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If corrective measures described above fail, New Horizon proposes to observe and reevaluate the <br />situation. A combination of the first two methods described or some variation therein will be <br />applied. These activities can include, but are not limited to, rock channels, contour furrows or <br />laterals with rock or matting bottoms, V ditches made with the dozer or motor grader, and <br />subsequent revegetation. <br />Head cutting in channels will be controlled by a number of methods. If the area is at a point that <br />concentrates runoff, the area will be improved to accept this runoff. This would include <br />reshaping the channel and channel bottom, covering with erosion matting, seeding, or rocking. <br />Inlet channel erosion will be controlled down to the average water level of the ponds. Remedial <br />action on pond slopes will extend as far down the slopes as equipment access allows, which at a <br />minimum will be below the level of the principal spillway of each pond. <br />In other areas, depending on the extent of erosion and time of year, the area will be regraded, <br />disked, and seeded as needed. Straw bales, erosion matting, or rock fill may also be used to <br />stabilize the area. Pond 007 will remain for stock use by the landowner. <br />1. Design Methodology <br />The precipitation runoff (peak flow and volume) is estimated using the Soil Conservation <br />Service (SCS) triangular hydrograph techniques. <br />Design of Small Dams (U.S. Dept. of Interior, 1977). <br />Computations necessary for this runoff estimating technique have been computerized by various <br />individuals and agencies. The SEDCAD program was used for the design of Pond 007. <br />The input consists of precipitation amount (inches), watershed area (acres), time of concentration <br />(hours), runoff curve number (CN), representative particle -size distributions of the soil types in <br />the watershed, sedimentology information, spillway information, etc. <br />The precipitation amounts for the New Horizon Mine for the design storm durations were <br />obtained from the NOAA Precipitation Frequency Atlas Precipitation - Frequency Atlas of the <br />Western States Volume III - Colorado, 1973, and are listed below: <br />10 -year, 24-hour - 2.0 inches <br />25 -year, 24-hour - 2.4 inches <br />100 -year, 24-hour - 3.0 inches <br />Page 2.05.3(3)-7 January 2016 (TR -70) <br />