Appl form/activities affecting water resources

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e Project Name and/or Number: Nelson Restoration Project(AES 12-0975) Attachment 1 (continued) PART THREE. General Project/Site Information Overview: The applicant is pursuing a"Letter of Permission"(LOP)from the U.S.Army Corps of Engineers and a"No-Loss Determination"from the Minnehaha Creek Watershed District(MCWD, the Local Governmental Unit for the site). No mitigation is proposed, since no wetlands will be lost and significant improvements in ecological function, values, and integrity are anticipated. Previous Work/Approvals: Since 2012,data review, site assessments,field data collection, and several meetings with regulatory agency staff have been completed to develop this restoration/enhancement plan. The wetland associated with the proposed project(Wetland A) was delineated by Applied Ecological Services, Inc. in May 2013. The Minnesota Wetland Conservation Act Notice of Decision approving the Wetland Boundary and Type was issued June 2, 2014. Existing Conditions: The proposed project entails ecological restoration/enhancement of an existing, severely degraded wetland (Wetland A). The contributing drainage area to the wetland is approximately 16.5 acres. The wetland's outlet consists of a 24"CMP culvert on the west side of the basin;this culvert has a maximum flow capacity of-23 cfs. Wetland A is 2.98 acres and consists mostly of invasive cattails, purple loosestrife, and reed canary grass. The MCWD classifies the wetland as Manage 3 (lowest quality) and"Low"for Vegetative Diversity/Integrity. Minnesota Land Cover Classification System (MLCCS) mapping identifies the wetland as containing 51-75%cover by invasive purple loosestrife. The Minnesota Routine Assessment Method (MnRAM v3.4) was used to assess Wetland A's existing functions and values (see Attachment 2 for the Wetland Functional Assessment Summary under existing conditions). MnRAM scores the wetland as"Low"to "Moderate"in almost every category,with Vegetative Diversity/Integrity scoring "Low"for all wetland plant communities present. Proposed Conditions: The applicant proposes to herbicide invasive vegetation throughout the wetland, followed by a prescribed burn and a second herbicide treatment. Under frozen conditions, an excavator will be used to excavate approximately 2,588 cubic yards of soil (:54 ft deep)from a 0.5-acre portion of the wetland in order to create an area of Deep Marsh habitat and to control invasive vegetation. The upper foot of soil (approximately 807 cubic yards)will be infested with propagules of invasive vegetation (i.e., cattail tubers), and therefore will be removed from the site. The remainder of the excavated material will be thin-spread (51 ft thick) over lower portions of the wetland to a maximum elevation of 964.5 feet in order to maintain wetland conditions. In order to maintain existing intermittent flows in the wetland, two meandering channels will be constructed between the proposed Deep Marsh area and two existing culverts beneath Tonkawa Road: an existing equalization culvert(on the south edge of the wetland) and the existing wetland outlet(on the west edge). These actions will restore the wetland to a diverse habitat complex of native Wet Meadow, Deep Marsh, and Lowland Hardwood Swamp(see Plan Sheet 3.0). Surrounding upland buffer areas are currently being restored through invasive plant removal (e.g., buckthorn, garlic mustard)and installation of native seed and plants. Two proposed rain gardens (designed separately) will manage and treat 1.42 acres of runoff prior to entering the wetland. An existing compost pile located near Wetland A will be moved away from the wetland or removed from the site altogether. An existing woodchip trail located in the uplands east of the wetland will be extended in the uplands. Plan Sheet 3.0 illustrates all elements of the proposed restoration/enhancement project. The MnRAM Wetland Functional Assessment Summary for Wetland A's proposed conditions(post- restoration/enhancement) is provided in Attachment 2. The proposed project will result in"no-loss"of wetland quantity, quality, or biological diversity(see Attachment B-No-Loss Applicability). The comparison of Wetland A's existing and proposed conditions (using MnRAM) indicates a significant increase in wetland functions and values. A portion of the wetland will change wetland type (approximately 1.6 acres from Type 3 to Type 2, and approximately 0.5 acre from Type 3 to Type 4); however,this will result in an increase in uncommon native Wet Meadow habitat, and the created Deep Marsh area will provide greater habitat diversity within the wetland, benefitting native waterfowl and waterbirds (currently not able to use the wetland), as well as provide more and enhanced habitat for native reptiles and amphibians and possibly small fish. The upland buffer surrounding the wetland will also be improved significantly in terms of its ecological integrity and function through invasives removal and planting of native trees, shrubs, graminoids, and forbs with wildlife value. Minnesota Interagency Water Resource Application Form February 2014 Page 6 of 9