Meach Pov holds his palm perpendicular to his aged doorframe, half a meter above the ground, signaling how bad the flooding can get inside his one-room house. Though flooding is common in Cambodia's capital Phnom Penh, the effect is anything but innocuous. Just a little more than a meter below him, a putrid river of human waste and garbage is visible between the rickety floorboards.

The 34-year-old lives at the end of one of Phnom Penh's major exposed sewage canals. The stagnant water slices through 30 blocks of the city's center, its arresting odor permeating bordering roads.

Meach, now unable to work due to sickness, spends long stretches at home, reliant on assistance from his wife and neighbors, and exposed to the waterway's air. In the dry season, the grey substance filling the ravine remains still, but with rain it oozes and periodically rises onto surrounding streets - and directly into Meach's home.

Consequences of urban growth

Phnom Penh has undergone significant development recently, with a growing number of high-rises and shopping centers. Unprecedented urban migration has more than tripled the city's size since 1997. According to a 2015 World Bank report, Cambodia had the second-highest urban population growth rate in East Asia.

But with gaps in city planning, leadership and regulation, the influx of growth has brought with it major challenges, including insufficient waste management and development-induced flooding - with the poor often suffering the effects.

"The living conditions of many urban poor are really horrible," Piotr Sasin, country director for the NGO People in Need (PIN), told DW. He added that high-density environments, a lack of solid waste systems, security threats and social ills such as gender-based violence are some of the challenges they face. PIN supports 20 urban poor communities. 

Some of the poorest residents are relegated to live along the canal, where rents are among the cheapest in the city. At the south end, known as Boeung Trabek, wooden and zinc shanty houses clutter the water's edge. Organizations say the river is a serious hazard to this community, which lacks access to clean water and electricity.

According to PIN, The health impacts are dire, with high incidences of skin diseases, respiratory infections, diarrhea and eye rashes. The local urban NGO, Sahmakum Teang Tnaut (STT), claims these ailments disproportionately affect women, who spend more time at home, and children, who play around and in the canal.

 "The rubbish and open sewage is a haven for all kinds of bacteria, viruses and parasites," adds Sasin. "[People] shouldn't be living in a place where they constantly risk their lives and their health."

Canal system faces rising pressure

Meong Yim rents a small room in an alley near the waterway for $50 per month. When she first moved to the area, the stench severely affected her. "I could not even eat rice," she told DW. But after three years, she has adjusted - a phrase oft-echoed by canal residents. Last year, her room, filled with only a wooden sleeping platform and cooking implements, seriously flooded twice with sewage.

Refurbished in 2002 to reduce flooding in Phnom Penh's lowlands, the canal has been used for the last two years to funnel both rainwater and sewage from huge swaths of the city to the southern outskirts, for eventual treatment at a future sewage plant.

This added pressure on the system has been compounded by a growing economy and population. According to the Japan International Cooperation Agency (JICA), increased water consumption, waste and plastic clog the system and lead to overflows.  JICA has partnered with the government since 1999 to improve and expand the city's drainage. "It's really a challenge," JICA project formulation advisor Togo Uchida, told DW.

In addition, natural reservoirs, which traditionally absorbed the impact of floods, are being filled to create sellable land. According to STT, between 2009 and 2015, the Boeung Trabek lake was steadily redeveloped, and the remainder is in danger of being filled. This would push wastewater further south, where another lake - Boeung Tompun - is being reclaimed to create a satellite city. "The lack of comprehensive, strategic planning is a very big issue," said Sasin.

Canal zone blight on development

Despite its drawbacks, the canal is lined by staples of Cambodian life - open-air restaurants, hotels, barbershops, massage parlors and repair stands. But the area remains a blight on the city's development.

In the first nine months of 2015, real estate and construction in Cambodia totaled $1.7 billion (1.6 billion euros). But almost no new development has occurred along the canal, according to real estate company Independent Property Services. "It's undervalued compared to the blocks either side of it," country manager Grant Fitzgerald told DW.

At the waterway's edge, Moeun Sothear's family prepares banh xeo pancakes for sale. He rents the stall there for its comparatively lower cost - about $100 a month, versus $200-$300 elsewhere. With heavy rain, the canal can rise to knee height, and Moeun claims he gets fevers monthly due to the air. "But I have no choice," he told DW.

Behind him looms the first major development to border the channel - a 217,000-square-meter property with condominiums and a mall. Moeun hopes that, once completed, the attraction will bring additional customers.

For the area's transformation to occur, however, the government must remedy the sight and smell of sewage. According to JICA and Phnom Penh city hall, there are no immediate plans to cover the canal, as it remains undecided which authorities will finance this.

A lid could also make maintenance more difficult. "They [the government] are concerned," said Uchida. "So they want to [address] that, but it's a matter of whether they can do that financially or capacity wise."

Residents are vulnerable 

In the meantime, Boeung Trabek residents remain vulnerable. If the canal pump is not operated correctly or malfunctions, they are at risk of devastating floods, warns Uchida, adding that pumping capacity is being increased. And amid a canal-widening project and rumored new high-rises, the community faces a new threat - eviction.

Residents are accused of encroaching on state land, but STT asserts this is a tactic to clear the property for sale. "We appreciate it if it's a trustworthy development,"  advocacy programe manager Soeung Saran, told DW. "But it's all about the price speculation."

Yet city hall spokesman Met Measpheakdey says no final decisions have been made, and that officials are working to upgrade the canal with minimal impacts. "We think about the development, but we also think about the people," he told DW.

If relocated, people could lose jobs, support systems, and access to public services. But residents feel they will have little choice. "If we are told to leave, we will not argue," Chon Sreypov told DW, adding that the community fears confrontation with authorities.

Meach, whose rent is just $35 (32 euros) a month, will have few if any options to remain within city limits. Asked about his plans, he says he does not know what he will do. "I will wait until that day comes," he said.