Bangkokians have had a lot of time over the last few days to ponder why the city is regularly underwater. All those times you stayed home when you wanted to go out, sat half-submerged in standstill traffic or sat hostage in your office at the end of the day because the streets were flooded, you probably asked yourself, “Why is this happening?”

Four factors are blamed for the seemingly insoluble flooding in Bangkok every time the capital city is lashed with widespread torrential rains.

Several experts around the city have weighed in on why the city is underwater on a near daily basis lately (Aside from the obvious reasons of rainy season and current storm patterns)

The first reason is that the city doesn’t have enough “monkey cheeks,” or small areas created by making a gradient beside a roadway where water collects immediately to be drained slowly over the coming hours.

The city has 25 existing monkey cheeks, but requires 10 more. Thes additional water collection areas could hold an additional excess 25 million cubic meters of water.

The Bangkok deputy governor Amorn Kitchawengkul has also noted that the monkey cheeks at Makkasan swamp, Bung Gum and Bung Ekamai are not large enough.

The second reason is rapid city expansion that encroaches on land that had been used to collect excess water. Lat Phrao was cited as an example of a place formerly used to hold water and now taken over by housing. The former governor noted that water retention area in Bangkok had been reduced by 40 percent due to recent urbanization.

The third reason is trash.  Garbage blocks an already overtaxed drainage system at some of the most crucial points. Ten to 20 tons of waste are pulled daily from klongs, which are main way of draining water from the city into the Chao Phraya river, reported Thai PBS.