Monday, 9 December 2013

Storm surge

Last week the geography, planetary alignment and weather combined to cause misery to hundreds of families around Britain.

Tides around Britain naturally have a big range, the second highest tidal range in the world is in the Bristol Channel in Britain's south west. Tides vary depending on the alignment of the sun and moon, when the Sun and Moon are at the same side of the Earth (new moon) or opposite sides of the Earth (full moon) the tides are higher than when they are not in alignment. The highest tides are called spring tides, whatever time of year they occur.

The North Sea is roughly V-shaped, getting much narrower at the southern end. Last week a storm swept across the country, driving very strong winds from the north east down the North Sea coast forcing water in the sea towards the narrow part. The storm was, as usual, a deep low pressure system. With the low pressure over the sea, the water level will rise in a so-called storm surge.

The spring tide, the storm surge and the extra water blown down the North Sea created a lot of water pushing up against sea defences along the North Sea coast, particularly the southern end. In addition the waves thrown up by the stormy winds made topping the sea walls inevitable. Flooding followed.

Earlier this year I surveyed a new, small road close to the Humber Bridge, Wintersgill Place. Sadly the road was flooded. The houses now look finished, but there are three for-sale signs and one sold sign for the six houses. I wonder just how planning permission was granted for these houses when the area is clearly a flood risk. Now the small field next to these new houses is also set to be developed.

I tried to look at the local council's forward planning map to see if they agree that the area is a flood risk. The map was curiously off-line over the period of the storm and just after. Now it has lost the most detailed zoom level and the newly built houses are not on the map at all. I hope the planners have better information available, but since they have allowed houses to be built that have flooded before they were even sold, maybe they don't.