Searsville Alternatives Study Initial Technical Studies Summary of Existing Biological Conditions Technical Memorandum
Draft - June 2013
Prepared for Stanford University by URS URS Corporation 1333 Broadway, Suite 800 Oakland, CA 946 12
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Table of Contents
1 Introduction ...... 1 1.1 Purpose and Scope ...... I I .2 Methods ...... 1 1.2.1 Study Area ...... 1 1.2.2 Database Searches ...... 1 1.2.3 Literature Review ...... 2 1.2.4 Interviews ...... 3 1.2.5 Field Reconnaissance ...... 3 1.3 Organization of this Technical Memorandum ...... 3
2 Regional Setting ...... 5 2.1 Searsville Reservoir ...... 5 2.2 Corte Madera Creek downstream of Searsville Dam ...... 5 2.3 San Francisquito Creek ...... 6 2.3.1 Bear Creek to Los Trancos Creek ...... 6 2.3.2 Los Trancos Creek to San Francisco Bay ...... 8
3 Wetlands ...... 9 3.1 Riparian Wetlands ...... 10 3.2 Freshwater Marsh Wetlands ...... 11 3.3 Tidal Marsh Wetlands ...... II 3.4 Potential Non-Wetland Other WUS ...... 11
4 Vegetation ...... 14 4.1 Special-Status Plant Species ...... 14 4.1.1 Federally and State-Listed Plants ...... 15 4.1.2 CNPS Rare, Threatened, or Endangered (List I and 2) Plants ...... 16 4.2 Plant Communities ...... 16 4.2.1 Searsville Reservoir ...... 19 4.2.2 Searsville Dam to Los Trancos Creek ...... 19 4.2.3 Los Trancos Creek to San Francisco Bay ...... 20 4.2.4 Native Plant Species in All Reaches ...... 23 4.2.5 Nonnative Species in All Reaches ...... 24
5 Benthic Macroinvertebrates ...... 25
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - i Searsville Alternatives Study
6 Fish ...... 30 6.1 Fish Communities ...... 30 6. t. t Searsville Reservoir ...... 30 6. t.2 Searsvitte Dam to Bear Creek ...... 35 6. t.3 Bear Creek to Los Trancos Creek ...... 37 6. t.4 Los Trancos Creek to San Francisco Bay ...... 37 6.2 Steelhead ...... 37 6.3 Crayfish and Minen Crabs ...... 42 6.3.1 Crayfish ...... 42 6.3.2 Minen Crab ...... 43
7 Wildlife ...... 44 7.1 Terrestrial Invertebrates ...... 44 7.2 Amphibians ...... 45 7.2.1 California red-legged frog ...... 45 7.2.2 Bullfrog ...... 48 7.2.3 California Tiger Salamander ...... 48 7.3 Repti les ...... 49 7.3.1 Western Pond Turtle ...... 50 7.3.2 San Francisco Garter Snake ...... 51 7.4 Birds ...... 53 7.4. t Searsville Reservoir and Corte Madera Creek Delta ...... 53 7.4.2 San Francisquito Creek to San Francisco Bay ...... 56 7.5 Mammals ...... 57 7.5.1 San Francisco Dusky-footed Woodrat...... 58 7.5.2 Salt marsh harvest mouse ...... 59 7.5.3 Bats ...... 59
8 Recommendations ...... 62 8.1 San Francisco Garter Snake ...... 62 8.2 Benthic Macroinvertebrates ...... 62 8.3 Steelhead ...... 63 8.4 Wetlands ...... 63 8.5 Vegetation ...... 63
9 References ...... 64
Initial Technical Studies ii -June 2013 Summary of Existing Biological Conditions Table of Contents
Tables
Table 4.1 Common Native Tree and Shrub Species, their Bank Location, and General Habitat Type within the Study Area ...... 23 Table 4.2 Common Nonnative Tree and Shrub Species Within the Study Area ...... 24 Table 5.1 Average number of aquatic invertebrate taxa and individuals captured per trap and sampling event at three locations near Searsville Reservoir ...... 28 Table 6.1 Fish Species known to occur in SF Creek ...... 31 Table 6.2 Fish Species not recorded in SF Creek but found in other South Bay drainages or near where SF Creek enters San Francisco Bay ...... 32 Table 6.3 Documented Steelhead Occurrences in SF Creek ...... 39 Table 7.1 Listed Wildlife Species Potentially Occurring in Study Area ...... 44 Table 7.2 Common Reptiles Recently Occurring on Stanford University Properties ...... 50 Table 7.3 Possible bat species identified at Jasper Ridge ...... 61
Figures
Figure 2.1 Upper San Francisquito Creek Watershed ...... 7 Figure 3.1 Potential Wetlands in the Study Area, Searsville ...... 13 Figure 4.1 Jasper Ridge Biological Preserve Vegetation Map 2012 ...... 17 Figure 4.2 San Francisquito Creek Biotic Habitats Upstream of Los Trancos Creek ...... 22 Figure 5.1 Middle Lake (dry) on October 31, 2012. The low vegetation covering much of the lake is underwater during the wet season ...... 27 Figure 6.1 Photograph taken August 9, 2012 showing the typical channel substrate in Corte Madera Creek between Searsville Dam and Bear Creek ...... 36 Figure 6.2 Summary of Stanford University Survey Results Showing Number of O. mykiss per Mile ...... 41 Figure 7.1 Summary of Stanford University Survey Results Showing Presence of California Red-legged Frogs and Bullfrogs ...... 47 Figure 7.2 Summary of Stanford University Survey Results Showing Presence of Western Pond Turtle ...... 52 Figure 7.3 Bobcat markings on a tree growing on the sediment delta of Corte Madera Creek, photographed November II, 2012 ...... 58 Figure 7.4 The entrance to one of two caves created by geotechnical exploration during construction of Searsville Dam ...... 60
Appendices
A CNDDB Species List B USFWS Species List
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - iii Searsville Alternatives Study
List of Abbreviations and Acronyms
BCI Bat Conservation International, Inc. BMI Benthic macro invertebrates CCC Central California Coast CDFG California Department of Fish and Game CDFW California Department of Fish and Wildlife, formerly called California Department of Fish and Game CESA California Endangered Species Act CFR Code of federal regulations CNDDB California Natural Diversity Database CNPS California Native Plant Society CWHR California Wildlife Habitat Relationship CTS California tiger salamander DO Dissolved oxygen DPS Distinct Population Segment EL Environmental Laboratory ERDC Engineering Research and Development Center ESA Endangered Species Act JRBP Jasper Ridge Biological Preserve JWD Jurisdictional wetland delineation mglL Milligrams per liter NRCS Natural Resource Conservation Service OHWM Ordinary high water mark ppt Parts per thousand SF Creek San Francisquito Creek SLAC Stanford Linear Accelerator Center USACE U.S. Army Corps of Engineers USDA U.S. Department of Agriculture USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Survey WUS Waters of the United States
Initial Technical Studies iv - June 2013 Summary of Existing Biological Conditions Introduction
1 Introduction
The Searsville Initial Technical Studies, Summary of Existing Biological Conditions technical memorandum presents a summary of existing biological information, one of several technical studies conducted by URS to assist Stanford University (Stanford) in gathering information needed to inform the subsequent effort of selecting alternatives for the Searsville Dam and reservoir. This section presents the purpose and scope of this technical memorandum and the methods used to develop its content.
1.1 Purpose and Scope This technical memorandum summarizes existing biological conditions as documented in existing reports and unpublished data in relevant portions of the San Francisquito Creek (SF Creek) watershed, and documents the sources of the information summarized. The conditions summarized here and the sources referenced are to be considered when evaluating the potential biological effects of specific future actions.
The scope of this technical memorandum includes reviews of reports and data provided by Stanford, analysis of state and federal databases, and review of other readily available scientific literature. Specific resource areas to be addressed include wetlands, vegetation, benthic macroinvertebrates, fish, and wildlife. Limited field reconnaissance was conducted to provide familiarity with the study area and enable interpretation of existing data, but no new data were collected and no focused surveys were conducted in support of this technical memorandum.
1.2 Methods This section presents the methods used to gather existing information presented in this technical memorandum.
1.2.1 Study Area The study area for this summary of existing information includes those areas most likely to be affected by the potential future actions being considered by Stanford for Searsville Dam and reservoir, which are assumed to include Searsville Reservoir, marshes and wetlands upstream of Searsville Reservoir (to upstream limit of areas of sediment deposition or directly influenced by Searsville Reservoir and Dam), and Corte Madera and SF creeks downstream from Searsville Dam to San Francisco Bay.
1.2.2 Database Searches Database searches included online generation of a species list from the Sacramento Office of the U.S. Fish and Wildlife Service (USFWS) website and a search of species occurrence records in the California Natural Diversity Database (CNDDB). In both cases the search included the Palo Alto, Redwood Point, Mindego Hill, Cupertino, Woodside, La Honda, Newark, San Mateo, and Mountain View U.S. Geological Survey (USGS) 7.5-
Initial Technical Studies Summary of Existing Biological Conditions June 2013-1 Searsville Alternatives Study minute topographic quadrangles. The CNDDB report is included in Appendix A and the USFWS species list in Appendix B. Additionally, to evaluate vegetation and where wetlands and other waters of the U.S. could potentially occur in the study area, the following databases and information were reviewed:
• All records from the Palo Alto USGS 7.5-minute quadrangle and eight adjoining quadrangles in the National Wetlands Inventory database, maintained by USFWS (USFWS 2009). The eight adjoining quadrangles include San Mateo, Redwood Point, Newark, Woodside, Mountain View, La Honda, Mindego Hill, and Cupertino. • The Natural Resource Conservation Service (NRCS) soil maps (USDAlNRCS 2013) were reviewed for hydric and partially hydric soils. • Aerial photographs of the study area and vicinity. • California Native Plant Society (CNPS) species list for Palo Alto USGS 7.5- minute quadrangle and the surrounding eight quadrangles were reviewed. All CNPS species with records from these quadrangles and meeting the criteria for inclusion are addressed in this memorandum (CNPS 2009).
1.2.3 Literature Review Multiple reports and other background information were reviewed during preparation of this technical memorandum. All documents cited are listed in the references section. The following sources were particularly important to the compilation of existing information:
• Fee, C., A. Launer, and S. Rottenborn. 1996. Biotic assessment of upper Searsville Lake and the lower floodplain of Corte Madera Creek. October 21. • H.T. Harvey and Associates. 2001. Searsville Lake Sediment Impact Study: Biotic Resources Synthesis Report. Prepared for Northwest Hydraulic Consultants, Inc. Project No. 1856-01. May 9. • Jones and Stokes Associates. 2006. Lower San Francisquito Creek Watershed Aquatic Habitat Assessment and Limiting Factors Analysis (Work Product N.l). Prepared for Santa Clara Valley Water District. Jones and Stokes Associates, San Jose, CA. • Launer, A., and D. Spain. 1998. Biotic Resources ofthe San Francisquito Watershed: Report on 1997 Field Activities Associated with Streambed Alteration Agreement #934-96. March 12. • Mudd, T. 2007. Assessment ofthe status ofbats at Jasper Ridge, preliminary draft. Jasper Ridge State ofthe Preserve Assessment. • Standard biological references and field guides, including the Jepson Manual (Baldwin 2012). • Olberding Environmental, Inc. Jurisdictional Wetland Delineation Report (Olberding 2007). • Jepson Online (The Jepson Online Interchange, California Floristics), University of California, Berkeley. • A Manual ofCalifornia Vegetation (Sawyer, Keeler-Wolf, and Evans 2009) • The most recent version (December 2009) of the List of California Vegetation Alliances (CDFG 2009).
