In two months, Poondi Reservior, a major storage point for the city’s drinking water needs, will have floating cages to rear fish in.

A Fisheries Department initiative, this will help keep fish within a limited space, while also letting them swim about in the water and eat their feed. Rs. 3.31 crore has been allotted for the scheme, under the National Mission for Protein Supplements by the Central government.

“This is a pilot project that we are implementing. The water body is quite large, (the reservoir spans about 121 sq miles) and we want to keep the fish within a particular area,” said a source in the Fisheries Department.

Frames of the 64 cages, which are presently being fabricated, are made of steel and marine plywood. To keep the cages from moving too fast or tilting in the wind, moorings will hold them down and plastic barrels filled with air will keep them buoyant.

The rectangular 6 m x 4m x 4m cages will be placed in three sets, referred to as batteries. The first battery consisting of 16 cages will be used to grow fingerlings from seed to a 10 cm stage. Five lakh fingerlings will be reared in eight months. The other two batteries consisting of 24 cages each will be used to rear regular fish.

Pilot tilapia common carp and pangasius are some of the kinds of fish that will be let into the cages.

“The feed will float on the water and the fish will come up to eat it. Local fishermen will be involved in the project as it has to be replicated in other water bodies too. We want to propagate an intensive cage culture as this will help increase the catch,” the source added.

At present, the Poondi reservoir has water at a level of 636 million cubic feet (mcft), against its capacity of 3231 mcft. Nearly 500 cubic feet of water is discharged per second from it to to water bodies in Red Hills and Chembarampakkam to distribute drinking water to the city.

Officials of the Water Resources Department said that the Poondi reservoir has water in it all year round. Fish rearing is carried out throughout the year. However, as the Fisheries Department has obtained fish rearing rights, they do not seek permission for any of their projects.

“We do not get any revenue from the fish rearing activities. The Fisheries Department informs us about their projects,” said an official. The department ensures that a minimum level of storage is always maintained in the reservoir.

More In: Chennai