The Delhi Water-Works.
The new water-works at Delhi, says The Indian Engineer, which were designed and carried out by Mr. Parkes as chief engineer, were formally opened in November.
The works, which were begun in the early part of 1890, are calculated to supply an average of ten gallons a day for a population of 173,000, equal to a total daily supply of 1,730,000 gallons. It may here be mentioned that ten gallons of water are about equal to a large-sized mussuck. The population to be supplied is included in the city, the fort and cantonments, and in the civil lines and suburbs. Of the total quantity about seventy per cent will go to the city population. So far only half the estimated number of wells have been sunk. This was done in order to determine accurately the absolute number that would eventually be required for the complete supply, the method of obtaining filtered water from a river by a line of wells in close proximity to the running stream being unique in India. The number of wells constructed up to date is forty-three, the total daily supply obtained from them during the month of June last, when the water in the river was at its lowest level, hence at the most unfavorable season of the year, was 872,000 gallons in an ordinary day’s pumping. This quantity is equal to about three-fouiths of the full allowance for the city. With the completion of the wells the full supply for the city will be obtained, as well as that for the suburbs and cantonments. The water is led from the wells to the engine house by a three-foot conduit, 500 feet in length, consisting partly of brick masonry and partly of cast-iron pipes, imbedded in concrete. The majority of these pipes were successfully cast in Delhi at Bhana Mai and Gulzari Mai’s foundry. The laying of the conduit under water necessitated continuous pumping, which delayed this part of the operations very considerably. The machinery used for pumping the water consists of two high-pressure Worthington tripleexpansion jet-condensing engines, each of 100 horse-power, and two multitubular Babcock & Wilcox boilers, together with two economizers for heating the feed water to the boilers by means of the waste heat from the furnaces. Each engine, boiler and economizer is capable of raising, separately and independently, 1,750,000 gallons of water in sixteen hours from the well underneath the engine house, and forcing it through 6000 feet of rising main eighteen inches diameter to the reservoir, the total vertical height being 140 feet.
The reservoir is built on the highest point of the ridge, immediately to the east of Hindu Rao’s house. The top water level in the reservoir is ninety feet above the average level of the city. The dimensions of the reservoir are 300 feet in length and 150 feet in breadth, and when full it will have a depth of ten feet of water. The cubical capacity is over 2 500,000 gallons, equal to one and one-half days’ supply for the whole population. The inside of the reservoir has teen plastered with a thin coat of Portland cement, in order the more effectively to scour and clean it out on occasions when this has to be done. The walls of the reservoir are constructed of stone masonry, and the roof consists of concrete arches, the whole being covered in with earth to keep the water cool. The water can, at any time, when required, be pumped direct into the city main, through a by-pipe, without passing through the reservoir.
From the reservoir to the city the water flows through a main about 8000 feet long. This main has a diameter of twenty-four inches as far as the canal crossing. In order to permit of the extension of the system to the suburbs of Delhi, three branch pipes take off in this length, one for the Sabzimandi, the second for the civil lints, and a third to supply the suburbs of the Sadar Bazaar and Paharganj. From the canal crossing to the Lahore Gate of the city the main is reduced in size to twenty-one inches diameter. Within the city the total aggregate length of piping is 111,500 feet, rather more than twenty-one miles, varying in diameter from eighteen inches to three inches. This piping supplies all the intramural population, exclusive of the fort, the cantonment at Dariaganj. and the railroad station. Hydrants have been erected along every line of main piping, at intervals of 200 to 400 feet, according to the density of the population. To facilitate the extension of the pipe system, and to permit of the eventual introduction of house connections in every street and guli, extra branch pipes have been provided, where necessary, on all the mains. The total estimated cost of the works is about $500,000, of which $440,000 have been expended up to date.