Okay, have finally tracked the figures in a friendly format and the ability to check across multiple years. The three charts, namely 1. Amount of water stored in the Bhumipol Dam., 2. Accumulated amount of water entering Bhumiphol Dam for each year for 2005-2011, and  3. Accumulated discharge of water per year in the Bhumipol Dam for 2005-2011, have to be considered together.

1. Amount of water stored in the Bhumipol Dam per year for 2005-2011

Google Chrome

Source: Irrigation Department – the graphic when you click on the page is interesting to watch and if you put the mouse over a line in the graph, you can find the exact amount of water in the dam on that day.

NOTE: Left-hand vertical axis is million cubic metres. The normal reference is 100% capacity. The years from left to right are 2005 (2548) – 2011 (2554). These are the default years for the full data.

BP: In some ways the early months were not unremarkable although by March 2011 you can see that instead of the amount of water decreasing as water is released in previous years it has plateaued and then by May it begins the ascent upwards.

2. Accumulated amount of water entering Bhumiphol Dam for each year for 2005-2011

Google Chrome

Source: Hydro and Agro Informatics Institute (an agency under Ministry of Science and Technology) although it states it figures are from the Irrigation Department.

Note: Left-hand vertical axis is million cubic metres. Horizontal axis is date. It is every 26 days (no idea why!), but it goes from January to December. Full data is only available for these 7 years.

BP: 2011 has the most amount of water entering the dam reservoir. As can be clearly seen, about twice as much water entered the dam reservoir in 2011 than for the normal years (2005; 2006-2009). It is around June 6 that water entering the dams in 2011 that it goes past the other years, but you can also see the line goes up much earlier than most years very early on. Nevertheless, as can also be seen even in the driest year (2010) around 5 billion cubic metres entered the dam reservoir from rain during the rainy season so even on a bad year you are still going to get a lot of water entering the dams. On August 1 (that is when the line for 2011 really starts to go vertical), we go from 3.353 billion million cubic metres of water to 11.689 billion cubic metres on November 1. This is 8.336 billion cubic metres in those 3 months or an average of around 90 million cubic metres a day.

NOTE: There is a lag from the date it rains to the date the water flows into the reservoirs so it doesn’t mean that suddenly the rain started in June, but you can see the early start to the rainy season in March – as per this post on the rainfall for Northern Thailand –

3. Accumulated discharge of water per year in the Bhumipol Dam for 2005-2011

Google Chrome

Source: Hydro and Agro Informatics Institute (an agency under Ministry of Science and Technology) although it states it figures are from the Irrigation Department.

Note: Left-hand vertical axis is million cubic metres. Horizontal axis is date. It is every 25 days (no idea why!), but it goes from January to December. “Full” data is only available for these 7 years.

BP: You see how little water was discharge early on. It was around February 26, 2011 when only 1.545 billion cubic metres had been discharged (see the 1,500 line) where the amount of water being discharged started to diverge from the average. Then, on May 12, 2011 the amount of water being discharged had been 2.5 billion cubic metres up until this point and it started to completely plateau compared with the average. For 2007-2010, 3 billion cubic metres had been discharged by early/mid April, but it took until August 16 for 3 billion cubic metres to be discharged in 2011.

In fact by August 2 – when 2.838 billion cubic metres had been discharged – the amount of water discharged in 2011 slipped below 2005 and became the lowest amount of accumulated discharge of water in any of the 7 years at that point. This is despite the fact that you also had more water, at this point, going into the dam than in any of the previous years. Then, of course, it quickly accelerated form August 2 onwards which was likely done to keep the capacity of the dam under 100%.

Hence, the problem is as Dr. Smith asserts that not enough water was discharged early on the rainy season and particularly from March-July before the flooding started. Yesterday, in the Bangkok Post, there was an explanation by the head of the Electricity Generating Authority of Thailand:

The critical period was in July, when water levels began to rise sharply and the focus of the country and bureaucracy was on the general elections and formation of the new Pheu Thai-led government. But Mr Sutat says it is unfair to drag the agency into political mudslinging over the cause of the floods, which he pinned on the abnormally heavy rains this year.

“The country is in the middle of a serious natural crisis. Rather than accuse each other, we should be cooperating to solve the problems,” he said.

Mr Sutat said the popular belief that water releases by the upper northern dams contributed to the floods was wrong.

Just the opposite, he said _ if not for the two major dams, the Central Plains would be inundated by over 30 billion cubic metres of water, or two to three times the amount today.

The Irrigation Department says that over the first 10 months of the year, 11.488 billion cubic metres of water were collected at the Bhumibol Dam, with 4.085 billion released downstream. [BP: Wrong! 6.163 billion cubic metres was released - see here to confirm]

For the Sirikit Dam, 10.3 billion cubic metres of water were collected with 6.573 billion released.

The Central Plains are now flooded from water running from five rivers _ the Ping, the Wang, the Yom, the Chao Phraya and the Sakae Krang rivers.

The Bhumibol and Sirikit dams, which supply 20% of the water used for irrigation in the central provinces, were running relatively low at just 45% to 50% capacity from the end of 2010 to this past May due to drought.

When tropical storm Haima hit in June, the country’s free-flowing rivers, including the Sakae Krang, the Yom and the Wang, all burst their banks and caused flooding in Phitsanulok, Sukhothai, Phichit and Nakhon Sawan.

Both the Bhumibol Dam, with a capacity of 13.46 billion cu m, and the Sirikit Dam with 9.51 billion cu m, halted water discharges during the period.

From the end of July through to last month, four more major storms hit the country, leading to nearly all of the country’s dams reaching full capacity, including the Bhumibol and Sirikit dams.

Egat was forced to open spillways for the Sirikit Dam from the end of August until early September, while spillways at the Bhumibol Dam opened last month.

“Over the past 30 years, Thailand typically has been hit by two or three major storms a year,” Mr Sutat said. “This year, we were hit by five storms, one after another. There was no time for the water to drain into the Gulf of Thailand.”

BP: See the strawman argument? The criticism is not that we have a dam, but that more water could have been released earlier in the process. One has to believe there is something lost in translation as there is no way that “Mr Sutat said the popular belief that water releases by the upper northern dams contributed to the floods was wrong” is correct. So discharging water from the dam, does not contribute to flooding at all? More water flowing downstream does not increase flooding/the risk of flooding?

Look, it is fine to say that during the tropical storm of Haima which hit Thailand in late June 2011 and that during this time they shouldn’t have released more water so as not to exacerbate the flooding – doesn’t this go against the argument that releasing water does not contributed to the flooding though???. However, as you can see from the amount of water discharged in 2011, it is not just late June where the amount of water being discharged was lower than normal. From March-July in 2011 , it was lower than the average in previous years. BP accepts that there are multiple factors to consider and the rainfall in the North was high from March onwards, but to release so little water so late has only exacerbated the flooding problem.

*NOTE: The last two paragraphs have been corrected. They were left unfinished. Not quite sure what happened.