The Narmada also called the Rewa, is a river in central India and the fifth longest river in the Indian subcontinent. It is the fourth longest river that flows entirely within India, after the Ganga, the Godavari, and the Krishna. It is also known as "Life Line of Madhya Pradesh" for its huge contribution to the state of Madhya Pradesh in many ways. It forms the traditional boundary between North India and South India and flows westwards over a length of 1,312 km (815.2 mi) before draining through the Gulf of Cambay into the Arabian Sea, 30 km (18.6 mi) west of Bharuch city of Gujarat.