Author Topic: Floods after Thursday's rain raise questions on drainage  (Read 552 times)

0 Members and 1 Guest are viewing this topic.

Offline thaiga

  • Korat forum specialist
  • *****
  • Posts: 16172
Floods after Thursday's rain raise questions on drainage
« on: September 08, 2012, 12:07:00 PM »
BANGKOK: -- Yesterday's flooding in many Bangkok areas pointed to flaws in the capital's drainage systems, according to experts, some of whom also questioned the government's decision to direct upriver run-offs into the sea through the heart of the capital.

Meanwhile, the National Water Resources and Flood Policy Committee (NWRFPC) said its plan to install water-pushing machines and other flood-prevention devices in canals in eastern Bangkok had saved residential areas near Lat Phrao Canal from flooding on Thursday night.

The NWRFPC said these machines had smoothly drained flood water from Lat Phrao Canal into the Rama IX flood-diversion tunnel, which would drain the water into the Chao Phraya River.

The Bangkok Metropolitan Administration (BMA) said the flooding in the residential areas surrounding Lat Phrao Canal was caused by the NWRFPC's incomplete dredging.

The NWRFPC cancelled its plan to open the watergate at Klong Song Canal after heavy overnight rain and thus prevented the discharge of water into Lat Phrao Canal.

The drainage test scheduled for yesterday was supposed to examine the efficiency and capacity of Lat Phrao Canal to drain water into the Rama IX diversion tunnel.

After cancellation of the drainage test, the NWRFPC decided to run all the flood-prevention machines, including pumps and water-pushing machines, which previously had been installed for the drainage test. The use of the machines was aimed at helping the BMA drain water out of the capital and also study the capability of these devices.

Because of the heavy rain on Thursday night, the level of water in some canals in Bangkok rose sharply - to 145 millimetres in Saphan Sung district, and 109.5mm in Sai Mai district and Klong Saen Sab.

"The decision to cancel the drainage test was based on academic knowledge, not on pressure from the BMA," said NWRFPC member Royol Chitradon, who is director of the Hydro and Agro-Informatics Institute.

Joint decision

The NWFPC jointly made the decision with BMA Deputy Governor Wanlop Suwanphakdi to cancel the test, he added.

The water level in the canal before the rainfall was measured at 60 centimetres from mean sea level. After the heavy rain on Thursday night, the level in the canal was measured at 1 metre from mean sea level.

"We would not be able to control the situation if the level of water in the canal continued to rise," Royol said.

Meanwhile, Samai Jai-In, an NWRFPC member, said the committee had seen many weak points in the drainage system in many canals, particularly Lat Phrao Canal, which is on a low plain area and has been shallow. Moreover, a lot of garbage has been found in the canal, especially in the Rama IX flood-diversion tunnel, which makes drainage difficult.

"The flood-prevention equipment that we had installed in this canal could drain water within three hours," he said.

Bangkok Governor MR Sukhumbhand Paribatra posted comments in his Facebook account and told Bangkokians not to be worried about the flood situation. He added that the level of water in Klong Song was too high and that was the reason the BMA did not want the NWRFPC to open the watergate.

"I can handle any problem during the government's drainage test, discharging water into the heart of capital," he said.

He later held a news conference to explain the cancellation of the test, saying he wanted to thank the government for listening to the recommendation from his agency.

"The BMA's facilities were good enough to drain flood water into Rama IX flood diversion by midnight," he said.

Professor Thanawat Jaruphongsakul, a senior seismologist at Chulalongkorn University, said the government should divert flood water to areas outside the capital, as flood-prevention infrastructure in Bangkok was not ready to cope.

Meanwhile, Prime Minister Yingluck Shinawatra said the government might consider running the drainage test again next week.

The Nation

Anyone who goes to a psychiatrist should have his head examined.


  • Guest
Re: Floods after Thursday's rain raise questions on drainage
« Reply #1 on: September 08, 2012, 12:56:51 PM »
If rainwater floods the streets, then perhaps the first thing to do is clean the drains - and repeat the process at regular and frequent intervals throughout the year. Flood relief schemes work only if the water can reach them.

Offline thaiga

  • Korat forum specialist
  • *****
  • Posts: 16172
Re: Floods after Thursday's rain raise questions on drainage
« Reply #2 on: September 08, 2012, 03:27:05 PM »
The Royal Irrigation Department (RID) monitored the water flow for data that would help develop future flood prevention plans, he said. According to the RID, the water flowed at a speed of 17.136 cubic metres per second in Khlong Lat Phrao yesterday.

Mr Royol said water-pushing machines could speed up water drainage in the canal, where 29 machines have been installed.

"There was no flooding in Khlong Lat Phrao despite the high amount of rainfall on Thursday night. This shows that our machines were working well," he said.

Propellers on a water-pushing machine move the current along Khlong Lat Phrao on Lat Phrao Soi 56 yesterday. A downpour on Thursday flooded nearby roads and raised the water level in the canal. A planned water drainage test was called off yesterday after the rains raised water levels in the city’s waterways. The picture was taken from a camera mounted on a remote-controlled helicopter.

Water flow-accelerating devices from the Royal Thai Navy are installed in Khlong Thawi Watthana to speed up the flow in the canal. The government planned to release water to test the city's drainage system, despite concerns the trials could lead to flooding in the capital

Anyone who goes to a psychiatrist should have his head examined.