New buildings under construction in Phnom Penh on April 25, 2018. Photo: AFP / by Tang Chhin Sothy

Don’t let the humorous memes featuring soggy commuters trudging through water-laden Phnom Penh streets fool you; urban flooding is a serious problem, and one that receives regular discussion but sparks little concrete action. 

Typically, if flooding in Cambodia is discussed at all, it’s brought up in relation to its rural impacts. Rural flooding affects large swaths of agricultural land and homes and threatens the incomes of these communities. Urban flooding, by comparison, gets relatively little coverage despite the large number of people affected and the damage to property it causes. 

One aspect that makes urban flooding so problematic is how unpredictable it can be, with sudden heavy downpours swamping many communities in Phnom Penh, and rendering roads impassable. Just recently, for example, after a heavy deluge, there was flooding in Por Senchey district’s Kakap commune. 

There are direct and immediate economic impacts of urban flooding. Inundated roads paralyze transportation, preventing people from reaching their workplaces, disrupting local and national supply chains. These impacts are particularly harmful for small and medium-sized businesses that are already susceptible to other kinds of shocks. 

Urban flooding is also a public health issue. Waterborne diseases – particularly diarrheal diseases such as viral and bacterial gastroenteritis, dysentery and cholera – appear to increase during flooding. 

Looking beyond the immediate impact, Phnom Penh’s floods can lead to extensive property damage, which in turn erodes savings and increases indebtedness, thus deepening cycles of poverty vulnerable urban families are already exposed to. 

Flooding events are expected to get worse. The Mekong River Commission warned in May that between June and July of this year Cambodia would experience more rain and flash floods, an issue that is certainly linked to climate change. 

However, urban flooding is not entirely a natural disaster. While Phnom Penh’s floods are exacerbated by the increasing frequency and intensity of precipitation patterns, human decisions – rapid, unchecked land development, the reliance on aging, outdated and inadequate urban infrastructure, and failure to invest in infrastructure improvement – only serve to worsen outcomes. 

The past two decades have brought rapid economic growth and structural development to Cambodia, and it’s a trend that isn’t expected to slow down. Phnom Penh is continuing to expand. In February, the government announced that after the construction of bridges is completed, the Arey Ksat and Svay Chrom areas will become a satellite city. Phnom Penh’s population is expected nearly to double to 2.86 million inhabitants by 2035. 

Flashy high-rises and glittering air-conditioned malls are popping up at an ever-increasing rate. The Ministry of Land Management, Urban Planning and Construction issued permits for 728 new projects in the first two months of this year alone. That’s an increase of 28.1% from 568 in the same period last year. These projects cover a total of 4.2 million square meters, which is an increase of 34% year-on-year compared with the first two months of 2019.

The city’s aging and inadequate drainage systems simply cannot keep up. 

Existing infrastructure is being stretched past its limit by an increasing population and unchecked development. Making matters worse, Phnom Penh lacks a comprehensive drainage and flood-protection system. 

Only four central districts – Charmkar Mon, Doun Penh, Prampir Makkara and Toul Kork, which have benefited from donor assistance – have sufficient drainage and wastewater collection. The rest of the city relies on an outdated sewage system, and broken water supply lines. Even a small amount of rain overwhelms this infrastructure. 

Lack of investment on the part of the government is part of the problem. Yong Kim Eng, the director of non-governmental organization the People’s Center for Development and Peace, told The Phnom Penh Post that historically, the government has prioritized road infrastructure, rather than focusing on drainage systems.

For example, the Cambodian government devoted 13,031 million riels, just over US$3 million, to water drainage-related initiatives in Phnom Penh in 2014, which equals just 0.3% of the 2014 national budget of $3.4 billion. 

Another factor of the flooding is waste management, or lack thereof. Phnom Penh Governor Khuong Sreng identified the source of the issue as the “indiscriminate disposal of rubbish, which flows into the drainage system.”

