River Eating Away My Land - What To Do ?

[mangomannen]

I have a river close to my house and with the last years rain it have been eating away about 4 meters of my land. Now i have only 5 meters left until it reaches my house.

I need to make a river wall in a cheap way. My own idea was to fill the river side with 20-40 trucks of big stones making a stone wall. My border to the river is about 25 meters.

River is about 10 meters wide at rainy season and 5 in the dry season. Depth is about 4-5 meters and most of the time the river is not moving.

Does anyone with expeience have any idea what i should do ? Many tks in advance.

[nidge]

I had experience of this in the Uk while i was studying for my Geophyisics Degree. A river was eroding on the outside curve, (this is normal river evolution), and just like you the owner of the land was worried about losing his land. The river bank was reinforced with concrete and this stopped the erosion very effectively. However the erosive energy of the river does not go away. Shortly after the concrete was in place the inside bank of the river started to erode causing landslides. There were houses built on the land above and these were subsiding as the land started to disappear.

So you could use concrete very effectively but if there are buildings the other side of the river you may suddenly find yourself in "deep water" with the owners.

Good luck

[Gary A]

I think you have the most economical and best idea already. Rocks, lots of big rocks. Concrete would be great if you had someone skilled at making retainer walls and were willing to pay the price.

[VocalNeal]

A sad tale and an interesting project unfortunately not my area of expertise. Only my 5c worth.

If the river has eaten away 4m then replacing the 4m with rocks would not , in theory effect the opposite bank but 4m of rocks 5m deep is a lot. But you need big rocks first and get progressively smaller and fill in all the gaps. (Discovery Channel program on the Dubai Palm Island) The river will undermine a solid structure if not done properly. 5m is a lot otherwise you could have used a standard precast wall and back filled it. Maybe you can get 5m precast wall posts? Depending on where you are piling crews are not outrageously expensive you could investigate driving a cofferdam and then fill it with stuff. Can you get access to the river bed in the dry season?

From what I have seen even the experts build models and try different things.

[chownah]

What will work depends on the high water flow and the geometry of the channel. Sounds like whatever you do won't be cheap....probably the cheapest thing is to move the house or abandon it and build another. If you get rocks then you should probably get the biggest ones you can find....it won't be cheap....concrete will work....it won't be cheap.....drive piles with bridging between them will work....it won't be cheap......planting deep and strong rooted plants might work but only in certain situation....that might be cheap but will not work in many situations.

If you want to be confident that what you do will work then hire an engineer to give you some advise.....maybe get a few opinions.

chownah

Edited December 4, 2007 by chownah

[PhilHarries]

As nidge has intimated, be very careful when messing with waterflow or you could make things worse. Dumping rocks along the riverbank within your property may be a short term solution but sooner or later water will start to filter in behind them starting at the upstream end. Little by little this water will wash away the earth so you may end up with a riverside property (literally) looking out on a rocky island. Alternatively the rocks may deflect the flow causing erosion of the opposite bank.

Best option is to seek professional advice and, unfortunately, be prepared to fork out for a permanent solution and quick, four metres in one rainy season suggests a major problem. You also need to consider what, if any, developments have been done on the opposite bank or upstream that may have affected the flow.

[DanBlack]

I would be very interested in the outcome of your unfortunate situation, as I am interestred in some river property

[billd766]

Before the rains this year the stream at the bottom of our land was about 4 or 5 metres wide and at its height during the rains it was close to 50 metres wide in places and I have never seen the village flooded before. Now it is back to the normal levels for the time of year but the stream be is now about 20 metres wide.

My wife wanted some photos so that she could claim from the government as it is farming land and most people have done the same.

Fortunately the stream is at the bottom of the land about 400 metres horizontally and 6 metres vertically away from the shop.

Everybody has left the stream alone except for people digging for sand.

[jaideeguy]

I had the same situation, but smaller river and did the local solution of filling rice sacks with a mixture of 10 sand-1 cement and stack the dry bags like bricks as a retaining wall sloping up, then backfill with rocks. sand and rocks, we got from river and only cost was cement and bags and labor. for added strength. rebar could be driven and woven thru sacks while still dry. the water eventually seeps up and hardens the cement. ideally, you would do this in the dry season.

[cm-happy]

find a naive buyer and sell

[macan]

There was a thread on this subject a few months ago http://www.thaivisa.com/forum/index.php?showtopic=130314