Local Weather News and site updates

18th January 2007

 

The river Severn floods once again. Although we expect the Severn to flood at least once a year, it seems recently it has been flooding on and off every couple of months.

The first major flood was December 2006, then again in January 2007, twice during the summer, and now this January.

 

So just why is this happening?

Well its all down to the weather patterns that we have been seeing over the past 12 months. It all started last January when we saw the first major flood event in Worcester and down the length of the Severn (see multimedia area for pictures), then of course again in the summer where over 100mm fell in one day. Every time the river floods it indicates that the ground is saturated and thus the water table has reached the surface, the water table takes many months to recede with dry conditions but of course if you keep the spells of high rainfall coming then eventually (and quickly) the table rises once again to the surface. Expect this time it takes allot less rainfall because its already quite high, this is the effect we have been seeing throughout the last 12 months, what started off as a wet spell in January '07(and indeed in december '06) is still giving these flash floods.

Its not just down to water table fluctuations though, ofcourse the very thing that controls this is the amount of water falling on the ground, weather systems. Over the past 12 months the rainfall and indeed the rate at which it fell has at times been incredibly high. For example in July, here at the station over 100mm of rainfall fell in less than 12 hours, that gives a very high rate of fall, and this as expected gave way to flash (in some cases extreme flash) flooding. Most of Worcester became cut off and many areas including in the vicinity of the weather stations had a huge amount of surface run off and patchy flooding.

 

Its the effect of these rainfall events that vastly increase the level of the water table, so in effect it doesn't take much after such events to once again saturate and flood ground levels. The news however seem to want to pin this down to global warming, however I'm pretty positive that this is just a run of the mill pattern fluctuation that has been occurring for thousands of years. Indeed we must remember that flood plains are just that, low lying areas around rivers that commonly take the overspill when a river reaches heights. The problem is that with ever increasing urbanization around those areas, they are only now (in a chain of rain events like we are now seeing) showing why we should not build on these areas.

In some cases it has been said that the solution could be part of the cause. Take these barriers for instance, yes they stop flood waters encroaching on built up areas, but where does all that extra held back water go?, more to the point if you imagine putting your finger over the end of the hose what happens?. This could well pose a cause for concern in the future, if you prevent flood plains from flooding then all that water and funneled power is going to go downstream and make the situation far far worse in those areas which cannot afford such systems.

 

Are we going to see of this?

I'm afraid the answer could well be yes for the time being. As the water table and underground aquifers are full to the rim through wales and the west / south midlands , it will only take another 'stuck' weather system to cause this flash overspill once again.