Overgrowth of the invasive seemai karuvelam (Prosopis juliflora) in the dry riverbed of Palar covering Vellore, Ranipet and Tirupattur districts, is threatening the waterbody by blocking free flow of excess rainwater from reservoirs.
Officials of the Water Resources Department (WRD), which maintains the river, said that lack of provision for river cleaning work has hampered the removal of the plant, resulting in thick overgrowth in the river bed. The overgrowth of the plant has blocked the free flow of water in the river especially during monsoon when excess rainwater was released from the reservoirs.
“After informing us, voluntary organisations and colleges through their outreach activities can remove the plant in the dry river as a service. Even the civic body can do it for the same purpose. However, we cannot allocate funds for the cleaning work” said a WRD official.
Siting an example, WRD officials said that more than five years ago, students of VIT did a similar river cleaning exercise between Viruthampattu village and Green Circle, a roundabout below the Chennai - Bengaluru Highway (NH 44), a distance of around 4 km. They mainly removed the invasive species from the river bed. Such an exercise has helped discharge excess rainwater into the river during monsoon and helped to prevent inundation in residential areas and villages. It has also helped to prevent low level bridges and causeways in these districts from getting washed away in the floods.
At present, the river between Vaniyambadi town (Tirupatur) and Melvisharam town (Ranipet), a distance of around 100 km, has at least 20 bridges, including 10 causeways which are maintained by the State Highways. Most of the riverbed between these two towns have been covered with the invasive plant.
As per norms, such river cleaning work, especially removal of invasive plants, are done only for new bridge check dams and culvert works in water bodies.
Before starting any new work like construction of bridge or culvert across the river, they clean the river bed for at least 2 km on both sides. However, once the work is completed, no river cleaning work will be done thereafter.
“We will remove only during massive floods when such invasive plants threaten the existing bridges and culverts,” said an official of State Highways.
Earlier such invasive plants were allowed to be removed by brickkiln operators as they can use it as firewood to burn bricks. However, due to operational difficulties, the practice was discontinued. As a result the overgrowth of the plant has become a threat to the Palar river.
