C6 Draft Delineation of Waters of the United States on the Newell Ranch Property
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C6 Draft Delineation of Waters of the United States on the Newell Ranch Property DRAFT DELINEATION OF WATERS OF THE UNITED STATES NEWELL RANCH PROPERTY NAPA COUNTY, CALIFORNIA April 2015 This page intentionally left blank DELINEATION OF WATERS OF THE UNITED STATES NEWELL RANCH PROPERTY NAPA COUNTY, CALIFORNIA Submitted to: American Canyon 1, LLC 1001 42nd Street, Suite 200 Oakland, California 94608 Prepared by: LSA Associates, Inc. 157 Park Place Point Richmond, California 94801 510.236.6810 Project No. ACC1401 April 2015 This page intentionally left blank TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................... 1-1 1.1 PROPERTY LOCATION AND DESCRIPTION ...................................................... 1-1 1.1.1 Location ......................................................................................................... 1-1 1.1.2 Description .................................................................................................... 1-1 1.1.3 Vegetation and Plant Communities ............................................................... 1-1 1.1.4 Soils ............................................................................................................... 1-2 1.1.5 Hydrology ...................................................................................................... 1-2 1.2 REGULATORY BACKGROUND ............................................................................ 1-3 2.0 METHODS .......................................................................................................................... 2-5 2.1 WETLAND IDENTIFICATION METHODOLOGY ................................................ 2-5 2.2 FIELD METHODOLOGY ......................................................................................... 2-6 3.0 RESULTS ............................................................................................................................ 3-7 4.0 CONCLUSION .................................................................................................................... 4-9 5.0 LITERATURE CITED ...................................................................................................... 5-11 FIGURES (located in Appendix A) Figure 1: Regional and Site Location Map Figure 2: Soil Type Map Figure 3: Potential Waters of the United States APPENDICES A: Figures B: Photographic Log C: Data Sheets P:\ACC1401\Delineation\Delineation report Draft Chip_NM.docx (04/09/15) iii This page intentionally left blank iv P:\ACC1401\Delineation\Delineation report Draft Chip_NM.docx (04/09/15) LSA ASSOCIATES, INC. DELINEATION OF WATERS OF THE UNITED STATES APRIL 2015 ON THE NEWELL RANCH PROPERTY NAPA COUNTY, CALIFORNIA 1.0 INTRODUCTION This report presents the results of a delineation of the extent of waters of the United States, including wetlands, on the Newell Ranch Property (property) in Napa County, California. Waters of the United States are subject to U.S. Army Corps of Engineers (Corps) regulation under Section 404 of the Clean Water Act (CWA). The Corps has primary authority to determine the extent of CWA jurisdiction, and the conclusions of this report are subject to verification by Corps staff. This report was prepared by LSA Associates, Inc. (LSA) on behalf of American Canyon 1, LLC for use as a guide in project planning and for use in project permitting, should impacts to regulated features/habitats be unavoidable. 1.1 PROPERTY LOCATION AND DESCRIPTION 1.1.1 Location The approximately 103-acre project site is located southeast of the intersection of Napa Junction Road and Watson Lane in American Canyon, Napa County, California. The property is located in Section 19 of Township 4 North, Range 3 West, of the Cordelia USGS 7.5 minute quadrangle (Figure 1). The property comprises Napa County Assessor’s Parcel Number 059-030-005 and a portion of 059-030-006. Access to the project site is via State Highway 29 via Paoli Loop Road to Watson Lane or from the northern end of Newell Drive, north from American Canyon Road. 1.1.2 Description Elevations range from about 110 feet NGVD (National Geodetic Vertical Datum) in fields at the northwestern and southern portions of the site to 220 feet in the hill slopes in the eastern portions of the site. The site is bounded on the west by a residential neighborhood and a former quarry/cement facility, on the north, northwest, and northeast by hay fields and fallow grassland, and on the southeast by Newell Creek and the Newell Ranch Open Space Preserve. The project site consists of primarily relatively flat agricultural lands planted in oats and Italian rye, a hilltop residence and associated outbuildings, and an abandoned barn/farmstead. 