On the subject of flooding towns along rivers as in the news lately. Ok, so we know the area is prone to flooding. Why not have a contingency plan to route the water with whatever size pipe would be necessary to send it to a controlled zone where it could possibly be routed elsewhere. The trick would be to control the situation enough to start siphoning at critical spots along the flood zone, which could be scientifically figured for the best result. At the very least, the water could be directed away from highly populated areas. We spend a lot of money to pipe gasoline for long distances, why not water. There are many areas that could really use the water. Perhaps even the area being flooded could design a way to contain the water in a holding area until they could use it. Water is becoming more and more a hot commodity. This rainwater if caught appropriately might at time be cleaner than water that has been reprocessed to be used again, such as dirty rivers. What do you think?

River valleys are already the lowest places around. There is no downhill to drain the water to except for downstream. If you are thinking of pumping the water, think again, the volume to be displaced is enormous. Pretty much a totally nonworkable idea.

Better levees.
The flooding typically is a result of a levee failure.
And a under-evaluation of the maximum flood possible in the area.

Another possibility is getting rid of almost all of the leveees. When a flood occurs like just happened in Iowa levees can make a bad flood worse. When they fail it can be catastrophic. If people were not allowed to build houses in the flood plain ( notice the derivation of the term ) they could be used as the natural buffer that they are supposed to be for floods. Levees concentrate flows too much, they concentrate the stream as it decends it gets worse.

I almost forgot one more good point of getting rid of levees. Flood plains are some of the richest agricultural areas there are. The regular inundation of flood waters is what fromed these. If you let them flood naturally their soil will be recharged by fresh deposstions every so many years and they will remain the fertile croplands that they are.

Hard to tell my family in Iowa that, but yeah. I wonder how much for taxpayers to buy out the farmers + lost crops in those plains vs. once every 15-years flood relief. Please don't flame; I really don't know.

The land should be available for farming but not for inhabitation. If someone wants to live next to a river that floods every 15 plus years they should not be asking the government to bail them out. They could be offered a buyout to move away from the river, but if they tunred it down then we could say they were given every chance. Citys could be protected by levees but I have seen those things set up to protect what is mostly farmland. These areas could be huge buffer zones when needed.

My older sister has been saying for years that "We ought to be able to divert flood water were it is needed or store it up somewhere to be used later" You could put gates in the levees to allow water into catch basins for use later.

Since I live right in the very center of the flood zone, the first thing you need to know is there is WAY more water than can be managed. Someone posted a video of the outflow of the Coralville Dam outflow on AOL Video a week before the flow reached maximum. The flow rate through the 18 ft. diameter tunnel was about 27,000 cubic feet per second. A few days later, the flow went over the huge spillway of the dam and the flow was estimated to be ~80,000 cu.ft./sec.; you don't manage or divert this flow, you get out of the way. Compared to Cedar Rapids, which was on another river, we had relatively few people displaced from their home; variously reported between 500 and 800, as opposed to CRs 3500. That's largely because we learned our lesson in 1993 at the last 500 year flood. Only one new development of fancy townhouses and condos was effected by the flood as well as a large modern church that were both built in a very flood prone area. Those people were idiots, frankly and many people told them so. Anybody around for 93 new better, and yet they built. I agree with Sub on this; one chance at a buyout, or so long and thanks for all the fish. Our suburb, Coralville, didn't fare as well. About 10 blocks of their main street flooded from a creek tributary backing up. This creek winds right through this business district and almost exactly repeated the flood of 93. We have a hard luck Chinese Buffet that has been burned out 3 times and flooded out twice now in the same building in the last 20 years. I'm thinkin it might be a good time to consider moving up hill. Levees aren't very practical in our valley since the sides are rather steep and the floodplain is pretty narrow. The apartment building, which I lived in 30 years ago, is now a UofI dorm and, while sited at a beautiful point, had a great deal of damage to it's mechanicals in the sub levels and will be uninhabitable until at least Jan. 09. Take a look at the flow rate in the AOL video and see if you think you could manage 3 times as much.

http://video.aol.com/video-detail/iowa-coralville-dam-june-7th-2008/591129303

Another important lesson learned by a lot of people this year compared to 93 is that when the "Authorities" order you to evacuate, think very carefully before you cooperate. You may be very sorry in the long run.

The question I have after reading all of the comments is, Why wait until the flood waters are unmanageable? Start at the beginning of the flood path and pull away water, as well as multiple places along the flood path. The point is to stop all of the water from upstream collecting to hit downstream. Of course, as it goes downstream it is going to get larger and gather strength. Could you not take some it away so it would not be as huge and damaging. Just brainstorming.

[quote]My older sister has been saying for years that "We ought to be able to divert flood water were it is needed or store it up somewhere to be used later"[/quote]

We ought to be able to? We already can! We've known how for hundreds of years.

