTH new access roads would be needed to fulfil emergency evacuation procedures.
The Arup report claims that ‘the Kirksanton site, like the rest of the coastline between Haverigg and Silecroft, is subject to man-made coastal defences.’
There are no man-made coastal defences at the proposed Kirksanton site.
The nearest ones are at Silecroft, one mile away, where there are a few scattered gabions to protect individual buildings.
Coastal erosion is reportedly 0.5m/year at Silecroft, reducing to zero at Kirksanton, with a build up of 0.3m/year at Haverigg.
Local residents can confirm that the foreshore at Layriggs Lane end, which runs through the proposed site of the nuclear power station, is eroding rather than being in a state of equilibrium. The hard standing car park and turning area at this location has disappeared in a series of storms between 1978 and 2008 and the area continues to be eroded.
It is still possible to trace the runways on the old wartime airfield but today, standing at the location of the marine SAR access track, only remnants of the ramp to the shore can be seen. This ramp was in good condition only 30 years ago.
This section of the coastline is eroding.
Ongoing surveys suggest that the data which Arup’s “desk top study” used here is well out of date. Climate change can only add to the assessment of erosion along this coastline. Such an assessment should look at the frequency of severe gales. One particular north-westerly storm removed 6m (20′) of shoreline in one night.