The Vembanad ecosystem has a total area of about 1512 sqkms. It flows through three districts in Kerala namely Alappuzha, Kottayam and Ernakulam. Many canals are interconnected to Vembanadkayal and it lies at sea level separating the sea by a small island. The lake surrounds some islands like Pathiramanal, Perumbalam and Pallippuram. Some of the rivers that flow into this include Achenkovil, Manimala, Meenachil, Muvattupuzha, Pamba and Periyar.
An important feature of this lake is the Thanneermukkom salt water barrier. It has a length of about 1252 metres and was built to prevent the action of the tides and also to prevent the salt water from enter into the low lands of Kuttanad region. This barrier classifies the lake into two parts, one is the brackish water and the other is the fresh water. Yearly snake boat race is conducted in an extension of Vembanadkayal called as PunnamadaKayal and is also a main tourist attraction.