Sornnimul Khut l Palladium - Mar 22 2022
How Protecting Cambodia’s Groundwater Could Save its Cities from Sinking

Source: 3i

This year’s World Water Day focuses on groundwater, which is “water found underground in geological formations of rocks, sands and gravels.” Groundwater accounts for 30 percent of total freshwater on earth.

And though groundwater is out of sight, it can have immense impacts if not handled carefully. Currently, groundwater is pumped out to support everything from drinking water, farming, and industry to health and sanitation systems. But if groundwater isn’t properly replenished, it can cause wide ranging repercussions.

When groundwater depletes, wells dry up, water quality deteriorates, and lakes, streams and rivers lose water. Most worryingly, perhaps, is that excessive groundwater pumping is causing cities to sink. One such city is Jakarta, Indonesia, where the sinking is up to 6.7 inches per year due to excessive groundwater pumping, with predictions that much of the city could be underwater by 2050.

Shifting Away from Groundwater for Sustainability

In nearby Cambodia, information about groundwater is lacking. While the country’s urban areas are largely located along rivers and lakes, making it convenient to extract water, the rest of the country depends on several different sources of water based on the time of year, including groundwater.

But there is competition, and both citizens, agriculture, and industry are pulling from the same sources throughout the year. Farming and industry consume a considerable amount of both surface and groundwater, creating the potential for a water shortage and increased dependency on groundwater.

What’s the solution?

Investing in Infrastructure (3i), an Australia Department of Foreign Affairs and Trade-funded project, hopes to address the issue by shifting to piped treated surface water in Cambodia. Since 2015, the program has co-invested with private water operators to establish and expand their facilities and networks to rural villages in Cambodia, 95 percent of which use surface water such as ponds, rivers, lakes, or reservoirs.

This wasn’t always the case. At first, the program provided funding grants to operators no matter their water source. Before providing grants to those operators largely dependent on groundwater, 3i would conduct field surveys of local wells and study the history of groundwater use in the area to determine the depth of the well operators should drill. If the results showed abundant groundwater in the area, they received grants.

Later, 3i conducted a separate study of groundwater across Cambodia, which found that there was insufficient evidence to support use of groundwater due to concerns around the sustainability of operators extracting water from this source over time. As a result, 3i shifted away from operators who depend only on groundwater in its programming activities.

Since the shift, all applicants must prove that they depend largely on surface water.

“Groundwater is very easy to extract, and mostly easy to treat as well compared to surface water as the water is usually clear,” says Mola Tin, 3i Chief Operating Officer. “But it’s not sustainable. That’s why surface water is key priority for the program.”

Besides state-owned water sources such as rivers, lakes, reservoirs, or streams, 3i also supports the development of privately owned water sources: ponds. Out of all of 3i’s 80 partnerships with operators, only 27 use ponds, either partially or in full, to supply water for their consumers.

“We have helped them dig ponds to collect rainwater and runoff to feed their water treatment plants,” explains Tin. “Our engineers calculate the expected amount of water need annually and determine where and how big and deep the pond should be to collect enough water to supply all year round.”

"Groundwater is very easy to extract...But it's not sustainable."

Breaking the Cycle of Ungoverned Groundwater Extraction

Sources of water vary from location to location across Cambodia. But increased population and business activities in some rural areas have put pressure on the current existing water sources, and more and deeper wells are dug to meet demands, creating a tenuous groundwater situation.

The 3i team is hopeful that as more households are connected to a reliable piped treated water network, the groundwater pumping can gradually reduced. “We observed that there is an ungoverned extraction of groundwater at village level by households and small and large businesses when the piped treated water is not in place,” adds Tin. “However, the cycle is broken after they are connected to piped treated network. For instance, some broken wells or water pumps are not fixed or replaced as the families now can use water from the pipe network.”

In an effort to further reduce ungoverned extraction, the program is now piloting a bulk project to connect those private water operators close to rich sources of water with other private water operators who may be short on surface water access.

3i is working closely with the Ministry of Industry, Science, Technology, and Innovation, which licenses and regulates commercial piped clean water supply, to standardise the contract agreement between water operators. With that in place, it will standardise the practice of bulk water selling across the country.

“We believe this is a very strategic approach to supply water to operators who are short of water sources,” says Tin. “Doing so would help prevent the over-pumping of groundwater from the areas.”

Shifting how water is sourced in the piped water supply sector, together with supporting pond development, has maximised the extraction of surface water. With the contracts approved for the sale of water between operators, it’s expected that extraction with be reduced, removing further pressure on groundwater.

However, that alone is not enough to protect groundwater; more needs to be done in other sectors including farming and agriculture to maximise surface water use and to further reduce the dependency on groundwater, leading to better conservation of aquifer’s groundwater in Cambodia.

3i is implemented by Palladium and funded by Australian Government through Department of Foreign Affairs and Trade (DFAT), 3i aims to provide over one million rural Cambodians with access to pressurised piped treated water. For more information, contact