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11 <br />I <br />t <br />C <br />1 <br />21 <br />instance, in 2000, well 10 -10 -28 -BBC (I /z mile from the river) was nearly constant <br />through April and May, while the river fluctuated though a wider range but was also <br />fairly constant. In 1999, with several rain events, the well had a substantial and sustained <br />rise during April and May, while the river had a smaller rise and then receded to near its <br />original level. <br />During March 2000, the river at the Alda transect was higher than in the same period in <br />1999. Well 10 -10 -20 -AAA, located 1 -1/2 miles from the river, was lower than in March <br />1999. None of the other wells were monitored in March of both years. There was no <br />significant precipitation in March of either year. <br />The conclusions that were drawn from the 1999 data are supported by the 2000 data in <br />several ways. <br />The general rise in ground water that occurred in April and May 1999 along with <br />frequent precipitation did not occur in 2000 when there was minimal precipitation. <br />This difference occurred even though river levels in March and April were very <br />similar for the two years. May 1999 saw higher river elevations, but they subsided <br />by the end of the month to levels comparable to 2000 flows, while the ground water <br />continued a steady rise into early July. <br />• Ground water levels within a few hundred feet of the river are strongly influenced by <br />the river level. Three wells within 200 feet of the river were monitored in 2000 and, <br />as in 1999, these wells reflect the river level on a daily basis. <br />• The relationship with the river weakens with distance and at 1/2 mile the wells appear <br />to be fairly independent of the river elevation. The failure of well 8- 19 -3 -ABB to <br />detect changes of 6 inches in river level over several days demonstrates the lack of <br />influence the river has the ground water only 1/2 mile from the river. <br />• The wells that were monitored in 2000 appear to respond to precipitation events of <br />one -half inch or greater. The rises were from a few tenths of an inch to a little more <br />than a foot, and nearly always began declining the day after the rainfall. <br />• Excessively dry soil conditions are thought to have minimized well response to the <br />rainfall events of June 12 and 19 and July 3 and 4. The response that did occur <br />generally occurred at the same time or before the river rise, indicating that the water <br />table rise and the river level rise were both responses to the precipitation. <br />• Some of the wells rose slightly during May without precipitation while the river level <br />was declining. This is apparently due to regional ground water flow from areas <br />where the water table is at a higher elevation. As shown in figure 2, the direction of <br />Ground Water and River Flow Analyses <br />