The rajas of Vijayanagar in 1521 constructed nine dams across the Tumbudra river, and had channels of 89 miles of total length. The old travellers, Conti and Ctesar Frederick, tell of cool streams flowing through the streets of the city. In 1860 the Madras Canal and Irrigation Com pany undertook to bring a navigation and irriga tion canal from the river, throwing an anicut across at Sankasala; its history is useful.
It was intended to provide for the continuous irrigation of the Bellary district, of the Koondey valley and the Nellore district. The weir across the Tumbudra at Sankasala was 1500 yards in total length of clear overfall, which was broken into two lengths by an intervening island. The Hindry Aqueduct carried the canal, 90 feet broad and 8 feet deep clear waterway, over that river, at an elevation of 32 feet, by 40-feet arches, the length between the abutments being 651 feet ; the cost of the first 75 miles was £8710 per mile ; the next 115 miles cost £2900 per mile ; and the whole canal cost £5260 per mile. It has not produced all the hoped-for benefits for irrigation, and for navigation it has not been applied. Indeed, navigation and irrigation seem incompatible.
At Baiswara, 60 miles from the sea, an anicut or dam 1250 yards long, with a base of 305 feet, has been thrown across the Kistna river, and its chann els irrigate the Guntur and Masulipatam districts. The delta covers an area of 10,000 square miles. From the E. side the main channel is divided into two branches, one to Masulipatam, the other to Ellora. It was constructed by General Charles Orr. The main western channel divides into the Nizampatam and Commamur branches.
The Krishna Canal, in the Bombay Presidency, is excavated from above the dam near Kurvar in the Satara district.
The Ekruk tank is four miles north of Sholapur on the Adela, a branch of the river Bhima. Its dam is 7200 feet long, and 72 feet high in the centre, and the lake formed is square miles. It submerged five villages, two of them in the Nizam's territory, but 35,840 acres are brought under the influence of the tank.
An anicut was completed across the Pennar river at Nellore in 1855. It was breached by the
hurricane of 1857, but restored in 1861, and in 1863 the irrigated area was 32,874 acres. It is 520 yards in length.
The Cauvery and Colerun anicuts are the most ancient in Southern India, and those to which the British first directed their attention. At the head of the island of Srirangam, near Trichinopoly, the main river divides into two branches, the southern retaining the name of Cauvery, the northern Wing called the Colerun ; and the tendency was for the Cauvery to silt up, and the whole of the water to pour into the Colerun. The native anicut had been built about the third century of the Christian era, and consisted of a solid mass of rough stone 1080 feet long and 40 feet broad, irrigating 669,000 acres. Sir Arthur Cotton threw a masonry anicut, 750 yards long, across the Colerun, rest ing it on three lines of wells 6 feet in diameter in the sandy bed of the river, which has thrown the water into the Cauvery and cleared the bed of the Colerun. In 1836 an anicut was thrown across the Colerun to regulate the supply of water for S. Arcot. Colonel Sim was the engineer.
The Mann Con wai river iSin Mysore, with the Nun door Sreeramadwara and Maseehully reservoirs.
The Periar river runs to waste into the Cochin marine lagoon, and it has been proposed to turn it into the eastern districts by a cutting 140 feet deep and a dam 60 feet high, and add to the water supply of Madura and Ramnad, now obtained from the Vaiga.
The Tambrapurni river waters the Tinnevelly district. It has been crossed by several dams in very ancient times.
The East Coast Canal from Madras to Sadras is for traffic. • The Grand Canal of China has been led through and near a series of lakes, some Of considerable extent, extending all the way from Nan Wang, in lat. 35° 55' N., long. 116° 30' E., down to the Yang-tze-kiang.—Moral and Material Progress, 1871-2 ; Markham's Embassy; Annl. Ind. Adm. ; Report on the Administration V the Panjab; Powell's Handbook, EC011. Prod. Panjab ; Jack son's Manual. See Irrigation.