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Sedi m,e nt Control <br />During construction, deadheading, and reclamation of the deadhead routes, Seneca will <br />utilize toad berms, silt fence, and hay bales to minimize sediment runoff. These same <br />techniques were used during construction of Haul Roads "A" and "B". As previously <br />mentioned, should a culvert be required, the sizing will be based on the information in <br />Attachment 13-9, Light-Use Roads Generic Culvert Design. Because of the disturbance in <br />[he drainage channel underneath the PSCO/WAPA powe [lines, a temporary diversion ditch and <br />reclaimed drainage channel needed to be designed. Addendums 13-10A and 13-lOB contain the <br />design information for both these channels, respectively. <br /> SEDCAD+ was utilized to design both the channels using the erodible/riprap channel <br /> options. Th e disturbed drainage has a watershed of 1,145 acres and a very conservative <br /> curve number of BO was input to calculate the runoff volume and peak discharge. The <br /> vegetation types in the drainage area were reviewed to come up with an acceptable average <br /> for the curv e number used. The temporary diversion will be a triangular ditch with 2:1 <br /> sideslopes, have a 1 percent bed slope, and at a minimum, be 1.5 feet deep. Once the <br /> dragline is past the disturbed drat nage channel, construction of the reclaimed drainage <br /> channel will begin. The resulting reclaimed channel will be trapezoidal with a 2-foot <br />• wide bottom, 'nave 3:1 sideslopes, a bed slope of 1 percent, be at least 2.25 feet deep, <br /> and be lined with a Dao riPrap size of 9 Inches. <br />Feclamation <br />As was stated earlier, all constructed deadhead roads will be reclaimed as soon as the <br />dragline passes and equipment can operate safely. All disturbance and reclaimed acreages <br />associated with the dragline move will be provided in the 1996 Annual Reclamation Report. <br />All areas disturbed will be graded back to app [oxl mate the original contours. The areas <br />where topsoil was windrowed out to the edges of the read will be replaced in the same <br />manse[. Upon completion of topsoil replacement, seeding will be accomplished on all <br />disturbed acres, even these where topsoil was not moved. Seve[al tables in Tab 22 were <br />r=wised to corn ain the pertinent acreages related [o ihls project. The two main seed <br />mixes which will be planted are Seed Mix 1B (shrub grassland) and Seed Mix 3 (Alkaline <br />lowlandsl. Seed Mlx 3 will be planted in the drainage channel, and all other areas will <br />be done wish Seed Mix 18. The tables in Tab 22 were revised to reflect a maximum <br />disturbance of 65.0 acres, but in reality, [his will not be the case. <br />r1, <br />u <br />13-10-5 Revised 08/23/96 I <br />