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-15- It has been brought to the attention of the Division by the State Engineer's Office that the work area sediment pond might not be capable of releasing stored water in excess of 2 acre feet within 36 hours in accordance with C.R.S. 1973 37-87-122(3). (See Attachment No. 3 of this document.) Based on information presented in Annexure H of-the application, it does appear that the storage volume below the elevation of the dewatering device is in excess of 2 acre feet. The following stipulation is necessary. Stipulation No. 2 WITHIN TWO MONTHS OF PERMIT ISSUANCE THE PERMITTEE MUST PRESENT INFORMATION ~ THE DIVISION DEMONSTRATING .THAT THE WORK AREA SEDIMENT POND IS CAPABLE OF RELEASING STORED WATER IN EXCESS OF 2 ACRE FEET WITHIN 36 HOURS OR SUBMIT RN APPROPRIATE APPLICATION FOR A COURT APPROVED AUGMENTATION PLAN TO REPLACE THE WATER S2t~RED OUT OR PRIORITY. Based on personal correspondence with Mr, Jim Hall of the State Engineer's Office, it has been determined that no augmentation plan will be necessary for water which "flows to the bottom of the pit" as is indicated in Attachment No. 3. Runoff from above is diverted around the active pit. water which accumulates in the bottom of the pit is limited to precipitation within the boundaries of the pit and is rapidly Zost to infiltration or evaporation. Rules 4.05.3 and 4.05.4 provide performance standards for stream diversions and stream channel reconstruction. Exhibit 7 of the original permit application contains discharge calculations and post-mining cross-sections. In response to concerns expressed by the Division in the preliminary findings document of December lI, 1981 the applicant has revised Map Z9 (May, 1982) to show the reoonstructed stream channels and the reaches of stream that would be rock lined, has provided additional calculations concerning the sizing of the reconstructed stream channel and diversions (January, 1982 and September, 1982), and has provided information concerning. the sizing, placement, and selection of riprap for the channels (September, 1982). AZZ pre-mining stream channels, with the exception of some minor drainages__ filled-in by the Streeter Fill, will be restored to their approximate historic location after mining. The other recronstructed stream channels and the Streeter Gulch permanent div_ers~~are a~I_sized to pass the 100-year_event._ - - (EVen'though the ZO-year event would be sufficient in some cases.) Those reaches of channel in which the design velocity exceeds_5_fps_wi11 be riprapped with material 1 1/2' to 4' in diameter. The Division finds that the channel re_a?nstruction_plan is_satisfactory_with_regard_to_the_performance standards.