District may face shortage of potable water

KOCHI: Destruction of wetlands and mangroves situated on the islands bordering Ernakulam district can have a direct impact on the availability of drinking water in the district, say environmentalists. These structures filter the sea water from mixing with the rivers and other sources of inland water.The backwaters surrounding Mulavukad, Vallarpadam, Vypeen and other little islands fall in the area where the sea water meets the fresh waters of the Periyar river. “During high tides, the sea water flows into these backwaters and onto the islands here. Islands like Mulavukad which is bordered by the wetlands provide a trap for the sea water to flow in and get settled within a few hours of the high tide. Once the high tide is over, the saline water flows back into the sea, leaving the wetlands shallow. Due to this natural barrier, the rivers which flow into the backwaters are saved from the mixing of salt water. Even the mangroves perform the same function,” said Ansily Arooja, co-convenor, Mulavukad Vikasana Samithi. This samithi had once led a successful campaign against the destruction of a river in Mulavukad for the Container Road project.Also, this natural phenomenon during high tide does not stop with backwaters and rivers but also affects the salinity of the groundwater. “As of now, Ernakulam gets most of its potable water from the Periyar river. Therefore, increased levels of salinity in the water can have a direct bearing on its availability. Increased salt content in the river water will affect the groundwater in the areas bordering the river as well. Which means, even wells and other sources of drinking water will eventually get affected,” said M K Prasad, an environmentalist.“Another area of concern is that the inflow of sea water from the opposite direction can reduce the speed of the river flowing into the sea, which can result in the stagnation of water in the river. This is already happening to the Periyar river. Also, the sea levels are rising owing to global warming making it more difficult for the rivers to maintain their one-sided flow. This only adds on to the value of wetlands and mangroves,” he said.