Substitute Water Supply Plan Forum September 1 2004

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5 12.8. If the proposed final reclamation of the mining operation as approved in the Division of Minerals and Geologypermit, does not include backfilling or lining of all ground water eMosed within the mining boundaries, sufficient replacement water must be dedicated-to the plan to cover the expected depletions which would occur at the site due to evaporation The expected depletions from evaporation must include the surface area which would occur if dewatering operations at the site ceased and the ponds were allowed to fill er lined apen r-eelamatien sWI iwed suffleient r-eplaeement water- available in the event the deweF;ng pumps were stopped e any reason. If the final reclamation does not include backfilling or lining, the applicant can still provide sufficient bonding (through the Division of Minerals and Geology) to cover lining or backfilling dig -epees until such time as a court approved augmentation plan is obtained or until all depletions at the site have ceased and all dela end depletions have been replaced. In the event that the operator of the pit walks away from the site prior to final approval of an augmentation plan or prior to replacement of all delayed depletions, the dedicated water or bond will be used to insure that depletions will not occur a the site or that depletions will be replaced. As part of the proposed plan the applicant must clarify if they will dedicate water to the plan or whether a bond has been approved. If the applicant has obtained a bond they must indicate the amount of the bond and show that the bond is adequate to line or backfill the water surfaces that will be exposed during the plan ep riod. 13.9- The effect of stream depletions from the operation shall be evaluated. It will not be assumed that depletions occur instantaneously unless the euts de edge e the exposed ground water in the pit is located within 100 feet from the river or ste -site- specific geologic and hydrologic information warrants this assumption. Generally, timing of depletions may be calculated using Glover techniques [parallel drain theory, stream depletion factor (SDF)], or numeric modeling. Special procedures may be necessary to analyze depletions and injury on intermittent streams. 14.4-9- Historical native vegetation (including phreatophytes) consumptive use may be credited against monthly gross evaporation only if engineering documentation is included. The credit shall only be applied for the area under the free water surface and cannot exceed the amount of gross evaporation. Documentation of the vegetative growth shall be based on aerial and perspective photographs depicting the growth. Consumptive use analysis of this growth shall be based upon published engineering studies acceptable to our office and engineering analysis of site specific information for the type of growth, ground water depth, and soil information. In accordance with the State Enizineer's Office Policy 2004 -3 phreatophyte credit cannot be claimed for sand and gavel mining operations which are not approved through a permit with the Division of Minerals and Geology. Credit cannot be claimed for historical native vegetation under the free water surface exposed prior to January 1, 1981.