Laserfiche WebLink
<br />.. . r . <br />, . f 1 <br />...)w.J- <br /> <br />70 <br /> <br />METROl'OLITAN WATER DISTRICT <br /> <br />with the less important bottom storage. Lake Mead stored water is <br />now of better quality (softer and less saline) than at any time since <br />the first filling of the reservoir. The tabulated data are consistent <br />with the summarized analyses at the aqueduct intake as listed above <br />but show the margin or difference by which the Lake Havasu water <br />may still improve during the winter of 1952-53. This immediate <br />optimistic expectancy is subject to the qualification, of course, that <br />renewed use of the lower gates at Hoover Dam may occur in 1953 <br />and again rewlt in harder water at the aqueduct intake. <br /> <br />Aqllcd-lIct It.'ate,. t(;lIIpcr((tl/.)'c~ , <br />Temperature of the diverted Colorado Hiver (Lake Havasu) <br />water in 1951-52 averaged 65 degrees, or two degrccs lower than <br />the previous year, with a range from 45 degrees in midwinter to <br />84 degrees in the late summer. At Hayfield, the last of the aqueduct <br />pumping plants, the water pumped averaged 63 degrees or about <br />one degree cooler than the previous year v"!'J'ing seasonally from <br />one degree to four degrees (month]y averages) cooler than Lake <br />Havasu water. In the open canal sections of the aqueduct, the <br />flowing water is exposed in transit to one day's desert sun but the <br />cooling effect of the tunnels and covered conduit sections more <br />than offsets the heating, even under such extreme desert conditions. <br />Tabulated for comparison are monthly and annual water tem- <br />peratures along the aqueduct, with adjacent mean air temperatures <br />which are a controlling factor in the seasonal and yearly variations <br />of the water temperatures. Thege data supplement table 13 of the <br />Seventh Annual Report which summarized such temperature rec- <br />ords for the operating period 1941-1045. <br />The listed mean air temperatures for 1951-52 show a departure <br />from the norma] of _1.80 at Gene Camp, _1.50 at Hayfield pump- <br />ing plant and -0.1 G at Pasadena (Eagle Rock). The current year <br />was thus s]ightly cooler on the average, than the record mean or <br />anticipated normal temperature, and from one to two degrees <br />cooler, as a seasonal average, than the previous year. <br />Aqueduct water temperatures in 1951-52 at the Weymouth soft- <br />ening and filtration plant near La Verne averaged 62 degrees, or <br />1.3" below the mean air temperature at Lake Mathews, the imme- <br />diate source of the aqueduct water, where at present rates of COn- <br />sumption, storage for a year or more occurs. Water delivered to <br />consumers in most of the member cities had a mean temperat.ure <br />of 63 degrees with a seasonal range from 52 degrees to 76 degrees. <br />The mean rose to about 64 degrees at the ends of brunch aqueduct <br />