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April 11, 2017 Page 2 The proposed boardwalk will likely be a wood surface with either driven support piers or a system of steel footer plates that sit on the ground surface of the wetland. An example of this latter system is depicted in the photograph in Attachment A. Either support structure will not result in in a loss of wetland under the WCA as it would not alter the wetland's cross-section or hydrological characteristics, obstruct flow patterns, change the wetland boundary, or convert the wetland to non -wetland (MN Rule 8420.0111, Subps. 26 and 32and 8420.0415 A.). Further, the boardwalk supports would not constitute wetland fill under Section 404 of the Clean Water Act as they do not have the effects of replacing any portion of a water of the U.S. with dry land or change the bottom elevation of any portion of a water of the U.S. There is a minor change to the language originally included in Attachment B of the application in that the boardwalk deck will not sit higher than 30 inches above the ground surface of the wetland as something higher would require handrails along the entire length of the boardwalk to meet building code safety requirements. The boardwalk deck will likely sit just under 30 inches from the ground surface of the wetland but when including the underlying cross beams and stringers, the separation distance will be less. 2. Please provide some discussion on how the proposed stormwater ponds will not result in drainage of the adjacent wetlands since they are quite deep. Please include a comparison of the NWL for the ponds and the elevation of the wetlands. Response: The normal water levels (NWL) of each pond are set by the outlet elevations, which are shown on the grading plan. The outlet elevations were derived from piezometer readings of the groundwater elevation gathered throughout 2016. See Attachment B which includes a summary of piezometer readings during 2016, a map depicting the piezometer locations, and existing conditions with the wetland boundary and topography. Ponds 12 and 13, adjacent to the north part of Wetland 2 have an outlet elevation of 927.0. The delineated wetland in this area lies between a 927.0 and 928.0 elevation. Ponds 16 and 17 have an outlet elevation of 928.0; the Wetland 2 boundary in proximity to Ponds 16 and 17 ranges between 928.0 and 929.5 elevation. Pond 10 has an outlet elevation of 928.5; Wetland 2 boundary in this location is around 928.0. Ponds 18 and 19 have an outlet elevation of 929.5; the Wetland 2 boundary in this location ranges between 928.0 and 929.0.