2008-11-26_PERMIT FILE - M2008080 (3)

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Kersey Gravel Wetland Delineation Report Ecological Resource Consultants. Inc. Wetland B is a manmade swale historically dug from uplands. The swale begins in the central western portion of the Study Area and flows offsite where it connects to Plumb Ditch and eventually drains into to the South Platte River, approximately 1.3 miles east of the Study Area. The swale meets all of the characteristics defining a wetland. Table 4. Summarv of Identified Features Name Classification Size* Description Hydrological Connection WETLANDS Wetland A Palustrine 4.79 ac Depressional No connection. Emergent wetland, hydrologically isolated. Wetland B Palustrine 1.53 ac Manmade linear Connects to Plumb Ditch which Emergent swale. flows into the South Platte River approximately 1.3 miles east of the Stud Area. DITCHES North Branch Irrigation 1,714 ft / Manmade ditch, Plumb Ditch flows from a headgate Plumb Ditch Ditch 0.28 ac excavated in on the South Platte River (Section uplands. 13, Township 5 North, Range 65 South Branch Irrigation 1,718 ft / Manmade ditch, West) for 2.3 miles before entering Plumb Ditch Ditch 0.40 ac excavated in the Study Area on the west side. The uplands. main channel of Plumb Ditch flows back in to the South Platte River approximately 1.3 miles east of the Stud Area. Total acreage of identified wetlands and ditches within the Study Area = 7.0 ac Note: *Size of feature measured within Study Area. Acres = ac Linear ft =ft The attached wetland delineation map dated July 10, 2008, represents the delineated wetlands and irrigation ditches within the Study Area. These areas may be regulated by the USACE under Section 404 of the Clean Water Act. The placement of fill material or any general land disturbance within mapped waters of the U.S./Jurisdictional wetlands will require prior authorization from the USACE. In accordance with the November 13, 1986 Federal Register (Page 41217) Guidance and May 30, 2007 Rapanos Guidance (page 36), the Corps of Engineers generally does not consider non-tidal drainages and irrigation ditches excavated on dry land to be waters of the U.S., except on a case- by-case basis. In this case, the North and South Branches of Plumb Ditch are manmade ditches excavated wholly in and draining only uplands. Flow of water is regulated by a headgate, and is therefore not considered permanent. The USACE will need to make a jurisdictional determination of this site feature. Wetland A is a hydrologically isolated, irrigation influenced wetland. Under current USACE guidelines, wetlands which are not adjacent to or abutting TNWs or waters which flow to TNWs are typically considered non jurisdictional (USEPA & USACE 2007). Wetland A sits lower in the landscape than the surrounding ditches and does not contribute a surface hydrologic 10 116