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<br />'''---..'''--.-'- . <br /> <br />" <br /> <br />OQl106 <br /> <br />Above the layers which cenfine the artesian aquifer, the sands and gravels also. <br />bear water. This "uncenfined" aquifer can be cenceived ef as a large spenge en <br />the surface ef .the Valley. The "spenge" is kept meist by spring runeff frem the <br />meuntain slepes, irrigatien diversiens, and to. a small degree by upward leakage <br />frem the artesian aquifer. Like a dry spenge left en a wet kitchen ceunter, <br />capillary actien slewly dist'ributes water threugh the whele system. The spenge <br />becemes evenly damp. In the sump area ef the Clesed Basin, the effect ef the <br />sun en the surface ef the land is like a heat lamp being fecused en eur <br />"spenge." The tep surface feels dry but, in fact, water meves threugh it all <br />the time and evaperates into. the atmesphere. The Preject is, quite simply, <br />designed to. capture seme ef this water befere it evaporates. <br /> <br />A pipe apprepriately sletted belew the water table"which is inserted into. the <br />uncenfined aquifer, will fill, up with water to. abeut the level ef the water <br />table. If the water is to. reach the surface, it must be pumped. The Preject <br />wells are designed to. werk this way. Preject effects to. the uncenfined aquifer <br />are limited to. the area within the Preject beundries. This is the secend way <br />that the Preject will minimize lecal ecenemic effects. By law, the eperatien ef <br />the Preject cannet lewer the water table mere than 2 feet eutside the Preject <br />beundaries. Observatien wells have been established areund the periphery ef the <br />Project area. Except fer abeut 30 minutes a year to. clear eut sediments, these <br />wells are net pumped at all. They are strictly there fer allowing menthly <br />measurements ef the water table to. be made. These measurements are a public <br />recerd. The Preject salvage wells inside the beundaries werk by creating a <br />drawdewn in the water table (see figure B-1). The design calls fer them to. be <br />spaced and pumped at a rate so. that ever the whele 130,000-acre Preject area <br />the water table will be lewered by an average ef 4 to. 8 feet while net drepping <br />mere than 2 feet at er bey end the beundaries. The water belew and the vegeta- <br />tien en tep ef all land eutside ef the Preject beundaries will net be signifi- <br />cantly affected by the eperatien ef the Preject. <br /> <br />Seme peeple find the scale ef seme ef the Preject's statistics to. be alarming <br />(150 to. 180 wells, 130,000 acres ef Preject area, 104,000 acre-feet ef yearly <br />salvaged water). In fact, these statistics sheuld be reassuring. The Preject <br />design calls fer an average ef less than eue well per sectien. Virtually no. <br />place else in the Valley are wells so. widely spaced. The preject's planned <br />104,000 acre-feet annual yield is tiny when cempared to. the water preduced by <br />enly the new center pivet systems intreduced in the Valley fer anyene year in <br />the 1970's (see sectien VI, questien 2). The reasen that there are so. many <br />wells is because they will be widely spaced and each ene will recever enly rela- <br />tively small ameunts of water. This is the aspect ef the preject's design which <br />allews enly the ameunt ef water to be salvaged which would evaperate naturally. <br /> <br />The third aspect ef the Preject which relates to. minimizing lecal ecenemic <br />effects has to. de with the character ef the land which is within the 130,000- <br />acre Project beundaries. Water has centinueusly evaperated from the surface ef <br />the Clesed Basin sump fer centuries. The minerals disselved in that water are <br />left behind en the greund surface. As a result, much ef the land surface is <br /> <br />7 <br />