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Wattenberg Lakes Gravel Mining Revised Compensatory Mitigation Plan Weld County,Colorado Compensatory Mitigation Compensatory mitigation replaces and improves permanently impacted resources. For this project, compensatory mitigation focuses on providing functions similar to or better than functions provided by the impacted wetlands. The impacts from mining activities and reservoir construction were largely to the Huett Ditch and Lupton Slough. Onsite mitigation originally and currently proposed are focused on recreating the form and function of the ditch and slough. Mitigation associated with Huett Ditch has already occurred, resulting in the successful re-establishment of a wetland channel with varied flow, gradual banks, and native vegetation. Mitigation for the Lupton Slough wetland impacts will occur in Phase III, Mine Area 2 (Figure 2), designated as Mitigation Area 4 on Figure 4. The goal of the proposed mitigation in this area is to recreate the functions of the previous saltgrass/wet meadow wetlands disturbed by project activities, as well as create palustrine scrub shrub and palustrine herbaceous wetlands to provide a highly diverse, highly functioning wetland that equals or exceeds the functions and values of the impacted wetlands. Four main mitigation areas would be constructed in the originally designated Phase III, Pond 2 Mining Area and Mining Area 2 in the northwestern portion of the project area (Figure 2 and Figure 4). Mitigation Area 1 is an existing herbaceous emergent wetland area that would be protected and connected to the other mitigation areas in the Phase III mining area (Figure 4). Mitigation Area 2 is proposed to be a willow scrub-shrub wetland area that would be created to provide diversity and overstory and would be east of Mitigation Area 1 (Figure 4). Mitigation Area 3 would be a saltgrass wet meadow complex with native herbaceous wetland vegetation south of Mitigation Area 1. Mitigation Area 4 would be southeast of Mitigation Area 3 and would consist of a native palustrine emergent wetland complex. Monitoring and evaluation of the subsurface hydrology and establishment of a native plant community appropriate to the area is anticipated to achieve the desired functional results,with more detailed discussion provided below on proposed approach. In addition to the proposed mitigation areas described above,the Heutt Ditch wetlands previously established would remain north and south of the proposed spillway(Figure 3). No modifications to these wetland mitigation areas are proposed and these areas will continue to be monitored as part of the overall mitigation monitoring requirements. The objectives of the mitigation plan are to mitigate in the project area at an aerial and functional compensatory mitigation ratio of no less than 1:1. Mitigation onsite is necessary to maintain a healthy watershed, provide wildlife habitat and continuity of a wildlife corridor along the South Platte River, and recreate the functions and values previously provided by the wetlands onsite. The onsite mitigation would benefit the South Platte riverscape as an integrated system of interworking parts to promote the ditches and stream channel,floodplain,terraces, riparian communities, and wetlands to all function together. The restoration of wetland and riparian vegetation communities in the project area would improve watershed health by creating and sustaining aquatic and wildlife habitat, storing groundwater and recharging aquifers,and maintaining water quality. Compensatory mitigation would improve wetland functions using a variety of persistent native vegetation types to replace wetlands,which are also likely to enhance general wildlife habitat,and ERO Project#22-078 5 ERO Resources Corporation