have erased its backwaters and cut it off from its flood plain.
C. Today, the river has lost 7 percent of its original length and runs up to a third
faster. When it rains
hard in the Alps, the peak flows from several tributaries
coincide in the main river, where once they arrived
separately. And with fourfifths
of the lower Rhine’s flood plain barricaded off, the waters rise ever
higher.
The result is more frequent flooding that does ever-greater damage to
the homes, offices and roads that sit
on the flood plain. Much the same has
happened in the US on the mighty Mississippi, which drains the
world’s second
largest river catchment into the Gulf of Mexico.
D. The European Union is trying to improve rain forecasts and more accurately
model how intense
rains swell rivers. That may help cities prepare, but it won’t
stop the floods. To do that, say hydrologists,
you need a new approach to
engineering not just rivers, but the whole landscape. The UK’s Environment
Agency which has been granted an extra £150 million a year to spend in the wake of floods in 2000 that cost
the country £1 billion- puts it like this: “The focus is now on working with the forces of nature. Towering
concrete walks are out, and new wetlands : are in.” To help keep London’s feet dry, the agency is breaking
the Thames’s banks upstream and reflooding 10 square kilometres of ancient flood plain at Otmoor outside
Oxford. Nearer to London it has spent £100 million creating new wetlands and a relief channel across 16
kilometres of flood plain to protect the town of Maidenhead, as well as the ancient playing fields of Eton
College. And near the south coast, the agency is digging out channels to reconnect old meanders on the river
Cuckmere in East Sussex that were cut off by flood banks 150 years ago.
