Laserfiche WebLink
<br /> <br />G rJ,l : 'i'S <br /> <br />Chapter 2 <br /> <br />Supplemental Water Use <br /> <br />The purpose of this chapter IS to Identify. In general <br />terms. the Opportunllles for use of supplemental water <br />in Nebraska OpportUnI!leS, for purposes of this <br />chapter, are SItuations where supplemental water could <br />be used. even though economic. enVIronmental, or <br />other factors may constrain such use to the pomllhat <br />It IS judged not worthwhile. For Instance, lack of waler <br />and sUitable lands may create an opportunity 10 pro. <br />fltably use water for JTngalion once It has been <br />transported to some parts of the stale. However. the <br />cost of transporting waler to that area may be such a <br />constraint that IllS not considered a worthwhile eKpen. <br />dilute. Thus, "opportunity" refers 10 an ability 10 use <br />available water once It is prOVided to the site. <br />Four sltuallons will be discussed which demonstrate <br />such opportunities. They are the precip!tatlon pattern, <br />areas of groundwater decline. areas wllh pOlenlla1 for <br />Irrigation development based upon land SUitability. and <br />general areas with oppor1unllles lor speCifiC uses <br /> <br />q;- '\.' <br /> <br />ry~~ <br /> <br />...'" <br /> <br /> <br /> <br /> <br />~"oE>' <br /> <br />~?o~'l <br /> <br />A. PRECIPITATION PATTERN <br /> <br />Perhaps the major situation in Nebraska which <br />creates an opportuOlly to use supplemental water is lhe <br />precipitation pattern, both in space and in time. The <br />key word in both dImensions is variable. <br />Figure 2-1 indicates the mean annual precipitation <br />In the state by area for the years 1941 through 1970. <br />Annual average water reqUirements for maximum yield <br />by crops vary from about 25 Inches lor corn to 22 in- <br />ches for grain sorghum and soybeans (USDA, 1971). <br />This quantIty IS needed In the growing season and often <br />dunng speCific tImes in the growing season. Some 01 <br />the requirement may be met by stored soil moisture. <br />However, most of the reqUirement must be me! by <br />precipitatIOn which may not be available totally to crops <br />because of evaporation, runoff and groundwater <br />recharge. Further, as Figure 2.' shows, many areas <br />of the state will nOI receive enough precipitation annual- <br /> <br />",0 <br /> <br />~ <br /> <br /> <br />I /~~.. <br />-/I <br /> <br /> <br />n.'" <br /> <br />C,':~~' <br />\ <br /> <br />.~~ <br />,!>O <br /> <br />(559) <br /> <br />(610) <br /> <br />17621 (81311864) <br /> <br />(6601 (711) <br /> <br />FIGURE 2-1 <br />MEAN ANNUAL PRECIPITATION IN INCHES (MILLIMETERS) BASED ON THE PERIOD <br />, 900-1979 <br /> <br />2-, <br />