Initial Technical Studies 2-June 2013 Summary of Existing Biological Conditions Introduction
• Terrestrial Vegetation ofCalifornia (Sawyer, J. J.T. Keeler-Wolf, and J. Evans 2009».
1.2.4 Interviews On February 12,2013, URS biologists Jonathan Stead and Norm Ponferrada interviewed Dr. David Moreno Mateos, Stanford University Postdoctoral Research fellow, Biology (School of Humanities and Sciences), regarding insect trapping in the SF Creek watershed. Dr. Mateos' efforts include sampling in the Middle Lake, Searsville Reservoir, and a portion of SF Creek downstream of the confluence with Bear Creek.
On February 13, 2013, URS biologists Jonathan Stead and Norm Ponferrada interviewed Joan Ball, University of California, Berkeley researcher (Ph.D. student), who is studying the adult Odonata species found along Searsville Reservoir and SF Creek during 20 II and 2012 sampling.
1.2.5 Field Reconnaissance On February 6,2013 URS biologists Ode Bernstein, Michael Carbiener, and Jonathan Stead conducted a reconnaissance survey of the SF Creek watershed, including Jasper Ridge Biological Preserve (JRBP) (primarily Searsville Reservoir, wetlands and riparian habitats within the footprint of the original reservoir, Corte Madera Creek downstream of Searsville Dam, and several locations on SF Creek) with a focus on wildlife habitat.
On February 7, 2013, URS biologists Michael Carbiener and Norm Ponferrada conducted an additional reconnaissance survey over a similar area, but with a focus on aquatic and fish habitat.
On February 14 and 20, 2013 URS biologists George Strnad and Chris Hargreaves performed a wetlands and vegetation survey of the watershed to help characterize vegetation communities and wetland habitats.
1.3 Organization of this Technical Memorandum The content and format of this technical memorandum are intended to provide the reader an understanding of the biological resources within the study area. This technical memorandum is a summary of existing reports and the information within this technical memorandum is limited by existing available information. The technical memorandum is organized as shown below.
Section 1.0 Introduction - introduces the technical memorandum, presenting the purpose and scope, methods used, and describes the organization of the document.
Section 2.0 Regional Setting - presents the regional and local setting and describes the study area.
Section 3.0 Wetlands - presents the results of the wetlands background review and identifies wetlands present in the study area.
Initial Technical Studies Summary of Existing Biological Conditions June 2013-3 Searsville Alternatives Study
Section 4.0 Vegetation - presents the review of existing vegetation data and an evaluation of the potential for specific vegetation resources to be present in the study area.
Section 5.0 Benthic Macroinvertebrates - presents the review of existing benthic macroinvertebrate data and an evaluation of the potential for specific benthic macroinvertebrate resources to be present in the study area.
Section 6.0 Fish - presents the review of existing fish data and an evaluation of the potential for specific fish resources to be present in the study area. This section also addresses crayfish and mitten crabs.
Section 7.0 Wildlife - presents the review of existing wildlife data and an evaluation of the potential for specific wildlife resources to be present in the study area.
Section 8.0 Recommendations - Provides recommendations for future studies that could be useful to evaluate potential effects of future specific actions on biological resources.
Section 9.0 References - lists all references cited in this technical memorandum.
Initial Technical Studies 4-June 2013 Summary of Existing Biological Conditions Regional Setting
2 Regional Setting
Searsville Reservoir, Corte Madera Creek, and SF Creek are located in the eastern Santa Cruz Mountains near Portola Valley and Palo Alto, California, within the SF Creek watersjed. The watershed is approximately 45 square miles and extends from Skyline Boulevard to San Francisco Bay. Five primary streams feed Searsville Reservoir: Corte Madera Creek, West Ridge Creek, Sausal Creek, Dennis Martin Creek, and Alambique Creek (Figure 2.1). The confluence of these five streams is within JRBP at Searsville Reservoir. After spilling from the reservoir water flows through the short section of Corte Madera Creek downstream of Searsville Dam, before joining with flow from Bear Creek and continuing down SF Creek to San Francisco Bay.
The study area has a Mediterranean climate, with over 90 percent of the annual precipitation occurring between November and April (Western Region Climate Center 2013). Cool coastal fog alternates with clear skies and warm weather during the months of May through October. The mean annual temperature is 57 degrees Fahrenheit and the average frost-free season ranges from 300 to 320 days. Annual precipitation averages approximately 15 inches.
2.1 Searsville Reservoir Searsville Reservoir is a reservoir that is rapidly filling with sediment due to historical and current episodes of erosion and sedimentation. Open water habitat with emergent vegetation dominates Searsville Reservoir (H.T. Harvey and Associates 200 I). The riparian zone upstream from Searsville Reservoir is a complex mosaic of lentic, lotic, and terrestrial habitats. This habitat mosaic is produced and maintained by the dynamic nature of stream channels, sediments, and water levels in the floodplain. The floodplain is dominated by flood-tolerant and early-successional species such as willows (Salix spp.) and cottonwoods (Populus spp.) (Fee et a1. (996). The reservoir provides habitat for fish and helps maintain shallow water tables that support wetland habitat on the Corte Madera Creek and Sausal Creek alluvial floodplains. Along with its surrounding alluvial habitats, Searsville Reservoir hosts a number of nonnative species, including nonnative fishes and crustaceans (Freyberg and Cohen 200 I). The dramatically reduced sediment flux may have contributed to the geomorphic changes in the Corte Madera and SF Creek channels that have been observed in a number of downstream reaches.
2.2 Corte Madera Creek downstream of Searsville Dam The most downstream reach of Corte Madera Creek begins downstream of Searsville Dam and continues approximately 0.35 mile downstream to the confluence with Bear Creek (Figure 2.1). At its upper end, this reach is a constricted riparian corridor lined with narrow and somewhat degraded riparian wetlands (Olberding 2007). It supports a corridor of deciduous riparian trees including white alder (Alnus rhombf{olia), black cottonwood (Populus trichocrapa). big-leaf maple (Acer macrophyllum), and California
Initial Technical Studies Summary of Existing Biological Conditions June2013-5 Searsville Alternatives Study bay (Umbellularia californica). Farther downstream, the floodplain decreases in size and Corte Madera Creek is more deeply incised. The number of riparian tree species decreases and the banks are dominated by California bay and coast live oak (Quercus agrifolia) near the Bear Creek confluence. Stream flow in this reach consists mostly of what spills over Searsville Dam. There is leakage through the dam, and the extent that leakage contributes to stream flow is currently being evaluated. The reach is intermittent; often drying to a series of disconnected pools during the dry season, and in some years dries completely (H.T. Harvey 2001). As is typical of streams immediately below a dam, this reach is sediment limited or starved, with a relatively angular, embedded substrate.
2.3 San Francisquito Creek The SF Creek begins where Corte Madera Creek and Bear Creek come together, downstream of Searsville Dam. It provides a lush backdrop to residences, business, institutions, agricultural lands, and recreational and conservation areas. For the purposes of identifying resources at different locations along SF Creek, this document identifies two distinct reaches downstream of Searsville Dam:
• Bear Creek to Los Trancos Creek • Los Trancos Creek to San Francisco Bay
2.3.1 Bear Creek to Los Trancos Creek Moving downstream, the first reach of SF Creek extends from the confluence of Bear Creek downstream to the confluence of Los Trancos Creek, downstream of Interstate 280 (Figure 2.1). This approximately 3.7-mile long reach supports a dense riparian corridor, including large stands of alder and big-leaf maple along its lower banks. It also supports dominant understory shrubs present within the Valley Foothill Riparian habitat type. Breaks in riparian canopy are occupied by native shrubs. Coarse woody debris is stored on flood terraces and in the channel creating blockages that help create pools and trap sediment. The channel bed is highly dynamic, displaying a moderately incised, unchannelized stream that is largely unaltered by hardscape erosion control interventions. The reach of SF Creek upstream of Los Trancos Creek includes a well-developed native plant overstory and understory (H.T. Harvey and Associates 2001). Based on previous surveys during the summer low flow period, water quality in this reach is generally good, with low water temperatures. There are approximately 14 pools within this reach, ranging from 1.1 - 4.5 feet deep, with tall canopies that provide shading (Carmen 2007).
Initial Technical Studies 6-June 2013 Summary of Existing Biological Conditions Reg ional Setting
,~'" .. \"'Ieo~ D Sanf~IOC,,,,,,\'4'eM«l D SIn Franeaq.obC/'Ml $ib.WI~~ o Sllnbd~tnn.1wy .J..... ",,, __...... _.I... s.aOo/. -.·... ,..o... .. ~ ~ -.-~o.....:1Dt). .-:m ~
Sc.nmllrY 01EJ i&ting Upper SlW'I Frenci~ , to Figure 2.1 Biological ~ form elion Qeek Watefshed
Figure 2.1 Upper San Francisquito Creek Watershed
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 7 Searsville Alternatives Study
2.3.2 Los Trancos Creek to San Francisco Bay The lower reach of SF Creek runs from the confluence of Los Trancos Creek downstream to San Francisco Bay. This reach is comprised primarily of Valley Foothill Riparian and Coast Live Oak Woodland but also supports abundant nonnative tree and shrub species throughout. The length of this reach is approximately 8.7 miles and in its less developed areas is bordered by Stanford Golf Course, homes, and undeveloped lots. The edge of the creek and riparian corridor is defined in most cases by public streets and parking easements, commercial development, backyards, pedestrian paths, parks, or barriers such as fences, walls, and levees. This reach of SF Creek is primarily a low gradient stream that is channelized throughout the reach. Within the upper portions of this reach, riparian vegetation is fairly well developed and substrate consists of cobbles and rubble with rime and pool habitat. Moving further downstream the channel becomes more incised, substrates become muddier, there is more concrete and riprap present, and riparian vegetation is replaced by saline emergent species. Human influence increases throughout this reach moving downstream, with increasing garbage and other anthropogenic evidence. Portions of this reach become dry in the summer months. Roadway crossings occur at Junipero Serra Boulevard, Sand Hill Road, EI Camino Real, Middlefield Road, Chaucer Street, University Avenue, Newell Road, and U.S. Highway 101 (Highway 101).
Initial Technical Studies a-June 2013 Summary of Existing Biological Conditions Wetlands
3 Wetlands
For the purpose of this document, wetlands and other aquatic resources, such as rivers, streams, and natural basins, are a subset of waters of the United States (WUS) and are protected under Section 404 of the Clean Water Act. The U.S. Army Corps of Engineers (USACE) has the primary federal responsibility for administering regulations that concern waters and wetlands. In this regard, USACE acts under two statutory authorities: the Rivers and Harbors Act (Sections 9 and 10), which governs specified activities in "navigable waters," and the Clean Water Act (Section 404), which governs specified activities in WUS, including wetlands. Additionally, Regional Water Quality Control Boards have jurisdiction over waters of the State, which include all waters of the United States, in addition to all surface waters that are not waters of the United States, groundwater, and territorial seas.
Additional information about these natural resources can be found in the following documents:
• A Field Guide to the Identification ofthe ordinary high water mark (OHWM) in the Arid West Region ofthe Western United States. A Delineation Manual. Robert W. Lichvar and Shawn M. McColley. August 2008. United States Corps of Engineers, Engineering Research and Development Center. ERDC/CRREL TR- 08-12. • ERDC/EL 2010. Engineering Research and Development Center/Environmental Laboratory. Interim Regional Supplement to the Corps ofEngineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region. USACE Wetlands Regulatory Assistance Program. Vicksburg, MS. • ERDC/EL 2008. Engineering Research and Development Center/Environmental Laboratory. Interim Regional Supplement to the USACE Wetland Delineation Manual: Arid West Region. USACE Wetlands Regulatory Assistance Program. Vicksburg, Mississippi.
