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HomeMy WebLinkAboutWetland Delineation Report (2)Fort Collins Nissan Wetland Delineation Report Army Corps of Engineers Wetland Delineation Report 1.0 Location of the Proposed Project The proposed project is located at 5811 South College Avenue, Fort Collins, Colorado, approximately 0.8 miles north of the intersection of Trilby Road and College Avenue (US Highway 287). The legal description of the site is a portion of Sections 2 and 11, Township 6 North, Range 69 West of the 6th Principal Meridian in Larimer County, Colorado, and the site can be found on the USGS Fort Collins Quadrangle. A project map is provided in Section 6. The proposed project site is dominated by agricultural land with a broad slope that drains to Fossil Creek, approximately 0.2 miles to the north, and Lang Gulch (tributary to Fossil Creek), approximately 0.1 miles to the west. The Fossil Creek Trail is located just to the south of Fossil Creek in the project area. The objectives of the wetland delineation were to help with project design and planning and to notify the U.S. Army Corps of Engineers (COE) of the wetlands on the site. 2.0 Description of the Proposed Project The proposed project is illustrated on the Fort Collins Nissan – Kia Dealership Development Site Plan dated June 24, 2021, here incorporated by reference. The proposed project is illustrated on the Fort Collins Nissan – Kia Dealership Development Site Plan dated June 24, 2021, here incorporated by reference. The proposed use for the 25-acre site is the construction of two new automobile dealerships. The current dealership, Fort Collins Nissan, will be taken down and a new Kia dealership will be constructed. A new Nissan dealership will be constructed on the site just to the north. In addition, a parking area for extra vehicle storage will be constructed just west of the dealerships. Detention ponds and water quality ponds will be located west of realigned Venus Avenue. There are natural features, including wetlands and a significant rock outcropping that will be buffered and preserved. 3.0 Methodology Wetlands were delineated by Matt Tobler and Craig Severn on April 8, 2021, in accordance with the U.S. Army Corps of Engineers Wetland Delineation Manual (USACOE, 1987) and the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Great Plains Region (Version 2.0) (USACOE, 2010). The Web Soil Survey (http://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm) was accessed prior to undertaking field investigations to identify local soil types. Three sets (upland/wetland) of sample plots were evaluated in the project area for vegetation, soil and hydrologic wetland indicators. Wetland boundaries in potential impact areas were flagged and surveyed and a wetland location map was produced. Fort Collins Nissan Wetland Delineation Report 4.0 Results Three wetland areas were identified in the project area: 1) Lang Gulch (tributary to Fossil Creek), 2) remnant irrigation ditch and 3) Fossil Creek. The National Wetland Inventory (NWI) has mapped Lang Gulch as PSS1A and Fossil Creek as PEM1A. New Louden Ditch does not have an NWI designation. A summary of vegetation, soil and hydrologic findings for wetland and upland sample plots is presented in Table 1. Sample plot photos, a project map and wetland delineation data forms follow in Sections 5, 6 and 7, respectively. Table 1. Summary of vegetation, soil, and hydrologic characteristics for sample plot location. Plot ID Lat/Long Dominant Vegetation (indicator status) Soils Hydrology Wetland W1 40.50678/ -105.08215 Salix Amydagloides (FACW Elaeagnus angustifoia ((FACU) Phalaris arundinacea (FACW) Schoenoplectus pungens (OBL) Depleted Matrix (F3) Surface Water (A1) High Water Table (A2) Saturation (A3) Yes U1 40.50679/ -105.08214 Salix Amydagloides (FACW Elaeagnus angustifoia ((FACU) Symphoricarpos albus (UPL) Bromus inermis (UPL) None None No W2 40.50622/ -105.07998 Populus deltoides (FAC) Fraxinus pesylvanica (FAC) Juncus balticus (FACW) Redox Dark Surface (F6) Saturation (A3) Water Marks (B1) Hydrogen Sulfide (C1) Yes U2 40.50621/ -105.07994 Bromus inermis (UPL) Juncus balticus (FACW) Redox Dark Surface (F6) None No W3 40.50970/ -105.07935 Phalaris arundinacea (FACW) Carex emoryi (OBL) Depleted Matrix (F3) High Water Table (A2) Saturation (A3) Yes U3 40.50967/ -105.07933 Bromus inermis (UPL) None None No Proposed wetland impacts occur in three locations as indicated on the project map provided in Section 6. Construction of a stormwater outfall structure at Wetland 1 will permanently impact 0.002 acres of forest/shrub riparian wetland on Lang Gulch, which flows to the South Platte River via Fossil Creek. Construction of a parking lot over the surface of Wetland 2 will result in permanent loss of 0.60 acres of wetlands associated with an abandoned irrigation ditch. These wetlands are not identified by the National Wetland Inventory and there is no connectivity with other wetlands. Sufficient water flow from this wetland would reach Lang Gulch, then Fossil Creek and the South Platte River but only by flowing over uplands for approximately 165 feet. Construction of a stormwater outfall structure at Wetland 3 will permanently impact 0.005 acres of freshwater emergent wetland on Fossil Creek which drains to the South Platte River. Table 2 below summarizes wetland impacts. Table 2. Proposed wetland impacts resulting from construction at the Fort Collins Nissan Dealership. Fort Collins Nissan Wetland Delineation Report 5.0 Photos Photo 1. View to the west looking downstream along Lang Gulch (tributary to Fossil Creek) at wetland sample plot W1 (shovel on left) and upland sample plot U1 (shovel on right). Wetland Centroid National Wetland Inventory Designation Acres of Permanent Impact Latitude Longitude 1 40.5059 -105.08127 Forested/Shrub Riparian (Rp1FO) 0.002 2 40.50618 -105.07993 None 0.060 3 40.50944 -105.08013 Freshwater Emergent (PEM1A) 0.005 Total 0.067 Fort Collins Nissan Wetland Delineation Report Photo 2. View to the east looking at wetland sample plot W2 (shovel on right) and upland sample plot U2 (yellow clipboard on left). Fort Collins Nissan Wetland Delineation Report Photo 3. View to the east looking downstream along Fossil Creek at wetland sample plot W3 (shovel in center) and upland sample location U3 (yellow clipboard on right). Fort Collins Nissan Wetland Delineation Report 6.0 Project Map Fort Collins Nissan Wetland Delineation Report Fort Collins Nissan Wetland Delineation Report 7.0 Data Forms