Public Works Department is contemplating constructing a series of check-dams on the river
CHENNAI: With the launch of the Rs.1,200-crore Cooum river beautification project, the State government is making yet another attempt at cleaning the Cooum, which has been eluding a lasting solution.
Compared to the Adyar river, the Cooum is more polluted and its problems are more complex.
Senior officials who are associated with the project say that the government has consciously chosen the Cooum which, they feel, is more challenging and the success of this venture will quicken the process of eco-restoration of other water courses in the city.
Originating from the Cooum village in Tiruvallur district, the river meanders for 54 km in that district before reaching the limits of Chennai Corporation. For another 18 km, it travels and joins the sea near the Napier Bridge. Of the total length of 72 km, the river flows in urban and peri-urban areas for 30 km and rural areas for 42 km.
A host of factors has contributed to the Cooum problem. Intensive use of surface water upstream for agriculture, indiscriminate pumping of groundwater leading to reduced base flow in the river, formation of sand bar at the mouth of the river, discharge of untreated sewage and industrial effluents and encroachment along the banks of the river are some of them.
Conscious of the fact that some options for attacking the problem consume more time, the authorities are now focussing on one aspect – removing encroachments in the city limits and developing the areas retrieved into parks. This will ensure aesthetic appeal and utility, an official says, adding that the Chennai Corporation has been entrusted with the responsibility of developing parks.
Approximately, the total length of encroached areas is six km. The removal of encroachments is expected to be completed in a year, the official adds.
There are 9,000 families, which are enumerated by the authorities as having encroached on the banks of the river. Of them, 3,000 are covered under the resettlement and rehabilitation component of the proposed elevated corridor to be executed by the National Highways Authority of India (NHAI). The State government will have to take care of the rest.
As for other components of the project, the strengthening of sewer network and stormwater drains and augmentation of the capacity of sewage treatment plants are among them. The authorities are clear that all sewage outfalls have to be arrested. If only the secondary-treated sewage is let into the river, this will be sufficient for reviving the aquatic life, they say.
The Water Resources Department of the Public Works Department is contemplating constructing a series of check-dams on the river, which, on an average, records (at Thiruverkadu) six thousand million cubic feet (tmcft) annually. Continuous dredging at the mouth is another option being considered by the authorities.