The price of mitigating the flood risks associated with filling in Phnom Penh’s Boeng Kak lake could bring the cost of developing the site to unacceptable levels, an independent researcher said Friday.
Ben Caddis, co-author of a December report that predicted heavy flooding in Russei Keo district if filling continues at the lake, said by telephone Friday that although flood damage control is possible “in the theoretical sense,” it might not be financially realistic.
“The problem comes from the actual cost that would come with mitigating the damage. By the time you’ve considered the level of mitigation that’s required, it would probably make the development unfeasible,” Caddis said in a telephone interview from Brisbane, Australia.
The independent report, commissioned by the local NGO Sahmakum Teang Tnaut and conducted by the Australian consulting firm BMTWBM, predicts that peak flood levels in Russei Keo will rise by as much as 40 cm because of development at Boeng Kak. The frequency of floods is also predicted to increase.
“The combined effluent and stormwater drainage system in Phnom Penh means that any flooding will have serious water quality and public health implications,” the report stated.
The authors of the report went on to say that if Phnom Penh municipality wants to alleviate those risks, it should produce detailed hydraulic models of the likely impacts of the Boeng Kak’s development and come up with plausible drainage solutions.
“There would need to be considerable drainage canals up through the Russei Keo district, and the size of those channels would need to be significant,” Caddis said Friday.
He added that the municipality would have to expand on the existing Tuol Kok and O’Veng drainage canals, which would mean reclaiming private land on either side of both waterways and upgrading the roads and pipes that cross them.
“It’s just too expensive to be able to do that,” Caddis added.
Mao Hak, director of the Ministry of Water Resources’ hydrology and river works department, said Thursday that the ministry had recommended that City Hall build two 10-square-meter pipes to carry excess water to the Kilometer 9 water basin area. The recommendation also included widening the O’Veng canal to between 40 and 50 meters to take excess flow to the Kob Srov dike basin.
However, Mao Hak added that he was not sure if these recommendations would prevent flooding caused by filling in Boeng Kak lake.
“I am only talking about the big systems. Even if they do all of this, step by step, there are still other small sewage systems,” he said.
Caddis also said that those recommendations “would not be sufficient.”
Phnom Penh Deputy Governor Pa Socheatvong restated Thursday that flooding as a result of filling Boeng Kak will not be a problem.
“If it floods every year, no one would vote for us [the ruling CPP] anymore,” he said.
Late last year, hundreds of families in Russei Keo complained of never-seen-before flooding that inundated schools, roads and homes to a depth of nearly one meter, and which they blamed on the activity at Boeng Kak.
(Additional reporting by Adam Becker)
