The New Student's Reference Work/Water-Works
Water-Works, a system of pipes and conduits connected with reservoirs or pumping-stations for the supply of water to communities. The ordinary supply of water to communities where the population is scattered is from shallow wells, but in crowded cities such wells become very dangerous on account of the contamination of the water by impurities from the soil. The water-supply of large cities often forms a very difficult problem, and large reservoirs and long conduits often have to be built to get an ample supply of pure water. The common sources of supply are streams, lakes, springs and wells, if the water is derived from streams or lakes, the great difficulty is to get a drainage-area which has not been rendered impure by the refuse of the surrounding population. The water of New York City is derived from the watershed of the Croton River and is led into reservoirs in New York City (q. v.) through an aqueduct 29.6 miles long. This aqueduct has an average diameter of over 13 feet. (See The Century Magazine for December, 1889.) Chicago and Cleveland pump their water from the neighboring lakes, a tunnel of several miles being bored out under the lakes in each case so as to secure water free from shore refuse. Where the water for public supply is taken from wells, the wells are always sunk or driven several hundred feet into the lower strata, where the supply is more constant and is freed from surface impurities. Two systems of distribution are in use: the reservoir and the pumping system. In the reservoir system the water is collected by natural flow or by pumping into reservoirs and then distributed by gravity to the houses. In the direct-pumping system the water is pumped into the mains by pumps which are kept working day and night. The latter system is cheaper to install, but more expensive to operate. Where there is no natural elevation for a reservoir, it is common to erect a large, steel stand-pipe, which will have sufficient capacity to furnish part of a day's supply. The daily consumption of water in American cities is about 106 gallons per person. This is from two to three times the amount used in European cities. To check the waste of water, it is common now to supply water by meter, so that each user pays according to the amount consumed by himself.