For about a year or so now, they have been constructing a bridge over Sukhumwit Road in Bang Pu District of Samut Prakan. When they first started I thought it was a bit strange. As it is a bit like a bridge to no-where. On the southern side of the road there is only a small factory of some kind, a small community and some shrimp farms. The road here runs close to the coastline. So there is only 500 meters between the road and the Gulf of Thailand. I then later heard that this was actually going to be part of a drainage canal between Suvarnabhumi International Airport and the sea. I went back there again today with my camera to see what they were doing.
This is the bridge over Sukhumwit Road. Behind me is the way to Bang Pu Seaside Resort, Ancient Siam and Paknam. In front of me is the way to Suan Kularb School and Samut Prakan Central Prison at Klong Dan Sub-District. This point is directly south of Suvarnabhumi Airport (see map). What has puzzled me the most every time I have passed this construction, is the “thickness” of the bridge. It looked reinforced for heavy loads but the support pillars below look like normal ones. I recently found out that this was a kind of aqueduct to transport water from the canal on the northern side of the road to the sea 500 meters away. There is about 6 meters of clearance below the aqueduct. The top of the aqueduct is 12 meters above the road.
This is the view to the south of the road looking towards the Gulf of Thailand which is about 500 meters away. Notice that the aqueduct has a sharp slope down to the other side. In the background you can see what looks like silos belonging to the nearby factory.
On closer inspection of the bridge, I found a gap which shows that it isn’t solid but is a kind of flume to transport the water. I would say the water will not be running in pipes but freely in this aqueduct.
This is again on the southern side of the road. The sea is now behind me. As you can see, at the bottom of the slope there is still a wall. You can just see a man which gives you some indication of the height.
This gives you a closer look of the drop from the aqueduct down to ground level. It is 25 meters wide and the walls are 3.15 meters high.
This is looking south towards the Gulf of Thailand. This is obviously a drainage flume. At the far end is the sea. On the left is the factory. On my right is open ground that was once a shrimp farm and beyond that a small community. Hopefully, when the floods are at their highest levels the water won’t go over these walls and flood the local community. I have driven down Sukhumwit Road several times on a day when there was no rain. However there were bad floods when the sea was higher than the land.
This is a closer look showing a mud embankment at the far end stopping the sea entering the canal. This drainage flume seems to be finished.
This is now on the northern side of the road showing the aqueduct going towards the building with a green roof. This is the pumping station.
The pumping station will be forcibly pumping water out of the drainage canal, up this steep ramp, across the aqueduct, and then down to the flume on the other side where it will finally end up in the sea. The water will be moving at a rate of 100 cubic meters per second. I am no expert but I would reckon that a lot of power would be needed just to raise the water 12 meters over the traffic of Sukhumwit Road. Wouldn’t it have been more efficient to keep the canal at ground level and build a car bridge over it?
This is another view of the pump statioin which is still under construction. I am looking south towards the sea and the airport is about 16 kilometers north of here. This whole project is expected to cost at least 11 billion baht and will be finished in 2010. It is unknown how much money is needed to run this large pumping station.
This is now looking north towards the airport. This is the drainage canal that will take the water from the watershed around the airport and Samrong Canal and bring it down to the sea. The canal is about 40 meters wide and 10.5 kilometers long. On both sides there will be a new highway which will link the Bang Na-Trad Highway with Sukhumwit Road along the coast. From what I can tell, the canal will go as far as Theparak Road. They are already constructing a car bridge over this road. Samrong canal is just north of Theparak Road. I am not sure yet how they will connect that canal with the drainage canal.