2009-10-16_PERMIT FILE - M2009082 (13)

Home Browse Search

east as overland flow, is collected in the borrow ditch along WCR 25 and returned to the Cache la Poudre River. Subbasin H7 contains approximately 22 acres. The boundary extends from the intersection of WCR 25 and the Cache la Poudre River east along the north bank of the river to the west bank of the deep cut channel which drains the slough in Subbasin H2 then north along the channel to it intersection with WCR 25 and then along the centerline of WCR 25 which forms the western boundary. The subbasin is generally located in the West One-Half of the Northwest One-Quarter of Section 31. The slope is generally between 0.2 percent and 1.5 percent with a subbasin average of 0.4 percent. Storm water drains from northwest to southeast as overland flow and is returned to the Cache la Poudre River as such. Subbasin H8 contains approximately 85 acres. The boundary begins at the intersection of the eastern property line and the Cache la Poudre River and courses west along the north bank of the river to the deep cut channel draining Subbasin H2, north along the channel to the centerline of WCR 25, north along WCR to the Whitney Ditch, east along the Whitney Ditch, and then turns south to follow a divide that separates drainage that leaves the property to the neighboring lands and drainage that returns to the Cache la Poudre River directly from the property. The subbasin is generally located in the Southwest One-Quarter of Section 30 and the North One-Half of the Northwest One-Quarter of Section 31. The slope is generally between 0.5 percent and 3.3 percent with a subbasin average of 1.0 percent. Storm water drains from north to south as overland flow and is returned to the Cache la Poudre River as such. Subbasin H9 contains approximately 25 acres. The boundary follows the eastern boundary of the property and the basin divide with Subbasin H8. The subbasin is generally located in the East One- Half of the Southwest One-Quarter of Section 30. The slope is generally between 0.5 percent and 2.0 percent with a subbasin average of 1.7 percent. Storm water drains from northwest to southeast as overland flow and leaves the property as such. Drainage conditions during mining were considered for Phase 1 of the mining plan. Subsequent phases result in a similar condition for each phase. Water captured by the mining area will be pumped from the pit and discharged to the Whitney Ditch, one of the sloughs, or the Cache la Poudre River. At the close of each phase, reclamation of the completed mining phase will coincide with the mining of the subsequent phase. Phase 1 of the mining drainage conditions was modeled as 14 subbasins, P1-1 through P1-14, affecting the historical basins H2, H8, and H9, as shown on Exhibit 2. The remaining historical basins are unaffected by Phase 1 and will remain undisturbed. Each phase of the Parsons Mine site will be reclaimed immediately following the completion of the mining and will precede concurrent with mining operations in subsequent phases. The reclaimed drainage conditions were modeled as 18 subbasins, RB 1 through RB 18, as shown on Exhibit 3. All the basins return to the historical discharge points unless captured by open water ponds left by the reclamation process. -4- Revised Preliminary Drainage Repott.docx