Cambodia’s small-scale hydropower offers potential and risk

Local dam operations provide Cambodian communities with electricity, but the Mekong River stations generate problems as well as kilowatts

August 5, 2022
Cambodia’s small-scale hydropower offers potential and risk
Lounh Samnang, a 21-year-old dam operator, sits on a 12-kilowatt micro-hydropower dam on O’Porng Morn Kraom river in Cambodia’s northeastern province of Stung Treng.

The stiff, rusted grate forming a metal ramp scraped its stone anchor and bent under Lounh Samnang’s weight as he clambered onto the small-scale dam he operates and maintains.

Water rushed from the reservoir and gurgled through the dam’s turbine before flowing down O’Porng Morn Kraom, a tributary which eventually meets the Mekong River. The waterway passes the shell of the first dam built by the Lounh family for Koh Sampeay village in Cambodia’s Stung Treng province.

“From the very beginning, this dam supplied the village and pagoda without problems before the national grid arrived,” Samnang said of the 12-kilowatt dam. “We actually helped the village a lot.”

Samnang’s dam on O’Porng Morn Kraom, naturally hidden from view by a steep slope and dense tree canopy, mirrors Cambodia’s burgeoning interest in small-scale hydropower, which has proliferated in rivers worldwide.

While small-scale hydropower could aid the Kingdom’s goal of country-wide access to electricity by 2023 and improve development for rural communities, the necessary infrastructure could also further endanger the Mekong, which is reeling from the effects of dozens of large-scale dams.

“The major problem we have associated with smaller infrastructure, like small-scale hydropower, is the quantity,” said Thiago Couto, a freshwater ecologist at Florida International University’s Tropical Rivers Lab who studies the global boom of small hydropower projects. “Instead of building one single large dam, we’re building hundreds of smaller dams all over the place.”

Couto and other researchers warn the lack of scientifically informed oversight and indiscriminate expansion of small-scale hydropower could devastate river basins. A prediction that experts in hydropower reform urge developing countries to avoid by establishing regulations and considering alternative energy sources.

“We have an abundance of ways to be able to generate electricity and we can do that without relying on our rivers to create that electricity,” said Andrew Fisk, executive director of the Connecticut River Conservancy in the United States. “The costs of hydropower far outweigh the benefits. We would encourage other governments around the world to consider what those alternatives are.”

The debate over the advancement of this potential power leaves nations, including Cambodia, to delicately balance rural development and environmental protection.

Several times a week, Lounh Samnang checks his family’s micro-hydropower dam on O’Porng Morn Kraom river. In the past, dams operated by the Lounh family supplied energy to dozens of homes in Koh Sampeay village.

River realities and potential

The series of events that led to 21-year-old Samnang becoming a dam operator is heartbreakingly short: his dad died.

“My father didn’t know how to teach me, but he would bring me along to the dam and show me how he takes care of it,” Samnang said. “I learnt from him that way.”

Lounh Samnang, a 21-year-old dam operator, shows a photo of his father’s completion certificate from a training course on the fundamental knowledge and technology of mini- and micro-hydropower.

Regardless of size, most hydropower dams use a reservoir to control the release of water into turbines that then spin, creating electricity. Samnang’s dam operates similarly with water eventually being released into O’Porng Morn Kraom. Nearby utility poles transfer the energy generated by the dam to Koh Sampeay.

In the years before Cambodia’s central grid reached Koh Sampeay, the dam electrified dozens of homes in the village. 

The Hydro Empowerment Network supports the development of similar community-driven, small-scale hydropower projects up to 1 megawatt, which is equal to 1,000 kilowatts, according to a mission statement posted on the network’s website.

Turbines spin to create electricity as water flows from a reservoir behind a 12-kilowatt dam on a tributary of the Mekong River in the Kingdom’s northeastern province of Stung Treng.

As Cambodia considers continued investment in the nascent stages of this potential power, regions in the U.S. seem to be phasing out this type of energy generation.

“Around the world you are actually seeing the continuing development of new hydropower facilities. You don’t really see that in the United States, the construction of new hydropower projects is not happening,” said Fisk, whose organisation supports environmental protection of a major waterway in the U.S. region of New England.

Dozens of experts and conservation groups, including Fisk and the Connecticut River Conservancy, have joined the Hydropower Reform Coalition, which backs policies and regulations to minimise the environmental impact of dams.

Coalition members share cautionary tales of small-scale dam proliferation while emphasising the need for alternative energy sources, decommission funding and ecosystem-wide planning.

“What hydropower development does adversely to rivers, regardless of the size, is it changes the function of how water moves,” Fisk said. “Dams block the flow of soil, sediment and water which means the river cannot provide the ecological benefit to the fish, wildlife and humans.”

One of the conservancy’s priorities is evaluating small-scale dams for removal or restoration, Fisk said: “We are spending a tremendous amount of time, money and effort to remove these structures and the cost of removal is outweighing any related benefits.”

“When we see what is happening in the Mekong, we have very significant concerns about how new hydro development is going to exacerbate what we see as a bad trade off between the development of electricity and the impact of the ecological functioning of the river system,” said Fisk, who emphasised the importance of fish, silt and sediment through a floodplain ecosystem like the Mekong.

While planning environmental functions are critical to minimising the ecological impact of dams, “planning for the reclamation of our rivers is just as important,” said Mark Zakutansky, director of conservation policy engagement with the Appalachian Mountain Club and board member of the Low Impact Hydropower Institute.

