Minister assures Bengoh Dam is safe and sound, not leaking as alleged by opposition
The downstream wall of the Bengoh dam showing signs of water leak. — Photo courtesy of PKR Sarawak
KUCHING: Utilities Minister Dato Sri Dr Stephen Rundi Utom has assured all that the Bengoh Dam is technically and structurally sound and stable, and not leaking as alleged by PKR to the media recently.
He said the design and construction of the dam involved the input of experienced international dam specialists from United Kingdom (UK) and China.
“The contractor from China has built more than 200 dams around the world in collaboration with an established local contractor.
“This design and subsequent construction was further reviewed by a peer reviewer who is a world renowned dam specialist from Australia,” he told a press conference at the media room of the State Legislative Assembly (DUN) Complex here yesterday.
PKR Puncak Borneo chief Willie Monggin told reporters on Sunday that the Bengoh Dam situated at the upper reaches of Sungai Sarawak Kiri was showing signs that it was leaking from the lower part of its downstream face wall.
“Clearly visible were signs on the upstream face of the dam and on the banks of the dammed areas that the water level had receded by about five feet from its normal level.
“On the lower part of the dam’s downstream face, water could be clearly seen leaking from the wall of the dam and water was also gushing out from two diversion outlets from the dam at the lowest part of the downstream face wall,” he claimed.
Dr Rundi said the recent lowering of the reservoir water level was in accordance with the operation procedures advised by the dam’s consultant.
“It was a planned lowering of the water levels releasing the water through the draw-off culvert, and was not caused by any fault or dam leakage.
“As such, the dam’s integrity and safety are not compromised whatsoever,” he stressed, adding that this was confirmed by the dam consultant and their specialist from Halcrow Consultant, UK, during his recent periodic inspection visit to the site late last month. He explained that in the construction of concrete dams, construction, contraction and thermal movement joints are part of the structure.
“Some water flow through these joints is expected. What was seen on site was actually a design contraction joint, and not a ‘crack’ as alleged.
“Some seepages through the joint are expected and the wet patch seen on this area is due to this seepage,” he said, adding that the seepage joints have been made to allow movement to the dam structure.
Nonetheless, he said the dam contractors have advised that any seepages that have occurred must be rectified.
“It’s normal for concrete structure to have seepages after some time but patching can be done and will not affect the whole structure.”
Asked on when the seepage started, he believed that it started around two months ago.
“But that has nothing to do with the integrity of the structure,” he stressed and pointed out that contractors were now looking into the matter and will lower the water level of the dam to patch the seepage.
“They are now doing it and will have to reduce the water so that they can do the rectification work. Once this is done, they will raise the water level again.”
He added that consultants have recommended that the dam’s water level be lowered to 65m to enable contractors to patch the seepage. Currently, Bengoh Dam’s water level is at 77.6m.
Dr Rundi also assured that an Emergency Response Plan (ERP) was already in place in accordance with the standard operating procedures for all dams constructed worldwide.
“In the very unlikely event of an emergency situation, the relevant parties, including the downstream residents, would be informed immediately and an evacuation plan triggered.
“Evacuation areas on higher grounds have been designated, and the emergency response plan would be immediately executed.”
He said a dialogue and workshop on the ERP had also been organised last year which was participated by all relevant government agencies, the contractor and consultant, the village chiefs of all the affected villages and the media.
“Routine monitoring of movement of the dam body to ensure its safety has been carried out since the construction stage, and is continuing as part of the dam’s standard operating procedures.
Also present at the press conference were Assistant Minister of Rural Electricity Dr Abdul Rahman Junaidi, Assistant Minister of Water Supply Datuk Liwan Lagang, and Ministry of Utilities permanent secretary Alice Jawan.