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<br />1 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />amendment. However, the impact from the new lands will be offset by increases in alluvial aquifer <br />storage in unlined ponds lefr on the previously permitted lands after reclamation. Th~: acreage of <br />unlined ponds in the previously permitted areas (Rockin' WP North and Miller Pit) results in an <br />increase in aquifer storage on those previously permitted lands. <br />Table 6 presents the impacts to the alluvial aquifer-stream system due to the mining operation at the <br />previously permitted azeas. Due to the high ratio of unlined ponds created (98 acres) ver>us alluvium <br />removed through mining (159 acres), the aquifer storage in this area will increase. Tie net affect <br />of the increased aquifer storage will be to increase flows from the streams to alluvial ret:hazge in the <br />spring and to increase discharge flows from the alluvium to the stream during the fal. and winter. <br />Historically, roughly 53 ac-fr of water flowed out of the streams to recharge the alluvium, primarily <br />during the months of April and May. The same amount of flow (roughly 53 ac-fr) was discharged <br />back to the stream from the alluvium, mostly between September and March. In the future, due to <br />the increased storage in the unlined pits, an average of about 2 i 6 ac-ft will flow from '.he stream to <br />recharge the alluvium, including the ponds, again primazily during April and May. T'he same 216 <br />ac-ft will be dischazged from the alluvium and ponds back to the stream when water I~~vels decline <br />between September and March. Therefore, the new mining operation will result in about 163 ac-fr <br />(216 - 53) more alluvial storage. The increased storage will result in less flow in the stream during <br />the historical recharge period in the spring and more flow in the stream during the f~.ll and winter <br />witen the alluvium typically discharges back to the streams. The greatest decrease in flows will be <br />in May, when approximately 98 ac-ft less flow will remain in the stream, on average fallout 1.64 cfs). <br />The increase in streamflows will be greatest in September when approximately 60 ac-ft more flow <br />will discharge to the stream (about 0.98 cfs). <br />As the data presented in Tables 5 and 6 suggest, [he impacts on the alluvial aquifer-~.tream system <br />relationship due to the amended mining application aze essentially offset by the impacts brought <br />about by the previously approved mining applications. In other words, the elimination of a large <br />amount of alluvia] storage in the amended application offsets the addition in alluvial storage which <br />has or will occur due to the previous permits. This is shown in Table 7. When the entire mining <br />-30- <br />/lnhip Rrn,rlru .l.rsr~,'ielrr. /ur. <br />