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. .., II 'l nrq , ,," UU .... Wetland Mitigation A- 13 mitigation is necessari, then the Applicants will perform additional mitigation. The goal will be functional replacement of lost values, as close to the point of impact as is practicable. At this point, Sponsors cannot provide detailed designs of individual indirect impact mitigation areas. This is because access to all mitigation sites has not yet been secured, so their finllllocations and boundaries are not yet known. Also, the potentially long lead times associated with the NEP A process could render obsolete site-specific information by the time project operation is imminent. Site-specific designs will be available in the Final Wetlands Mitigation Plan (See below). The Sponsors do have sufficient information to provide generalized pllins. Streambank wetlands have been delineated, the potential effects of erosion are known, and the geomorphic character of the river has been mapped. Greystone, who performed the original delineations, has prepared a series of Wetland Creation and Mitigation Profiles that Sponsors propose to use as guidelines. Their concept designs are attached as Appendix A. Creation of new wetlands in the Uncompahgre floodplain will often involve some lowering of surface elevations so that the water table is available to plant roots. SCS maps, as well as Greystone's soils sampling, confirm that hydric soils are abundant throughout this floodplain. Elevation lowering will usually produce enough hydric topsoil that soil augmentation is not necessary. If a special situation occurs where soil augmentation is necessary for plant success, then the soil can be drawn from adjacent, non-wetland sources. Any excess, excavated soil will be removed to an upland location. Specific sources of plant materials cannot yet be committed, since the potential date and quantities associated with site activation are not yet known. However, the following sources are anticipated: . Ditch, electric utility and road maintenance activities (willow sprigs, cottonwood poles, rhizomes and tubers). . Ongoing agency activities, such as pothole creation under the lower Gunnison Salinity Control Program (various seeds, sprigs and tubers). . Seed collection from existing wetlands (cattails, willow sprigs, grasses) (as approved by the CaE). . Colorado State Forest Service (woody species; seeds, saplings and poles). . Commercial nurseries. The Sponsors will follow planting and handling guidelines established by the SCS, CaE and other agencies. Appendix B contains general guidelines Sponsors anticipate using in There may be occasions when a short-term, net adverse effect is identified, but it is obvious to all parties that the impact will either disappear or be naturally replaced within a short period of time. Sponsors would like to preserve the flexibility to avoid implementation of mitigation in such situations, when the Corps is in full agreement that additional mitigation is unwarranted. AB Lateral Hydropower Project July 2000 . ,~'-'>~