Numerous efforts have been made to implement a flood mitigation plan for Sibu town but without any concrete follow-up action to date, residents complain they have been living in fear of floods whenever it rains for too long

FOR years now, the people of Sibu have had to put up with floods that seem to occur whenever there is heavy rain. While many are trying to bear with it, others are growing increasingly frustrated.

What causes floods? How can they be prevented? When will the nightmare end? These are questions commonly asked by people living along the mighty Rajang, the longest waterway in the state.

Poor drainage in the town and siltation in the Rajang are often blamed but there may be other contributors to the perennial problem that might have been overlooked.

Sibu residents are now asking besides heavy deforestation and earth-digging activities upstream, could development on the banks of the Rajang or over utilisation of these areas be another major cause of floods?

Are the on-going projects narrowing the channel for water to flow downstream by causing greater erosion of the river banks that leads to siltation?

Recently, two shipbuilders told thesundaypost it was getting difficult to navigate a big ship along the Rajang because the water was becoming shallower.

“I’m not surprised if I run out of business one day because fewer ships are now docking in Sibu. Many are turning away to dock in Tanjung Manis,” said one of them from Lebaan.

Asked why he thought the river was becoming shallower, he claimed it was due to serious siltation from residential, commercial or industrial development along the river banks.

“Modifications to the banks could narrow and slow down the water-flow, causing erosion and sedimentation in the river and along the shores.

“As the riverbed becomes shallow, a large volume of water flowing from upstream, which cannot be retained, will overflow into the city and cause floods,” he said.

At the same time, he noted, slower water-flow downstream was affecting the shipping industry as ships could not sail through as long as the water level was low.

He wondered if the authorities were aware that the extensive development activities were affecting the environment.

His co-builder pointed out that sedimentation was apparent at Seduan, Kreto, Kwong Hua and Lebaan.

Satellite photos of Sibu taken from Google Earth show two noticeable sharp bends at Seduan along Batang Igan, a tributary to Rajang River, and another at Kreto. From the direction of the Upper Rajang, after Pulau Kreto, the river splits into two channels — to the right is Batang Igan and the left is Sarikei. Along Batang Igan, there is a pointed cape and an operating industry.

The pointed cape may look man-made but this has remained a question mark until a recent visit to the Sarawak Land and Survey Department in Kuching. Two topography maps of Sibu town, including Batang Igan, are available at the department — one printed in 1973 and the other in 2001.

The sharp bend can be found on both maps. In fact, in the 1973 version, the pointed cape looked sharper and its bay was less curved than that of 2001. This suggests that erosion has been taking place.

Soil erosion is claimed by many as a major problem leading to siltation in Rajang River. According to the 1973 map, the about 100-hectare cape was covered with swamps, rubber plantations and a relatively large padi field. The nearest village to the padi field was Rumah Lon. But by 2001, the area had buildings and patches of secondary forests plus a road network.

The question foremost on residents’ mind is whether industrial activities coupled with natural occurrences like siltation and sedimentation at Telok Blangoh area would have resulted in ‘natural formation’ of land that had been a cause of floods affecting Sibu in the past few years.

Several well-placed sources have claimed that since industrial activity began in the area, ‘land formation’, perhaps by several hundred feet, was noticeable over the years.

“Over the years, it has widely affected river flow as the ‘land formation’ has caused the width of the river channel to become narrower,” said one source.

One clearly visible feature is the formation of a sandbar at the opposite side, thus causing more problems to the river flow.

Said another source: “Put it this way; it is just like a blood vessel. A healthy vessel will enable the smooth flow of blood to the heart and other organs. But once there are cholesterol deposits in the vessels, these vital blood channels will slowly constrict and this is where trouble begins.

“Blood flow is affected and this will eventually lead to serious problems to the human body.

“This is what is happening to the Telok Blangoh area.”

It is still unclear if measurement of the width of the river channel had been taken at the stretch over a period of several years to determine if any ‘river constriction’ had taken place. It is high time for the authorities to look into the current situation and take remedial measures before the situation worsens.

“Indeed over the last 10 years the channel at the stretch in question has become narrower and narrower, thus affecting flow of river water,” said the source.

A middle-age resident of Sungai Merah said modifications to the natural environment along the rivers were causing a lot of undesirable environmental effects.

“This is the result of changing the natural structure of the environment,” he said, pointing to a big piece of sandbar near the jetty along Batang Igan. He said ships found it difficult to dock at the jetty unless the sandbar was removed.

“Dredging has to be done frequently because sand and soil from upstream are constantly being deposited here. And each dredging costs at least RM30,000,” he pointed out.

