People living along canals in Bangkok are worried that the drainage test - run today by the national water protection agency - will affect their homes and fields.
Rueng Lerdlob, a 49-year-old rice farmer, wakes up every morning to check the level of water in Bang Ku Wiang canal. He fears the drainage test in the west of Bangkok will raise the canal's water level and flow into his 20-rai field.
Bang Ku Wiang canal is a small waterway connected to Thawee Wattana Canal, which the National Water Resources and Flood Policy Committee, will use to test the drainage system today.
According to his visual calculation, the level of water in the canal - next to his paddy field - was only 50 centimetres below the riverbank.
To prevent damage from the drainage test, Rueng has stored over 500 sandbags for a temporary dyke to protect his paddy field and single-storey wooden house, which were submerged under 2 metres of floodwater for more than two months last year.
"The horrible memory about the severe flood is still stuck in my head," he said, while preparing sandbags in his small storehouse.
Rueng said he wanted the government or related agencies to inform him and other villagers along the canal of the exact period for the test, and the amount of water that will be released into Thawee Wattana Canal to check the drainage system, so they can prepare preventive measures against flooding.
"No one from related authorities has told us where and when they will discharge water [up to] today into the canal and what the impact would be," he said, adding that he had had to follow developments by himself via the media.
Hydro and Agro Informatics Institute director Dr Royol Chitradon, a member of the National Water Resources and Flood Policy Committee, said the national water protection agency would run the drainage test in western Bangkok from 2pm to 6pm today.
They will release water at 7 cubic metres per second from Thawee Wattana water gate into Thawee Wattana Canal and through the Phasi Charoen Canal.
Discharged water will flow into Bang Waek, Phraya Ratchamontri canal and the Tha Chin River.
The release is aimed at testing the efficiency of drainage from Bangkok to the sea. The weakest point in the western area is where the Thawee Wattana Canal narrows near Phetkasem Soi 69, where drainage drops from 45 to 10 cubic metres per second.
The committee will also run a drainage test in eastern Bangkok on Friday, starting from 2pm to 4pm. The water agency will open the water gate at Klong Song Canal and release 3 cubic metres per second.
Water will flow through Klong Thanon Canal beside Phaholyothin Road, Klong Lat Phrao Canal, Rama 9 flood diversion tunnel, into the Chao Phraya River. More water will flow from Bang Bau Canal and Bang Khen Canal to the Chao Phraya.
The water agency wants to test the efficiency of the Rama IX flood diversion tunnel and Bang Bau and Bang Khen canals. They have found Bang Khen Canal will be a weak point for the test, as water will flow close to Vibhavadi Rangsit Road and Lat Phrao Soi 56.
Taxi driver Amnuay Chokchai, 43, whose house is located near Lat Phrao Canal, said he has ready for flooding and had tried to reduce the risk by lifting all personal belongings and electronic devices to higher places. But he said he wasn't worried about the impact of the drainage test in Bangkok's east on Friday because Lat Phrao Canal was ready to receive large amounts of water after officials removed mud and sewage from it.
"If the Bangkok Metropolitan Administration opens the water gate, the level of water will recede quickly," he said.
Meanwhile, Prime Minister Yingluck Shinawatra said the government would stop the test immediately - within five minutes - if there was an error or problem.