The Bangkok City Administration (BMA) is usually preparing a major redevelopment of the capital’s draining system to increase its drainage capacity in a fresh drive to combat the city’s flood problem.
Bangkok chief excutive Chadchart Sittipunt chaired a remote meeting final month about drinking water management with authorities from the BMA’s Section of Drainage plus Sewerage, 50 region offices and state agencies to write down ideas ways to end the city’s flood issues.
In the meeting, the division forecast rainfall throughout 60-80% of the capital this month, along with accumulated amounts of 200-250 millimetres.
Mr Chadchart said the city has generally relied on two drainage systems — canals and passageways.
Until recently, the City Hall provides carried out four tube projects — the Prem Prachakon drinking water diversion system, Makkasan swamp, Saen Saep and Lat Phrao canal tunnels, and also the tunnel running below Bang Sue channel.
But these tunnels, stretching a combined 20 kilometres, can handle only two hundred cubic metres (m³) per minute of drinking water, far below the two, 000 m³/minute outflow required on the traditional western and eastern sides.
Mister Chadchart said the particular city’s core drainage system is the canal, which can help press water along routes to the Chao Phraya River. In this regard, the particular efficiency of the channel must be boosted rather than only focusing on canal projects.
“I believe the drainage system within the capital will get much better, ” said Mr Chadchart.
To ensure the efficiency of the water pump, every spot across the capital must be checked such as the electrical systems within 190 water channels.
Channel dredging is also necessary to drain water, as well as a technique known as pipe jacking to increase the surface and ground drinking water storage area. This will help using the drainage of excess water from local community areas into the canal.
Overflowing canals can also be forked to drain directly into both tunnels and floodgates.
“Floodgates and channel dredging do not cost as much as tunnel projects. The most important thing is to create canals and tunnels equally as both systems rely on each other, inch said Mr Chadchart.
However , the BMA’s Overflow Control Centre still lacks information about draining problems in the coronary heart of some communities, he said.
District offices must survey those areas and look for options while other companies, such as the army, will also be ready to provide assist for people affected by inundation, he said.
Aside from the drainage systems, Mr Chadchart said rubbish is also a source of damage to the water pump. Mr Chadchart asked everyone in order to more litter-aware. BMA staff collect 3 tonnes of garbage dumped in Boom Sue canal every day, while Rama IX’s adjacent canal offers even more debris, sometimes up to 5 tonnes, for officials to clear on a daily basis.
Mr Chadchart also sent his thanks to Prime Minister Prayut Chan-o-cha for permitting soldiers to help expels people affected by the floods.
The 1st Army Region had told the BMA of hemorrhoids of rubbish stuck the Rama IX tunnel, connecting Saen Saep and Bekv?m Phrao canals and Phra Khanong tunnel, causing a decrease in its drainage capability.
The army is also assisting with dredging Bekv?m Phrao canal within the north to make it deeper and increase the drainage capacity, while a similar operation within the south is being carried out by the BMA, Mr Chadchart said.
Apart from surges caused by rainfall, the issue seems to be aggravated by runoff and rising amounts of seawater.
The National Water Command Centre has followed up forecasts by the Thai Meteorological Department (TMD).
The TMD forecast heavy rainfall in some parts of the country during Aug 2-10 as a south west monsoon blanketed the Andaman Sea plus Gulf of Asia while a monsoon trough prevails in Myanmar and the north and upper northeastern regions of the country.
After assessing the water situation from your TMD and Hydro-Informatics Institute, the centre predicted that heavy downpours may lead to a build-up of drinking water and flash floods and runoff within 38 provinces including Bangkok and its adjacent provinces.
Mr Chadchart said the Department associated with Drainage and Sewerage, with assistance from the army, the Royal Irrigation Department, TMD, National Water Command Centre and Electricity Generating Authority of Thailand stand ready to deal with problems because they arise.
Staff have also been positioned in certain spots to handle any inundation problems and provide prompt assistance.
The particular BMA also inspected the sturdiness of 79. 63km of defensive lines set up in the capital with a capability to handle 3, 500 m³/minute of drinking water flowing along the Chao Phraya River, Bangkok Noi, Mahasawat and Phra Khanong canals.
Bangkok also has flood walls stretching 88km, which eight spots fit in with the private sector.
The department has also been instructed to closely keep track of 23 residential areas and specific zones — 14 areas in Phra Nakhon districts and 9 in Thon Buri districts — where the walls may have been damaged, he said.
Meanwhile, Sitang Pilailar, a lecturer at the Water Sources Engineering Department at Kasetsart University, recently said the city’s sewers and drains are only able to operate at 50% capacity.
Based on the lecturer, with the aid of pumps, the city’s canals and sewers need to act as polders which drain excess water from the surface into larger bodies of water. As such, ideally, when rainfall falls, water over the streets will flow into sewers plus canals before entering the Chao Phraya River.
The water level of the river is normally greater than the canals, so pumps play an essential role in managing the city’s drainage system.
But everything now seems difficult to manage, with rubbish getting stuck in the sewers, Ms Sitang said.
At present, drainage pipelines zigzag underneath the city with little regularity, and sediments such as sand often flow to the sewers, adding to obstructions that result in severe above-ground floods.
As waste materials water and rain water flow along the same pipes in the city, Ms Sitang suggested an increase in the capacity of the pipe should be made a high priority.
“As waste drinking water and rain water are now going through exactly the same system underneath the town, the BMA ought to increase the capacity of the pipes to ease the ton problems, ” Microsoft Sitang said.
She furthermore suggested the BMA expand water-catchment places to prevent floods, along with invest in better climate forecasting and communication systems to ensure more precise forecasts plus accurate feedback about the magnitude of water damage in each town area as they occur.