Try the Battery river[the name might have changed since!] behind the suburb of Pallavaram, 12 miles from the city and next suburb to Meenambakkam. I am sure this river flows behind St Thomas' Mount and comes out at Guindy bridge, then flows out to Santhome.You will have to walk about 2 to 3 kilometres along the bunded walls of paddy fields, some babool forest and rocky tracks beyond Veteran lines. We caught Kanartic carp there when we were knee high to a grasshopper and the tackle was bamboo rods, fixed catgut, peacock floats and small hooks[size 8 i think!]We also caught small catfish and Korovai, all on worms and dough bait. The local fishermen were experts at hooking the larger fish and used a kind of red paste comprising idli, cochnil and ground peanut.Find a spot where the rapids run into a large deep pool. Some areas are crowded with dhobies so try and fish away from them naturally.Also not a bad spot for a picnic!Perhaps it may be a good idea to check it out on google earth before you venture out.