2019-07-09_REVISION - M2004044 (35)

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2019 Wetland Delineation Report Tucson South Sand and Gravel Mine—Brighton, Colorado 1.3 Regulatory Setting 1.3.1 Clean Water Act All discharges of dredged or fill material into jurisdictional waters of the U.S., that result in permanent or temporary losses of Waters of the United States (WOTUS), are regulated by the U.S. Army Corps of Engineers (USACE) under Section 404 of the Clean Water Act (CWA). The USACE regulates projects in navigable waters under Section 10 of the Rivers and Harbors Act. Under USACE and U.S. Environmental Protection Agency (EPA) regulations, wetlands are defined as "those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas." In non-tidal waters, the lateral extent of USACE jurisdiction is determined by the ordinary high water mark, which is defined as the "line on the shore established by the fluctuations of water and indicated by physical characteristics such as clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas" (33 CFR 328[e]). Depending upon the level of impacts to the jurisdictional features, a preconstruction notification (PCN) and an approved jurisdictional determination (JD) by the USACE may be necessary for the Project. For permanent impacts less than 0.1 acre, no PCN would be required. If impacts to jurisdictional waters cannot be avoided, the Project will require permitting under the CWA § 404 program administered by USACE. The Denver Regulatory Office of USACE recommends consultation on projects that may exceed these thresholds to determine the need and/or type of permitting. 2. Desktop Analysis Methods and Results The following sections briefly describe the methods used for this series of wetland determinations. Results of the desktop analysis are shown in Attachment 1, Figure 1. 2.1 Wetlands and Other Waters of the U.S. Desktop Methods Tetra Tech conducted a desktop analysis of the Project area to identify potential jurisdictional wetlands or other WOTUS in the proposed construction area. Desktop analysis used information described in the following sections. The U.S. Fish and Wildlife Service (USFWS) online Wetlands Mapper tool (USFWS 2015a) depicts mapped wetlands as part of the National Wetland Inventory (NWI) Program. The NWI dataset identified one wetland in the Project area. NWI wetland polygons situated in the Project area are depicted in Attachment 1, Figure 1 2