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<br />o <br />(";) <br />.',"" <br />..-I <br />,7) <br />t":; <br /> <br />7 <br /> <br />Above the layers ..hich confine the artesian aquifer, the sands and gravels <br />also bear water. This "unconfined" aquifer can be conceived of as a large <br />sponge on the surface of the Valley. The "sponge" is kept moist by spring <br />runoff from the mountain slopes, irrigation diversions, and to a small <br />degree by up..ard leakage from the artesian aquifer. Like a dry sponge left <br />on a ..et kitchen counter, capillary action slowly distributes water through <br />the ..hole system. The sponge becomes evenly damp. In the sump area of the <br />Closed Basin, the effect of the sun on the surface of the land is like a <br />heat lamp being focused on our "sponge. 11 The top surface fee Is dry but J in <br />fact, water moves through it all the time and evaporates into the <br />atmosphere. The Project is, quite simply, designed to capture some of this <br />water before it evaporates. <br /> <br />A pipe appropriately slotted below the water table, ..hich is inserted into <br />the unconfined aquifer, will fill up with water to about the level of the <br />water table. If the water is to reach the surface, it must be pumped. The <br />Project wells are designed to work this ..ay. Project effects to the uncon- <br />fined aquifer are limited to the area within the Project boundries. This <br />is the second way that the Project will minimize local economic effect. By <br />la.., the operation of the Project cannot lower the water table more than 2 <br />feet outside the Project boundaries. Observation wells have been <br />established around the periphery of the Project area. Except for about 30 <br />minutes a year to clear out sediments, these wells are not pumped at all. <br />They are strictly there for allO\Jing monthly measurements of the water <br />table to be made. These measurements are a public record. The Project <br />salvage wells inside the boundaries work by creating a dra..down in the <br />water table (see figure B-1). The design calls for them to be spaced and <br />pumped at a rate so that over tbe whole 130,000-acre Project area the water <br />table will be lowered by an average of 4 to 8 feet while not dropping more <br />than 2 feet at or beyond the boundaries. The water below and the vegeta- <br />tion on top of all land outside of the Project bondaries ..ill not be signi- <br />ficantly affected by the operation of the Project. <br /> <br />Some people find the scale of some of the Project's statistics to be <br />alarming (150 to 180 ..ells, 130,000 acres of Project area, 104,000 acre-feet <br />of yearly salvaged ..ater). In fact, these statistics should be reassuring. <br />The Project design calls for an average of less than one well per section. <br />Virtually no place else in the Valley are wells so widely spaced. The <br />Project's planned 104,000 acre-feet annual yield is tiny when compared to <br />the water produced by only the new center pivot systems introduced in the <br />Valey for anyone year in the 1970's (see section VI, question 2). The <br />reason that there are so many wells is because they will De widely spaced <br />and each one will recover only relatively small amounts of water. This is <br />the aspect of the Project's design <<hich allO\<5 only the amount of water to <br />be salvaged which would evaporate naturally. <br /> <br />The third aspect of the Project which relates to minimizing local economic <br />effects has to do with the character of the land,..hich is within the <br />130,OOO-acre Project boundaries. Water has continuously evaporated from the <br />surface of the Closed Basin sump for centuries, The minerals dissolved in <br />