It rains in Phnom Penh. It rains hard and it rains often. That’s not strange, considering the rainy season has started. Every year, from June until October, there are only a few days it does not rain. But if it is so normal, why are they so ill prepared?
Last Friday we cycled from the office to our home, a ten-minute ride we had been cycling for two weeks, so we knew the way. The moment we left the office we heard the first thunder and the sky turned black, so when it started to rain after a few minutes of cycling, it was no surprise. We sought some shelter beneath the corrugated iron roof of a carwash, although it soon started to rain inside as well. Usually the rain stops after a while and then starts again and so on. This time it kept raining and it only rained more over time. Besides, that makes a beautiful sound on a large corrugated iron roof, we literally couldn’t hear anything else anymore, but that’s not the point here. After waiting for three quarters of an hour we (I) were fed up with it and decided to start cycling again. Within a minute we were soaked and couldn’t get any wetter, so no need to worry about that anymore.
As we cycled on, there was more and more water on the street, a kind of brownish, filthy water. The moment it reaches the height of your tube it’s still funny, although it’s good to know where the potholes are in the road. When the water reaches the hub of your wheel, you start to raise your eyebrows, but when you’re cycling through a fast-moving river reaching up till the upside of your wheel, it starts to become a bit frightening. At some parts we had to pedal really hard to move against the current and at crossing streets we felt the water pull at our steering.
As a consequence, usually busy roads were almost deserted. The engines of tuk-tuks and mopeds got wet and the stopped working. Even cars had to stop after the water reached up to the midst of their doors, some of them drifted to the other side of the road. Just the high on their wheels 4×4’s and human powered bicycles could continue their way. It was a total mess. A lot of shops got flooded, in at least one school the ground floor was completely flooded and our own terrain was flooded as well, fortunately we live on the second floor.
It wouldn’t be that bad if this was a unique situation, but it happens regularly. The city simply is not made for heavy rainfall (anymore).
The sewage system in Phnom Penh dates back to French colonial times, that is to say, before 1956, when the city was much smaller anyway. So the system is old and dilapidated, and moreover a lot of rubbish enters the system so it’s capacity diminishes even more. But no sewage system, however good, will be able to handle this kind of rainfall without other water storage capacity. And that is what went wrong in the last years.
The area where Phnom Penh is built, was a swamp hundreds of years ago. In the swamp a dike was built around what became the centre of Phnom Penh. Later the city was expanded a lot. For a long time the waterways and large and small lakes in the area were kept intact, so the water had an easy flow to the three large rivers alongside the city. In the course of time, more and more waterways were filled up to be used as building area or for roads. The last few years even the three large lakes were filled in to become large (and expensive) city development areas. All together this means there is no water storage capacity left inside the city borders.
Moreover, most buildings do have gutters and drainpipes, but the water they drain mostly ends up on the roof of the ground floor (don’t ask me why) after which it clatters down on the ground, or the drainpipe ends just above street level. In both cases the water from the roofs ends up on the streets, what more or less triples the amount of water there. No problem when buildings are placed far apart with gardens between them, but it does become a problem when there are rows of houses without any space between them.
Finally, the water cannot enter the soil either. The soil might be able to soak up a lot, but the water cannot reach it. Cambodians have paved the streets in Phnom Penh during the last years and they have done it very thoroughly. No permeable cobblestone streets or grass borders, but tarmac and tiles laid in concrete that doesn’t absorb a drop of water.