AMONG the causes of the flash flood that hit the state capital on September 8 was the extraordinary rainfall between 1.20pm till 2.20pm, Deputy Chief Minister Datuk Seri Panglima Yahya Hussin said.
He said the Drainage and Irrigation Department’s study showed that the rainfall recorded during that one-hour period was 118mm compared to the average intensity of between 11mm and 30mm an hour.
Yahya, who was replying to Likas assemblyman Junz Wong, disclosed that based on the analysis of records collected, the rainfall on September 8 was higher than the 25 years return period or event of similar rainfall intensity within 25 years interval or 4 per cent chance of happening.
The Agriculture and Food Industry Minister added that the rainfall recorded in Damai was 154mm, Taman Khidmat 155mm, Babagon 147mm and Upper Moyog 108mm.
“The Drainage and Irrigation Department took note that the flood in most of the affected areas receded within four hours except for low-lying areas. The heavy rainfall this time was also a natural phenomenon that was caused by global warming that has changed the global weather pattern as well as seawater intrusion,” Yahya said.
He also said the Drainage and Irrigation Department had taken remedial measures to reduce the frequency of flash floods and pointed out that the state government had approved the ‘Review of Kota Kinabalu Drainage Master Plan’ study under the 10th Malaysia Plan’s fourth Rolling as a long-term plan to resolve the problem.
“This study will identify the capacity of existing main monsoon drains as well as make recommendations on how to upgrade and improve them,” Yahya said.
“As a short-term remedial measure for flash floods, the department has cleaned up and removed the silt from all drains under its purview. The department will also dig up the sediments at river mouths such as Sungai Rampayan and Sungai Gudon as well as deepen shallow rivers.
“The Drainage and Irrigation Department is now applying for allocation from the federal government to upgrade rivers in the state capital including Sungai Rampayan, Sungai Menggatal, Sungai Dambai, Sungai Keliangau, Sungai Gudon and Sungai Darau,” Yahya said.