1977-09-29_PERMIT FILE - M1977315

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I1located on the northeast corner of the property. Pit ' drainage water will then be conducted via the storm sewer to the Cache La Poudre River at a point one mile ft north of the subject tract of land. i)(iReturning the water immediately to the aquifer by means ' of recharge wells along the north side of the site. lWith either procedure, the de-watering operation will lower . the water table in the pit to the bedrock elevation and will L'. permit dry-process extraction of the remaining portion of the gravel down to the bedrock elevation. I' C. The extraction of gravel from the site will result in a substantial lowering of the ground level in the mine area I' as overburden material is replaced in the pits after extrac- tion is completed. After the removal of the gravel, the parcel will of necessity include a lake which is projected to have a water surface area of approximately 14 acres. . E d. De-watering the pit will create a ground water depression which will migrate in a northeasterly direction to the Cache La Poudre River. The gain to the Cache La Poudre River which results from return of the water drained from the pit will exactly equal any depletion to the stream, and the precise impact on streamflow will depend upon. which technique has been utilized to return the drainage water to the stream: L' (i) Recharge wells would return the pit water immediately to the ground water formation at a rate exactly equal L' and opposite to the depletion caused by pumping. There, would be no net impact, either positive or negative, on the rate of flow in the Cache La Poudre Rivera (ii) Pit drainage water introduced directly to the river via L' the storm sewer will cause a net streamflow effect that will be either positive during periods in which the pit is being de-watered, or negative while no pit water is L' - 3 -