I went to the Tambaram Sanitorium/Chitlapakkam lake, which is a huge lake right inside the Chennai city. It measures more than 46 acres and they have built a beautiful walkway all over one side of the lake. This lake is near the Temple on the Chitlapakkam main road.
t seems you can see birds from Apr-Sep, but I didn’t find many when I went. The Govt. is planning to construct a garden and introduce boating, shortly. Till then you can go and casually walk along the perimeter walkway. Here are some pics taken there: