4.3 BIOLOGICAL RESOURCES DRAFT EIR NEWMAN RIDGE PROJECT APRIL 2012 4.3 BIOLOGICAL RESOURCES INTRODUCTION The Biological Resources chapter of the EIR evaluates the biological resources that occur within the Newman Ridge Project (proposed project) area. Existing plant communities, wetlands, wildlife habitats, and potential for special-status species and communities are discussed for the project site. The information contained in this analysis is primarily based on a Biological Resources Report1 (See Appendix F) and a Delineation of Potential Jurisdictional Waters of the United States2 (See Appendix G), both prepared by Vollmar Natural Lands Consulting. The impacts already identified in the Initial Study that was prepared for the proposed project (See Appendix A) as having no impact (conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance; conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan) are not further addressed within this chapter. The impacts identified as potentially significant in the Initial Study are addressed below in this chapter. It should be noted that this chapter addresses impacts related to biological resources of the Edwin Center North Alternative as well as the proposed project. Information for the Edwin Center North Alternative analysis and discussion is primarily based on a biological resources addendum and a preliminary assessment of potential jurisdictional wetlands prepared 3,4 by Vollmar Natural Lands Consulting (See Appendix P). EXISTING ENVIRONMENTAL SETTING The following sections describe the regional setting of the site, including the Edwin Center North Alternative, as well as the existing biological resources occurring in the proposed project area. Regional Setting The site is located in Amador County, west of the City of Ione city limits, between State Route (SR) 88 to the south and SR 104 to the north, and project site elevation ranges from approximately 320 to 480 feet above sea level. The proposed project site consists of two main components – the Newman Ridge Quarry and the Edwin Center. The Newman Ridge Quarry area is largely oak woodlands and grasslands, and includes seasonal wetland swales, vernal pools, seasonal wetlands, and seasonal creek channels, including a portion of Dry Creek. The Edwin Center area supports oak woodlands and grasslands with some scattered seasonal wetland swales, channels and vernal pools. The Edwin Center portion of the project site is located near numerous active and former mine sites. Chapter 4.3 – Biological Resources 4.3 - 1 DRAFT EIR NEWMAN RIDGE PROJECT APRIL 2012 The project site is situated at the transition between two major geographic regions (the Central Valley region and the Sierra Nevada Foothills region) whose distinct characteristics are interspersed throughout the project site. The portions of the site exhibiting characteristics of the Central Valley region are characterized by flat to undulating terrain with intermixed moderate to steep hills. The geology of this area consists of alluvial (river-deposited) formations derived from granitic and volcanic sources. Most of this area supports open grasslands, blue oak savanna, or blue oak woodlands. All of the vernal pools that occur on-site are concentrated in the portions of the site exhibiting characteristics of the Central Valley region, on recent to ancient alluvial terraces with flat to gentle terrain. Geologic formations on the project site associated with the Central Valley region are the Modesto-Riverbank formations and the Valley Springs formation. The portions of the site exhibiting characteristics of the Sierra Nevada Foothills region are characterized by generally hilly terrain cut by ephemeral to seasonal drainages, except for alluvial valleys formed along Dry Creek, which support dense oak and mixed woodlands and riparian woodlands along with some stands of chaparral. Hydrology The site supports several types of surface hydrological features including a seasonal creek (Dry Creek), vernal pools, portions of a large seep, seasonal wetlands, seasonal wetland swales, unvegetated channels, and active mining ponds. Dry Creek is the one larger seasonal creek on the project site. Dry Creek generally runs north to south and is present on the project site only where the creek crosses the southern portion of the haul road. In addition, smaller seasonal and ephemeral drainages exist that flow into this creek or off the site, as well as scattered vernal pools and swales, other seasonal wetlands, and various man-made ponds and ditches mostly associated with past or current mining. Soils The varied terrain of the site is strongly correlated with the underlying geologic formations, which