The Olberding Jurisdictional Wetland Delineation Report, hereafter referred to as JWD (Olberding 2007), was particularly relevant, was thoroughly reviewed, and is summarized in this document. The Jurisdictional Wetland Delineation Report for the Corte Madera Creek Restoration was developed in September 2007 for the purpose of identifying the extent of USACE jurisdictional wetlands and other waters of the U.S. within the identified boundaries of a specific study area. The study area at that time was limited to approximately 30 acres along Corte Madera Creek, a tributary of Searsville Reservoir from the south. This previous delineation area is roughly confined on the west by the existing residential area within JRBP and on the east by the steep serpentine slopes of the JRBP hills.
The JWD identified approximately 22 acres of regulated jurisdictional waters and wetlands within the previous study area. The unvegetated Corte Madera Creek channel,
Initial Technical Studies Summary of Existing Biological Conditions June 2013-9 Searsville Alternatives Study
including narrow intermittent bands of wetland vegetation (1-2 feet wide) along the edge of the channel that occur below the OHWM were identified as WUS. The flood plain to the west, identified as Wetland I in the JWD, and a small area to the east of the creek channel identified as Wetland 2 were delineated as wetlands based on the presence of hydrophytic vegetation, wetland hydrology, and presence of hydric soils.
Based on the reconnaissance surveys, Searsville Reservoir, its tributary creeks, and their vicinity include numerous and very extensive wetlands in addition to those identified in the JWD. In addition to the JWD, the National Wetland Inventory database (USFWS 2009) and field reconnaissance were used to assess potential wetlands in the study area. Three categories of potential jurisdictional wetlands were identified during the reconnaissance, in addition to potential other WUS. The three wetland categories, riparian wetland, freshwater marsh, and tidal marsh, are addressed below.
3.1 Riparian Wetlands Riparian wetlands consist of dense stands of mature trees and associated understory vegetation that is well developed and often impenetrable. Tributary flow that flows into the Upper, Middle, and Searsville lakes is the primary source of water for the riparian wetlands in the study area. Dominant trees within riparian wetlands are arroyo willow (Salix lasio[epis), red willow (Salix laevigata), shining willow (Salix lucida), and black cottonwood (Populus trichocarpa). Stands of white alder (Alnus rhombifolia), coast live oak, big-leaf maple, California bay, and box elder (Acer negundo var. californica) also occur, but in lesser numbers. Understory shrubs that occur within the riparian wetlands include American dogwood (Cornus sericea), poison oak (Toxicodendron diversilobum), blue elderberry (Sambucus mexicana), mule fat (Baccharis salicifolia), California blackberry (Rubus ursinus), gooseberry (Ribes sanguineum), and French broom (Genista monspessulana). Annual and perennial herbs include mugwort (Artemisia douglasiana), hedge nettle (Stachys bullata), mint (Mentha spp.), Italian thistle (Carduus pycnocephalus), cow parsnip (Herac/eum lanatum), and cut-leaf geranium (Geranium disseclum ).
Riparian wetlands occur in the study area upstream of Searsville Dam within a wide corridor along the banks of Corte Madera and Alambique Creeks. The Corte Madera Creek corridor is confined by a rise in topography to the east and west and extends from Stanford's JRBP property boundary near the mid-portion of Corte Madera Creek to the confluence with Searsville Reservoir. The Alambique Creek corridor is confined by residential development to the north and south and extends from the JRBP property boundary directly south of the intersection of Portola Road and Mountain Home Road to the confluence with Searsville Reservoir. Recently, coastal redwood tree (Sequoia sempervirens) saplings have begun establishing and encroaching into the upper riparian habitats upstream of the Searsville Reservoir.
Downstream of Sears ville Dam, the constricted riparian corridor of SF Creek is lined with narrow and somewhat degraded riparian wetlands. Near the bay, there is limited freshwater marsh and tidal marsh near its mouth where SF Creek leaves the confines of the existing levees. Due to the constricted channel conditions, the riparian wetlands that
Initial Technical Studies 10 - June 2013 Summary of Existing Biological Conditions Wetlands line the creek's banks are annually exposed to a large variation of flows and water depths as can be observed from the water-deposited debris high up in the canopies of the riparian trees.
3.2 Freshwater Marsh Wetlands Freshwater marsh wetlands consist of dense stands of wetland vegetation dominated by annual and perennial emergent species. Freshwater marsh wetlands have saturated or inundated soils throughout most of the year, except in some cases, when soils dry during the dry months of late summer. Tributary water retained by Searsville Reservoir, Middle Lake, and Upper Lake is the principal source of water for freshwater marsh wetlands in the study area. Commonly occurring species observed in the freshwater marsh wetlands are broad-leaved cattail (Typha lalifolia), rushes (Scirpus aeulus, S. mieroearpus, and S. robuslus), knotweed (Polygonum eoccineum and P. prlnelatum), and pondweed (Potamogeton illinoensis, P. pectinalus. P. /oliosu.f;, and P. pusillus). Less commonly occurring species include the American water fern (Azollajiliculoides), broad-fruited bur-reed (Sparganium euryearpum), common water nymph (Najas guadalupensis), common water plantain (Alisma plantago-aquatiea), duckweeds (Lemna minor and Lemna minima), Pacific marsh purslane (Ludwigia paluslris), hornwort (Ceratophyllum demersum), whole-Ieafmilfoil (Myriophyllum verticillalum). and Pacific oenanthe (Oenanthe sarmentosa) (Olberding 2007).
Freshwater marsh wetlands occur in the study area within a narrow band (10-25 feet wide) along the mostly steep banks of Sears ville Reservoir, at the mouth of Corte Madera Creek at Searsville Reservoir, in a wide band surrounding Middle Lake and its drainage channel into Searsville Reservoir, at the confluence of Dennis Martin Creek and Sausal Creek near Middle Lake, as well as in a wide band surrounding Upper Lake. Narrow bands of freshwater marsh line the banks of SF Creek along its levees near its mouth in a segment between U.s. Highway 101 and the San Francisco ~ay, before they transition into the brackish and tidal marsh at the mouth (described below).
3.3 Tidal Marsh Wetlands Tidal marsh wetlands can be found in the lower sections of the Los Trancos Creek to San Francisco Bay stream reach, specifically downstream of U.S. Highway 101. A small tidal marsh is located at the mouth of SF Creek where it leaves the confines of the levees. This tidal marsh is dominated by brackish water open areas with halophytic plants such as pickleweed (Sa/icornia virginica). saltgrass (Disliehlis spicata), and alkali heath (Frankenia salina).
3.4 Potential Non-Wetland Other WUS Additional aquatic elements in the study area were identified as potentially jurisdictional non-wetland other WUS as well as waters of the State, based on the presence of defined bed and bank, drift lines and/or OHWM. These features lack the hydrophytic vegetation typically required to qualify as a wetland. Their limits are set by the OHWM. The OHWM is defined as the upper boundary of the active river channel or lake along the
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 11 Searsville Alternatives Study bank and by lack of vegetation below it. WUS occur within the study area as creek channels, and the open waters of the Upper, Middle, and Searsville lakes. These features were reviewed using aerial photography and on-the-ground reconnaissance.
Figure 3.1 indicates the location of previously identified potential jurisdictional wetlands and WUS.
Initial Technical Studies 12 - June 2013 Summary of Existing Biological Conditions Wetlands
FreshWllter ElMr,11'II WillaRd _ FreshWIIll r FO r l~ 41 S Ilf UO ...... U~nd
Frn hWllte r Po nd _ La kl Olberding I!"nvlronmenll l WeUl nd O.lInUllon
R.,. ~ n _ ...,et.e r oIll'1e U.S. Stan!ord plCperfy bolindary ... N '. _-'~:iOC 1. ""'\3)1 2. UItS :znJ,. _ u...·...... ~J A
St.THna-y of EJ.istin g Poten6a1 Wejll"lds in tIM Study Area: 1liaIog1cal klfarmalion So."'" Fi pe 31
Figure 3.1 Potential Wetlands in the Study Area, Sears ville
Initial Technical Studies Summary of Existing Biological Conditions Ju ne 2013 -1 3 Searsville Alternatives Study
4 Vegetation
This section describes the vegetation present in portions of the SF Creek watershed based on existing data. Special-status plant species within the study area are described, as well as the plant communities present within the various habitats in the study area.
4.1 Special-Status Plant Species For the purpose of this document special-status plant species are defined as species that are legally protected under the fedeml Endangered Species Act (ESA), the California Endangered Species Act (CESA), or other regulations, and species that are considered sufficiently mre or endangered by the scientific community to qualify for such listing. Special-status plants are species in the following categories:
• Listed or proposed for listing as threatened or endangered under the fedeml ESA or candidates for possible future listing as threatened or endangered under the federal ESA (SO CFR §17.12) • Listed or candidates for listing by the State of California as threatened or endangered under CESA (Fish and Game Code §20S0 et seq.) I • Listed as rare under the California Native Plant Protection Act (Fish and Game Code § 1900 et seqi • Meet the definition ofrare or endangered under CEQA §IS380(b) and (d). Species that may meet the definition of mre or endangered include the following:
Species considered by the CNPS) to be "rare, threatened or endangered in California" (Lists lA, I B, and 2) Species that may warmnt consideration on the basis of local significance or recent biological information - Some species included on the CNDDB Special Plants, Bryophytes, and Lichens List (CDFG 2008)
1 A species. subspecies, or variety of plant is endangered when the prospects of its survival and reproduction in the wild are in immediate jeopardy from one or more causes, induding loss of habitat, change in habitat, over-exploitation, predation. competition, disease, or other factors (Fish and Game Code §2062). A plant is threatened when it is likely to become endangered in the foreseeable future in the absence of special protection and management measures (Fish and Game Code §2067). 2 A plant is rare when, although not presenUy threatened with extinction, the species, subspecies, or variety is found in such small numbers throughout its range that it may be endangered if its environment worsens (Fish and Game Code §1901).
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The potential that species meeting the above status criteria occur in the study area was evaluated using the database information and literature sources. The evaluation was based on three parameters:
• Historic and current distribution • Presence of suitable habitat • Documented occurrences from within 10 miles of the study area
A total of 28 special-status plant species may occur or are known from within 10 miles of the study area (CNPS 1994, CNDDB, USFWS 2013). Based on the background review and field reconnaissance, ten of these plants have potential to occur in the study area. Four of these species would only occur in the downstream portion of the study area, below Highway 101, These four species are Point Reyes bird's-beak (Cordylanthus maritimus ssp. palustris), Contra Costa goldfields (Lasthenia conjugens), slender-leaved pondweed (Potamogetonfiliformis), and California seablite (Suaeda californica). Detailed descriptions of the remaining six special-status plant species with the potential to occur in the study area are provided below. The remaining 18 species are not likely to occur either because of the absence of suitable microhabitats, and/or because they have been considered extirpated from the study area, including: San Mateo thornmint (Acanthomintha dUllonii), Santa Cruz manzanita (Arctostaphylos andersonii), alkali milk vetch (Astragalus tener var. tener), Congdon's tarplant (Centromadia parryi ssp. congdonii), San Francisco Bay spine flower (Chorizanthe cuspidate var. cuspidata), Palo Alto thistle (Cirsium praeteriens), Ben Lomond buckwheat (Eriogonum nudum var. decurrens), Hillsborough chocolate lily (Fritillaria biflora var. ineziana), fragrant fritillary (Fritillaria Iiliacea), San Marin dwarf flax (Hesperolinon congestum), legenere (Legenere limosa), Crystal-Springs lessingia (Lessingia arachnoidea), woolly-headed lessingia (Lessingia hololeuca), robust monardella (Monardella villosa ssp. globosa), white-rayed pentachaeta (Pentachaeta bellidiflora), hairless popcorn-flower (Plagiobothrys glaber), San Francisco campion (Silene verecunda), and caper-fruited tropidocarpum (Tropidocarpum capparideum).