It is believed the confluence of water flow from Sungai Merah and Batang Igan could be aiding erosion and deposit of sand at the jetty.

The resident said he could clearly recall when he was teenager, the sand bar was ‘a

very small piece of land’ but now, it was like ‘a small island’.

“And at that time, the water was also clearer with a lot of Tapah fish which, unfortunately, no longer exist in the murky water.”

He believed besides upstream activities, industrial activities at the cape could also have contributed to the water pollution and other existing environmental problems.

He said problems such as erosion, sedimentation and pollution did not take place overnight, adding: “It takes sometime to see what adverse effects change in the natural environment causes.”

A recent speedboat ride we took along the Rajang was, indeed, a revelation – the extensive change to the geography of the river was evident.

“The river is shallower and at certain area were narrower now due to sedimentation and siltation,” the boat driver said.

At Kreto, the view of the high class residential area opposite Pulau Kreto was spectacular. But the concrete and geometrical boundary of the residential area seemed to have narrowed the water channel.

Once again, comparing the two maps at Sarawak Land and Survey Department, not much difference could be observed.

Some claimed the residential and commercial centres along Upper Jalan Lanang were examples of modifications along the banks that had contributed to serious erosion and sedimentation of the Rajang.

A member of the public remembers the river was broader 20 years ago, saying people living here long enough would have noticed that the river’s width had shrunk by a few hundred metres.

He also said there had been talks of future plans to reclaim some land near the commercial centre for tourism.

Further downstream along the Rajang towards Sarikei and Daro are several industries operating along the bank. There, the boat driver slowed down and pointed to the shore.

“Last time, there was a small river here where boats could take a short cut to downstream Rajang but now, the river is getting shallow due to sedimentation and boats can no longer pass through.

“In time to come, this small river will be completely covered and overgrown with vegetation. I believe it will look like a natural geological formation,” he added.

The boat driver recalled 20 years ago, the villagers along the bank would often shout out to boat drivers, asking them not to come near the shore because strong waves caused by the boat engines would wash away the soil from the bank.

“But now, they don’t have to remind us anymore because water level is too low. And navigating this river, only experienced boat drivers know which part to use and not to use because the water in certain areas is very shallow.” The boat driver, who has been plying the river for more than three decades, said it took him 20 minutes longer now to take the same route along Rajang compared to 20 years ago. At Lebaan, the fork-tail junction to Sarikei and Daro, it was unbelievable how shallow the river was – in fact the water was so low that the speedboat’s propeller hit the riverbed.

“At this junction, the riverbed closer to Sarikei is very shallow and to get in there, you have to manoeuvre to the right towards Daro and make a big turn to redirect to Sarikei,” the driver said.

In the recent State Assembly sitting, Urban Development and Tourism Minister Dato Sri Wong Soon Koh said the proposal for an Integrated River Basin Management Study for Batang Rajang had been put up under the Eighth and Ninth Malaysia Plans. And the state would continue pursuing with the Federal government to obtain funding for the study to formulate an overall river basin master plan.

He said there was a need for a broader and holistic approach to water resource management in the state’s river basin.

“The Integrated River Basin Management approach takes into account all factors linked to land and water resources, including social and economical activities.

“Its broad scope not only covers water resources but also environmental management aspects such as pollution control, development planning and biodiversity conservation,” he said.

Although most of the public believe dredging and building monsoon drains are the best solution to mitigate floods in Sibu, experts think differently. On April 18, a local consultant studying the flood mitigation plan for Sibu Town, recommended it would be more viable to build bunds around the town than dredging the Rajang and the Igan or building over-sized monsoon drains.

He made this observation while presenting a master plan on flood mitigation in Sibu at a forum held at the Sibu Public Works Department office.

The consultant said dredging the rivers would cost RM1.6 billion and building deep and over-sized drains to store flood waters would drain away the underground water, resulting in greater ground subsidence at most places.

He suggested bunds be built along the banks of the Rajang and the Igan parallel to the Seduan — the three major rivers surrounding Sibu.

“This bunding may involve elevating the level of Jalan Lanang, Jalan Kampung Nangka and other roads along the Seduan banks. It may also include building monsoon drains along these roads to store tidal water,” the consultant said.

The forum was chaired by Wong and attended by five flood experts from China. Wong announced the government had allocated RM400 million for flood mitigation in Sibu town. Although there have been numerous discussions and efforts to start the flood mitigation plan, the process is taking too long — it’s just too slow.

Sibu residents say they have for too long been living in constant fear of floods whenever it rains.