2 May 2012

More rain brings flood risk

After the wettest April on record in the UK, the beginning of May looks set to continue with an unsettled theme. Further heavy rain is expected across southern parts of England and Wales during the next two days with a risk of flooding.

The flood risk comes as much of England is in the midst of a drought and as Environment Secretary Caroline Spelman raised the possibility of standpipes in the UK next year if the country is hit by a third dry winter in a row.

As I explained in a recent blog, despite there being such a large amount of rain falling during the past month, it’s nowhere near enough to offset two consecutive dry winters and many months of below average rainfall.

At the moment, it’s the groundwater levels that are low across most of England and Wales and unfortunately, it’s a time of year when water struggles to percolate deep down because evaporation rates are high and growing plants draw up large amounts of water through their roots.

Despite water lacking deep down at groundwater level, it’s been a very different story for water near the surface in rivers, reservoirs and soils. Across much of England and Wales, soils are at or close to full capacity in terms of the amount of water they can hold.

In this situation, when heavy rain falls, because the soil is saturated, water quickly flows through catchments and into rivers, causing them to rise quickly and heighten the risk of flooding.

During the past few days, parts of the south Midlands and south west England have been hit by localised flooding – mainly where streams and rivers have burst their banks.

More heavy rain is expected across southern parts of England and Wales during the next 48 hours. Around 10-20mm is likely to fall, with a narrow area of heavier rain giving 30-40mm in places.

The Environment Agency has said that there is a low risk of some flooding – especially where river levels are high from the rain that fell during recent days.

There’ll be a brief respite from the wet weather this weekend as a ridge of high pressure extends across the UK. It’ll mean colder weather with frosty nights, but apart from a few showers, most places will be dry with sunshine.

Don’t forget you can stay up to date with the weather at any time on the Channel 4 Weather website, or you can join me for weather chat on Twitter – @liamdutton

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