Does anyone else think, that if rivers were cleaned more that they wouldn't cause as many floods?

Answer 1

Not sure but I bet we get a hosepipe ban when we eventually get a summer!!!!

Answer 2

If it's a case of cleaning debris from the surface and banks of rivers then this can help reduce flooding.

Often when a river floods much debris is carried downstream, this can become lodged under bridges, against trees etc and effectively creating a dam causing the water to back up. When the bridge or dam collapses there's a sudden surge of water which can cause more damage then had the water flowed naturally. This is what happened in Lynemouth in Devon - bridges upstream of the town became dams and when they bust a torrent of water surged forward taking out more bridges and sending wall of water surging through the streets. 34 people lost their lives, hundreds lost their homes, had it not been for the damming upstream the death toll could well have been lower.

Clearing river beds can sometimes do more harm than good. It disturbs the silt and creates a fast flowing channel. This faster flowing water can then carry sediments downstream which are deposited elsewhere in slow moving waters. As the sediments built up they impede the river, sometimes causing it to change course but also causing it to flood more easily when the river is in spate.

Rivers have always flooded, many of them have large flood plains alongside them. The problem is that people are all too willing to build on the flood plains. It seems an ideal place, flat, fertile and with riverside views but they tend to overlook the flood risk. Flood plains are a natural occurence, they're perfect agricultural land but not building land.

Answer 3

Our rivers are far cleaner than in the past.

The flooding is not just because of heavy rainfall.

Long dry spells mean the ground is hard and dry and water that would be absorbed into the soil cannot do so. .

Development in recent years has seen natural flood plains built upon.

Development that has encroached into areas that previously were part of the normal river course forcing the water into a smaller area.

Rain is a natural thing - you cannot control when or where it it falls or in what quantity. Because drains are something you cannot see it is easy to forget they exist.

More and more development means that rain cannot be absorbed and the drains are being forced to carry loads they were not or are not designed for.

Developers are only interested in making money.

Because an area only floods once every 50 years they start the count from when they build, not bothering what part of the cycle they are at.

Drainage systems have been installed that are not designed to handle extreme weather conditions.

Once they have your money then it is your problem.

Answer 4

Floods are not created by rivers ,it is the rain.The rivers are properly cleaned and the water drained properly in the sea,the flood level some extent read and the action can be useful.Not only that, most of the rivers,ponds ,lakes never cleaned up by any Govt.they don't give any care at all.That is why after agreat shower in 2005,and not a regular rain fall in 2006,no agriculture is possible in most part of TN, in India.

Answer 5

Yes. In the last couple of summers, I've canoed along the river Uck in East Sussex and it is chocked in many places with fallen trees and accumulated debris. However, the Environment Agency operates a policy of benign neglect, refusing to clear the river and arguing that this contributes to environmental diversity. The effect will be to compound flooding when heavy rains hit East Sussex again as they did in 2000.

Answer 6

Flooding has little to do with whether silted up rivers are cleaned.
It occurs because the drainage system in the UK is antiquated.
Most cities,towns and villages rely on drainage systems which were put there in Victorian times.
When we have deluges like we are experiencing at the moment, the drainage system cannot cope.
Our government needs to put money into modernising the systems, then we would not get the problems we are experiencing at the moment.

Answer 7

Sorry Lisa, the cleanliness of rivers has nothing to do with flooding. But I have seen a river so polluted it caught fire!

It is called Muggah Creek or Sydney Tar Ponds. Look it up in your browser. It is so polluted they can't even afford to clean it up, all they can do is bury the whole thing and pretend it doesn't exist.

Answer 8

Good question.
but the answer seems counter intuitive, restricting the water flow by dams, swales, tree cover etc reduces the flash surface water run-off that is giving the Uk it's current problems.

Conversly clearing rivers, especially headwaters, paving drives, mean that rainfall just heads for the lowest point quicker and not spread over time.

This is more noticable in generally dryer environments where soil errosion due to deforestation & other human activities is very obvious.

Answer 9

Rivers are natural habitats and not glorified drains to be dredged into deep channels for our own use.

It has been suggested a part of the problem is urbanisation itself. The natural ability of the ground to soak up water is diminished by a waterpoof shell of tarmac roads and pavements, buildings and other large expances of concrete and car parks.

The first and foremeost cause here is freak heavy rainfall

Answer 10

No. Since the implementation of the Clean Water Act in 1972, the quality of our waterways has improved greatly.

http://www.epa.gov/region5/water/cwa.htm

The biggest impact on flooding is continued growth / development of land for urban/suburban use.

When you reduce the available land for water to soak into, run off water is created quicker and ends up in our waterways quicker than most waterways can drain. The result.......floods occur quicker.

Answer 11

It may help in some places, but that is not the problem. it is the extra rainfall in such short periods of time after a very dry period that causes the problems (Bizarre weather patterns - climate change!)