Flooding Kotte to Save Colombo?February 21, 2014, 8:18 pm
by Eng. K. D. A. H. Nanayakkara
Senior Deputy Director of Irrigation (retd.)
I recently spoke to an economist appointed by the UNP as its Kotte organiser. I thought, being a non resident of Kotte, he was not familiar with the real problems of Kotte such as floods drainage, garbage, pollution etc.
The economist gave me clear account of how the World Bank had proposed to help prevent flooding, which I believe was part of the of the USD 213 million loan under a project now well known as MCUDP.
It was embarrassing for me to disagree with proposed solutions which looked something like the methods used by the police to control––using hand signals to direct the flow of traffic. Sadly no one can control floods the way we control traffic because flood waters cannot be controlled by intermittently blocking canals against the natural direction of flow of water especially during major floods.
Having returned home in a bid to confirm what had been discussed I sent the economist a photocopy of an article in my possession exposing how so many countries had faced serious problems by following the WB prescriptions with Argentina and Russia among them. Sadly, when WB proposals fail the WB cannot be held responsible or accountable and the poor victim countries have to bear the loss. My only hope is that Sri Lanka will not be the next victim.
The next shock came to me when a resident of Kotte (not an engineer) brought to my attention that the main canal of the 19 square mile catchment of Madiwela had been completely and permanently blocked with a costly wide gabion wall as shown in the picture. Fully conversant with the important part played by the 19 sq. ml. catchment of Madiwela during floods this was really shocking to say the least.
I am a senior irrigation engineer who did the hydrological study for the government approved 1966 study for the Reclamation of the Swamps in and around the City of Colombo––(Government sessional paper 26 of 1966)––which led to the commencement of the development of Kotte. It was later appointed the first DGM to commence the reclamation work for the New Parliament and Administrative Complex at Kotte, also while serving as DGM responsible to get the Colombo canals transferred to the Reclamation Board (now SLLR & DC) from the historical custodian of the canal network, namely, the Irrigation Department with the intention of effectively controlling of floods and drainage requirements of the City of Colombo. If not for this move by me to have the canals transferred––which I now regret very much––there would have been no SLLR & DC today.
Sadly, all costly efforts of the past to deal with Colombo floods have come a cropper because those who knew the subject were always overruled or replaced by those who did not know it as the following examples will show. The government has lost millions if not billions as a result.
1. Every effort made by me from mid 1980s to point out that the over 100-year-old Dutch built Kelani South Bund is in the wrong place has been ignored.
2. It was a bad decision to transfer canals from the historical custodian the Irrigation Department to a corporation that did not have the required expertise to handle the canal system.
3. A study of Colombo canals entrusted to W. S. Atkins was wrongly done under the Water Board that had nothing to do with canals.
4. The resulting chaos created in forcing the unwilling Reclamation Board to accept and implement the report that had not been done under their directions and they knew nothing about.
5. Transfer of the Board from the original and rightful custodian, the Ministry of Irrigation, to the Ministry of Urban Development, which has nothing to do with flood protection.
6. The Task Force was appointed to restudy the Flood Problem. The Institution of Engineers Sri Lanka offered the services of two engineers for the study but the engineer with experience in relevant work was dropped and the one familiar with building research and no experience in flood problems of Colombo was accepted.
7. Unfortunately, this report is not available to other experts for comment.
It is against this backdrop that the Cabinet Approved Study of Kelani Ganga Left Bank Unprotected Areas of 2008 becomes relevant. The scope of this study was to go through all the existing reports on the subject by both local and foreign experts for the last fifty years and to recommend the best option to control Colombo floods in the most cost effective, scientifically acceptable and technically feasible manner to the government.
Unfortunately, this study was transferred under SLLR & DC due to lack of funds within the ministry and the five appointed consultants had to face unbearable hardships sometimes even humiliation under the engineer who was appointed to look after the interests of the five consultants. The work of two absentee consultants had to be done by the Team Leader free of charge in the interest of the project and the project was completed on April 29 2009. The errant engineer having no alternative then penalised the team leader and denied his last payment amounting to Rs. 52,700 not paid to date. Somehow, it did not take too long for retribution to strike this errant engineer when our good Defence Secretary showed him the door!
If the WB has now realised that Colombo’s problems are caused by the surplus flood waters of the 19-square-mile catchment of Madiwela it is all right, but attempts to block the main canal and other connected canals run counter to the aim of flood control for the city of Colombo and the more viable method as given in the 2009 report in the annexed plan under Development of Kelani Ganga Left Bank Unprotected Areas.
The following features embodied in the report are important:
1. The City of Colombo is protected from Floods of Kelani Ganga by flood bunds built by the Dutch more than 100 years ago. The bund referred to as the South Bund is not in the right place as pointed out by the writer way back in mid 1980s, but no remedial action has been taken to date.
2. Colombo, a coastal city, is blessed lavishly by nine outfalls for drainage as shown in the Plan but not made full use of. Most prominent is the state of the Mutwal Tunnel the only sand bar free outfall for the Colombo North catchment; today it is full of shanties.
3. The wrongly placed South Bund has bisected the Kittanpahuwa canal at Gothatuwa cutting the historical outfall for the Madiwela catchment and forcing the flood waters of Madiwela to reverse the natural direction of flow and enter Colombo causing many unnecessary hardships to the people of Colombo.
4. This is not the only reverse flow. Under Atkins’ proposals, too, Mahawatte Canal flowing north has now reversed its direction to enter Heen Ela flowing south and combined with Madiwela water coming through the new Nawala bridge to cause serious flood problems to the residents of Lake Gardens, compelling them to shift upstairs during floods leaving their luxury cars on top of the nearby high level bridge for safety. The excuse given is that this area is six feet below sea level whereas in fact the area is six feet above sea level!
5. If the south bund is placed in the correct place as shown in the new plan this will open a large land mass (unprotected areas) for the expansion of the City of Colombo which area is now fast becoming a massive shanty area where all types crimes are committed and an eyesore for the City of Colombo hoping to become the Wonder of Asia some day.
6. If this area is developed as a New City––report by London Marine Consultants of Kent England paid for by a local group of national minded professionals at no cost to the government and approved by the ministries of irrigation and urban development and the Chairman UDA––Colombo will continue to remain as the Commercial hub, while Kotte will remain the Administrative Capital and the proposed New City will be the main Residential City for the people of both Colombo and Kotte.
7. This New City project also has many other possible new unique features such as (a) Ring Road for the City of Colombo (b) possible new overhead electric railway from Godagama to Fort to ease traffic problems (c) dual water supply scheme and many other features never conceived before by anyone.
Finally, the writer was horrified to be informed that the new Task Force appointed to deal with Colombo Flooding in its report seems to have recommended the construction of an artificial trans-basin-canal called the South Diversion which is expected to take the surplus flood waters from Kotte, to reverse the natural direction of flow of the catchment, through a wide artificial canal from Kotte west to Bellanwila to Bolgoda and to Veras Ganga––these areas are already affected by water logging––and finally discharge it into the Sea at Panadura many miles south of Colombo. (Please see plan) If implemented, this, I feel, deserves to enter the Guinness Book of World Records.
I, as a senior chartered civil engineer, expect my observations and comments to be responded to by an equally qualified engineer with long years of experience on Colombo Floods and the national interest foremost in his or her mind, preferably the Director General of Irrigation who is an Ex-Officio Member of the Board of Directors of SLLR & DC or a senior engineer from he Ministry of Irrigation willing to justify the costly construction of this canal as a wise move overlooking other technically sound, economically feasible alternatives, available to save Colombo.
Last Updated Apr 25 2017 | 10:49 pm