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Request for Permit- Floodplain Development Application Y-81 Kegonsa-Sun Prairie Rerate Project Page 2 Dane County,Wisconsin 1.0 Project Overview On behalf of the Project proponent, American Transmission Company (ATC), GAI Consultants, is pleased to submit the enclosed application materials in support of the ATC Y-81 Kegonsa — Sun Prairie Rerate Project (Project). This application is being submitted to the Dane County Planning and Development Department to request issuance of a Floodplain Development Permit, per Chapter 17 of the Dane County Code of Ordinances. 1.1 Purpose and Need, Scope of Work and Schedule ATC is planning to perform maintenance on the existing 69-kilovolt (kV) Y-81 electric transmission line. The rerate maintenance involves rerating the 69 kV Y-81 transmission line between the Kegonsa and Sun Prairie Substations to a thermal rating of 200°F for all seasons. Clearance and thermal concerns have been identified and the proposed fixes include replacing seventeen structures, reframing twenty- seven structures, lowering distribution on four structures and relocating one aerial clearance obstruction. Eight of the structures requiring replacement or reframing are located within the 1-percent Annual Chance Flood Hazard area (floodplain), as defined by the Federal Emergency Management Agency (FEMA); six of those structures are located within the regulatory floodway. Temporary placement of timber matting in wetland areas may be necessary to facilitate access if unstable ground conditions exist at the time of construction. Project activities will be conducted within ATC's existing right-of-way (ROW), with off-ROW access being utilized where appropriate to minimize environmental impacts and to reduce safety concerns from road traffic. Construction is planned to commence on or around May 1, 2017, and will be completed on or around July 25, 2017. It is anticipated that restoration activities will begin on or around July 25, 2017, and be completed within one month. There will be no new permanent impacts to the floodplain; the proposed activities will not cause any increase in the regional flood height due to floodplain storage lost, and there will be no new obstructions to flow. Reframe activities will occur near the top of the existing poles, and will be above flood elevation. Structure replacements will be pole-for-pole, meaning that for each new pole that is installed an existing pole will be removed. For these reasons detailed engineering analysis by a professional engineer was not determined to be necessary. 1.2 Project Location The overall Project is located in the Townships of Pleasant Springs, Cottage Grove, and Sun Prairie; the Village of Cottage Grove; and the City of Sun Prairie; Dane County, Wisconsin. Of this area, planned construction and associated access in floodplain and floodway areas exists in Sections 17, 20, 28 and 29 of the Town of Sun Prairie, Township 8 North, Range 11 East. Figure 1, attached, depicts the project location and site topography. The Project activities and associated access routes located in the floodplain and floodway are shown on the Environmental Access Plan (EAP) (Figure 2). A pre- construction photo log is included as Attachment 1. 1.3 Land Use and Land Cover In floodplain areas, the proposed Project site primarily consists of undeveloped land in the existing transmission ROW, with off-ROW access routes being utilized as necessary. The Project's adjacent landscape consists of agricultural fields and areas adjacent to local roadways. Access to structures located in the floodplain will be conducted directly from roadways or by traversing agricultural fields. Floodplain areas impacted by the project are located on Flood Insurance Rate Maps (FIRM) 55025CO289H and 55025CO286H; these maps are included in Attachment 2. Dl 60245.00/March 30, 2017 gal consultants