Laotian hydro dam collapse: more about risks
Aug 8th, 2018
Last week we discussed a recent catastrophic failure. Now we delve more into the Laotian hydro dam collapse: more about risks. We go back to the first-cut estimates we published. They delivered staggering values at portfolio level and, of course, intolerable risks.
Image of the Area of Interest (AoI) courtesy of MDA
The image above courtesy of MDA shows an image with the:
- location of the collapsed dam,
- partially drain reservoir,
- flooded fields and changes in river channels, and finally,
- flooded villages.
In an international current-affairs magazine for the Asia-Pacific region we read interesting confirmation of our preliminary estimates. We quote verbatim:
“The Lao dam disaster in Attapeu province has cast a long, dark shadow of doubt. That is about the safety standards and viability of dozens of other hydropower projects. This entirely preventable man-made catastrophe left 6,000 people homeless from floods and over 1,000 villagers unaccounted for….The Lao government had initially tried to lay blame on the heavy monsoon rain.”
Reportedly, the director of Southeast Asian Studies at University of Wisconsin-Madison University, stated, like we did, the rains were predictable and “normal” for this time of the year and added the dam broke due to a combination of poor water management and poor construction. This conclusion is a general one, world-wide, as we pointed out in a publication entitled A systemic look at tailings dams failure process, presented at Tailings and Mine Waste 2016, Keystone, Colorado, USA, in October 2016.
A general state of affairs
The Laotian government has already completed 51 hydro-electric dams with another 46 under construction. Most of these projects began in the last 10 years, with the government arguing hydro-power could lift landlocked Laos out of poverty while becoming “the battery of Asia.”
Based on prior experience with earth dams, we all know that even apparently minor dams can generate huge risks. For example, agricultural dams in the US created a huge problem decades ago, before they were systematically breached to reduce their risks.
China has a long history of dam disasters, including the worst dam disaster in history, which killed 171,000 and displaced 11 million in 1975.
Tailings dams in the mining industry, dykes and levees built to protect cities and agricultural land have a long history of failures.
- geotechical investigations,
- monitoring and finally
all the way to end of service life Dam construction is a highly challenging, potentially high-risk process.
A public reaction is brewing
According to the director of Southeast Asian Studies at University of Wisconsin-Madison University, “Many Lao people are very upset about the breaking of the dam, calling for the Lao government to re-assess plans to build so many dams in the Mekong River Basin. This level of concern is unprecedented in Laos.”
Detailed view of one of the flooded villages and surrounding areas, courtesy of MDA
Long before this dam construction, the director co-authored an Environmental Impact Assessment (EIA) on Fisheries. The EIA reportedly recommended the following. “We recommend to drop plans to dam and divert the upper Xe Pian from the project. Only in this way can it will be possible to protect the fisheries, wildlife and village resources of the area.” Evidently, the recommendation fell through the cracks.
Lao Prime Minister Thongloun Sisoulith admitted it was the worst disaster faced by the small Southeast Asian country in decades.
If our first estimate is indeed correct, we will sadly hear more nefarious news coming from that corner of the world. In some cases accidents’ consequences will widely pass national borders.
Closing remarks on Laotian hydro dam collapse: more about risks
The results of decisions, choices made at dams’ projects inception will generate risks for decades in the future. We reached the same conclusions for tailings dams portfolios years ago. That’s why Riskope built ORE2-Tailings, a universal platform capable of building dams’ portfolio risk assessments from inception of strategic and tactical planning.
ORE2-Tailings can seamlessly use Space Observation data delivered by MDA to derive initial risk estimates and rational updates. Interested readers can learn more about the data required in this blog.
We will teach a one day course on ORE2-Tailings in cooperation with MDA at TMW2018 (third down in the list). See you there!
Tagged with: collapse, hydro dam, Laotian, risks, tolerance
Category: Consequences, Risk analysis, Risk management
• Key issues & reforms for the Dam Sites:
1. Emergency Spillway System Construct somewhere behind the upstream area must be first priority to meet such kind of happened, easily escaping from high flood situations.
2. The Diversion Tunnels as per design criteria round shape Complete before the heavy Rains & flood periods to bear the impacts of Static and other relevant forces like Sliding’s, Cracks, Sink Holes & settlements.
3. The Project sites need to be add in provision of specific Cofferdams to controlling the water potential of upstream areas and not passing towards the Dam side, especially protecting form the Leakages.
4. The Storage Capability in the Reservoir as per depend upon the Geological Site Condition of Soil and Rock Bedding Joint formation Strata like Horizontal, Vertical or inclined Shapes & (Earth Works Status, Earthquakes, Hydrology, previous disasters in 10 years) and Drilling Blasting’s during in 5 years (Fracture areas of right Banks, Left Banks also near Structures Zones + other Weak portions need to address)
5. Reviews must be considering as per Site Conditions of design criteria during the Construction execution stages.