Kosasthalaiyar River

The Kosasthalaiyar River is one of the three rivers flowing in the Chennai Metropolitan area. It is a long river that starts near Pallipattu, Thiruvallur District. Its northern tributary, the Nagari River, starts in Chitoor district, Andhra Pradesh. It joins the main river in the Poondi Resorvoir. It pass over the pulicat lake
Kosasthalaiyar River catchment area spreads in Vellore, Chitoor, North Arcot, Thiruvallur and Chennai districts. The discharge capacity of the river is 110000m3/sec. The flood discharge capacity is about 125000m3/sec.