WHAT'S HAPPENING TO WATER? — ROBINOVE 383 



1913. By 1900 the local water supply was obviously going to be inade- 

 quate for the anticipated population growth, and other possible 

 sources of supply outside the local area were investigated. As a re- 

 sult, a 215-mile aqueduct was built to import water from Owens Val- 

 ley on the east side of the Sierra Nevada. By 1930 the population of 

 the coastal basins near Los Angeles had increased to over 2i/^ million. 

 To supply the growing population, the Colorado River was tapped 

 and an aqueduct, 240 miles long, with a capacity of 1,500 cubic feet 

 per second of water, was constructed by the newly formed Metro- 

 politan Water District of Southern California and began delivery of 

 water in 1941. The Metropolitan Water District now supplies water 

 to Los Angeles and surromiding cities with a combined population of 

 over 7 million and also supplies water to San Diego County. 



At present the State of California plans to store and divert water 

 from the upper Feather River drainage area in northern California 

 for use in the Central Valley, San Francisco Bay area, and southern 

 California. The magnitude of these efforts to provide water for 

 municipal and other uses is testimony to the expense and effort 

 needed to adjust the natural distribution of water to sustain the life 

 and economy of southern California. 



In many regions the quality of water is the fourth major water 

 problem. Water quality is determined by the dissolved chemical 

 constituents and by the sediment carried in the water. The chemical 

 quality of water is extremely variable, and in some parts of the 

 Nation the water has always been "poor" — that is, miusable for 

 most purposes because it contains excessive amounts of dissolved min- 

 erals. Much of the water in the ground is of poor quality — possibly 

 more water of poor quality than of good quality is stored in the 

 ground. A person may say that his water is 994%oo percent pure, 

 but such a statement is only figurative. The amount of dissolved 

 minerals in natural water is measured in p.p.m. (parts per million), 

 that is, parts of mineral constituents per million parts of water. A 

 water that could be said to be "994yjQQ percent pure" would contain 

 5,600 parts per million of dissolved mineral matter and would be 

 unfit for drinking. Drinking water usually should have no more 

 than 500 p.p.m. of dissolved minerals. Sea water usually is about 

 96V2 percent "pure." 



Sea water may mix with surface and ground water and thus impair 

 the quality of the fresh water. The sea water off the coast opposite 

 New York City has a normal chloride content of about 18,500 p.p.m. 

 The tidal estuaries of streams flowing into the Atlantic Ocean near 

 New York City have somewhat lower salinities, from about 2,000 

 to 16,000 p.p.m. of chloride, because the fresh water of the streams 

 is mixed with the sea water. The ground water in parts of Queens 



672-174—63 28 



