KUALA LUMPUR - The widespread flooding seen in many states in Malaysia in the last three days was caused by one-in-a-100-year heavy rainfall, a senior official at the country’s Environment and Water Ministry said on Sunday (Dec 19).

“The annual rainfall in Kuala Lumpur is 2,400mm and this means yesterday’s (Saturday’s) rainfall exceeded the average rainfall for a month. It is something beyond expectations and only occurs once every 100 years,” the ministry’s secretary-general Zaini Ujang told a news conference. He was referring to rainfall as measured by a rain gauge.

Referring to measuring stations around Selangor-KL, he said as quoted by Bernama, that the Sentul station recorded the highest at 363mm, Gombak (247mm), Jinjang (258mm) and Sungai Bonus Jalan Tun Razak (273mm).

“This is an exception because during the monsoon season, only states in the East Coast receive heavy rain,” Datuk Seri Zaini said. “But this time, the entire peninsula, especially the central east coast and northern peninsula regions are receiving continuous heavy rain.”

The heavy rains started falling on Friday but were most intense on Saturday. Authorities were expecting more heavy rains on Sunday.

Malaysia mobilised its armed forces and police to assist with flood evacuation, as more than 34,000 people have been displaced, following severe flooding in at least six states, including Selangor.

While preparations to deal with the floods had been made in states like Kelantan, Pahang and Terengganu, Prime Minister Ismail Sabri Yaakob said late on Saturday that Selangor had been caught off guard.

“In Selangor, it is rather chaotic because the floods were sudden as such occurrences rarely happened during the monsoon season,” Datuk Seri Ismail Sabri was quoted as saying by The Star daily.

“This is opposed to other states like Pahang and Kelantan, which would have anticipated the effects of the year-end monsoon season,” he added.

"God willing, we will do our best to help those stranded and get it done tonight."

He said his government will allocate RM100 million (S$32.4 million) for post-flood repairs for homes and infrastructure nationwide.

“The RM100 million is an initial funding. If it is insufficient, we will add on,” he told a news conference while visiting Klang district in Selangor, one of the worst flood-affected areas.

Malaysia's King, Sultan Abdullah Ahmad Shah, likened the flooding to the major disaster of 1971, when flash floods caused by heavy monsoon rain in Kuala Lumpur and Selangor affected 180,000 people and killed 32. At that time, Malaysia's total population was 10 million - a third of what it is today.

The King said that although 50 years had passed, Malaysians should take the floods as a lesson and be prepared to deal with them, especially in December and January.

Sultan Abdullah on Sunday visited five relief centres in Selangor and KL to speak to evacuated Malaysians and hand out donations.

He was seen wading into knee-deep flood waters at the World Trade Centre in KL on Saturday night.

A total of 5,731 relief centres are being prepared nationwide to accommodate up to 1.63 million flood evacuees if necessary for the monsoon season, which started in October and is expected to end in March.

The Stormwater Management And Road Tunnel tunnel in Kuala Lumpur was closed late on Saturday to allow flood water to drain through it.

Police are also on standby following an emergency discharge of water from the Klang Gates dam in Hulu Klang, whose water level had breached the danger mark.

At 1.40am on Sunday, the Malaysian Meteorological Department issued a red danger alert, the highest level on a three-tier scale, for extreme heavy continuous rain for Kuala Lumpur, Selangor, Perak and Pahang until Sunday.

It also issued an orange alert, the second-highest level, for heavy continuous rain in several states, including Kelantan and Penang, until Sunday.

Scores of motorists were left stranded on Saturday night after a landslide and several uprooted trees blocked a part of the Kuala Lumpur-Karak Expressway heading towards Bentong.

Klang MP Charles Santiago, whose constituency was badly hit by floods on Saturday, made an urgent request for aid on Sunday, saying his team needed four-wheel drive (4WD) vehicles and boats to reach victims trapped by flood waters, and items such as dry food, water and blankets.

“Our staff and volunteers are victims of flooding too. (Thus), we are also facing a shortage in manpower to distribute food and water. Therefore we need to recruit more volunteers for food distribution and rescue work,” he said in a Facebook post.

Social media was awash with photos and videos of flooded roads in Selangor, including in Shah Alam and Port Klang, with many stranded in their vehicles, homes and other buildings.

Instagram user nurullainabdulhamid posted on Sunday photos of her home in Shah Alam deluged with chest-high flood water, calling for help to rescue her 21 cats.

Meanwhile, Health Minister Khairy Jamaluddin said late on Saturday that all flood victims would be screened before being allowed to enter shelters, and that those who are symptomatic, at risk or test positive for Covid-19 will be sent to quarantine centres.

The National Hydrographic Centre posted an advisory on Twitter on Saturday warning of strong winds and heavy rain over the west coast of Malaysia and the Malacca Straits due to a tropical depression, otherwise known as a tropical cyclone.

Selangor Menteri Besar Amirudin Shari said on Saturday that the floods in the state were caused by the highest rainfall ever recorded.