in turn strongly influence soil type. A total of four different geologic formations are mapped on the site (See Table 4.3-1). It should be noted that the resources shown in Table 4.3-1 are typical resources for each of the four geologic formations; however, these resources do not necessarily occur on the proposed project site. Figure 4.3-1 shows the distribution of these formations on the site. Open grasslands and oak savanna are concentrated on more recent river floodplains and terraces associated with Dry Creek. The site also contains some areas of the Ione geologic formation, consisting of sandstone formed from sand deposited more than 60 million years ago along the former edge of the North American continent. Geologic formations on the project site associated with the Sierra Nevada Foothills region are the Gopher Ridge Volcanics and the Ione Formation. Chapter 4.3 – Biological Resources 4.3 - 2 DRAFT EIR NEWMAN RIDGE PROJECT APRIL 2012 Table 4.3-1 Geologic Formations Mapped on the Newman Ridge Project Site Geologic Associated Sensitive Surface Age Parent Material Origin Resources Volcanic island arc formed 170 in a mid-ocean environment Gopher Volcanic rocks million then transported and Ridge extruded as mid-ocean Oak Woodland years emplaced on the former Volcanics rises or islands (my) continental edge through tectonic plate subduction Ione Manzanita Chaparral (does not Consolidated sands and occur on-site); clays deposited in shallow potential special-status beach or lagoon 40-50 Quartz sandstone plants Ione manzanita, Ione environments along the my and consolidated clay Ione buckwheat, Irish shores of an ancient inland Hill buckwheat, sea that formerly occupied Bisbee Peak rush-rose the Central Valley region (none documented on- site); Oak Woodland Vernal pools; low- quality California tiger salamander breeding Deposited as ashfall and ponds; federally-listed Valley 20-35 Acidic rhyolitic ash and alluvium from acidic, vernal pool shrimp Springs my tuff explosive eruptions along habitat; special-status the ancestral Sierra Range VP plant pincushion navarretia habitat; Oak Woodland Vernal pools; low- Mostly granitic alluvium quality potential 0.05 - Mostly granitic deposited along major California tiger Modesto- 0.1 alluvium, some rivers; some locally derived salamander Riverbank my metamorphic alluvium metamorphic alluvium breeding ponds; along secondary creeks federally-listed vernal pool shrimp habitat Source: Vollmar Natural Lands Consulting, Biological Resources Report, May 2011. Chapter 4.3 – Biological Resources 4.3 - 3 DRAFT EIR NEWMAN RIDGE PROJECT APRIL 2012 Figure 4.3-1 Geologic Formations within the Project Site Edwin Center North Alternative Boundary Chapter 4.3 – Biological Resources 4.3 - 4 DRAFT EIR NEWMAN RIDGE PROJECT APRIL 2012 In the greater project vicinity, vernal pools are primarily associated with the Valley Springs, Laguna, North Merced Gravels, and Modesto-Riverbank formations, but within the project site boundary they are restricted to the Modesto-Riverbank and Ione formations. The Modesto- Riverbank and Ione formations are all alluvial formations with areas of flat to nearly flat terrain conducive to vernal pool formation. In addition, the soils associated with these formations tend to form subsurface ‘hardpans’ which created the ‘perched’ water tables required to support vernal pool hydrology. The Ione Formation weathers into unusual reddish to cream-colored clay soils and acidic sandy soils. The sensitive plant community Ione Manzanita Chaparral, as well as three constituent listed plant taxa, are almost exclusively associated with the clay or sand soils of this formation, and all have highly restricted ranges in the local Sierra Nevada foothills with core populations less than one mile from the project site, although they do not occur on the project site. Stream Corridors and Riparian Habitat The only stream corridor and riparian habitat on-site are associated with Dry Creek, which flows from northeast to southwest across a section of the Newman Ridge Quarry portion of the site (See Figure 4.3-2). Dry Creek is a seasonal creek with an established channel (bed and bank). Riparian woodlands occur in open to dense stands along Dry Creek. However, Amador County does not have local regulations protecting riparian habitat. The Dry Creek stream corridor within the ordinary high water mark (OHWM) covers approximately 1.50 acres on the project site. The associated riparian habitat outside of the OHWM covers approximately 0.76 acres. The 100-year flood zone is also shown on Figure 4.3- 2. Dry Creek runs through the project site for approximately 459 feet. As outlined in Table 4.3-2, the riparian