Go visit Hoover Dam for a demonstration.

www.earthscape.org/p2/hp/hp_sum99/hp_sum99a.html

I went to this site. It was very interesting reading. I think sometimes we have to deal with huge problems by asking ourselves. What would it take to solve this problem if we had unlimited means to do so. This unleashes all the issues that take away creative thinking. Once the obstacles of money and our own negativity are put away, the human mind can be quite creative. No we don't have unlimted dollars to spend on things but sometimes if we think of a very expensive way to solve a problem we can branch from that and figure out how to scale back the cost and still have a solution or two. An open mind is a curious and productive one.

Remember What if that water in valleys is already as low as it can get without flowing downstream on its own. There is no way to empty a stream ahead of time. Even if you could the amount you pump out ahead of time would be neglegible compared to the amount of new water flooding in. The only reasonable answer is to let a flood plain be a flood plain. You may be able to save a few major cities, in fact if you destroyed most of the levees the existing levees around cities would probably be high enough to protect them as the increased buffering of letting flood plains do their job would keep the floods from getting so high.

You would need to pump out the water to other grounds. The city of New Orleans does this whenever it rains.

Yes, but with limited success.

Ah, love Google. Yes into Lake Ponchartrain (had to look it up for spelling). New Orleans is unique in having this handy, nearby, low lying body of water. There is no equivalent body of water or area in Iowa where the floods just were. You would have to pump massive quantities of water enormous distances. It is not feasible. And of course everyone knows that when the levees failed in New Orleans the pumps were totally worthless. They can handle a relatively small flood, or even rain, but nothing massive.

The solution, as others have said, is very, very simple. Don't allow people to build in the flood plain. This can easily be done by refusing to sell them insurance.

The Mississippi, in the areas of flooding, is currently a quarter of the width it was when the area was first settled. The same volume of water flows through it now as then. The difference? It's been artificially made deeper, by the levees and other man-made constraints. It is, quite simply, a disaster waiting to happen.

Flood plains, not surprisingly, offer land at bargain-basement prices, and as a result of the low cost development has soared in these areas, which are the most vulnerable to flooding. Insane insurance practices, greed and an apparent collective loss of short-term memory have conspired to make flooding in the area far, far more disastrous than it should be. Development has to be pushed back away from the river and limited to high ground, and people have to stop being rewarded for foolishness by replacing their losses through government-subsidized flood insurance.

It isn't a matter of figuring out how to manage the water. It's a matter, as someone above said, of being smart enough to know when to get out of the way. There's no reason or excuse for this mess.

One small step they could take to correct this matter is NOT to give any help to rebuild within the flood plain. Any rebuilding with government funds should be done outside that area. Also if you get someone to move that land would have to be limited to agricultural use only. As I said in a previous post occasional floods are good for flood plain soils, the occasional lost crop could easily be replanted. No heroic measures would be needed to save them.

[quote]One small step they could take to correct this matter is NOT to give any help to rebuild within the flood plain. Any rebuilding with government funds should be done outside that area. Also if you get someone to move that land would have to be limited to agricultural use only.[/quote]

Absolutely, except for restricting land use. If someone wants to build their own version of the Taj Mahal down there - on their own land, with their own money - I say let them do it. But don't give them any aid, and let the insurance companies write their policies with the clear understanding that no help is going to be forthcoming in the event of any flooding. We're a free country, after all, and people should have the freedom to be fools if they choose to be. The rest of us just shouldn't be required to pay for their foolishness.

sub. et.al.. I've uploaded 3 aerial pictures of the flood of 08 that were released today after the flood has partially receded. They illustrate your point to a T. The picture named Flood 2 is a new development with a large church in the foreground. This entire area was flooded in the Flood of 1993 and was productive farmland the rest of the time. It may not look too bad now that the water is receding, but most of these buildings had 5-6 feet of water in them 10 days ago. Even though this area has been built up for less than a decade, at a meeting last night, many of the residents suddenly want a buy out.
The picture named Flood 7 shows the Coralville Dam from the North with water running over the Emergency Spillway near the peak of the flood this year.

Sub, you may be interested in the picture Flood 9. This shows the Coralville Dam Emergency Spillway after the water ceased going over it. During the flood of 1993, water reached 6 feet deep over the top of the spillway and the force of the water tore away a small hill and wooded area clear down to bed rock and then stripped some of that away. The exposed limestone was found to be a treasure trove of Devonian Era fossils and led to the discovery of several unknown species. The new flood tore away more of the strata exposing new fossil beds. You should also note that the overflow washed away a paved road across the bottom of the spillway that connected with the road up the dam and the road to the tailrace.

http://www.flickr.com/photos/10158271@N07/sets/72157605814467030/