Be prepared for rainy season

By Ranil WIJAYAPALA

The heavy rains lashing many parts of the country during the past few days especially in the Western Province created havoc in many cities due to huge traffic congestions and inundation of roads and even buildings due to the overflowing drains.

Schoolchildren, office-bound workers and shopkeepers were left stranded as the roads leading to their schools and workplaces went under water making those roads impassable. It was with great difficulty that some people crossed these floods which was sometimes to their knee level in some parts of Colombo.

The situation in the Colombo was the worst scenario as more than eight places came under temporary flooding due to the high intensity of the rainfall during the past few days.

The Meteorological Department has already given signals that the situation will worsen in the coming months too as they are expecting active monsoonal rains this year with heavy rains compared to the rainfall experienced during the past few years.

Floods in Colombo is a common occurrence in the Colombo City even after a few hours of high intensity rainfall but the situation is going to be worse in the coming week according to the weather forecast. The Colombo Municipal Council which is responsible for the city drainage system is the first to get the blame for this situation.

Therefore, the Sunday Observer inquired from the City administrators about the reasons behind the flooding in the city when it comes to a high intensity of rainfall.

It is a fundamental fact that floods of this nature cannot be stopped at any level, but our effort was to learn how the drainage system in the city functions and the measures the relevant authorities have taken to minimise such situations in the City.

The Chief City Administrator Omar Kamil and the Director Engineering in charge of the Water Supply and Drainage, D.H Gunasekera had a fair number of reasons for the flooding in the City. According to them the drainage system and the canals to the extent of 350 to 400 km within the City is not the sole responsibility of the CMC.

"Sri Lanka Land Reclamation and Development Corporation is in charge of the canal system in the City which are connected either to the Beira Lake, Kelani river or directly to the sea while the Port Authority is in charge of the Beira Lake", Omar Kamil added.

However, the cleaning and the maintenance of the drainage system within the City is the responsibility of the CMC and its six District Engineers Offices.

The City drainage lines are connected to the perimeter canals and then they are connected either to the Kelani river, Beira Lake or directly to the sea.

It was due to the incapability of the canals to take the huge quantity of water flowing through the drainage lines that cause it flooding in any areas.

"These canals have to be properly dredged so that they can effectively take the water coming into them to the sea or to the river", Engineer Gunasekera said explaining the situation.

The regular flooding in Horton Place and the areas adjacent to the BMICH is due to the increase of water level in the canals soon after high intensity rain fall, so the flow of water in the main drain lines connected to the canal is automatically blocked inundating the roads.

As a solution to this the Colombo Municipal Council is now constructing a third opening of the main drain into the canal on Bauddaloka Mawatha. "This is to minimise the flooding in Horton Place, Wijerama, Kynsey Road etc.", Gunasekera added. Another project is also going on to reduce flooding in Reid Avenue and Stanely Wijesundera Mawatha mainly to reduce flooding at Thunmulla junction at a cost of Rs. 15 million. Apart from this we are also working on a few more projects to improve the drainage system in Bloemendhal Road to reduce flooding in Thotalanga junction, Aluthmawatha and Fussels Lane.

"We are implementing 12 such projects at a cost of Rs.52 million to improve the City drainage system", Gunasekera added.

In addition it has also been found that flooding is also caused due to high water level of the Beira Lake during rainy season.

"The water flowing to the Beiral Lake through canals get blocked due to higher water level of the Beira Lake and starting the flow of water upward", he said.

The flooding in Norris Canal area is due to this reason. "The relevant authorities have identified this situation and has taken a decision to lower the water level of the Beira Lake to prevent this situation", Gunasekera added.

The blockade of one drain line directly connected to the sea through the Colombo Port from Mutwal area due to security reasons, is also creating blockades in the main drains thus creating floods in Jampettah Street and Pettah area.

Steps have also been taken to improve the flow of water to Kelani river at the Nagalagam gate connected to the Kelani river by pumping the additional water into the river. However, Omar Kamil said flooding in the City is not only due to the inadequate City drainage system, it also caused due to blockades in the drains and canals due dumping of garbage, growing of salvinia, and the construction of unauthorised structures covering the main drain lines and the blockade of some drains and canals due to security reasons.

But that was not the prime reason behind flooding becoming a common occurrence in the City.

"It was due to the incapability of the City drainage and storm water system which was designed and constructed 101 years ago to cater to only 80,000 to 100,000 population in the city to cater to the current requirement", Kamil added.

"Today the same drainage and storm water system has to cater to over 600,000 population in the City and nearly 400,000 floating population daily visiting the City", he said.

The situation is worse as hundreds of thousands of buildings have come up within the city limits, creating bigger problems for maintaining City drainage network.

"The biggest problem is due to the filling of retention area in and around the Colombo City for the construction of huge buildings. Due to this situation the retention areas have been drastically reduced over the past few decades", he added.

So designing of a drainage system to cater to the current requirement in the City and maintaining water retention areas has become an urgent need to avoid the City been inundated during heavy rains.

According to Engineer Gunasekera a request has been made to the Disaster Management Ministry to design a new drainage system and it is being discussed at various levels at the moment.

However, according to Omar Kamil it is also the responsibility of the public to extend their support to the relevant authorities to keep the drainage lines clean without dumping waste into drain lines and canals and constructing unauthorised structures blocking the flow of water into the canals and drains.

The removal of manholes in the drainage lines and dumping of debris into canals after construction work done by some agencies in the road network has also become a problem for the CMC to maintain the drain line and canals.

"We are doing our best to keep the drain lines and canals clean during the rainy season and I appeal to the public to extend their support towards this endeavour by dumping garbage through proper channels and at proper places but not to the canals and drains," Kamil added.

"What we have found is always it is due to human activities that had caused the flooding in the City before they complain of the situation they must consider whether they have done their part to avoid flooding", he added.

But, this situation is not confined to the City of Colombo. Various other major cities are also facing the same problem at different levels. So it is the responsibility of the relevant local bodies and authorities to keep their cities ready for the coming rainy season.