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<br />,... 2'2( I
<br />",/' .- .1 ' 53 I (".-----'''1 17. - -
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<br />I ~ ; 54 : i <l>, 11 -\
<br />"r /[' ---{'I"T{ I -,.~-- -56~1 ~~ "'~,~,~~"'- 1!_~~~e"~,,~~l 5J___",,___ \
<br />'W _:.50 - ~ I I I ' ,.'6 c^' L ..; IJ2
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<br />,/ / /";, .~ ! 49; M : I r I: ,,9 /
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<br />
<br />,( L: Ii?: [ :.' I nj .19~l"t:5 []l'J2--'I.23 f.-,8.~ '_uu. 7 ,/
<br />,/"-~~~ ~\- 45 I ..
<br />"'~ >__ 44' -- -~4~ .42:.,~. I 33 :g'i.'.'-'--'~.L~ljl _CQ\l,otYFa=,,:~_asl__'_T_/-_
<br />'\ .:::~ ::, L. ,..34....:....~: :, " ,
<br />\ '" -~ - -:.::._~ ~ - ,-E; I · I
<br />"~ Besse~er Ditch ^' '2 r-- I 1
<br />\ I '~'-< "" -"- -"-->->", - 'I ..... N: South R4ad 5 ....-
<br />.. L,,,t~an3f,,t \(^~rr:~jl. <-T ... .... .:~~Fr-,,,,~l
<br />(21 wells) ,,_.1 \,~, I / "" I V' ,,: ..-- \ II ~i>""
<br />. 3 to less than 6 feet "("~j '^; I l' C;
<br />(25 wells) C.. Study Area ' ,. ..... --- ~ ) q"
<br />. 6 feet and greater ~ Boundary - 'J-~"''''' - j
<br />(11 wells) \ '
<br />44 Well number (table 1) \
<br />
<br />.
<br />
<br />00'983
<br />~ I \lJ)
<br />
<br />104034'
<br />
<br />r [/
<br />[/
<br />
<br />/1
<br />
<br />
<br />o
<br />f-
<br />o
<br />
<br />1/2
<br />
<br />0.5
<br />
<br />.
<br />
<br />104030'
<br />
<br />
<br />ii
<br />---0
<br />'"
<br />
<br />
<br />
<br />r'
<br />
<br />38014'
<br />
<br />1-1/2
<br />
<br />2 MILES
<br />
<br />Figure 4. Maximum change in depth to water in wells, St. Charles Mesa (Apri/1997 to October 1998).
<br />
<br />1.5
<br />
<br />2 KILOMETERS
<br />
<br />.
<br />
<br />
<br />
<br />B B
<br />
<br />BASEMENT #2
<br />
<br />[jEEPE~T PEPTH r6WATER (~TE WINTER)
<br />
<br />PUMPING )(,
<br />WATER-LEVEl:.
<br />
<br />Figure 5. The relation between the depth of a base-
<br />ment and the depth to water (DTW), how that relation
<br />determines whether a basement can become flooded,
<br />and the effect of a pumping well on the depth to water.
<br />
<br />Areas where the high water tahle may be a problem
<br />
<br />The November 1997 depth-to-water measurements were
<br />selected to represent the high water table because the highest
<br />water table occurs in most wells in autumn. The November
<br />measurements were converted to elevations of the water table
<br />above sea level, which were used to create a water-table
<br />surface. A land-surface-elevation map was created by digitizing
<br />the topographic contours, with a lO-foot interval, from the USGS
<br />topographic maps of the area. The water-table surface was
<br />subtracted from the land-surface-elevation map to yield a calcu-
<br />lated depth to water. The advantages of using this method were
<br />(I) the changes in the land-surface elevation could be taken into
<br />account, and (2) the depth to water could be calculated where
<br />there were no measurements. These calculated depths to water
<br />were then contoured to produce the depth-to-water map (fig. 6).
<br />The differences between the calculated and measured depths to
<br />water in wells ranged from 0.01 to 1.75 feet; the average differ.
<br />ence was 0.34 foot in 95 percent of the wells, and the difference
<br />was less than 0.5 foot in 40 wells.
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