Why heavy floods? 1

[Finch24]

Hello Community!

As we all knows that Asia especially Pakistan is badly affected by the heavy floods and rains. I've a question, what's the role of dams then? Can we avoid these disasters by more and more dams? Thanks!

 

[BridgeSmith]

This forum is more for the 'how' than the 'why'. Perhaps there is a place for this discussion on the site, but I don't think this is it.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[JedClampett]

Go to forum815, post your question and you will get a wealth of opinions from us gasbags.

 

[cvg]

dams, dikes and levees are commonly built for flood protection. but only part of the solution. development in flood plains is probably the root cause of these "disasters". move to high ground and you avoid flood damage

 

[Tomfh]

Good question, but the wrong forum for it

 

[GeoPaveTraffic]

Dams can certainly play a part in reducing flooding and flood damages. I have not been following the flooding in Asia and do not know what kind of rain events occurred and how widely distributed the rainfall occurred. Dams require valleys to be flooded, you have to store the water somewhere. The more storage, the better the dams function as flood control structures. There are many dams in the US where flood control was the primary reason for the construction. Some impound some water all the time and have secondary purposes, while others are dry except following rain events.

In the end it takes the will to build the dam(s). This always means you have to have the funding. In most cases you have people and possibly industries that have to be displaced and some amount of environmental consequences to deal with.

 

[cranky108]

If you look it up, one of the states that has a good number of dams is Kansas, and what they do with many of them is to install a small pipe in the lower part of the dam. The intent is to control the amount of water being released to a manageable amount. This limits the floods in the rivers and creeks to the amount the dams allow to flow.
A limiter for the flood waters.

 

[GregLocock]

Pakistan has always been flood prone, the difference now is that there are more people living on the flood plains. This is what is happening in Australia as well. The alarmists claim this is due to climate change, it isn't, it is because people build houses in flood plains.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[JedClampett]

Where floods unintentionally flood areas, dams intentionally flood areas.

 

[spsalso]

Dams can flood SMALLER areas. With some planning.


spsalso

 

[BridgeSmith]

Dams can flood SMALLER areas. With some planning.

It depends on the landscape. In the US, most everywhere that creating a reservoir is feasible, has one.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[TugboatEng]

Diversion is also a strategy. See the aqueducts of Los Angeles, to deal with their monsoonal rainy season.

 

[spsalso]

Yup.

When I was a wee lad and lived down there, the street we lived on (El Monte Avenue) had extra high curbs. It (intentionally) turned into a river, on occasion. LA seems to be very good at getting rid of downpours.

I see by a quick street-view visit that those high curbs are gone.


spsalso

 

[TugboatEng]

We know why they lowered those curbs

 

[FacEngrPE]

In the past several years we have seen a large number of ponds, and dry swales installed to limit the peak flow storm drainage systems and potentially rivers need to handle.

This has had the side effect of the environmental industry using the phrase "Best Management Practices" (BMP) as a noun.