4.1.1 Federally and State-Listed Plants The following sections describe Federal and State-listed plants that have potential to occur in freshwater habitats in the study area. Potentially suitable habitat for each of these species may be present in the vicinity of Searsville Reservoir, and these species may occur on the banks of SF Creek.
4.1.1.1 Two-fork clover (Trifolium amoenum) This annual herb is federally listed as Endangered, with no state listing, and is a CNPS Rank I B species. It occurs in valley and foothill grasslands and sometimes on serpentine soils. The blooming period extends from April through June. The range of this species includes Marin, Santa Clara, San Mateo, Napa, Solano, and Sonoma counties.
4.1.1.2 Fountain thistle (Cirsium fontina/e var. fontina/e) This perennial herb is state and federally listed as endangered and is a CNPS Rank I B species. It occurs in serpentine seeps in valley and foothill grassland and chaparral
Initial Technical Studies Summary of Existing Biological Conditions June 2013 -15 Searsville Alternatives Study habitats. The blooming period extends from June through October. This species is endemic only to San Mateo County.
4.1.1.3 San Mateo woolly sunflower (Eriophyl/um latilobum) This perennial herb is state and federally listed as endangered and is a CNPS Rank I B species. Itoccurs in serpentinite soils in cismontane woodland habitat, often on roadcuts. The blooming period extends from May to June. This species is endemic only to San Mateo County.
4.1.1.4 Dudley's lousewort (Pedicularis dudleyi) This perennial herb is considered rare by the state and is a CNPS Rank 1B species. It occurs in maritime chaparral; deep, shady woods of older coast redwood forest; and valley and foothill grasslands. The blooming period extends from April through June. The range of this species includes Monterey, Santa Cruz, San Luis Obispo, and San Mateo counties.
4.1.2 CNPS Rare, Threatened, or Endangered (List 1 and 2) Plants The following section describes CNPS Rare, Threatened, or Endangered (List I and 2) plants that have a potential to occur in the study area.
4.1.2.1 Western leatherwood (Dirca occidentalis) This deciduous shrub is CNPS listed as 18. It occurs in a variety of habitats including cismontane and riparian woodland, preferably on moist, shady slopes. The blooming period extends from January through April. The range of this species includes Alameda, Contra Costa, Marin, Santa Clara, San Mateo, and Sonoma counties. This species was observed near Corte Madera Creek upstream of Searsville Reservoir and in several other locations around Searsville Reservoir during reconnaissance surveys. Potentially suitable habitat may be present at other locations in the vicinity of Searsville Reservoir and on the banks of SF Creek. Western leatherwood is one of the best-mapped plant species at Jasper Ridge, thanks to work by several JRBP docents. Iowa State Professor William Graves is currently conducting studies of this species at JRBP as the center of Dirca's regional distribution. He found significant genetic differentiation among geographically separated populations of Dirca within the Bay Area but relatively little variation within popUlations, and he recently confirmed the capacity of Dirca to reproduce asexually as well as by seeds (Graves and Schrader 2008).
4.2 Plant Communities The plant communities in the study area range from riparian and redwood forest in the upper reaches of the study area to oak woodland and grassland in the middle reaches. Only a small portion of the fresh and tidal marshes that used to occur between Highway 101 and San Francisco Bay still exists today. The JRBP, with its 482 hectares (1191 acres) of protected area in the eastern foothills of the Santa Cruz Mountains, located only 5 kilometers (3.1 miles) west of the main campus of Stanford University is regionally significant. The vegetation in the JRBP is diverse, representing many plant communities
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J d I I I I . "l! " • I H I! I i •,• I •• • I ! [I I Hllld· 1l 11l !1l •• • •••
. 1-
! ---,
- ,I I , ,• I , , ! . j I i , ! -i -I'P!II • l ~ ;I oJ J .! 1 II : i " "Be ~ ~< i, I, I,
Sourr;e: Stanford University, Jasper Ridge Biological PreseNe, 2012.
Figure 4.1 Jasper Ridge Biological Preserve Vegetation Map 2012
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 17 Sears ville Alternatives Study
of the California central Coast Range. These communities are delineated in Figure 4.1 below.
The following plant communities are present in the study area. Communities within JRBP are described only where they occur in or intersect the study area.
Shrub-Shrub habitat consists of areas dominated by shrubs with little or no trees present. Native and nonnative shrubs are included.
Valley Foothill Riparian-Valley Foothill Riparian consists of riparian habitat dominated by mixed, native trees and shrubs. Native tree species include willow, and cottonwood species. Native shrub species primarily include California blackberry, California rose (Rosa cali/ornica), and mugwort.
Urban-Urban habitat consists of areas where nonnative species comprise more than 50% of the habitat.
Eucalyptus-Eucalyptus habitat consists of areas dominated by one or more nonnative species of eucalyptus. Common species include blue gum (Eucalyptus globulus) and red river gum (E. camaldulensis).
Redwood-Redwood habitat consists of areas dominated by California redwood (Sequoia sempervirens).
Valley Oak Woodland-Valley Oak Woodland habitat consists of areas dominated by valley oak trees (Quercus lobata).
Coastal Oak Woodland-Coastal Oak Woodland habitat consists of areas dominated by coast live oak trees and can include other native trees such as California bay or California buckeye and native shrubs like California blackberry or coyote brush (Baccharis pilularis).
Fresh Emergent Wetland-Fresh Emergent Wetland habitat consists of areas dominated by pockets of freshwater marshes with wetland plants such as cattails.
Saline Emergent Wetland-Saline Emergent Wetland habitat consists of areas dominated by brackish marshes with saline tolerant plants such as pickleweed or saltgrass.
Open Water-Open Water Habitat consists of bodies of very slow-moving or standing (Ientic) freshwater of sufficient size and depth to preclude the growth of rooted marsh vegetation. Algae and some floating plants may be present in this deeper Iimnetic habitat, but shoreline plants such as rushes and tules are confined to the littoral areas of this habitat type.
The dominant biotic habitat throughout the study area is Valley Foothill Riparian. Open Water habitat dominates Searsville Reservoir itself, with Fresh Emergent Wetland habitat co-dominant along the banks. Saline Emergent Wetland dominates where SF Creek merges into the Bay tidelands. Small pockets of other biotic habitats, including
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Herbaceous, Shrub, Urban, Eucalyptus, Redwood, and Coastal Oak Woodland, exist above the top of bank, in small pockets, and within natural or anthropogenically generated breaks in the dominant Valley Foothill Riparian canopy.
Plant communities are described below for Searsville Reservoir, Corte Madera Creek from Searsville Dam to Bear Creek, SF Creek from Bear Creek to Los Trancos Creek, and SF Creek from Los Trancos Creek to San Francisco Bay. Section 4.2.4 lists the species and locations of some of the major native plants in the study area, and Section 4.2.5 lists some of the major nonnative plant species in the study area.
4.2.1 Searsville Reservoir Open Water, Fresh Emergent Wetland, and Valley Foothill Riparian habitat types dominate the limnetic and littoral zones of Sears ville Reservoir, as well as those of the Middle and Upper Lake marsh areas.
Valley Foothill Riparian forest habitat is present at the margins of Sears ville Reservoir near the confluence of Corte Madera and Sausal Creek, and at the margins of the Middle and Upper marshes (Figure 4.2, H.T. Harvey 200 I). Valley Foothill Riparian habitat around Searsville Reservoir generally exhibits a well-developed overstory and understory. Dominant canopy tree species are limited to black cottonwood, shining willow, red willow and arroyo willow; all considered to be early-successional species. Both dogwood and box elder are abundant understory species. White alder is found at scattered locations. Only a few individuals of redwood, oak, and California bay are present. Poison oak is common only in the upstream portion of the study area (Fee et al. 1996).
Shallow, slow-moving waters in upper Searsville Reservoir and the Middle and Upper marshes support aquatic vegetation. Large dense stands of mostly cattails, rushes, knotweed, and pondweed are present throughout the littoral areas of the lake and marshes. Also present are smaller assemblages of American water fern, broad-fruited burreed, common water nymph, common water plantain, upright burhead (Echinodorus berteroi), duckweed, hornwort, Pacific marsh purslane, whorl-leafed milfoil, and Pacific oenanthe. Vegetation around the Middle and Upper marshes displays a regular succession from emergent, perennial, herbaceous vegetation to willow thicket. Moving to the margins of the marsh, dense stands of young willow thin out, leaving more mature willows and some cottonwoods (H.T. Harvey 2001).
4.2.2 Searsville Dam to Los Trancos Creek This section addressed both the reach of Corte Madera Creek from Searsville Dam to Bear Creek and the reach of SF Creek from Bear Creek to Los Trancos Creek. The combined length of these two reaches is approximately 4 miles. The riparian corridor surrounding this reach consists of moderate to dense riparian forest that is widest immediately below the dam, followed by a narrowing in width along the right bank opposite JRBP (Figure 4.2). The riparian corridor becomes relatively narrow from the old Boething Treeland Farms (no longer present at this location) to Los Trancos Creek. Tree canopy closure ranges from approximately sixty to one hundred percent in the majority of the riparian corridor (H.T. Harvey 2001). A few bank segments, particularly in the lower
Initial Technical Studies Summary of Existing Biological Conditions June 2013 -19 Searsville Alternatives Study part of this reach from Boething Treeland Farms to Webb Ranch exhibit a moderate. forty to sixty percent canopy cover. The occurrences of nonnative tree and shrub species are relatively low from Searsville Dam to Los Trancos Creek, with the exception of nonnative grasses.
4.2.2.1 Searsvllle Dam to Bear Creek The reach from Searsville Dam to the confluence with Bear Creek is dominated by deciduous riparian forest ofa medium to large size class made up of alder, cottonwood, and big-leaf maple with occasional California bay. Oaks are present only above the top of bank. A wide band of serpentine, running along Jasper Ridge to the southeast and trending northwest along Bear Creek, is bisected by this 0.35-mile reach of Corte Madera Creek. Soils developed in serpentine parent material otTer potential habitat for an entire suite of rare plant species. While no special-status species were seen under the riparian canopy during field reconnaissance, the potential exists for several rare species to occur along this portion of Corte Madera Creek. Special-status plant species are discussed in Section 4.1.
4.2.2.2 Bear Creek to Los Trancos Creek Large stands of alder and big-leaf maple occupy the lower banks, particularly on the north-facing left bank within JRBP. Fewer cottonwood, box elder, and dogwood are present. Also scattered along the creek within the JRBP boundary are three small stands of medium sized, second growth redwood trees on floodplain terraces. These small stands do not enclose a large enough area to be considered a separate biotic habitat. Similar to redwoods, madrone trees were observed singly or in clusters throughout the reach above the top of bank near locations where thin rocky soils or rock outcrops intersect the creek. Valley oaks were seen singly or in sparse clusters throughout the reach within grasslands. As the SF Creek riparian corridor advances into more developed areas downstream of the JRBP boundary, it is gradually more infested with nonnative invasive plant species. The typical species are Himalayan blackberry (Rubus discolor), tree of heaven (Ailanthus aJtissima), French broom (Genista monspessulana), English ivy (Hedera helix), and blackwood acacia (Acacia melanoxylon). In some places, the giant reed grass (Arundo donax) still persists, despite previous removal attempts.
4.2.3 Los Trancos Creek to San Francisco Bay The SF Creek from Los Trancos Creek downstream to San Francisco Bay comprises primarily Valley Foothill Riparian and Coast Live Oak Woodland but also exhibits a high occurrence of nonnative tree and shrub species. The length of this reach is approximately 8.7 miles. The creek supports more native vegetation upstream where it borders less developed Stanford University lands, open areas, and the Stanford University golf course. Downstream, where the creek enters residential neighborhoods below the Stanford Golf Course, homes and lots border the creek banks. These structures have contributed to unstable banks and erosion necessitating installation of hardscape features such as rock rip-rap, gabions, and concrete bag walls to reinforce the banks. These areas often encourage invasive, nonnative species like English ivy, Cape ivy (Senecio mikaniodes), Himalayan blackberry, giant reed, and tree of heaven to outcompete and replace native species.
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4.2.3.1 Los Trancos Creek to EI Camino Real Below Los Trancos Creek, SF Creek borders the Stanford University Golf Course, other University lands with limited development, and a few residential homes. Habitat quality in this area is relatively high. Valley Foothill Riparian habitat is dominant throughout. Redwood, Valley Oak Woodland, and Eucalyptus habitat types also occur occasionally. Nonnative shrubs occur in quantities less than 25% in the understory in this reach.
4.2.3.2 EI Camino Real to Highway 101 Where the creek passes EI Camino Real and borders the Cities of Menlo Park and Palo Alto, it enters a more pronounced suburban environment as residential homes and lots abut the creek's banks. Because of the constricted channel, numerous erosion control improvements such as concrete bag, riprap, broken concrete, and reinforced concrete walls have been added to stabilize the channel. Valley Foothill Riparian community is prevalent but nonnative and ornamental vegetation is more pronounced within the riparian corridor.
4.2.3.3 Highway 101 to San Francisco Bay At the downstream end of the study area, after the creek crosses under Highway WI, it is more altered from its original natural condition and more constricted by levees. Saline Emergent Wetland habitat predominates within the low inter-tidal zone of this reach at the creek's mouth into San Francisco Bay. Tidal water enters pockets of freshwater emergent wetland encouraging the growth of saline emergent wetland plants such as pickleweed and saltgrass. Just upstream of where the creek flows into the Bay, a few scattered wilIows are present within the brackish marsh. The 1.8-kilometer (I. I-mile) reach from Highway 101 through the Palo Alto Municipal Golf Course to San Francisco Bay is periodically dredged.
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Figure 4.2 San Francisquito Creek Biotic Habitats Upstream of Los Trancos Creek
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4.2.4 Native Plant Species in All Reaches Table 4.1 lists the common native tree and shrub species found within the study area, the habitat type in which they would generally fall, as well as their typical location along the creek bank or top of bank region. Of the ten habitat types identified in Section 4.2, the Valley Foothill Riparian, the Coast Live Oak Woodland, and the Shrub types are the categories in which the bulk of the common native plants fall.
Table 4.1 Common Native Tree and Shrub Species, their Bank Location, and General Habitat Type within the Study Area
Bank Location Habitat Type Common Name Scientific Name LB MB UB UP COW VRI SHRUB alder Alnus rhombifolia x x arroyo willow Salix lasiolepis x x big-leaf maple Acer macrophyllum x x x box elder Acer negundo x x x x California bay Umbellularia califomica x x x California Rubus ursinus x x blackberry x x x x California Aesculus califomica x x buckeye x x x Califomia rose Rosa califomica x x x x x x California Platanus racemosa sycamore x x x coast live oak Quercus agrlfolia x x x x coyote brush Baccharis pilularis x x x x Fremont Populus fremontii spp. cottonwood fremontii x x x blue elderberry Sambucus mexicana x x x rnugwort Artemisia douglasiana x x x x x Oregon ash Fraxinus latifolia x x x poison oak Toxicodendron diversilobum x x x x x x red willow Salix laevigata x x x sand bar willow Salix exigua x x toyon Heteromeles arbutifolia x x x x
* LB-Lower Bank, MB-Mid Bank, UB-Upper Bank, UP-Upland; COW-Coastal Oak Woodland, VRI-Valley Foothill Riparian, SHRUB-Shrub habitat.
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4.2.5 Nonnative Species in All Reaches Table 4.2 lists the common nonnative tree and shrub species within the study area which increase in abundance from upstream to downstream as SF Creek evolves from a more natural setting to a more suburban and urban environment closer to San Francisco Bay. Fewer nonnatives exist upstream of Los Trancos Creek, with the exception of nonnative aquatic species within Searsville Reservoir itself.
Invasive Nonnative Trees within the Bed and Banks. Eucalyptus is the most common nonnative tree species present along SF Creek, occurring in extensive groves particularly in the portion of the project area downstream of Los Trancos Creek. Eucalyptus may pose specific problems to native species due to their allelopathic properties. Acacia, black locust, and tree of- heaven are smaller, nonnative trees that have infiltrated the SF Creek study area and can be found in patches downstream of Los Trancos Creek.
Invasive Nonnative Shrubs on the Stream Banks. English ivy, Cape ivy, Himalayan blackberry, and periwinkle are some of the most extensive nonnative shrubs that span the project area from Los Trancos Creek to Highway 101. Fennel, giant reed, and species of broom are also common nonnative shrub species that occur along SF Creek. All three have the ability to form clonal patches that preclude colonization by native species.
Invasive Nonnative Species in the Streambed. Introduced aquatic species in Searsville Reservoir and the Middle and Upper lakes and marsh are relatively confined to the margins of open water in the Fresh Emergent Marsh biotic habitats. These species include curl-leaved pondweed (Potamogeton crispus), yellow iris (Iris pseudocorus), parrot feather (Myriophyllum aquaticum), and several species of knot weed (Po/ygonum avicu/are, P. persicaria, and P. /apalhijo/ium).
Table 4.2 Common Nonnative Tree and Shrub Species Within the Study Area
Common Name Scientific Name acacia Acaciaspp. black locust Robinia pseudoacacia broom Genista and Cytisus sp. Cape ivy Senecio mikanioides English ivy Hedera helix eucalyptus Eucalyptus spp. fennel Foeniculum vulgare giant reed Arundo donax Himalayan blackberry Rubus discolor periwinkle Vinca major pampas grass Corladeria jubata tamarisk Tamarix spp. tree of heaven Ailanthus altissima
Initial Technical Studies 24 - June 2013 Summary of Existing Biological Conditions Benthic Macroinvertebrates
5 Benthic Macroinvertebrates
Distribution, diversity, and abundance of macro invertebrate fauna is often used to measure water quality in a stream system. Advantages of using benthic macro invertebrates (BMI) for biological monitoring include (Cairns and Dickson 1971, in Hennan 1995):
I. They are good indicators of localized conditions because many BMI have limited migration patterns or a sessile mode of life, and are particularly well suited for assessing site-specific impacts 2. BMI communities integrate the effects of short-tenn environmental variations. Most species have a complex life cycle of approximately 1 year or more. Sensitive life stages will respond quickly to stress, while the overall community will respond slowly 3. Sampling is relatively easy and has little effect on the resident biota; 4. BMI serve as a primary food source for many recreationally and commercially important fish 5. BMI are abundant in most streams
BMI communities differ between reservoirs and coastal streams. Their distribution is directly related to food availability and quantity, substrate type, and water quality (Callisto et al. 2005), factors of which vary widely between lentic (e.g., reservoirs) and lotic systems (e.g., coastal streams). BMI represents one of the groups most affected by habitat alteration resulting from reservoir construction. Previous studies of the effects of eutrophication in lakes and reservoirs have documented several benthic community responses:
I. Oligochaetes, chironomids, gastropods, and sphaerids increase and Hexagenia decreases 2. Number of oligochaetes relative to chironomids increase as organic enrichment increases 3. In the later phases of eutrophication oligochaetes are favored by the increased supply of organic matter in the sediments 4. The macroinvertebrate community becomes more homogenous, consequently, species diversity decreases in highly eutrophic waters (Swanson 20 II )
Stanford is particularly interested in how changes in BMI communities could affect the larger food web, since bird and bat communities, both of which thrive near Searsville Reservoir, may obtain substantial food resources from BMI. In coastal streams, BMI communities and composition can drastically change both spatially and temporally, largely in relation to environmental factors (Reece and Richardson 2000). Many of the invertebrates specific to streams are usually found in low numbers, although diversity is generally high (Reece and Richardson 2000). Conversely, impounded waters can have lower diversity but very high productivity of BM I when conditions are suitable. By developing an understanding of similarities or differences in the BMI communities in
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 25 Searsville Alternatives Study
Searsville Reservoir, SF Creek, and other wetland habitats in the study area, it may be possible to anticipate how specific management actions would affect those communities.
Herman (1995) examined the relationship between macroinvertebrates in SF Creek and water quality parameters including dissolved oxygen, pH, turbidity, conductivity, nitrate, ammonia, and phosphate. This study did not include any sampling from reservoirs in the watershed. Results showed that macroinvertebrates are impacted significantly by fluctuations in discharge and increases in stream temperature. both of which may result from water impoundment. Species richness was lower in the reach just below Searsville Dam than in other sampled reaches further downstream. This may also be partly due to low substrate diversity that often develops downstream of reservoirs. The reservoir captures bed load during storms, preventing the replacement of finer substrates immediately downstream during storm events, and reducing habitat diversity and availability for BMI. Sensitive aquatic insects in the orders Ephemeroptera, Plecoptera, and Trichoptera were most abundant in the reach above the Stanford Golf Course, just below the confluence of Los Trancos Creek (Herman 1995). Pollution tolerant insects in the Order Diptera were most abundant at the most downstream sampling stations, downstream of the Stanford Golf Course. This is likely due to increasing water temperatures and the accumulation of pollutants from the watershed.
Aerial invertebrate trapping was conducted at Middle Lake, Searsville Reservoir, and SF Creek immediately downstream of Bear Creek between August and September of 20 12 (Mateos, D.M., Stanford University Postdoctoral Research fellow, Biology [School of Humanities and Sciences], personal communication, 2013). These three locations represent three distinct habitat types present in the study area. Middle Lake is a broad, shallow body of open water ringed by dense emergent vegetation (Figure 5.1). Middle Lake occurs within the footprint of the historical extent of Sears ville Reservoir, is backwatered by Searsville Dam during the wet season, and typically dries up during the late summer or fall. Searsville Reservoir is the main reservoir, with open water habitat present year round, and wetland vegetation present along some of its shoreline. The SF Creek trapping site is within Jasper Ridge Biological Preserve, immediately downstream of the Bear Creek confluence. Trapping data for all aquatic taxa are summarized in Table 5.1. The average number of aquatic taxa trapped per trap and sampling event differed little among the three locations. Searsville Reservoir had a higher average number of individuals captured per trap and sampling event compared to SF Creek and Middle Lake.
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Figure 5.1 Middle Lake (dry) on October 31,2012. The low vegetation covering much of the lake is underwater during the wet season
Visual examination of the raw data revealed that all traps during all sampling events at Searsv ille Reservoir captured the taxon Chi ronomidae, and that chironomids were th e most abundant taxon at Searsvill e Rese rvoir. Chironomids, or nonbiting midges, are ,\ common, globally di stributed, and vcry diverse family offiies. Larval chironomids can be found in alm ost any aquatic habitat and are often assoc iated with dCb'Taded or low biodiversity ecosystems because some species have adapted to nearl y an ox ic conditions and are dominant in polluted waters.
If chironomids are excluded from the count of individual aquatic in vertebrates collected from th e three sitcs, then the avcrage number of individuals trapped per trap and sampling event at each locati on is grcatl y reduced at all sites, and the highest average count is at Middle Lake instead of Sears ville Reservoir (Table 5.1 ). The SF Creek traps had the lowest average count of aq uatic invertebrates per samplin g event. Data coll ecti on at all three locations occurred only in August and September, when stream flows arc relatively low, and these results do not provide insight into similarities or differences in the number of in vertebrates present aeriall y at oth er times of the year.
