Qualla: Don Sahong Dam

Don Sahong Dam: Introduction

Mon, 17 Aug 2026 00:00:00 GMT

Where the Mekong breaks apart at Si Phan Don, the river stops being a river and becomes a puzzle. Channels split around sandbars, rejoin, split again, and at the southern edge of the maze the whole system drops over the Khone Falls in a barrier of white water that migrating fish cannot climb. One channel is the exception. The Hou Sahong runs between the islands of Don Sahong and Don Sadam on a gentler grade, and it has long been understood as the door - the only passage through the Khone complex that fish can use in the dry season, and the principal route they use in every other season too. In January 2020, a 22.5-meter dam began operating across the downstream end of it.

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Don Sahong Dam: Four Turbines, One Channel

Mon, 17 Aug 2026 00:00:00 GMT

By the standards of Mekong hydropower, Don Sahong is small. It is a run-of-the-river plant rather than a reservoir project: 22.5 meters high, with four bulb turbines rated at 65 megawatts apiece for a total installed capacity of 260 MW. Mega First Corporation Berhad, a Malaysian ...

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Don Sahong Dam: Is a Channel the River?

Mon, 17 Aug 2026 00:00:00 GMT

That last detail - less than two kilometers - is why the project consumed a decade of regional diplomacy. Laos signed a memorandum of understanding with Mega First in March 2006 and a project development agreement in February 2008. Cambodia, Thailand and Vietnam argued that a dam...

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Don Sahong Dam: Faith-Based Mitigation

Mon, 17 Aug 2026 00:00:00 GMT

The fisheries argument turned on whether fish could be persuaded to go somewhere else. The developers proposed that the smaller channels around the dam site could substitute for the Hou Sahong once fish traps were removed and the depth and bathymetry were modified, and they maint...

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Don Sahong Dam: The Last Dolphin in Laos

Mon, 17 Aug 2026 00:00:00 GMT

A short distance downstream, straddling the Lao-Cambodian border, lies the deep pool known as Veun Nyang, or Anlong Cheuteal. It held the only Irrawaddy dolphins left in Laos, a handful of animals belonging to a critically endangered Mekong population. Conservation scientists war...

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Don Sahong Dam: What the Water No Longer Does

Mon, 17 Aug 2026 00:00:00 GMT

Khone Phapheng still thunders, but the project reduces flow into the falls and the surrounding channels, and Si Phan Don's candidacy as a Ramsar wetland of international importance was compromised by the construction. An alternative had been on the table. The Thako scheme would h...

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