A 12-kilowatt dam, considered ‘micro-hydropower’ in Cambodia, generates energy on O’Porng Morn Kraom, a tributary of the Mekong River in the Kingdom’s northeastern province of Stung Treng.

“Anytime you develop infrastructure, at some point in the future that facility will either need to be maintained, upgraded, enhanced or removed,” Zakutansky said. “What is important is that we don’t create environmental impacts that we have no ability to recover from when those developments reach the end of their lifespans.”

Decommissioning costs must be included upfront when considering the development of a new dam, according to Zakutansky. 

“Any country, including Cambodia, developing new infrastructure needs to plan for and price in the cost of ultimately removing that infrastructure,” he said. “If you’re building a dam now, you should be putting money aside that will be available in 50 years, or 75 years, to remove it.”

Regardless of how an individual dam is designed, Zakutansky expressed concern over a development boom.

“The way those dams are constructed, operated and removed does matter, but so does the number of dams in an ecosystem,” Zakutansky said. “The more dams, the bigger the impact.”

An unregulated surge of small-scale dams would have an outsized effect on the Mekong River, according to Brian Eyler, who helps manage the Mekong Dam Monitor, which tracks 45 of the largest dams across the basin.

The more dams, the bigger the impact.”

Mark Zakutansky, director of conservation policy engagement, Appalachian Mountain Club

The combination of mega dams on the mainstream river and major tributaries compounded by small-scale dams on contributing waterways would be ecologically devastating, said Eyler, who authored the book “Last Days of the Mighty Mekong.”

If the six countries the Mekong River flows through fail to coordinate the proliferation of small-scale developments, monitoring systems like the Mekong Dam Monitor would be unable to track smaller dams in the same way, according to Eyler.

“The Mekong is suffering a death of a thousand cuts and some of the small ones added together are just as impactful as the big ones,” he said.

Expansion and regulation

After being released from a reservoir and passing through a hydropower dam, water is released into O’Porng Morn Kraom river in Cambodia’s northeastern province of Stung Treng.

Small hydropower projects have become an alternative to large-scale developments because of the public outcry over the socioecological impact of these mega dams, according to the 2018 study co-authored by Couto. 

This shift has led developing countries to consider small-scale projects as a “critical component to future energy strategies,” Couto wrote.

Energy policy reports compiled in the study identified nearly 82,900 small hydropower projects operating or under construction in 150 countries, which the researchers said was a conservative estimate because national dam inventories generally undercount diminutive facilities.

China’s existing and planned projects dwarfed the number in Lower Mekong countries, with the tally of future small-scale development plans at nine in Cambodia and 22 in Thailand.

Cambodia’s nine sites were in an “advanced stage of study,” according to data from the Kingdom’s Ministry of Mines and Energy included in the UN Industrial Development Organization’s 2019 World Small Hydropower Development Report. The report found 39 sites across Cambodia at a “reconnaissance stage.”

A representative of the mines and energy ministry could not be reached for comment. 

Dok Doma, research and regulations department vice director for the Ministry of Land Management, Urban Planning and Construction, did not respond to multiple requests for comment.

Leaked presentations from the mines and energy ministry confirmed the Cambodian government’s “institutional promotion” of small-scale hydropower, which the documents characterised as a means to “scale-up access to electricity” in rural areas, reduce poverty and foster economic development.

Hydropower projects are defined by the amount of energy produced, with 1,000 kilowatts equaling 1 megawatt. In Cambodia, according to the presentations, 500 kilowatts or less is considered “micro” and “pico” hydropower, 501 to 5,000 kilowatts is “mini” hydropower and “small” hydropower falls between 5,001 and 10,000 kilowatts.

Two of the four presentations included a location map confirming the 39 proposed sites across Cambodia. The majority were on Mekong River tributaries, including 12 sites on waterways connecting to Tonle Sap Lake. The presentations did not indicate a private or government project development process.

New hydro is very much an old technology whose costs are not worth the benefits given the alternatives we have today”

Andrew Fisk, executive director, Connecticut River Conservancy

A primary development barrier for Cambodia is a “lack of policy and legal framework,” the UN report stated.

“No matter how much the investment has been from NGOs or development partners, all of these efforts have to be legitimised,” said Oudom Ham, an independent consultant for natural resource governance who has researched Cambodia’s small-scale hydropower. “The lack of regulation will not take it further.”

Creating a legal framework for small-scale dam development could secure future funding, Ham said, but this could prove difficult to do since the small-scale dams don’t have an internationally recognised definition, meaning the size and amount of energy produced by a “small” hydropower can greatly vary from country to country.

Fisk empathised with the needs of developing rural communities. If alternative energy options are off the table because of local layouts and hydropower is the only way, projects should not unnaturally block water flow and include fish passages.

“New hydro is very much an old technology whose costs are not worth the benefits given the alternatives we have today and small-scale hydro with less regulation in the wrong place would have a significantly bad impact,” Fisk said. “Don’t do it.”

Regardless of regulations and debates about long-term effects, Samnang said he hopes to continue operating his dam on O’Porng Morn Kraom.

After checking the dam, he reverses his climb over the grate connecting the structure to land and ascends the steep slope, passing through the dense foliage standing guard around what was once the only source of electricity in Koh Sampeay.

Photos by Anton. L. Delgado for Southeast Asia Globe

This article was supported by a News Reporting Pitch Grant from the Konrad-Adenauer-Stiftung Foundation in Cambodia.

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