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Table 5.1 Average number of aquatic invertebrate taxa and individuals captured per trap and sampling event at three locations near Searsville Reservoir
Middle Lake Searsville Reservoir SF Creek
Taxa 2.3 2.8 2.2 IndMduals (all taxa 28 86 17 combined) Individuals (all taxa 13 7 3 except Chironomidae)
Source: Mateos. D.M .• Stanford University Postdoctoral Research fellow. Biology [School of Humanities and Sciences). unpublished data. 2013.
These data present merely a snapshot of aquatic macro invertebrate diversity and abundance. Although additional analysis of these data could be performed, the data collection was not designed to compare abundance or diversity of aquatic invertebrates among habitat types in the study area. The sampling strategy was designed to evaluate movements of all winged invertebrates between wetland and upland habitats, and terrestrial invertebrates are far more abundant in the samples than are aquatic invertebrates (Mateos, D.M., Stanford University Postdoctoral Research fellow, Biology [School of Humanities and Sciences], personal communication, 2013). Recent sampling conducted during winter and that will continue through spring 2013 is designed to address this issue as well as detect any linkages with the surrounding oak woodland and forest communities, although the results were not available at the time this TM was prepared. As data collection and analysis continues, it may be that this study will provide a different picture of invertebrate use of the three habitat types being monitored, and linkages between them.
As part of an ongoing study, a researcher has been resurveying sites originally surveyed for dragonflies and damselflies (order Odonata) in 1914, including Searsville Reservoir, the plunge pool immediately below Searsville Dam, and the stream reach from below Searsville Dam to downstream of the Bear Creek confluence (Ball, J., personal communication, 2013). These sites are adjacent to one another and many species disperse among them. These 3 sites are among 80 sites throughout California and Nevada included in the study. The primary goals of this study are to determine how land use and climate influence Odonata species richness, community composition, and occupancy rates of individual Odonata species, and to document changes in these parameters over time.
Sampling conducted in fall 2011 and 2012 indicates that species richness for Searsville Reservoir is typical for lentic habitats in the region, with a total of II species collected from the reservoir. The species found in the reservoir are generally common species that can be found in a wide variety of disturbed habitats in the immediate and surrounding area.
Initial Technical Studies 28 - June 2013 Summary of Existing Biological Conditions Benthic Macroinvertebrates
Species richness at the reservoir outlet (the plunge pool immediately below Searsville Dam) was slightly higher than the reservoir, with a total of 14 species collected from the outlet pool. This is likely due to the combination of lotic and lentic species present at the site, which is a pool with water flowing in and out of it.
A total of II species were observed at the downstream creek sampling site, including several species more generally associated with streams. While none of the Odonata species at JRBP are considered to be rare or endangered, Aeshna palmata and Cordulegaster dorsalis, observed within the creek, are less common than the species breeding in Searsville Reservoir, and 3 out of the II species found at the creek site are considered habitat specialists.
Although in this Odonata study Searsville Reservoir and the creek sites yielded the same number of Odonata species, it was noted that the species found in Searsville Reservoir were all common species widely distributed in lentic habitats in the region, while the species in the creek included less common and habitat specialist species. Lentic sites generally support a higher number of very common Odonata species, because many are adapted to open, sunny habitats with abundant emergent and floating vegetation (Hof et al. 2006). The highest number of species was collected from the large plunge pool immediately below Searsville Dam, which supports both lentic and lotic adapted species. This pool may represent the diversity typical of large pools in the upper, less disturbed reaches of SF Creek between Bear Creek and Los Trancos Creek, although further sampling would be needed to support this speculation.
The data summarized from the aerial trapping study described previously may indicate a similar pattern of diversity; for example, chironomids are also typically more diverse and abundant in lentic waters than in lotic waters, but some rare taxa may be present in the lotic waters of SF Creek that would not be expected in the reservoir. The level of taxonomic identification in the trapping study, however, does not allow for this type of analysis. It may be reasonable to expect that because SF Creek contains lentic habitats in its larger pools, as well as a diversity of lotic habitats, overall BMI diversity would be higher in SF Creek than in Searsville Reservoir.
Aside from diversity, overall productivity of BMI is important in the context offish and wildlife use. BMI associated with both lentic and lotic systems are important forage for many species of fish, birds, bats, amphibians, and some terrestrial mammals, which are discussed below in Sections 6 and 7. The wetted area of Searsville Reservoir is presumably many times that of the original stream channels that traversed the site. Due to this increase in area of aquatic habitat, BMI production from the reservoir may be greater than the original stream channels of the impounded reaches. However, this relationship may change when considering riparian habitat, as riparian areas support productivity of insects that are also important forage for wildlife. Based on examination of historical topographic maps, the historical "Confluence Valley" that existed at the site of Searsville Reservoir prior to dam construction may have supported diverse stream, wetland, and riparian habitats and associated macroinvertebrate communities. The extent to which BMI abundance varied among pre-reservoir construction, existing conditions, and potential future conditions is unknown.
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 29 Searsville Alternatives Study
6 Fish
This section describes the fish community present in portions of the SF Creek watershed based on existing data. For the purposes of description in this document, the study area was divided into Searsville Reservoir and three separate stream reaches based on dominant habitat types. The stream reaches were defined based on variation in geomorphology and resulting channel morphology, variation in stream flow, differences in infrastructure along SF Creek, and potential differences in fish community, including possible steelhead utilization. The stream reaches are described in Section 2.1, and fish communities known or expected to be associated with these habitat units are addressed below, followed by a discussion of known or expected steel head utilization of the study area.
6.1 Fish Communities Approximately 22 species of fish are known to inhabit the SF Creek watershed (Table 6.1). There are 24 other species of fish which are not recorded from SF Creek but are found in the general area and may occur within SF Creek, including 14 native species (Table 6.2). Of the 22 species recorded from SF Creek, 8 are native and 14 are nonnative fish species.
6.1.1 Searsville Reservoir Upstream fish passage from Corte Madera Creek to Searsville Reservoir is blocked by Searsville Dam, and downstream movements can occur only over the spillway, a path that likely results in mortality of many fish that travel that route due to the stepped nature of the spillway and dam face. Therefore, the fish community in the reservoir is fairly isolated from downstream. The primary body of water in this habitat unit is Searsville Reservoir itself, but Middle and Upper lakes, as well as a portion of Corte Madera Creek, also occur within the footprint of the historical extent of Searsville Reservoir. Fish surveys conducted in 1995 and 1996 found an abundance of nonnative centrarchids, mosquitofish, and brown bullhead (Fee et al. 1996). Several of these species, most notably largemouth bass and brown bullhead are significant predators on other fishes, thus impacting the biotic communities in the area. Undoubtedly, largemouth bass is a major factor in structuring the aquatic, terrestrial, and semi-terrestrial community present at Searsville Reservoir.
Initial Technical Studies 30 - June 2013 Summary of Existing Biological Conditions Fish
Table 6.1 Fish Species known to occur In SF Creek
Common Name Scientific Name Native or Nonnative (with notes)
California roach Lavinia symmetricus native hitch Lavinia exilicauda Native (rare)
Sacramento blackfish Orthodon microlepidotus Native (very rare)
Sacramento sucker Catostomus occidentalis native rainbow trouVsteelhead Oncorhynchus mykiss irideus native threespine stickleback Gasterosteus aculeatus native prickly sculpin Cottus asper Native (uncommon) riffle sculpin Cottus gulosus Native (reported) goldfish Carassius auratus nonnative cornmoncarp Cyprinus carpio nonnative golden shiner Notemigonus crysoleucas nonnative black bullhead Ameiurus melas nonnative yellow bullhead Ameiurus natalis nonnative brown bullhead Ameiurus nebulosus nonnative rainwater killifish Lucania paIVa nonnative western mosquitofish Gambusia affinis nonnative green sunfish Lepomis cyanellus nonnative pumpkinseed Lepomis gibbosus nonnative bluegill Lepomis macrochirus nonnative redear sunfish Lepomis microlophus nonnative largemouth bass Micropterus salmoides nonnative
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 31 Searsville Alternatives Study
Table 6.2 Fish Species not recorded in SF Creek but found in other South Bay drainages or near where SF Creek enters San Francisco Bay
Common Name Scientific Name Native or Nonnative
Pacific lamprey Lampetra tridentata native Western brook lamprey Lampetra richardsoni native river lamprey Lampetra ayres;; native white sturgeon ACipenser transmontanus native green sturgeon Acipenser medirostris native harclhead Mylopharodon conocephalus native Sacramento pikeminnow ptychocheilus grandis native speckled dace Rhinichthys osculus native Coho salmon Oncorhynchus kisutch native Chinook salmon Oncorhynchus tshawytscha native coast range sculpin Coitus aleuticus native staghorn sculpin Coitus armatus native Sacramento perch Archoplites interruptus native tule perch Hysterocarpus traski native American shad Alosa sapidiSsima nonnative threadfin shad Dorosoma petenense nonnative fathead minnow Pimepha/es prome/as nonnative white catfish Ameiurus catus nonnative channel catfish Ictalurus punctatus nonnative brown trout Sa/mo trulta nonnative inland silverside Menidia beryl/ina nonnative striped bass Morone saxatilis nonnative smallmouth bass Micropterus dolomieu nonnative white crappie Pomoxis annularis nonnative
Temperature has been recorded by Stanford University at the Searsville Dam gaging station since 1998. Temperatures recorded at this location, which represent temperatures near the surface of the reservoir, range from 5.3 DC to 28.6DC. During winter months, temperatures range from 5.3 DC to 18.2DC, which is generally cool enough to support most native fishes present in the watershed. The records indicate that water temperature in the reservoir begins to rise in April. and typically reaches temperatures less suitable for cool water native fishes (23DC to 24DC) around late May. Summer temperatures as high as 28.6DC have been recorded. These temperatures are higher than what would be expected
Initial Technical Studies 32 - June 2013 Summary of Existing Biological Conditions Fish in a more natural stream environment, where water moves more quickly through the system and is shaded by a riparian canopy. When water enters the reservoir its residence time increases and it is more directly exposed to the sun's rays, resulting in warmer temperatures.
Sporadic collection of dissolved oxygen (DO) at Searsville Reservoir has been perfonned. A total of ten DO measurements were taken in the reservoir between 1998 and 2012, ranging between 3.7 and 8.8 mglL. The typical minimum DO levels for steel head without causing impainnent is 8 mg/L (Bjornn and Reiser 1991). Although they can survive DO levels as low as 5 mglL, growth, food conversion efficiency, and swimming performance will be impaired. Numerous studies have reported that salmonids have no impainnent if DO levels averaged 9 mglL (Davis 1975). On the other hand, centrarchids such as the largemouth bass, can tolerate DO levels between 4 and 8 mglL (Stuber et al 1982). A substantial reduction in energetics and metabolism occurs below 4 mglL, and DO levels below I mglL are considered lethal to both Salmonid and centrarchids species (Stuber et al 1982). According to the limited measurements of DO in Searsville Reservoir, the average DO content in the reservoir is 6.5 mglL. Because the average DO level is below 9 mglL, it is not capable of providing suitable habitat for any life history stage of steelhead without impainnent. However, DO levels are suitable for largemouth bass.
Due to the altered temperature and flow regime, as well as the reduced water quality, Searsville Reservoir (and Middle and Upper lakes, when they are inundated) is expected to support most, if not all, of the nonnative fishes present in the watershed, including goldfish (Carassius auralus), common carp (Cyprinus carpio), golden shiner (Notemigonus crysoleucas), black bullhead (Ameiurus melas), yellow bullhead (A. natalis), brown bullhead (A. nebulosus), rainwater killifish (Lucania parva), western mosquitofish (Gambllsia affinis), green sunfish (Lepomis cyanellus), bluegill (L. macrochirus), pumpkinseed (L. gibboSllS)3, redear sunfish (L. microlophlls), largemouth bass (Micropterus salmoides), and black crappie (Pomoxis nigromaclilatlls). Many of these species are adapted to slow, wann water environments and typically thrive in California reservoirs.
