Bihar and Jharkhand have signed an MoU to share the waters of the Sone River, settling an inter-State dispute of nearly 25 years. The Sone, a major right-bank tributary of the Ganga, rises in the Maikal highlands near Amarkantak and joins the Ganga near Patna, flowing through Chhattisgarh, Madhya Pradesh, Uttar Pradesh, Jharkhand and Bihar; Rihand, Kanhar and North Koel are its key tributaries. The Indrapuri (Sone) Barrage in Rohtas, commissioned in 1968, is a key irrigation structure. The pact will meet irrigation and drinking-water needs in both States.