Laos: Flooding starts, testing stops for NT2 hydropower project

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The Xe Bang Fai river in Laos started to break its banks over the last two weeks in some areas, causing testing to stop for the Nam Theun 2 project.

The rainy season in Laos is well advanced now, and the Province of Khammouane, where most of the Nam Theun 2 Hydroelectric Project (NT2) is located, has been hard hit over the last two weeks. Just over a week ago there was 225mm of rain over central Khammouane in one night, leading to floods in several places around the province – including the provincial capital of Thakek. Apparently there were places in Thakek up to a meter deep in water for a while: a combination of heavy rain and blocked drains, according to a local official. Those of us who were in Lao’s capital Vientiane during last year’s floods will vividly remember this.

As a result of this heavy rain, the Xe Bang Fai River, which drains a significant part of Khammouane, started to break its banks over the last week in some areas. The Xe Bang Fai is very significant to the NT2 as it is the river that will receive the water discharged from the hydropower facility when it is operating. The incremental impacts of NT2 water on the regular flood cycle of the Xe Bang Fai river has always been a concern for the project, and was studied extensively.

Longer flood duration and increased water depth in the river are unavoidable. Thus, the NT2 Downstream Mitigation and Compensation Program is designed and being implemented to help mitigate and compensate for these impacts through improving some flood gates, and helping communities adapt their livelihoods, among other things.

Another noteworthy feature of the NT2 project is to stop releasing water into the Xe Bang Fai once the river is close to topping its banks at Mahaxai – a town just downstream from where NT2 water is released into the river. This would prevent any worsening of the situation caused by natural floods during this time of the year. Practically, this means that no water would be released from the regulating dam into the downstream channel – a project built channel which carries the water 27km from the power station to the Xe Bang Fai.

Several hundred meters of road were underwater on the road leading to Mahaxai, a town just downstream from where NT2 water is released into the river.

I was visiting the project area last Friday. We were still a few kilometers away from Mahaxai when we saw a crowd of people and vehicles ahead, and as we drove closer the reason became clear: several hundred meters of road were underwater. Those in vehicles with high ground clearance were slowly moving forward, creating a bow wave down the road. Others were wading through the water, and some entrepreneurs were already offering lifts in boats. Our Land Cruiser was well equipped for the occasion, and we slowly drove through the water. Khammany, our driver, would occasionally stop and ask wading people for unusual directions – exactly where is the road that we’re driving on? At one point we had to pass a truck stuck in the water, and a villager helpfully stood at the edge of the road to let us know where it dropped off underwater.

I last visited Mahaxai in June, and the Xe Bang Fai looked very different this time because of the natural floods. Where we used to park at the top of the river bank and look down at the river some 10-20m below was underwater: instead of cars, there were boats. It was an impressive change, but apparently one familiar to old hands on the project. There were a few Nam Theun Power Company staff at the river’s edge monitoring the situation, and I did wonder to myself at the time as to whether this community was linking the surging flood waters to the NT2 project.

In reality the NT2 project is not yet operational, and the only water releases into the Xe Bang Fai have come from the testing of individual turbines. But given the profile of NT2 in the area, it is perhaps not realistic to expect people to think about the potential incremental affect of testing individual turbines on the mass of water passing down the river.

Where we used to park at the top of the Xe Bang Fai’s river bank was underwater. Now, instead of cars, there were boats.

We drove our car back through the road/lake, and on towards the power house. We crossed the downstream channel not long after, and it contained a significant amount of water. However, as we drove up the channel it became clear that the water was backfill from the Xe Bang Fai or rain water, as the aeration weir had no water flowing over it. Clearly, testing had stopped at least a day or so earlier.

That night I got a formal email announcement to all project lenders that the company had ceased testing when the water approached the flood level at Mahaxai. Since the race is on to be ready for commercial operations at the end of the year, this is a difficult time for the company to be suspending testing, but it was good news with respect to the company’s commitment to meet its social and environmental obligations.

Once back in Vientiane, I noted that speculation was starting on NT2’s impact in the Khammouane flood on a popular email list about Laos. The email included a link to a five year old speculative piece by a project critic, but no link to the wealth of other information available on probable impacts, the mitigation and compensation program, the project’s commitment in regards of stop releasing water into the Xe Bang Fai, etc. If NT2 is being linked to floods when it is not yet operating, we presumably can look forward to some interesting times when full commercial operations begin.


William Rex

Program Manager of the Cooperation in International Waters in Africa (CIWA) program

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