The Bangkok Metropolitan Administration (BMA) has announced that it will scrap the Khubon-Bang Chan water retention project because it is not worth the investment, which was recently estimated at about 11 billion baht.
The decision has drawn widespread criticism, particularly over the sharp increase in the estimated cost of the project and questions about why it has taken so long to proceed since it was proposed following the major flood in 2011.
BMA Deputy Permanent Secretary Jessada Chandraprabha and Chavalit Chantharat, a water management expert and CEO of TEAM Group, told the media yesterday that the proposed investment in the project would not even cover the cost of reclaiming the land, whose price has increased substantially since the project was conceived.
They said there would also be other costs, including the construction of a water barrier, floodgates, a pumping station and channels to direct water into and out of the retention area, as well as the installation of pumping machinery.
They also noted that although the planned retention area would have a capacity of 870,000 cubic metres, only 500,000 cubic metres could actually be used for water management, as some capacity must be reserved for system control.
By comparison, Nong Bon water retention area can hold and manage up to five million cubic metres of water and is connected to the drainage tunnel and major canals, allowing water to be drawn from eastern Bangkok into the main drainage system.
For a water retention project to be effective, it must have channels to bring water into and out of the retention area.
After the major flood in 2011, several plots of land, some privately owned, were proposed for conversion into water retention areas, and public hearings were held. However, no construction took place while land prices continued to soar.
The proposed Khubon-Bang Chan project has subsequently become a contentious issue, with critics questioning the delay in implementation and the rising cost of the project, particularly as Bangkok continues to face flooding during periods of heavy rainfall.
Referring to the heavy flooding in Bangkok over the past several days, Jesada said accumulated rainfall had exceeded 300mm, a huge amount compared with the capacity of the city's small water retention areas.
He said that even if the Khubon-Bang Chan water retention area had been available, it would not have been sufficient to absorb the excess water. The canal system, drainage tunnels and pumping stations were therefore used to drain the water into the Chao Phraya River.
