Multiple choice Which river has the longest dam in India? Ganga Godavari Sutlej Mahanadi Reveal answer Fill a bubble to check yourself D Correct answer Explanation Hirakud Dam built across the Mahanadi River in Odisha is the longest dam in India at 4.8 km. Other major dams like Bhakra Nangal (Sutlej) and Nagarjuna Sagar (Krishna) are significant but shorter in length.