Ethiopiaâ€™s Water Resources Management Policy of 1999 gives highest priority to supply drinkingrnwater as a national wide. Accordingly MoWE called attention to solve problems associate tornunstable states of deficient supplies and increasing demands. Mojo Town with rapid incrementalrnpopulation, the former existing water supply scheme found inadequate to meet the increasingrndemands of water for domestic uses. Hence, new water supply project for the Mojo town hasrnbeen executed and its works of construction on progress so far to alleviate such escalatingrndemands for the potable water due to advancing developments. The Mojo water supply schemerndepends on groundwater as the sole resource of drinking water from boreholes at Mojo wellrnfield. This well field system is designed containing of three deep boreholes where developmentrnfor each closer to Mojo Perennial River. All over again, this river is basically apprehensive ofrncontaminants because of existences of more than seventeen factories of tanneries, oil factories,rnwaste disposal site and six depots in which roughly all have established at about the brink of thisrnriver and most of the factories have not been facilitated with waste treatment plants so thatrnthese can be considered as the main sources of potential threats. Therefore; this research paperrnwas primarily initiated attributable to these conditions and was been conducted. As a return ofrnthis study, the maximum radius of influences was established fixing to be 3853m considering thernentire pumps in the boreholes were assumed working at once under case scenario of the wellsrnoperation with aquifer maximum transimissivity and minimum storativity and with the designedrnpumping rates. The minimum length of the plume position which existing at closest distant fromrnwell head is discovered at 2034m at the downstream of the well field. So the contaminant plumernis circumscribed in the influence zone of the pumping when the boreholes will start functioning.rnIt also elaborates the particular radii of influences as results of operating boreholes and realizesrnthat the cones of depressions are interacting with the Mojo perennial River and this river isrnsuspicious agents of the potential threats of contaminants sites as previously described. Capturernzone was also delineated at mean distance of 110m from the wells head considering casernscenario when the boreholes are all simultaneously operating, visualizing that this may supportivernin deciding remedying measures to protect the potential threatening of the contaminants fromrnadmittances into the boreholes at time when pumps in boreholes will be under equipped tornoperation. In determinations of differentiating influences of the long term operating boreholes,rnthe superposed drawdown for groups and individual boreholes under varying aquifer parametersrnwas approximated and noticed the intersecting of cones of depressions arrangements and thus inrnthis coincidence it recognized the happenstances of well interference at the Mojo well field whilernthe boreholes are operating.