Phnom Penh produces 3,000 metric tons of solid waste per day, and much of that waste winds up clogging critical water-drainage systems. The government removes as much as 10,000 tons of waste from the city’s sewage canal every year, a fraction of the waste that likely remains in these waterways. 

A third factor keeping Phnom Penh flood-prone are the land-reclamation projects that have filled in the capital’s lakes. A study on the spatial growth of Phnom Penh from 1973 to 2015 revealed that after 2006 the number of natural lakes and wetlands that had been converted to urban land areas increased by 34%. 

Water Resources and Meteorology Minister Lim Kean Hor has expressed concerns about the country’s diminishing ability to “overcome floods caused by opportunists who fill in lakes, rivers, canals and ponds.” At the same time, the ministry asked “the capital and provincial authorities to prevent the encroachment of construction on riverbanks, ditches, creeks, canals, water reservoirs and lakes to avoid the effects of water-drainage and flood disasters.” 

Speedy and lucrative development has clearly taken precedence over good management of the city’s waterways. As of 2019, 16 lakes have been filled in, 10 lakes have been partially filled and no lakes remain untouched in Phnom Penh, leaving water that would otherwise empty into these lakes to remain trapped in the city streets. 

Adding to this is the matter of concrete being laid over land previously used to store the water. The result is that natural drainage and wastewater-treatment systems have been obliterated. Water no longer flows the way it should, which increases surface runoffs, and aggravates flood risks. 

This is not to say that the government of Cambodia cannot or should not prioritize development projects. Rather, the country needs consistency in implementing long-term plans for development while simultaneously implementing flood-management policies. Efforts to prevent urban flooding do not automatically have to mean jeopardizing economic growth.

Take Singapore for example. It’s the most competitive economy in the world, but it proves that urban development and economic growth can go hand in hand with sensible, flood-sensitive urban planning. As it has developed, Singapore has focused on converting canals and reservoirs into streams and lakes, as well as constructing artificial wetlands to increase the city’s rainwater absorption capacity. Between 2010 and 2018, Singapore completed as many as 75 projects to mimic such natural flood defenses. 

China has also made urban flood management a priority. The country launched an engineering solution called “sponge cities” in 2015 in 16 cities to hold, clean and drain rainwater in natural ways across targeted areas. The approach is meant to reduce flooding but also to enhance water-supply security. The goal of the project was to be able to reuse at least 70% of the rainwater that falls on these target cities. 

It should be acknowledged that the Cambodian government has taken some steps to deal with urban flooding. For example, regarding the problem of waste management, the government has ended its contract with garbage contractor Cintri and adopted a new system. The government is reviewing the companies that have submitted bids for the rubbish-collection contract. Phnom Penh will be divided into three zones for at least three companies to collect waste. 

There have also been some efforts to enhance flood protection and drainage systems in Phnom Penh, such as the $27 million construction of a wastewater-treatment station in Choeung Ek, which was funded by the Japanese government. The project to build the station is set to begin by the end of this year.

The Ministry of Economy and Finance is drafting an “Urban Solid Waste Management 2019-2028” policy, and recently Phnom Penh City Hall, in cooperation with the Embassy of Japan in Cambodia and the Japan International Cooperation Agency (JICA), unveiled a mechanical screen to clear drainage pipes as part of the Project for Flood Protection and Drainage Improvement.

As well, in an attempt to build a resilient city, the government has laid out several thematic master plans, including the Urban Transport Master Plan 2035, Drainage and Sewerage Master Plan 2035, and Green City Strategic Plan 2016-2025.

But according to the World Bank, these plans fall short. “The city’s ambitious Master Plan 2035 lays out a strategic vision for growth, but lacks a corresponding detailed land use plan and accompanying regulatory framework to support implementation,” one World Bank report states. 

Managing flood risk and building a more resilient city will take more than just good planning. Tackling the problem will require commitment from all stakeholders, including land developers, politicians and communities. 

The calculus is clear. The government can invest now to mitigate future floods and minimize further damage, or pay later to repair the properties and restore the environment. The longer the government waits, the harder it will be to prevent future urban flooding.