Development projects in Phnom Penh that require lakes to be filled could endanger the city’s drainage system and the health of residents, a local organization warned last week.

Filling in lakes for housing and other projects can destroy waterways and cause sewage systems to back up, creating unsanitary conditions, according to Resource Development International Cambodia.

“I am really afraid that some toxins could flow into the Tonle Bassac, so now we are setting up a program to measure water quality,” said Mickey Sampson, RDIC’s country director. “We know now they grow a lot of morning glory there. I went to check and test the quality of those vegetables, and we saw some arsenic in them. I think this could very much affect the health of people and animals.”

The government must make steps to ensure the lakes and drainage are not blocked up, which could raise the level of toxins, viruses and parasites, especially after heavy rains and flooding, Sampson said.

Some of the cities main lakes, including Pong Peay, Sayap, Kob Sroy, Cheung Ek and now Boeung Kak, have been filled or are being filled in, following a development boom in the city.

Meanwhile, people living on the water can also raise the toxicity, Sampson said, citing 20,000 residents in Kampong Chhnang alone as an example.

Minister of Water Resources Lim Kien Hor said the government has already issued a subdecree to prevent the illegal filling of lakes.

Prime Minister Hun Sen has “vowed to take action, to crack down on anyone who violates the law,” Lim Kien Hor said.

Sam Rainsy Party lawmaker Son Chhay said subdecrees were not necessary, but the government should abide by a 2001 land law.

Pen Rainsey, a project officer for NGO Forum, said he worried the filled lakes in Phnom Penh could create more serious flooding.

“Normally, when they fill the natural lake like that, then there won’t be any place to block or store the water, so I am very worried that if they fill so many lakes, it could flood all over the city.”