No Solution To Flooding In Colombo!

By Camelia Nathaniel

While much has been said about the causes for flooding in Colombo and the suburbs, the irony is no practical solution to the problem has been taken yet. While the city and surrounding areas were developed and the city beautification took centre stage, there were many allegations levelled against the previous regime that the drainage system was not updated which resulted in the flooding these areas. It is believed that while new constructions have been built over the old drainage systems, there were major problems in finding plans of the old drainage system. No one had in fact paid attention to the flooding problem and the issue only comes up when there is a heavy rain and the roads are inundated. Had proper attention been given to planning the beautification of the city, this problem could have been addressed – at least to a greater degree.

Speaking to The Sunday Leader the Director of emergency of the Disaster Management Centre (DMC) Pradeep Kodippilli said that the flooding in Colombo has been addressed to a great degree by clearing and cleaning the canals and waterways.

“Prior to 2010 the situation was much worse and even the area surrounding the parliament were inundated for the slightest downpour. One of the main reasons for the flooding was the clogged drainage system and also the canals in and around the city were also blocked and the water did not drain out to sea. However, now that the canals, drainage system and the waterways have been cleared, the problem is much less,” added Kodippilli.

However he admitted that that a major contributory factor to flooding is the filling in marshlands for development purposes.

Human influences have caused significant changes in the marsh or wetlands. These changes have resulted from alteration of the physical, chemical and biological components of wetland ecosystems. Widespread land development and clearing have caused increased marsh area leading to increased sedimentation in lowland wetlands. According to environmentalist Jagath Gunawardena, this increased accumulation of sediment can alter the chemical and hydrologic regime of the wetlands in a relatively short time. Other human activities which can have lasting effects on wetland ecosystems include stream channelization, dam construction, discharge of industrial wastes and municipal sewage and runoff urban and agricultural areas.

Flooding in Colombo has worsened in recent years primarily due to a drop in the city’s ability to absorb water, because most of the marsh or wetlands in and around Colombo have been filled for building houses or other constructions. The drainage systems too have been blocked by encroaching constructions. According to the authorities, more than 30% of Colombo’s water retention capacity has been lost due to the filling of marsh or wetlands in the past 10 years or so.

Adding to this problem, the garbage disposal problems mainly in the city areas has led to many residents dumping their garbage in canals or drains in and around the city. This practice although illegal had been continuing for many years now, and is only getting worse. With the influx of the urban population over the recent years, garbage disposal has become a major issue, as with construction being carried out in every available land area, there is no room for garbage disposal. Hence most of the garbage ends up either in the drains surrounding the city areas or the canals. All these were compounded of course by the changing climate patterns. The weather is not only unpredictable, but also it makes rain arrives in increasingly short, heavy bursts, that can cause flash flooding.

Moreover sources of pollution have local and regional effects on the chemistry and quality of water flowing through wetlands. Point sources, such as municipal industrial sites, and non-point sources, such as agricultural lands and urban runoff, add materials to ground water and surface water that upset the balance of wetland water chemistry and the biogeochemical cycling of materials in wetland ecosystems.

According to environmentalists a one-acre of wetland can typically store about three-acre feet of water, or one million gallons. An acre-foot is one acre of land, about three-quarters, the size of a football field that is covered one foot deep with water. Three acre-feet describes the same area of land covered by three feet of water. Trees and other wetland vegetation help slowing the speed of flood. This action, combined with water storage, can actually lower flood heights and reduce the water’s destructive potential.

Using wetlands, such as drainage for agriculture and filling for industrial or residential development, can impose irreversible impacts on wetlands. In the past, the societal and ecological value of wetlands was not recognized widely and many wetlands were destroyed. Swamps, marshes, fens and bogs are natural water-storage features on the landscape. Once considered wasted land at best, or lurking-grounds for evil at worst, wetlands are essential wildlife habitat, massive natural water filters, and “natural sponges” that hold water when it rains; then they release water slowly.

“We have been pointing out these issues especially about the filling up of wetlands for the past 25 years. Marsh or wetlands are places where water is retained. By filling these wetlands, sometimes during heavy rains the water can get collected in the filled areas or in other instances the low lying surrounding areas. However to be honest there is no solution to this problem and in fact clearing of the canals is no solution to the flooding problem in and around Colombo.

The reason for this is that the canal beds are much lower than the sea level and as a result the water does not drain out to sea,” explained Jagath Gunawardena.

The previous government allocated US$ 233 million in a programme aimed at easing flooding in Colombo. The project is due to be completed by the end of 2017. However in spite of the city being beautified, there has not been any comfort for the thousands of people who are hugely inconvenienced whenever there is a heavy downpour.

During the recent rains last week, the city of Colombo recorded a 200mm rainfall while Ratmalana recorded the highest with 210mm of rainfall. Meanwhile Kandy, Matugama and Kalutara also witnessed high showers.

The Ratmalana area too is constantly under water during the rainy season and most of the by lanes from around Attidiya junction to Rawathawatte, invariably go under water. Although the Attidiya road has been renovated many times, the flooding has still not stopped and motorists are hugely inconvenienced during the rainy season.

A few days ago, Panadura also witnessed massive gales causing severe damage to nearly 500 houses. In addition many public buildings such as the Colombo Municipal Council and Maligawatte police station were also reported being a few feet under water. Meanwhile massive traffic congestions and delays of trains were also reported.

However consecutive governments have failed to address the issue of flooding and they have only managed to find temporary solutions. Many environmentalists are also of the view that building constructions haphazardly on these natural water retention areas is the main reason for the flooding and there is nothing that anyone can do now that the damage has been done. According to environmentalist Jagath Gunawardena, there is no solution to this huge problem.

The Urban Development Authority however under the previous regime attempted to reconstruct water retention areas, by renovating and giving a facelift to several areas such as in Rajagiriya, Ratmalana, Attidiya and many other areas. However environmentalists claim that this has little or no impact because these man-made wetlands may not have the same water retention capacity.

Colombo has 42 flood prone areas, according to findings of the Colombo Municipal Council (CMC). Maintenance of drains, canals, outfalls and gates is a joint responsibility of the CMC, Land Reclamation and Development Corporation (LRDC), Urban Development Authority (UDA), Coast Conservation Department and Irrigation Department.

However on the issue of flooding, these institutions keep passing the ball into each other’s court, and no one wants to take responsibility. As for the motorists, general public and the residents who are most affected during flooding, no solution in sight.

3 Comments for “No Solution To Flooding In Colombo!”

  1. Asoka

    Again yahapalana flooding raise there head.

  2. flooding no solution.ask mr gota is defense secrtary took the UDA under his ministry, did the swindle money. to day mr Gota and siblings,are main cause.the president want solve the water problem contact maysian country to help srilanka beauty the srilanka city

  3. One

    On the way to joining brother Maldives
    very soon look for homeland elsewhere as there will be landslides too.
    greed of building over marsh- result of infrastructure being localised.

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