What do they mean by "water shortage" and why are Britain's reservoirs shrinking?

Question

At one time hosepipe bans were put in place when there was no rain for 4 or 5 weeks at a time. Now we have 1 or 2 days of sun, and it is described as a "heatwave," neccesitating water restriction. Environmentalists consntantly claim Britain has a "water shortage." Last year thousands were left homeless by floods; this year it has rained torrentially almost every day. The same environmentalists also say that torrents of water rises from the Atlantic. They can't have it both ways. Now, water companies are raising prices beyond the grasp of most people, threatening to raise them higher, and even wanting to put metres in homes.

When I asked this recently, someone said that large amounts of rainfall in fact meant less water, meaning we had to be taxed higher and pay more.

Why?

Answer 1

Its because we don't have enough reservoirs and we just build more and more houses all using the same water source.  Its just lack of planning, we are an island - a very wet island.  There is no reason we should have water shortages!

Answer 2

there isnt any water.

Answer 3

when it rains the water is absorbed into the ground and by various means raises the water table which also helps to keep the reservoirs full unfortunately the expansion of cities and roads means there is less area for rain absorption meaning there is more surface water also air pollution over cities means that it will rain over the cities more than the country side more pollution more rain the rivers cannot handle the excessive amount of water running into them and therefore flood