The development of hydropower in LAO PDR has been very contentious. [6]. Then, the  US$1.2 billion Xe-Pian Xe-Namnoy project located on the Xe Kong River in Laos' Bolaven plateau, collapsed. The dam construction began in February 2013 and was expected to be completed in 2019. It is part of the dam construction boom in the country with the aim of generating electricity to be exported to Thailand and become the "the battery of Southeast Asia" [2]. The Mekong and its tributaries would the source of hydropower, which (in money terms) was 23 % of exports in 2017, from 47 hydroprojects that should reach 100 by the year 2020. 

The failed dam planned to export 90 percent of its electricity to  Thailand and the remaining amount was to be offered up on the local grid.

The project, which is the first build-operate-transfer (BOT) project to be undertaken by the Korean companies in Laos. The project achieved financial closure in February 2014 and is financed through 70% debt and 30% equity. Debt financing of approximately $737.5m is provided by a syndicate of Thai financial institutions including Bank of Ayudhya, The Export- Import Bank of Thailand, Krung Thai Bank, and Thanachart Bank. [1]

On 23rd July 2018 it was reported that there were at least 27 people have been killed and more than 100 are missing in flooding of at least six villages following the collapse of one of the subsidiary dams, known as "Saddle Dam D". More than 6,600 people have been made homeless. As of 30 July,  there are at least 27 dead, over 100 people missing and 16,000 affected. 

Workers found the hydroelectric dam in Attapeu province was partially damaged on Sunday, and villagers living nearby were evacuated.

The collapse of the dam Monday was not the first in Laos. Last year, a dam on the Nam Ao River that was being built as part of a hydropower project burst, although no deaths were reported after that accident [3].

Some residents whose villages were in the way of the hydropower project have resisted moving, saying the compensation they were offered was too small and the land they were offered was unsuitable for farming.

In a 2013 International Rivers sent a letter to the power company reporting what the organization saw firsthand on a field visit. People were struggling “with a lack of access to sufficient food, water and land.”

“In addition, families have found that the shallow soil around their homes is inappropriate for growing vegetables, fruits or staple crops, and consistently attest to going hungry,” the letter said [4]. The EJAtlashas recorded the details of building and opposition to several dams in Lao PDR. 

There has been criticism for many years against the building of many dams in the Mekong River. There was a typical reaction to the collapse of 23 July 2018 from one of the dam building firms, the  Mega First company which is building the 250 MW Don Sahong dam, also in Southern Laos near the Cambodian border. Their press release aserted that "Having reviewed the circumstances surrounding the incident, and the specific and unique characteristics of the Don Sahong Project, the board  is satisfied that present and future dam safety risks remain extremely low". Really? 

The government's figures on deaths are still increasing a few days later. [5]. A high-ranking Lao official suggested that the  dam collapse in Champassak province was the result of faulty construction and said the project’s developer should be held accountable, as the death toll from flooding has reached 30, with more than 20 hospitalized for injuries.

Xe-Pian Xe-Namnoy Power Company's (PNPC) 410MW Xe Pian Xe Namnoy hydroelectric power project is estimated to have an annual energy generation of approximately 1,860GWh.

The project includes the construction of three dams: Houay Makchan Dam, Xe Pian Dam, and Xe-Namnoy Dam along the Mekong River.

The "Saddle Dam D" was 8m wide, 770m long and 16m high - and was designed to help divert water around a local reservoir

It will consist of a large storage reservoir on the Xe Namnoy River, underground tunnels, shaft waterways, and an open-air powerhouse featuring four generator units (three Francis turbines and one Pelton turbine).

The Xe Namnoy reservoir will be 73m-high and 1,600m-long, and will have a capacity to store approximately 1,043 million cubic meters (MCM) of water. Approximately 1,000MCM of water will be collected from Houay Makchan and Xe Pian catchments and stored at the Xe Namnoy reservoir.