In the Ribble valley it is noticeable how the river rises and falls quickly after rain. Water runs off the land rapidly and this is due to land drainage work that has gone on over the years, principally in the 20th century. We only have to look at the one undrained local area to see what the alternative is like, in the fields of Long Preston Deeps; this area is mooted now to become a reserve, so rare is the habitat. Water often remains on the land into late spring or beyond, largely because there is impeded drainage. It provides for the birds, animals and plants that live there for months to come. Elsewhere they have to survive increasingly on what rain falls during the year, which is barely enough on limestone soils; the clays of the drumlins and the valleys are damp enough.
Another factor is a requirement for far more organic matter in the soil. Over the millennia mankind has cleared the forests that provided a supply of organic matter from autumn leaves which slowly decayed over the year, giving nutrients and holding on to the winter rains. On the fell tops there were larger areas of bog where drainage was far slower and the sphagnum mosses were plentiful, which held on to more water and for much longer. We can see the result of removing these natural sponges in the recent floods in Carlisle. The problem is that the catchment area of the River Eden was far more wooded in the past, especially on the lower slopes of the fells. Artificial drainage has also been added in the past centuries. Together these mean that much of the rain in January 2007 rushed off the land into the Eden and its tributaries and ended up in Carlisle very quickly. No wonder there are floods. One point of view is that this has nothing whatever to do with any supposed global warming, but everything to do with the effects of drainage.
This is a worldwide problem, due to over-population by man and exploitation of the soil. In the higher latitudes, there is a short growing season. For centuries, Britain farmed with small fields, low numbers of stock, adequate tree-cover and a low population. Once this balance is broken, floods are the consequence.