02-19-2013 Planning Commission Packet

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Originally, Wetland 1 on the site was given a protection classification of Preserve by the Minnehaha Creek Watershed District(MCWD) inventory. In January 2013 KES completed a MNRAM functional analysis for Wetland 1. Based on the analysis results, a revised protection classification of Manage 2 was determined. MCWD approved the management classification change on January 17,2013 (Appendix D). . Minnehaha Creek Water District(MCWD) revised their Wetland Protection Rule in September 2010. Similar to City of Orono rules, buffers widths are based on the management class of the wetland as determined by a functional analysis. However, MCWD base buffer widths are generally wider than City designated widths. The more restrictive of the widths must be represented on the grading plan. Wetland Buffer Protection,Augmentation, and Enhancement—Existina wetland buffers on the site have a_continuous dense layer of perennial grasses that have been unbroken for at least 10 consecutive years. Buffer adjacent to Wetland 1 will not be disturbed by construction activities; therefore,no buffer augmentation or enhancement is needed. Ecological Manage�nent Category Review-The site was assessed for City of Orono Ecological Management Category(EMC)ratings (City Code Sec. 78-1635(9)(4)), and Figure 6 illustrates observed category areas. Level 1 EMC areas are associated with wetlands and their buffers. Level 3 EMC areas are suitable for stormwater management. No Leve12 EMC areas (ecological opportunity areas)were observed on the site. Invasive Species and Diseased Tree Removal Plan Invasive Species Removal and Management Plan—Areas with invasive species observed on the site are illustrated in Figure 7. The primary invasive species identified on the site was common buckthorn. A detailed common buckthorn management plan is included in Appendix E. Trace amounts of other non-native, invasive species were observed (common mullein, motherwort, garlic mustard). Future seeding of invasive species management areas (outside of the graded home lots) is not anticipated because cut stump treatment and foliar spraying of buckthorn and other trace invasive species should not result in bare soil or un-vegetated areas. As invasive species comprise less and less cover over time,native species are `released'. Native species that have been dormant under the canopy of invasives are expected to naturally come back on their own. Although not precisely measured, buckthorn trees observed on the site represented approximately 99%of the total invasive cover. Buckthorn shrubs less than 1.5 inches in diameter will likely be foliar treated. Buckthorn trees greater than 1.5 inches in diameter should be stump cut, and their trunks and branches should be chipped or hauled off the site. Diseased and Dying Tree Removal Plan -Tree ID number, diameter breast height(DBH), and species and for all trees tagged during the field tree survey are induced in Appendix C.