Arizona republican., 1919-06-08

day Of continuous pumping 3-25 acre feet
 Pumping from wells similar to the one described above is not regarded as economically feasible for an additional water supply only, on account of the high lift and low yield Of water, It may, however, be regarded as feasible for drainage purposes. s
 Drainage throughout the valley, with few exceptions, can best be ac- complished through pumping, first for the reason that the porous under ground materials from which water must be removed, are too deep to be reached by ordinary drains. and sec ond, for the reason that pumping pro- vides a means whereby the ground water can be lowered to any required depth. Throughout the greater portion 1 of the valley the sands and gravels or i other porous materials through which 1 a free water movement takes place, are i found at depths of from 20 to 100 feet i or more below the surface. The water ] as it exists in these porous under ground strata, is under sufficient head 1 to cause it to rise to near the surface. l The wet condition of the soils is main tained largely by the upward motion of water into them. Drainage can be affected by pumping the water out of the porous strata below and permitting that in the solid to subside by down 1 ward motion.
 The areas where drainage by pump l ing is feasible and where it is believed that it offers the only satisfactory so- lution, include all of the affected lands on the south side. south and east of Tempe, nearly all of the lands on the north side of Salt river south and west of Phoenix, and along New river in the western portion of the project, and all, or nearly all of the lands north of Phoenix and extending eastward.to the Arizona Canal near the Arizona Falls Power house. On a portion of the lat ter area pumping has not yet been tried. It is consequently impossible, with the data at hand, to state posi- lively what results can be obtained from it.
 Direct drainage by means of open | trenches or covered drains is applicable ! where porous underground material through which water movement takes place, is sufficiently near to the sur face to permit of it being tapped by drains. It is applicaHe also in relat- lively uniform materials, for intercept ing water which is travelling down the slopes through the surface soils or over an impervious hardpan located at reas enable depths below the surface. The only places on the project where di- rect drainage may be necessary or ap- plicable, is a small area under the Ari Zona Canal north and east of Phoenix on the south side under the Western Canal, and on the bottom lands ad jacent to the river south and west oi Phoenix.
 Our principal conclusions may be summarized briefly as follows:
 First: The rise in ground water dur ing the past few years, and it's present proximity to the surface indicate clear ly that drainage is needed to protect the surface soils. over large areas, iron
 becoming water logged and alkaline and ultimately unfit for cultivation
 Second: That drainage is feasible both from the economic and engineer ing viewpoints.
 Third: That pumping generally may
 be regarded as the most feasible means for drainage but there are some area. where the effectiveness of pumpine has not been proven and where drain may be required.
 Fourth: The quantity Of water whicl must be removed during the next few years, it is estimated will amount t, about 100000 acre feet per annum. Fifth: That to remove this quantit, about 33 wells, in addition to thosa o1 ready provided for will be required.
 Sixth: That a more economic use O water will reduce the amount of drain
 age that ultimately will be needed. We recommend that provisions b, made for drainage in accordance witt plans herein outlined.