1.1.3 Vegetation and Plant Communities The dominant plant community on the site is non-native annual grassland and active agricultural oat and rye hayfields. The non-native grassland areas consists of species such as include slender wild oats (Avena barbata), ripgut brome (Bromus diandrus), Italian ryegrass (Festuca perennis), P:\ACC1401\Delineation\Delineation report Draft Chip_NM.docx (04/09/15) 1-1 LSA ASSOCIATES, INC. DELINEATION OF WATERS OF THE UNITED STATES APRIL 2015 ON THE NEWELL RANCH PROPERTY NAPA COUNTY, CALIFORNIA Mediterranean barley (Hordeum marinum ssp. gussoneanum) and soft chess (Bromus hordeaceus). Other non-native species such as sweet fennel (Feoniculum vulgare), vetch (Vicia sp.) thistles (Carduus sp., Circium sp., Silybum sp. and Centaurea sp.) and mustards (Brassica sp. and Hershfeldia sp.) are also abundant on the project site. No significant native woody vegetation occurs on the site, with the exception of coast live oak (Quercus agrifolia) surrounding the abandoned farmstead. Vegetation at the abandoned farmstead and the residence include ornamental plantings and several large eucalyptus (Eucalyptus globulus). 1.1.4 Soils The Natural Resources Conservation Service (NRCS Web Soil Survey, 2012) has mapped the following four soil map units on the site (Figure 2): 1. Clear Lake clay, drained. This soil series consists of poorly drained soils that formed in basins and old alluvial fans and is developed over alluvial parent material derived from sedimentary rock. These nearly level soils are used mainly for pasture and have a mildly alkaline clayey surface layer and a moderately alkaline clay subsoil. The water table is generally encountered at a depth of 5 feet. This series is deep and clayey, with thick topsoil horizons. Runoff is slow or very slow, and there is little to no hazard of erosion. This soil type occurs over the majority of the north central and northeast portions of the project site. 2. Fagan clay loam, 5 to 15 percent slopes. This soil series, used mainly for range and pasture, formed in uplands in material weathered from sandstone and shale. The surface and subsurface layers of this soil are a medium acid clay loam; deeper horizons become somewhat sandier and weathered sandstone is encountered at a depth of 46 inches. Permeability is slow, runoff is medium, and the hazard of erosion is moderate. This soil type occurs in the north central and central portions of the project site. 3. Fagan clay loam, 15 to 30 percent slopes. This soil occurs on steeper topography than the soil described previously and runoff is rapid. This soil is mapped along the steeper slopes of the northeastern portion of the project area. 4. Haire loam, 2 to 9 percent slopes. This soil series, formed from alluvium derived from sedimentary rock, consists of moderately well-drained soils on old terraces and alluvial fans and is used primarily for dryland and irrigated pasture. These soils are gently sloping and have a medium acid thick loamy surface layer and strongly acid subsoil layer. Permeability is very slow, runoff is slow, and there is little to no hazard of erosion. This soil type occurs only in a small area along the northern boundary of the project site. Only the Clear Lake soil is listed as predominantly hydric. Nonetheless, any soil series or map unit may contain inclusions of hydric soils. 1.1.5 Hydrology The project area drains to two distinct watersheds: the northern portion of the property west, likely via Rancho Del Mar Creek or a channelized reach of North Slough, to the Napa-Sonoma Marsh and the Napa River; and the southern portion of the property drains southeast via municipal storm drains and Newell Creek to American Canyon Creek and the Napa River. There 1-2 P:\ACC1401\Delineation\Delineation report Draft Chip_NM.docx (04/09/15) LSA ASSOCIATES, INC. DELINEATION OF WATERS OF THE UNITED STATES APRIL 2015 ON THE NEWELL RANCH PROPERTY NAPA COUNTY, CALIFORNIA are no streams on the property; most surface runoff is conveyed overland or through agricultural ditches. North Slough, Rancho Del Mar Creek, and American Canyon Creek each drain westward to the Napa River, located approximately 2 miles west of the project site. The Napa River is a tidal, traditional navigable Other Water of the United States. 1.2 REGULATORY BACKGROUND The Corps is responsible under Section 404 of the Clean Water Act to regulate discharges of fill material into waters of the United States. Waters of the United States and their lateral limits are defined in 33 CFR Part 328.3(a) and include streams that are tributaries to navigable waters and their adjacent wetlands. The lateral limits of jurisdiction for a non-tidal stream are measured at the line of ordinary high water (OHWM) or the limit of adjacent wetlands. Waters of the