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<br /> <br />water shortages) pll.l'ticularly in 1931 and;1934, caU$ed crop losses in <br />Imperial Valley, and a drop in the Sea level to another min:lm1llll of ~248 feet <br />in 1935. <br /> <br />Present Situation <br /> <br />Since commencement of storage behind :Hoover Dam. in 1935, there has <br />been ample water in the lower river, and the Sea has risen. It is now 237 <br />feet below sea level and the surface area'is 215,000 acres. For the past <br />several yell.l's it has been rising rapidly;: 1.5 feet in 1951. Sevel'al Wl'iters <br />have :l.m;plied that the rise was unaccountap1e,and that little is known about <br />the Sea. They make no mention of invlilsti~ations that 'have been m$.de or 01' <br />monthly gage readings of the elevation since 1904. '!hey :l.m;ply that the <br />rise thl'eatens the existence of Imperial and Coa.chel1a Valleys. One Wl'iter <br />attribu.tes the l'ise to seepage from. the GUlf' of California thl'ougl'l cracks <br />in the delta ~ an absurd theory. <br /> <br />Fallacy 01' Seepage Theory <br /> <br />The delta may be likened to a t'I.$l between Salton Sea basin and the <br />Gulf 01' Cali1'ol'nia; constructed with silt deposited as the RiVel' flowed back <br />and forth across its delta. This t'I.$l has a heigh.t 01' about 300 feet. In top <br />width a man~made dam would be, perhaps, 100 feet - nature1s dam is 8 to 10 <br />miles. A =~Iilade dm would have a freeboard 01' 5 or 10 feet - nature t s <br />has 35 feet. The base thickness of a lIIl3Ji-made dam. would be 2,000 feet ~ <br />nature's t'I.$l is 140 miles. Taking these ,factors into account, plUS the fact <br />that nature's dam has r.emained intact for centuries, it would seem that <br />Impel'ial Valley has little to fell.l' fl'om the possibility 01' seepage from <br />the Gulf. <br /> <br />Factors Involved in Rise of Sea <br /> <br />Ther.e is nothing unaccountable or unprecedented about the rapid <br />rise in the last several yeal's. Whenever inflow from local storms and return <br />flow from irrigation exceed evaporation" the Sea rises. A number 01' tilltes in <br />the last 50 years the Sea has come up asimuch as 1.5 feet in a yell.l'. Runoff <br />from single storms has raised the e1evat~on 0.75 to 1. 5 feet. SUllIIIler storms <br />followed by a cool, wet fall and winter were a decided factor in the 1.5 foot <br />rise 01' 1951. There had been few sunnner: storms for years. Other 1'actol's are <br />the 100,000 acres increase in irrigated acreage, and the increase in efficiency <br />of drainage in Imperial Valley, with conseCl.uent increase in return flow to <br />Salton Sea. In 1948, diversions frOlll. Colorado Rivel' to Imperial and <br />Coachella Valleys totalled 2,900,000 acre~feet; in 1951 the total was over <br />3,500,000. Another factor was a change ,in the crops grown. 1951 saw a <br />return. of cotton to Imperial Valley for ithe first t:l.llie in 20 years ~ 28,000 <br />acres in 1951 and 88,000 in 1952. Cotton is a heavy user of water and r.esults <br />in greater return flow than many other ~rops. These factors comb:l.ned explain <br />the rise of Salton Sea, and as developmEint of the area increases, will no <br />doubt result in a :f'ur:ther rise ~ it is nothing weird or :myst.erious and can <br />be 1'u11y accounted for. <br /> <br />~26- <br />