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<br />~AXI~UM DISCHARGE OF COLOl'IADO RIVE~ AT HOOVER DAM
<br />
<br />of the Colorado's average flow-enough to flood the entire State of New
<br />York with water 1 foot in depth.
<br />When filled to capacity, Lake Mead has a depth of 589 feet, a shoreline
<br />of 550 miles, and a surface area of 227 square miles. It extends upstream
<br />115 miles above the dam.
<br />With its great reservoir, the dam controls not only the flashy, lesser floods
<br />which may occur at any time throughout the year, but also the great flood-tide
<br />run-off occurring each spring and summer.
<br />The upper 72 feet of Lake Mead-9,500,OOO acre.feet-are reserved for
<br />seasonal flood-control purposes. The lake is so operated as to have this
<br />portion of its capacity available to store the yearly run. off. As a result the
<br />level of the lake is constantly changing. In the spring and early summer
<br />the lake level rises, and then during the fall and winter its level is drawn
<br />down to make room for the next flood.
<br />No longer at the mercy of the Colorado are the homes and the highly
<br />productive lands in the low, flat valleys of southern- California and south-
<br />western Arizona. These lands, carved out of the desert by the early pioneers
<br />represented, in 1930, property values of a quarter of a billion dollars.
<br />With Lake Mead functioning, the large floods passing the dam site can be
<br />reduced from 200,000 cubic feet per second to 45,000, and the extremely
<br />rare floods from 300,000 cubic feet per second to about 75,000. In 1941
<br />a flow of ] 22,000 cubic feet per second was reduced to 35,000 with no
<br />resulting damage below Hoover Dam.
<br />
<br />34
<br />
<br />f) 1769-
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<br />And so today, residents of the valleys below Hoover Dam need no longer
<br />fear ~he fury of the untamed river, provided the channels and the levees
<br />carrymg away the greatly reduced discharges are maintained.
<br />
<br />';\.0 More Drollght
<br />
<br />The second great benefit from Hoover Dam is the provision of a stable
<br />supply of 'water for irrigation.
<br />No more is the Colorado's water-precious as the O'old that lured th
<br />"49" d c e
<br />ers west war a century ago-\vasted into the sea during the Hood sea-
<br />sons, Instead, the Colorado's water is put to use.
<br />The irrigated land of the Southwest is the all.year vegetable and fruit
<br />basket ,of ,the Nat~on.. '\Vith an adequate and dependable supply of water
<br />for artIfiCIal applIcatron, the rich soil and warm climate make the Imperial
<br />and other valleys of the region veritable Gardens of Eden. From thi<;
<br />region of the Southwest come, in the dead of \:"'inter, great quantities of
<br />green vegetables and citrus fruit for the American diet. From these lands
<br />come also figs and dates, grapes and raisins, olives, avocados, walnuts.
<br />alm~nds, an~ other exotic fruits and nuts, once entirely imported fron;
<br />foreIgn, tropIcal lands.
<br />
<br />I1anesting head lettuce ou irrigateclland.
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