The nonnative fishes found in the SF Creek watershed are all widely distributed in most river systems throughout California except for yellow bullhead. Reports of this fish from northern California may be misidentified brown bullhead (Moyle 2002). Brown and black bullhead are often abundant in ditches, clear mountain lakes, wann turbid sloughs, intennittent streams, and other temporary habitats with low concentration of dissolved oxygen levels. However, it is not unusual to find these crepuscular species in trout streams with salinities in excess of 13 parts per thousand (ppt). Brown and black bullhead are abundant in Searsville Reservoir, are not uncommon in the first I mile downstream of
3 Lepomis species in Searsville Reservoir have been observed to hybridize readily and may best be described as a hybrid swarm (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013).
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 33 Searsville Alternatives Study the reservoir, and are uncommon in the rest of the stream reaches downstream of Searsville Reservoir monitored by Stanford University (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013).
Rainwater killifish and western mosquitofish are abundant throughout California due to their ability to adapt to a wide variety of habitats including tolerance of different salinity levels. Rainwater killifish can live in salinities up to 80 ppt, while western mosquitofish can be found in brackish sloughs and salt marshes as well as in freshwater ponds, lakes, and streams (Moyle 2002). Mosquitofish are present in Searsville Reservoir and scattered elsewhere in the SF Creek watershed (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). Rainwater killifish are present primarily in the stream reaches downstream of Stanford University property.
Centrarchids, a family of fishes that includes the more aggressive nonnative predatory fishes in the watershed (sunfish [Lepomis spp.], bass [Microplerus spp.], and crappie [Pomoxis spp.]) are expected to be most abundant in Searsville Reservoir (and associated Middle and Upper lake habitats) because they are adapted to low-flow and high-water temperature habitats with substantial aquatic vegetation.
Due to high residence time of water in the reservoir, associated decreases in water quality and increases in temperature, and the presumed abundance of predatory, nonnative fishes, Searsville Reservoir may not be a very hospitable environment for native fishes. The temperature data collected at the dam does not indicate to what degree thermal stratification occurs in the reservoir, but it is possible that native fishes could take refuge in deeper portions of Searsville Reservoir when surface temperatures are high. Native fishes may colonize the reservoir from upstream, but the reservoir itself may be a sink for most native fishes, where predation is heavy, thermal stress common, and reproduction low or nonexistent.
6.1.1.1 Middle and Upper Lakes Middle and Upper lakes provide fish habitat similar to Searsville Reservoir, but shallower and with more extensive aquatic vegetation. Water temperatures are probably similar to those measured at Searsville Dam, but without the potential for thermal refuge in deeper water. The lakes are backwatered by Searsville Dam when the reservoir stage is high in the winter. Nonnative fishes dominate these habitats (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013).
6.1.1.2 Corte Madera Creek Upstream of Searsvllle Reservoir Between the historical limits of Searsville Reservoir and the point downstream where the stream enters the current reservoir, Corte Madera Creek passes over a large delta of accumulated sediment. The delta supports a riparian forest, and the stream is highly braided through the forest. At higher flows the stream is not contained by a single channel, but instead travels many paths towards the reservoir. This is a "losing" reach, where much of the surface flow present upstream in Corte Madera Creek percolates into the accumulated sediment and is lost to groundwater. This stream reach dries completely during the dry season, so any fish present in this reach must recolonize the habitat from upstream or from the reservoir following when winter storms restore flow. Between the
Initial Technical Studies 34 - June 2013 Summary of Existing Biological Conditions Fish reservoir and the upstream boundary of Stanford University property there are typically very few fishes present (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). perhaps due to the temporary nature ofthis stream reach. This reach may be less important habitat for fishes than more permanent habitats upstream and down.
6.1.2 Searsville Dam to Bear Creek As it spills over Searsville Dam and plunges to Corte Madera Creek below, the water in the reservoir is re-oxygenated; low DO levels measured within the reservoir at the spillway do not represent DO levels in this reach below. Other effects of the reservoir. however, are pronounced in this reach immediately below the dam, upstream of the influence of other tributaries such as Bear Creek. Sediment transport is blocked by Searsville Dam, so that the water passing through this reach deposits little sediment, and instead tends to scour out available sediment and move it further downstream. What remains is a channel bed characterized by interlocking. angular rocks (Figure 6.1). This type of channel is typical below large dams. It provides less diverse habitat and fewer interstitial refugia for BMI (an important food resource for fish), and fewer (or no) spawning opportunities for steel head, compared to other stream reaches downstream of Bear Creek. Additionally, water temperature is influenced by warming upstream in the reservoir, and then is affected by air temperature as it spills over the dam due to increased surface area and exposure as it spills. Based on temperature data recently collected (December 2012 through March 2013) by Stanford immediately upstream and downstream of Searsville Dam, when the ambient air temperature is cooler than the reservoir water temperature, the water is cooled slightly as it spills, and when the ambient air temperature is warmer than the water it is warmed slightly as it spills. Depending on the relative ambient and water temperatures, the spill can have a warming effect during the day and a cooling effect at night. Water temperature in this reach is generally expected to be similar to that measured at Searsville Dam, elevated compared to reaches further from the reservoir, and variable depending on time of day and season.
Stream flow in this reach is typically continuous during the wet season but when the water surface elevation in Searsville Reservoir drops below the invert elevation of the spillway, stream flow is limited to minimal seepage through and under Searsville Dam. Flow in this reach is intermittent, with the stream typically drying to a series of isolated pools, or almost completely, during the dry season.
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 35 •
Searsville Alternatives Study
Figure 6.1 Photograph taken August 9, 2012 showing the typical channel substrate in Corte Madera Creek between Searsville Dam and Bear Creek
The nonnative fi shes dominant in the rese rvoi r sometimes survi ve the fall over the dam and coloni ze this reach from above. Nonnati ve fi shes have been found to persist in this reach mostl y during wet years, when increased runoff maintains stream now (A. Launer, Stanford Uni versity, Conservation Program Manager, pers. comlll., 20 12), although reproduction has been documented in the plunge pool at the base of the dam (A. Launer, Stanford Uni versity, Conservation Program Manager, pefs. camm., 20 13). Largemouth bass. green sunfish, bluegill , and mosquitofish have fl exible foragin g strategies and wide en vironm ental tolerances wh ich could make them persist in deeper pools for some time. During drier years the le vel of drying that occurs in the cnanncltends to be incompatibl e with persistence of 1ll 0st fi shes through the dry seaso n.
In additi on to th e primarily nonnati ve fishes described above, the native fi sh community in SF Creek includes steelh ead (Oncorhynchus mykiss), California roach (Lavinia symmelricll:;), Sacramento sucker (ColOslomlls occidellialis), threespine stickleb'lck (GasleroSIC!IIS oell/coIIlS) . and prickly sculpin (Conus awer). Hitch (L. exilicouda) are rare in the watershed, Sacramento black fi sh (Orthodon macrolepidotus) arc vcry rare, and riffle sculpin (c. gll/o.nls) have been reported (A. Launer, Stanford Uni versity, Conservation Program Manager, pers. comm., 2013). Sculpin, Sacramento sucker, threespinc stickleback. and steelh ead all typically occur ill similar habitat and together
Initial Technical Studies 36 - June 2013 Summary of Existing Biological Conditions Fish make up the primary cool-water fish assemblage native to the middle and upper reaches of the SF Creek watershed. Their habitat is described as high-gradient, cool water streams where rime and rocky substrate dominate (Moyle 2002). During summer dry-down of the pools in this reach, if nonnative centrarchids are present in the pools, native fishes could be subject to high rates of predation.
6.1.3 Bear Creek to Los Trancos Creek San Francisquito Creek begins where Corte Madera Creek converges with Bear Creek (Figure 2.1). The Bear Creek sub-watershed does not contain any major in-stream reservoirs and has substantial drainage area, so that habitat downstream of Bear Creek is characterized by increased sediment flux, greater and less regulated stream flows, and cooler water temperatures. Therefore, reservoir effects on stream habitat would be expected to diminish the further downstream towards the confluence with Los Trancos Creek because with other sources of inflow, the proportion of water in the stream originating from upstream of Searsville Dam decreases. This reach provides appropriate spawning and rearing habitat for steel head due to cool water flow and the existing gravel bed. Other native fishes found in this reach include abundant roach, sucker, and stickleback, and the uncommonly encountered sculpin (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). Nonnatives present include scattered largemouth bass and bluegill, fewer green sunfish, mosquitofish, and goldfish, and the rare bullhead.
6.1.4 Los Trancos Creek to San Francisco Bay This lower reach is identified where SF Creek converges with Los Trancos Creek and flows downstream towards the San Francisco Bay. This reach of the SF Creek borders the Stanford University golf course, has a more pronounced suburban environment, has been heavily modified with expanses of continuous concrete walls, and at its lower end supports saline emergent wetland habitat that dominates the low intertidal zone.
The suite offish found in the upper portion of this reach, from Los Trancos Creek to the downstream limit of Stanford property, is similar to that described above for Bear Creek to Los Trancos Creek, but with more sculpin (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). Downstream this reach may provide habitat for carp, Sacramento sucker, California roach, and threespine stickleback. Even though these species prefer cooler water temperatures, they can tolerate a wide range of stream temperature fluctuations (approximately 15-30°C) and variable salinity tolerances (> 13ppt).
6.2 Steel head Steelhead is the only special-status fish species known to occur in the SF Creek watershed. Steelhead and rainbow trout are the same species and the term steelhead may refer to resident rainbow trout that co-occur with steelhead. Steelhead within the SF Creek watershed belong to the Central California Coast (CeC) Distinct Population Segment (DPS), a population that is listed under the Federal ESA as threatened. SF Creek below Searsville Dam (including tributaries Bear Creek and Los Trancos Creek) is
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 37 Searsville Alternatives Study
included in Santa Clara Hydrologic Unit 2205 of designated critical habitat for CCC steel head (50 CFR 52488-52627).
Juvenile CCC steelhead typically rear in freshwatert usually from 1 to 3 years. Throughout their range, steelhead typically remain at sea for 1 to 4 years before returning to freshwater to spawn. Because juvenile steel head remain in the creek year-round, adequate flows, suitable water temperatures, and an abundant food supply are necessary throughout the year to sustain steelhead populations. The most critical period is in the summer and early fall t when these conditions become limiting. Steelhead also require cool, clean, well-oxygenated water, and appropriately sized gravel for spawning. Spawning habitat condition is strongly affected by water flow and quality, especially temperaturet DO, shade, and silt load; all of which can greatly affect the survival of eggs and larvae (USFWS 2006).
Juvenile emigration occurs between March and June (Moyle 2002), with peak emigration in SF Creek expected to occur during March and April. Spawning is expected to occur from January through March, with most spawning occurring in January and February. Coarse gravel beds in rime areas are used for egg laying and yolk sac fry habitat once eggs have hatched. Quantity and quality of summer rearing habitat with cool water pools and extensive cover for older juvenile steelhead is often a limiting factor for steel head in California streams (Moyle 2002). Sedimentation of pool habitat as a result of urban and agricultural development within watersheds, and the removal of woody vegetation for flood control purposes, has severely impacted steelhead summer rearing habitat.
