The Mahanadi has an estimated basin of 43,800 miles, and its rapid flow renders its maximum discharge in time of flood second to that of no other river in India. During unusually high floods 1,800,000 cubic feet of water pour every second through the Narâj gorge, one-half of which, uncontrolled by the elaborate embankments, pours over the delta, filling the swamps, inundating the rice-fields, and converting the plains into a boundless sea. In the dry weather the discharge of the Mahanadi dwindles to 1125 feet per second. Efforts have been made to husband and utilize the vast water supply thrown upon the Orissa delta during seasons of flood. Each of the three branches into which the parent stream splits at the delta head is regulated by a weir. Of the four canals which form the Orissa irrigation system, two take off from the Birùpâ weir, and one, with its branch, from the Mahanadi weir. On the 31st December 1868 the Government took over the whole canal works from the East Indian Irrigation Company, at a cost of £941,368, since which time the gradual prosecution of the Orissa scheme to completion has been sanctioned. The canals thus taken over and since completed, or carried to an advanced stage of construction, are the High-Level Canal, the Kendrâpâra Canal, the Tâldandâ Canal, and the Mâchhgâon Canal, with their distributaries, designed to irrigate a total of 1,600,000 acres.