LETTER | The never-ending torrential rain in Penang over the weekend was an act of God. A natural phenomenon which is a perpetual feature of our equatorial climate. Nobody would wish to have the heavens open up with such vengeance on any state.
Naturally, when the rain intensity is so great, floods will occur. We should always be vigilant during the annual monsoon season.
Flood mitigation starts from the local council and state government. Every council must take into consideration the terrain, rainfall and built up surfaces in their area. While we can always engineer ourselves out of a flood, there is always a cost versus benefit consideration. There are some low lying areas in a floodplain that will perpetually be flooded when it rains and if we situate developments in those areas, we have to be prepared for such events.
On a small island like Penang, with its hilly terrain, engineering flood mitigation measures must be a long-term and all-inclusive plan encompassing all urban growth zones. It will not be cheap, mainly due to the high land cost and the expense incurred to provide adequate storage for the surface runoff.
As the island develops, open permeable spaces will continue to diminish causing higher runoff to flow downstream into the coastal areas. Couple that with the tidal phenomenon and the incoming surface runoff will easily overwhelm the drainage system causing a rise in water level.
The question we should all be asking is how do we reduce the incidence of flooding? Unfortunately, especially with our tropical climate, it is quite impossible to entirely eliminate flooding. Anybody that promises that is telling you a blatant lie. With the right planning and engineering, we can reduce the incidence of flooding and lower the magnitude of the damage caused.
Penang's terrain bears many similarities to Hong Kong. Being in the path of tropical storms and typhoons from the Pacific Ocean, Hong Kong bears the brunt of some of the regions worst storms. On average, six tropical cyclones slam into Hong Kong every year. While flooding still occurs in Hong Kong, they have managed to reduce the damage it causes.
There are many lessons Penang can learn from Hong Kong. If DAP still wants to continue to develop the state in a sustainable manner, they must implement special flood mitigation requirements in addition to the ones provided by the JPS Masma manual. If the hills are being cleared, the increased runoff will tax the existing drainage system.
Siltation will occur, evident from the brownish flood waters, as topsoil and sediment from the hills wash down into the coastal plain. These sediments, unless periodically maintained, will clog existing waterways, thus reducing drainage efficiency.
The ultimate problem with highly built-up areas is the immense volume of runoff from storms. Sufficient storage areas in the form of retention ponds and green open areas should be provided to retard the flow of water into the rivers.
Due to its terrain and the high-density development on the island, it is expensive to provide adequate stormwater storage within a development. Catchment areas next to hillslopes also have a large volume of runoff moving at a high velocity. The damaging effect of erosion is quite evident on many of these hill projects. Sometimes water currents are so strong, even paved roads can be ripped apart.
Some of the more innovative solutions for Hong Kong's flooding problems like the underground stormwater storage system has worked very well over the years, together with a comprehensive drainage master plan. The Drainage Services Department of the Hong Kong SAR constructed massive underground tanks to route surface runoff intercepted from uphill catchments during storms, only to slowly release the stormwater into the natural waterways when the storm abates.
The Penang state government has a duty of care to the residents of Penang to ensure that disasters of such proportion should not happen. Over the past four years, a total of 119 incidences of flooding has been recorded in Penang. Penang is an economic powerhouse and home to some of the world most high tech electronics producers.
The state government has to provide a safe and secure environment for investors to house their production facilities and assets. Otherwise, multinationals might shun the island because of the cost of protecting and insuring their priceless assets. Productivity would be affected.
We will only find out the true financial cost of this disaster over the next few weeks. For Penang to recover from this tragedy, federal funding is required to repair all the damaged infrastructure within the state. The very least they can do is to provide a competent flood mitigation plan for the state, starting with a comprehensive drainage master plan study.
The Penang government has to be accountable to the people and not private developers. If certain waterways and catchment areas have to be gazetted as permanent drainage and storage areas, then so be it.
The safety and well-being of the rakyat have to come first. Lastly, in the interest of transparency, Penang has to launch an inquiry into how the local council approved property developments on Class III slopes without adequate slope protection.
The collapse of many retaining structures and slope failures in such risky locations is cause for concern because as right now, any dwelling structure located downstream to such development could possibly be the scene for the next Highland Towers.
The views expressed here are those of the author/contributor and do not necessarily represent the views of Malaysiakini.