Expressways shoved through wetlands and now we face floods, group says
An environment group has raised concerns of flooding in areas surrounding expressways, stating that wetlands, river basins and sensitive flood plains have been ignored, blocked and filled during construction.
Environment Conservation Trust Director Sajeewa Chamikara, told the Sunday Times that inland natural fresh water wetlands, such as rivers, streams, marshes, swamps, marine and salt water wetlands such as lagoons, mangroves and manmade wetlands such as paddy fields have been destroyed and damaged while constructing the Southern, Outer Circular and Colombo-Katunayake Expressways.
According to him, the floods caused by recent heavy rains at the Welipenna entrance and the exit on the Southern Expressway and surrounding areas was an example of what lies in store.
He said while building the three expressways, seven wetland areas and five catchments had been completely or partially damaged.
“The Colombo-Katunayake expressway, it goes through Muthurajawela wetland and bordering the Negombo lagoon. This is similar is with the Outer Circular highway where acres of paddy land were destroyed.
“The worst affected is the Southern Expressway with Bolgoda wetland, flood plains and river basins of the Kalu, Gin, Bentara, Nilwala Ganga flood plains and Halwatura wetland in Matara being affected by the construction of the expressway. Wetlands prevent flooding by holding water like a sponge,” he said.
Mr. Chamikara said environmental groups had expressed concern over the possible flooding threat and the lack of flood mitigation strategies.
“We were persistent about the need to build on columns. But officials said it was too late and plans had already been passed. Now even intermittent rains can lead to rivers overflowing and flooding nearby areas. Also, earth-moving and hillcutting can result in sludge flowing to wetlands and rivers,” he said.
He said though the Katunayake expressway area did not experience heavy floods this time, the blocking of natural streams through cut-and-fill construction could cause long-term harm to the area.
“The highways are located in the south-west monsoon region where heavy showers are expected annually. Authorities should constantly study the impact of weather and use flood and landslide mitigation strategies when constructing the proposed Colombo-Kandy highway,” he said.
The Director of Mainte- nance Management and Construction Division of the Road Development Authority, T.K. Ranatunge maintained the Kalu Ganga bridge, the Welipenna bridge and the Bentara Ganga bridge had been built in such a manner as to mitigate flooding.
“The bridges were built to prevent flooding to the areas as these areas are prone to floods, while continuing with the expressway construction. It is difficult to determine now that the expressway is causing flash floods,” Mr. Ranatunge said.
The RDA Project Director of the Colombo-Katunayake expressway, M.P.K.L. Gunaratne said his office had not received complaints over flooding or other environmental issues triggered by the construction of the expressway.
The proposed North-East (Colombo-Kandy) Expressway Project (CKH) beginning at Kadawatha on the current Colombo-Kandy (A1) Road links with the Katugastota-KurunegalaPuttalam (A10) road at Hedeniya and the KandyJaffna road (A9) at Katugastota.
“This road traces traverse river basins and sensitive flood plains that underwent severe floods in May 2010. In order to address the flood issues, construction of a 9km viaduct (overhead road) has been proposed for some sections of the expressway," the Ministry of Ports and Highways said.