The story is same every monsoon in the capital and for that matter in towns across Bhutan like Phuentsholing, Gelephu, Paro etc with clogged and overflowing drains and roads filled with water.
Thimphu also has the special charm of overloaded sewage pipes bursting out of manhole covers to cover entire streets and neighborhoods in human waste.
The Chief Environment Officer, Thimphu Thromde said the cleaning of water drains is done throughout the year and not just during the monsoon. Thromde employs nine people for the regular cleaning and clearing of debris from the drains.
Thimphu Thromde says has designated three major streams as a drainage system, whereby the monsoon rain can drain into the three streams, like the one which flows through Dechencholing, Chubachu and the stream that flows down the Memorial Chorten. The three drainage system is capable of withholding a high volume of the monsoon rain.
Currently, the construction of an embankment along the Wangchu is being carried out near Loselling Middle Secondary School. In the long run, Thromde plans to construct wider drains in accordance to the volume of stream and river, divert the stream if the carrying capacity of three designated drainage cannot withhold the monsoon rain, and cover the drains so as to deter dumping of waste into the drainage.
Thimphu Thromde said that its town planning is designed to make sure that water accumulated in the valley, especially during the monsoon season, is drained off without causing any major flood.
According to Thimphu Thromde, the chances of a flood occurring is minimal due to the topography of Thimphu. Thimphu Thrompon, Kinley Dorjee, said, “Thimphu is located in the hilly area, there are no chances of flooding, as water can easily flow downhill.”
According to the Chief Urban Planning Division, Thimphu Thromde, residential and commercial spaces in the broader areas are categorized under UV1. Under the zone, people are allowed to construct houses on only 40 percent of their plot. For areas on steeper zones (UV2) only 20 percent of the plot in this zone is allowed to be constructed on.
“The reason for allowing people to construct only a part of their plot in the broader area is to allow water percolation, and reduce the surface run off,” said the Chief Urban Planner.
He also pointed out that on either side of the river Wangchu, 30 meters of the land cannot be used for any development as it is to be kept as a green zone. Similarly, in the areas where the streams that feed into Wangchu, a minimum of 15-meter buffer zone must be maintained while carrying out any developmental activities.
“In the steeper areas, where there is vacant government land, we discourage allotment of land from construction,” the Chief Urban Planner said.