Discharges threaten lives downstream

[rooster59]

Discharges threaten lives downstream

By THE NATION

 

The Royal Thai Navy instals machines at the Songkram River at Nakhon Panom, to speed up floodwater drainage to the Mekong River.

 

Water released from dams in the Chi river basin add to flood misery

 

THE WATER crisis along the Chi River has reached the critical level. Dams in the Chi River Basin have had to discharge more water to stabilise their own structures and water levels, but the discharged water is adding to the extensive floods along the river in Kalasin, Maha Sarakham, Roi Et, Yasothon, and Ubon Ratchatani.

 

 

And it could get worse if plans made by several key agencies prove insufficient.

 

In a meeting between the Royal Irrigation Department (RID) and other related agencies yesterday at Kalasin, RID deputy director-general Thongplew Kongchan said that after facing Tropical Storm Sonca, reservoirs in the Northeastern region were full with the water and have to discharge the excess water to ensure the dam safety.

 

The meeting discussed the water situation in Chi River, including the continuing flow of water into Lam Pao Dam and Ubonrat Dam at the river’s headwaters that had forced operators to release excess stored water, which then intensified the flood situation in the area downstream.

 

Thongplew noted that RID asked groups at the meeting to discharge 30 million cubic metres of water per day from Lam Pao Dam for nine days to keep the water level in the dam to a safe level. If that is done, other agencies warned, the large amount of water – up to 270 million cubic metres –of water will worsen flood situation downstream.

 

 

Therefore, RID proposed a new plan to release only 25 million cubic metres of water per day from Lam Pao Dam for 15 days. They also would order Ubonrat Dam to lower the water discharge from the current pace of 15 million cubic metres per day to avoid the subsequent impacts on people downstream.

 

He also assured that all relevant agencies will work together and exchange information in the meeting every three days in order to make sure that there will be proper water management and avoid downstream impacts.

 

Lam Pao Dam now has a water storage level of 1,662 million cubic metres or 84 per cent of total capacity, with 30 million cubic metres of water entering the dam daily, while Ubonrat Dam’s current water level is 1,574 million cubic metres or 65 per cent of total capacity.

 

In Kalasin, Provincial Governor Suwit Khamdee warned people in five districts that the flood would worsen due to the rising water level in Phan River and Chi River. It was, expected that added discharge from Lam Pao Dam will increase the water level in the river by up to 30 centimetres by tomorrow.

 

Suwit said that as of now 15 districts in Kalasin have suffered from floods and 11 districts had already been declared disaster areas, with 37,136 affected families and damage to 195,301 rai (31,248 hectares) of farmland.

 

Meanwhile in Roi Et, the three districts of Phon Thong, Moei Wadi, and Selaphum also suffered severe flood from the Chi River overflowing.

 

Tambon Wang Luang in Selaphum District was one of the worst-hit flood areas, as the swift water current in Yang River, a tributary of Chi River, breached the river embankment and caused extensive damage to nearby villages. In total, 71 houses were reported damaged and eight houses collapsed.

 

In Roi Et, nine districts have been declared disaster areas, with 35,965 families affected, and 410,200 rai of farmland submerged.

 

The flood warning alarm was also given in Maha Sarakham. People in four districts near the Chi River were told to lift their belongings to high ground, as the water level in the river continued to rise. If the embankment fails to hold back water, there will be severe flooding.

 

Source: http://www.nationmultimedia.com/detail/national/30322830

 

 

-- © Copyright The Nation 2017-08-05

[YetAnother]

13 minutes ago, rooster59 said:

and exchange information in the meeting every three days

guess it must be an every-three-day crisis

[Godang]

They do not have much confidence in the dams if they need to drain before they are full. 

[MadMuhammad]

I've had discharge threatening my life on my return in the past....

[canuckamuck]

I see they have kept up with the water pushing machines. Good for them for not giving in to laws of physics.

They could save a step though, just pour all that diesel on the ground and light it on fire. You will have the same effect on the flow of water, but it will take less time to use up the fuel.

[robblok]

3 hours ago, Godang said:

They do not have much confidence in the dams if they need to drain before they are full. 

Its better to have a controlled release then a forced release.. Suppose a dam is full and a huge amount of water is coming at it they will have to release much more at one time then now. 

 

The reason 2011 was so bad was that the goverment decided not to release water early (to save rice) and ended up being forced to release the water at the worst possible time. This added to the overall damages occurred in 2011. 

[HiSoLowSoNoSo]

3 hours ago, Godang said:

They do not have much confidence in the dams if they need to drain before they are full. 

Many of the dams are earth walls with big stone blocks on-top. The Ratchaprapa dam in Surathani is made that way and its a massive dam. My local friend there told me that the company that made it guaranteed it for 30 years, it was built 1986!

[halloween]

4 hours ago, Godang said:

They do not have much confidence in the dams if they need to drain before they are full. 

Operating theory is that you try not to have a dam at 100%. Release gates have a limited flow rate and if the inflow is much higher than this, at 100% the excess goes over the spillway. Initially this flow will be quite small, increasing as the dam level exceeds spillway height. But increasing the water height increases the pressure against the dam wall, increasing the risk of dam failure.