Water Woes

[Robby nz]

What has prompted me to write this is the recent proposal by a certain, or uncertain depending on your viewpoint, Deputy PM to build a dam across the mouth of the Chaw Phraya river to prevent flooding in BKK.

Now I’m no hydrologist but most of my life has been associated with water in one way or another and for the last several years I have fished in the Chaw Phraya for a couple of days most weeks. This has given me some insight into how this river works through flood and low water and I have given a fair bit of thought to what could be done to give more control over the water.

First off:

The whole of central Thailand is in fact one big flood plain and in the past the annual floods are what sustained the rice farming in that part of the country. When the rains came the river swelled and the water spread out over the land. This saturated the land and deposited a layer of silt that acted as a fertilizer making it possible to grow great rice crops. The people prepared for this by building their houses on stilts, for want of a better term only, about 3 meters above ground. You can still see this today in a fair bit of the country.

Most of the water that causes flooding comes from heavy rain in North and Central Thailand. There are three ways this rain water can be dissipated they are: by evaporation, soaking into the ground and run off down a river. The first two can mainly happen when we have the flood plain in action but as it happens people have build towns and cities which they don’t want inundated by water. This means that the water is restricted in where it can go and the flood plain can’t work as it did in the past. The result being that there is more water running down the river.

So what to do?

I don’t believe a dam across the river mouth is the answer for while a spring tide and heavy sea can slow the escape of water to the sea and cause build up it does not stop it completely. If heavy seas and spring tides were the cause of flooding a dam could be the answer but if they were the cause then there would be flooding every time they occurred regardless of the river level.

The true cause of the flooding of BKK and other places on the river is heavy rain which can’t be prevented. This means that we have to look at ways of controlling the water once it gets into the river.

The way I see it we need to look to Cambodia and Vietnam for the answer. The Mea Kong, a much bigger river does not have the same flood effect there and there are reasons for this.

There are two natural things that restrict the flooding in those countries, one is the Tonal Saap a large lake in central Cambodia into which, when the river is high the excess water flows, then when the river level drops the water flows back into the river. The second is a large delta in Vietnam where the river splits into many channels allowing the water better access into the sea.

BKK is built over what was probably a delta of the C P river and the river is now restricted in where and how it can get to the sea. I don’t know if it would be possible to open up more channels and recreate a delta effect but if it is then that could be part of the solution.

A second part would be to create the lake effect, now it would not be possible to have a big lake like in Cambodia but it should be possible to create a series of smaller lakes along the course of the river. This is not a new idea as it was suggested by His Majesty the King several years ago and called ‘the monkey cheek effect’. However if I understand this correctly rather than lakes it was suggested that places be designated where the water of a flood could go.

What I have in mind would go farther than that and create (dig out) actual permanent lakes to take the overflow in a flood situation.

This would not be a quick fix but then I doubt that a quick fix is possible, rather it would be something like a 20 year or longer project. The first step would be to calculate the amount of water above normal flow needed to cause flooding from there the size and capacity of holding lakes to contain the excess water could be worked out. Next step would to work out the best places to put the lakes and the capacity of each individual one.

These lakes would of course displace people who for a start would have to be compensated for the loss of their land and homes. However each lake would not just be a place for flood water to go but would also be used for various purposes. For instance those close to cities could be for recreational use, some for recreational fishing others for water sports such as yachting, canoeing, etc. Others could be designated for controlled commercial fishing and others for fish breeding with the fish raised released into the river to raise its overall productivity.

All these things would need people to create and run them so those displaced by the lakes could be retrained to work as staff at each lake with, I would hope better returns, homes and lifestyle than they had previously.

These lakes would not only be there to contain flood water and for the uses already suggested but would, with careful control be used as a mechanism to maintain the river at or close to a consistent level along its whole length and giving some certainty to those who use the river and of course the water would be available for agriculture which would help alleviate a drought situation as well as a flood.

Robby

[geriatrickid]

Sir,

May I suggest you give such thoughts a pass. No good will come of it, for there is an unwritten rule in this land. Sound environmental practices are an impediment to progress which is defined as the safety and security of the folks living in the big houses. Be content to fish in the polluted waters and give your fanciful notions no additional thought. Attempts at intelligent planning will only cause you aggravation.

[RubbaJohnny]

Thanks Robby but I regret I have to agree with the rather cycnical reply.

The final solution will be of course to abandon the capital as has happened before C Saen C Rai Sukothai Ayuthya Thonburi.

I guess when the waves finally lap over the very lowest rung of Hi-Sos something may happen.

For those of us who regard Krng Thep as a sewer anyway the fate of thecity of the Angels is perhaps karmic as it sinks into its own sea of squalor.The sort of place the rich can murder the police with impunity.

[Robby nz]

Ah Gerry thought is indeed a great thing but unfortunately there are some who fail to think before they act, talk or even post on this site.

When you have no agenda or anyone to attempt to protect it can be an even more rewarding thing for then you can think of and comment on things as they really are.

When I post my thoughts on this site even though you may think it futile I believe that if one person reads them and it makes them think and maybe understand better it has been of some use.

In this instance I have no expectations that what I wrote will ever be acted or improved on in fact I know it wont because it would not be politically expedient.

However this and many other posts give me pleasure and in some cases researching what I write improves my knowledge.

Oh yes and try fishing some time it promotes good thoughts much better than sitting at one of these gadgets.