Son Canals
This article has been extracted from THE IMPERIAL GAZETTEER OF INDIA , 1908. OXFORD, AT THE CLARENDON PRESS. |
Note: National, provincial and district boundaries have changed considerably since 1908. Typically, old states, ‘divisions’ and districts have been broken into smaller units, and many tahsils upgraded to districts. Some units have since been renamed. Therefore, this article is being posted mainly for its historical value.
Son Canals
A system of irrigation works in the Districts of Shahabad, Gaya, and Patna, Bengal, which derive their supply from an anicut across the Son river at Dehri. The idea of using the waters of the Son for irrigation originated about fifty years ago with the late Colonel C. H. Dickens, and for many years the subject was under discussion. The project was undertaken by the East India Irrigation and Canal Company, but was handed back to Government in 1868, and work was not actually commenced until the following year. Sufficient progress had been made in 1873 to allow of water being supplied through cuts in the banks of the Arrah canal to relieve the drought of that year, and the canals were completed a few years later, They carry a maximum volume of 6,350 cubic feet per second. About 80 per cent, of the irrigation lies in Shahabad, 11 per cent, in Gaya, and 9 per cent, in Patna District.
The general plan of the works comprises the Dehri anicut, a main western canal branching off above the anicut on the left bank, and a main eastern canal branching off on the right. The anicut, or weir, which is 12,500 feet in one undivided length, and is, consequently, one of the longest weirs in existence, consists of a mass of uncemented rubble stone, with two core walls of masonry founded on shallow wells. The work was greatly facilitated by the presence of excellent building stone a few miles from the site. Scouring sluices were provided at each flank and at the centre. Those at the centre have since been filled up. The flank sluices serve to maintain clear channels in front of the canal head sluices, and they facilitate tlie regulation of the height of the water in the pool above the weir. The vents are operated, by means of shutters 20 feet 6 inches in length, on a system devised by the late Mr. C. Fouracres, by which the shock of the up-stream shutter when rising is taken by hydraulic tubular struts. The system has worked well, and there is a very complete control of the river even when it is in moderate flood. The total cost of the anicut, which was finished in 1875, amounted to about 15 lakhs.
The total length of the main canals is 218 miles, of the branch canals 149 miles, and of the distributaries 1,217 miles. The western main canal supplies the Arrah, the Buxar, and the Chausa canals, which all branch off" within the first 12 miles. The main canal is continued for a total distance of 22 miles, as far as the grand trunk road, 2 miles beyond Sasaram. Its prolongation for a farther distance of 50 miles to the frontier of the District, towards Mirzapur, was commenced as a relief work during the scarcity of 1874-5, but never completed. The chief engineering work is the siphon-aqueduct of twenty-five arches, by which a formidable hill-torrent, called the Kao, is carried under the canal. The Arrah canal branches off" at the fifth mile, and follows the course of the Son for 30 miles, when it strikes northwards, running on a natural ridge past the town of Arrah, and finally falls into a branch of the Ganges after a total course of 60 miles. It is designed for navi- gation as well as irrigation, but no permanent communication has been opened with the main stream of the Ganges. To allow for a total fall of 180 feet, 13 locks have been constructed. Besides four principal distributaries, the main offshoots are the Bihiya canal, 30 miles long, and the Dumraon canal, 40 miles. The Buxar canal leaves the main western canal at its twelfth mile, and communicates with the Ganges at Buxar, after a course of 55 miles ; it also is intended for navigation. The total fall is 159 feet, which is facilitated by twelve locks. Gaya and Patna Districts are served to a smaller extent by the eastern main canal, which was originally intended to run as far as Monghyr, but at present stops short at the Punpun river, a total length of only 8 miles. The Patna canal leaves the main canal at the fourth mile, and follows the course of the Son till it joins the Ganges at Digha, between Banki- pore and Dinapore. Its total length is 79 miles, of which 43 miles lie within the District of Gaya, and 36 in Patna.
The area irrigated in 1903-4 was 790 square miles. In 1902-3 the net revenue was 8-74 lakhs, giving a return of 3-27 per cent, on the capital expenditure; while in 1903-4 the receipts amounted to 13.24 lakhs and the working expenses to 5.38 lakhs. The capital outlay up to March 31, 1904, was 267 lakhs. The main canals are navigable, and the estimated value of cargo carried in 1902-3 was 10.2 lakhs ; Rs. 19,000 was realized as navigation tolls in that year and Rs. 23,000 in 1903-4.
