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path toward the Dolores River. Generally, the flows are parallel to and/or across the existing access road. <br />The surface flows appear to have had minimal erosion effects above or below the road cut. The existing <br />access road does not have any drainage structures crossing the road to control or manage the drainage <br />water from the hillside above the access road. Currently wafer sheet flows across the road or crosses in <br />shallow clhannelized flows. <br />The drainage flows from the hillside above the mine's operaticuial area, appear, based on topographic <br />information, to enter the operations area in shallow concentrated flows at several locations. However, due <br />to a significantly flatter surface slope, created by previous grading of the operations area, the flows slow <br />and spread out returning to a sheet flow character across the operations pad before exiting the operations <br />area. As the flows continue downhill after crossing the operations area, they exit the operations pad area <br />spilling onto the relatively steep sloped terrain east of the mine side. Upon exiting the operations area, the <br />flows appear to return to shallow channelized flow. Over the years, erosion in the operations area and the <br />adjoining slope areas appear to have been minimal to non - existent. <br />No previous drainage plans have been prepared for the site and there are no master drainage plans for the <br />area around the mine site on adjacent /adjoining lands. No irrigation facilities are located on the mine <br />property. Existing flow patterns are generally from west to east toward the Dolores River. Drainage from <br />the east side of County Road Z 2.40 is directed by natural terrain and the County road either north or <br />south prior to crossing the County Road onto the mine site. See Figure 7- Existing Flow Patterns for <br />general depiction of the flow patterns. <br />PART 111 — Potential Drainage Problem Resulting from Development <br />Potential drainage problems resulting from the development of the mine would come primarily from <br />improvements made to the site grading of the Operations Area and the access road. The existing access <br />road into the site and the staging area of the operations area could have limited impact on drainage. The <br />access road will be graded and shaped to assist in drainage management and to minimize erosion effects <br />of the drainage flows. The access road will be graded in such a manner as to direct water from the hillside <br />above the road, into roadside collection ditches /swales before crossing under the roadway. Flows will be <br />directed to culvert inlets for crossing the roadway, or will flows will maintain a non - concentrated sheet <br />flow character, discharging across the road surface. The roadside collection ditches will be generally <br />parallel to the road alignment. At appropriate locations based on terrain limitations and concentrations of <br />flows, the drainage waters will be collected from the roadside ditches into culverts where the flow will be <br />conveyed under the access road. Concentrated flows at the culvert crossings locations will be disbursed <br />and returned to a sheet flow condition by virtue of rock check dams or other disbursal means. The access <br />road is proposed to be surfaced with an all - weather surface material of base course or similar rock and <br />gravel based materials to stabilize the road surface and minimize erosion. <br />The flows generated in the Operations Area will generally have a sheet flow character. These flows will <br />be collected in their entirety into stormwater holding ponds for silt settlement and disposal by evaporation <br />and percolation. Provisions will be made for overflow from the holding ponds in the event of back -to- <br />back intense rain events. The discharge from the holding pond will be disbursed to a sheet flow character <br />through the use of rock check dams or other flow disbursing means similar to the discharge from the <br />culvert crossings described above. Discharge from the ponds will be in accordance with the requirements <br />established by Mesa County in its drainage manual. <br />Flows from the undisturbed areas of the mine site, i.e. the up slope area above the mine portal and <br />Operations Area, which will not be crossing the access road, will follow the current natural drainage paths <br />currently followed, which are dictated by the natural terrain. Runoff from this up -slope area will be <br />captured in holding ponds at the base of the slope west of the operations area before it is allowed to flow <br />9 <br />