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<br /> <br />reclamation increase is 10 of the annual yield, and salt loading would be at the <br />rate of i.6 :cg/yr. Williams Draw would be subject to a 2Z°~ reduction by sediment <br />ponds, a 2`k post-reclamaticn increase, and a salt loading of 21.4 y/yr. In Suddut.`. <br />Draw no additional sediment ponds would be built and the flow reduction would <br />remain 3~, following reclamation flow would be increased by 1°.:, and anticipated <br />salt loading would be 5.4 tig/yr. <br />In Bolton Draw, the most affected ~oatershed, the calculated effects would <br />severely overestimate probable effects. Areas of existing disturbance have already <br />been reclaimed, or soon will be reclair„ed. By the time anticipated future mining <br />in this watershed is conducted, reclamation of existing disturbances will be <br />complete, and probably the sediment control facilities will have been removed. <br />The .most severe effects in Bolton Draw have probably already occurred. <br />FI^7DIVG - The proposed operations have been designed to prevent material damage <br />to the hydrologic balance outside the permit area. <br />All of the effects identified in the analysis are short-term alteration of the <br />hydrologic balance. (see summary of Probable Hydrologic Effects). The analysis <br />has identified no irreversible, adverse effects on the hydrology of surrounding <br />areas. <br />Probable Hydrologic Conseeuences - <br />SL:M~~IARY OF SURFACE [DATER EFFECTS <br />1. Runoff and Erosion <br />Dur_'nq nining_, disturbed areas would be susceptible to erosion and runoff. <br />Mitigated by sediment control system. Sediment control cannot be z'emo•~ed <br />until revegetation is successful and erosion rates atop to natural levels. <br />;Jhile the sediment ponds are present, they :vill reduce runoff to the <br />receiving streams. (p. 780-126eeeee) <br />Receiving Stream <br />Bolton Draw <br />Bush Draw <br />Wi iliams Draw <br />Sudduth Draw <br />Percent Detention <br />15.8 <br />~.4 <br />17.4 <br />2.9 <br />This effect would be temporary, and would cease when sediment ponds are <br />removed. <br />Following reclamation, the disturbed site would, for a short period of <br />time, be susceptible to erosion, and would temporarily have increased <br />runoff rates. These problems are rectified with time as the reseeded <br />areas develop with plant root growth and as the fresh topsoil becomes <br />settled and stabilized. <br />Contour furrows will be used to retain water from precipitation as <br />much as possible within seeded areas during reclamation (would a15o <br />reduce erosion). During the early years following reclamation all of <br />the runoff should be retained by the contour furrows. <br />At the end of the bonding period, vegetative cover :sill be established <br />and the tobsoiZ stabilized, and contour furrows and sediment ponds will <br />-7- <br />