Unseen hindrance contributing to floods

Irresponsible act: Our rivers are dumping grounds for all sorts of rubbish including a refrigerator which was found at the floating boom at Sungai Batu near Taman Kolam Air.

A sofa, refrigerator and timber. These are some of the things found in our rivers and drains, which lead to floods occurring in our city.

These were some of the shocking findings by Kuala Lumpur City Hall (DBKL) during their maintenance checks on the main drains and rivers in Kuala Lumpur.

DBKL executive director (Project Operations and Implementations) Datuk Tan Keng Chok said irresponsible members of the public dumping garbage into drains and rivers was one of the causes of floods.

“We had fished out timber, mattress and even a refrigerator from rivers and drains.

“In the case of the timber wood, it was stuck in an underground drain along Jalan Duku.

“Our staff had to cut the timber bit by bit to remove it and the work took them half a day,” he said during an interview with StarMetro.

He revealed that DBKL collected about 20 to 40 tonnes of waste in the rivers every day.

A fallen tree found in an underground drain in Jalan Duku.

“Even with our efforts to clean and maintain the drains and rivers, we would be back to square one if people still continue to throw rubbish indiscriminately,” he said.

He said large objects and accumulation of rubbish decreases the drain’s capacity to channel water into the rivers hence causing flooding.

Tan said another cause of flood was the development in the city.

“Currently there are about 59 major projects going on. Before development, there would be turf or grass in an area.

“With vegetation cover in the form of trees and grass, some water will be absorbed before seeping into the ground and the excess flow into drains.

“However, with development, all of the water goes right away into the drain. So the volume of water running into drains and rivers would increase by three times in a particular area,” he said.

World climate change is also a contributor to floods in the city.

DBKL staff took about half a day to remove the dead tree in Jalan Duku.

According to the Drainage and Irrigation Department (JPS) Ampang Rainfall Station, the rainfall intensity in Kuala Lumpur has increased by 17% to 30% when comparing the duration of 1970 to 1980 and 2000 to 2007 periods.

“Our rainfall intensity has increased a lot over the years. As an example, on Aug 13, the rainfall intensity recorded was 125mm at Gombak Simpang Tiga and 111mm at Segambut.

“We consider 60mm of rainfall intensity as a very heavy storm and these numbers last month exceeded that by almost double.

“With the increase in rainfall intensity, the capacity of drains may not be adequate which is why we widen or deepen the drains. Some of the drains are also old, so we have to rebuild them,” he added.

Tan said DBKL estimated this year’s budget for drainage to be RM45mil. It is a 55% increase from last year’s RM29mil.

Multilayer of utility cables and pipes obstructing underground works to upgrade the drainage system in Jalan Sri Hartamas 1.

“The budget is bigger this year as it is high time to upgrade and increase capacity of the drains in view of the greater rainfall intensity,” he said.

However, upgrading the drainage system has its own set of challenges.

Tan said some of the upgrading works involved going underground by pipe jacking as the simpler method of open cut was not possible.

“In Kuala Lumpur, the volume of cars coming into the city is tremendous, so we cannot opt for open cuts.

“Doing pipe jacking is difficult as there will be risk of hitting utility cables and pipes that do not follow specification; cables are supposed to be at 1m depth but some are only few inches deep,” he noted.

He explained that the cost of project increased when a great amount of time was spent on moving the cables.

He cited the upgrading works at Kampung Datuk Keramat, which took up the biggest chunk of DBKL’s budget this year.

“We are making bigger box culverts in the area.

“The extra cost goes to relocating the underground utility cables. We have to pay more for the relocation and construction period will take longer, which incurs more cost,” he said.

Tan said time constraint in carrying out the works was another challenge they faced.

“We cannot carry out the works during the day due to the traffic volume and it will cause worse congestion.

“If we do work at night, residents surrounding the area will complain about noise,” he said.

Illegal hawkers refusing to relocate also prevented DBKL from carrying out upgrading works.

“Some illegal hawkers and workshop operators refuse to move. They are actually occupying the drain reserves illegally.

“We try to adopt a soft approach by talking to them but we are also in a dilemma,” he said.

He said if DBKL provided them an alternative site, the authority would be legalising them.

In the meantime, the local government is mapping out alternative solutions.

As part of their plan to overcome flashfloods, Tan said DBKL had proposed building seven underground flood retention ponds next year at Sungai Batang Tolak, Sungai Toba in Segambut, Taman SPPK in Segambut, Segambut Bahagia and Dutamas.