SF Creek supports one of the few remaining steel head runs in tributary streams to San Francisco Bay. Figure 6.2 illustrates the number of steelhead per mile collected from various reaches of Corte Madera Creek downstream of Searsville Dam, SF Creek and Los Trancos Creek between 1997 and 2006. The main limiting factors for steelhead production in the SF Creek watershed are availability of winter refuge (from high flows) habitat, high summer water temperatures, and impediments to passage (Jones and Stokes 2006). A number of potential barriers or impediments to steelhead upstream migration in the SF Creek watershed have been identified (Smith and Harden 2001, Stoecker 20 I 0). Steelhead are known to spawn within the SF Creek watershed including some portions downstream of Searsville Dam that flow through Stanford University property (Stanford University 2012).
Searsville Dam is a barrier to fish migration in the system, and prevents migrating adults from reaching potential steelhead spawning habitat upstream of the dam. Resident rainbow trout are present in the creeks upstream of Searsville Dam (notably Corte Madera Creek and Sausal Creek), and they are scattered throughout the system (Stanford University 2012). These resident rainbow trout upstream of Searsville Dam are not protected under the ESA.
Portions of the SF Creek and its tributaries remain as key refugia for steelhead in the southern San Francisco Bay area as described in Section 2.0. Bear Creek and lower reaches of Los Trancos Creek subwatersheds provide good spawning and rearing habitat for steelhead. Adult steel head are encountered in SF Creek during the summer months
Initial Technical Studies 38 - June 2013 Summary of Existing Biological Conditions Fish every few years (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). In addition to Stanford's records, Table 6.3 lists some of the documented occurrences of steelhead in SF Creek. Based on the documented occurrences and other anecdotal infonnation it is reasonable to assume that steelhead Guveniles or adults) are present in SF Creek year-round.
Table 6.3 Documented Steel head Occurrences In SF Creek
Year of Observation Description Source
1961 Small run of steelhead most winters in SF Creek Leidy 2005 Ten young-of-year steelhead were observed from the 1976 confluence with Bear Creek to the mouth Leidy 2005 Eight steel head ranging from 43 to 147 mm were found in 1976 the vicinity of Junipero Serra Boulevard Leidy 2005 Steelhead were common between EI Camino Real and June 1981 the Sand Hill crossing Leidy 2005 Two steelhead (51 and 73 mm) were collected near August 1981 Alpine Road Leidy 2005 One 212 mm (fork length) steelhead was captured below September 1994 Sand Hill Road Leidy 2005 47 steelhead 4 were captured. fin-clipped. then released Summer and (all 1996 in SF Creek Leidy 2005 One steelhead was rescued from the lower reach during 1998 dewatering of the channel Leidy 2005 Juvenile steelhead were identified throughout SF Creek Leidy 2005 1999 and 2001 from Highway 101 to Searsville Dam Steelhead Ouveniles during emigration and over- Young et al. 2003 summering) were observed in Bear Creek and Los 1999 to 2001 Trancos Creek subwatersheds during 1999-2001 surveys National Marine Fisheries Service and Stanford University Garza et al. 2004 2001 collected fin clips from steelhead in Los Trancos Creek Two adult steel head were photographed in lower SF Leidy 2005 2002 Creek Two adult steelhead were video·recorded in SF Creek at You Tube 2013 2013 Woodland Avenue
The 1998-2013 temperature data from Searsville Dam suggest that temperatures are at acceptable levels between Searsville Dam and the confluence with Bear Creek for the timing of spawning for adult steelhead between December and mid-March. Peak spawning in the SF Creek watershed is expected to occur January-March. Over the short
4 These fish were captured by Stanford University (A. Launer, Stanford University, Conservation Program Manager. pers. comm., 2013).
Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 39 Searsville Alternatives Study period of record, mean water temperatures stayed between acceptable spawning temperatures except in 2007 where temperatures increased earlier than other years.
High summer temperatures could cause considerable stress to or mortality of juvenile steelhead in Searsville Reservoir and the stream reach between the dam and the Bear Creek confluence, where reservoir water temperatures have been the best indicator of downstream water temperature. For juvenile steel head, the optimal temperature for growth is around lS-l SOC (Moyle 2002). Steelhead within California (Central Valley) tend to show significant mortality at chronic temperatures exceeding 25°C, although they can tolerate temperatures as high as 29.6 °C for short periods of time (Myrick and Cech 2000). The 1998 - 2013 data show that in the reach between Searsville Dam and Bear Creek (and in the reservoir) water temperatures are in the range preferred by steel head until approximately the end of April. Stress-inducing temperatures of 23-24°C typically occur in the warm months beginning in mid- to late-May, depending on the water year. In recent years, water temperatures have not reached levels considered potentially lethal to juvenile steel head until early- to mid-June. By this time during all years of record, water temperatures within the reservoir had reached potentially lethal levels for juvenile steel head.
Many factors affect placement choice within habitat by steel head including changes in the availability of food when temperature gradually rises (Moyle 2002). During times when temperatures become stressful in streams, juvenile steel head are faced with the increased energetic cost of living. They must move into fast riffles to feed because food are most abundant there, even though there are additional energetic cost associated with maintaining position in fast water. If sufficient food is available and other stressors are limited, survival under stressful conditions is more likely, but less favorable habitat conditions such as little or no stream flow may decrease chances for survival.
Besides temperature, the dam also significantly affects substrate that may contribute to reduction of habitat suitability of the reach between Searsville Dam and Bear Creek for steelhead. The reach of Corte Madera Creek downstream of Searsville Dam is sediment starved (H.T. Harvey 2001), a condition which changes the physical habitat, which in turn affects fish by altering the composition and structure of the streambed, lowering the quality of spawning and rearing habitat. Suitable spawning gravels carried downstream by high flows are not replenished from upstream, so spawning substrate is likely limited in this reach. The sediment starved condition is also associated with reduced substrate and cover for BMI. While abundant food resources can compensate for high water temperature, that may not be possible in this reach.
Initial Technical Studies 40 - June 2013 Summary of Existing Biological Conditions Fish
s.. ~ ...... "'~ o ~Ff~c..IIl'IJ""'* D SoarIFllI'OIqltC-mSlbW,lernCII o SW.bj :rt'*"itcll\Ol."t _ ThokUo.:• .....,._o.o.n:lOt:!. _____ n ...... 1<4I_ .-.IlI;oIoobil'...... 'I" ___:-l1O, \.lIS =c ll :-l l ),
Summary cl E.li6li1g St.nm~ cl Stanlord Un.\ Figure 6.2 Summary of Stanford University Survey Results Showing Number of O. mykiss per Mile Initial Technical Studies Summary of Existing Biological Conditions June2013-41 Searsville Alternatives Study 6.3 Crayfish and Mitten Crabs Crayfish and mitten crabs are nonnative crustaceans whose presence in California streams is generally believed to negatively affect native aquatic species. Because they are present in the SF Creek watershed, and management decisions affecting their distribution and abundance could affect other, native taxa, existing information for these two taxa are briefly summarized below. 6.3.1 Crayfish Nonnative crayfish occupy various types of habitat including, wet meadows, seasonally flooded swamps and marshes, and permanent lakes and streams (Brant 2004). Although all crayfish are aquatic, some species are adapted to survive periods when surface water is not present. Some species may use burrows during such low water, dry periods and/or during reproductive periods, while other species require constant flows of cold water. Periods of low water usually coincide with hot months in lower latitudes; therefore, crayfish are generally more active in the cool months in these areas. Generally speaking, crayfish are opportunists and feed on a wide variety of materials, including detritus, invertebrates, vertebrate larvae, algae, and plant matter. At least II molts are required before crayfish become sexually mature. The periods between these molts are temperature dependent with lengths ranging from 6-30 days (Brant 2004). Development is rapid enough to allow at least two generations per year. In laboratory conditions, maximum life span is about 4 years, with a typical life span of ] 2- 18 months. Nonnative crayfish have been implicated in the decline of many native organisms (Fee et al. 1996). At least three species of crayfish likely inhabit the SF Creek watershed; Pacifastacus leniusculus, Orconectes virilis, and Procambarus clarkii. Orconectes, however, has not been observed during Stanford University stream monitoring for some time (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). While there are many differences in behavioral ecology of crayfishes, they mostly eat a wide range of vegetable and animal matter. Dead animal matter is frequently scavenged, but living organisms, particularly eggs and larvae, are also consumed. Due to this type of predation on the vulnerable life stages of native organisms, combined with the high densities at which crayfish can occur, nonnative crayfish are viewed as a conservation problem. The more abundant nonnative crayfish are, the less likely a given site is occupied by certain native species of conservation concern, such as California red legged frog (USFWS 2002). In the SF Creek watershed, crayfish were observed scattered throughout the system during a 13 month survey period from May 1995 - June 1996 (Fee et al. 1996). They were commonly found in deeper and calmer pools in many stretches of the creek. Searsville Reservoir is likely a population reservoir for several of the nonnative crayfish. Some years ago, it was noted that following heavy winter rains, few crayfish could be found in the creeks, while they remained common in Searsville Reservoir. After that scour event, it appeared that the creeks were slowly re-colonized, possibly by popUlations holding in Searsville Reservoir. When filled to capacity, the reservoir deepens and Initial Technical Studies 42 - June 2013 Summary of Existing Biological Conditions Fish becomes less hospitable for some crayfish, particularly the Procambarus and Orconecles, which thrive in wann, shallow, and slow moving water. Based on surveys conducted over time, it is noted that Procambarus are common in Searsville Reservoir and just downstream, less common further downstream, but then are more common again approaching Alpine Road and downstream of Alpine Road (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). Pacifastacus is found downstream of Searsville Dam and scattered in Los Trancos Creek, but is less common downstream of Alpine Road. 6.3.2 Mitten Crab The Chinese mitten crab (Eriocheir sinensis) was first discovered in South San Francisco Bay in 1992 and quickly spread throughout the estuary during the next several years (H.T. Harvey and Associates 200 I). The adults reproduce in saltwater and the offspring migrate to freshwater to rear. During their fourth or fifth year, males and females migrate downstream attaining sexual maturity in the tidal estuaries. Females can carry 250,000 to 1,000,000 eggs that become planktonic for 1 to 2 months after hatching. The juveniles settle in salt or brackish water in late spring before migrating to freshwater to rear. Mitten crabs are omnivores with juveniles eating mostly vegetation, but preying upon animals especially small invertebrates as they grow. Mitten crabs have been known in SF Creek since 1996 (H.T. Harvey and Associates 200 I). In 1999, a relatively large number were reported as far upstream as the portion of SF Creek between Webb Ranch and the Stanford Shopping Center (downstream of the Los Trancos Creek confluence). The mitten crab could potentially become distributed throughout all waterways of the SF Creek watershed up to any migration barrier, such as large dams, and is known to circumvent small dams and weirs that would otherwise block its migration route. The number of mitten crabs in the Stanford portions of the creeks varies each year (Stanford University 2012). From 1996 to 1998, there were very few observations of mitten crabs upstream of EI Camino Real. In 1999 and 2000, hundreds of crabs were seen in SF Creek, some reaching the confluence with Bear Creek. During 200 I through 2007, very few crabs were observed in the system, with none being seen in the last 5 years. The extent and ecological impacts of this recent invasion are poorly understood, but may include the following effects. Mitten crabs construct burrows in tidal areas, which may lead to increased erosion. Although juveniles primarily consume vegetation, they do prey upon animals, especially invertebrates, as they mature. Invasion by mitten crabs may reduce populations of native invertebrates through predation and change the structure of benthic invertebrate communities (CDFG 1998). Searsville Dam is likely a migration barrier to this species, although some mitten crabs may be able to move around the dam by travelling through upland areas. Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 43 Searsville Alternatives Study 7 Wildlife Despite extensive development in the region, the upper portion of the SF Creek watershed is relatively undeveloped, and supports a substantial number of native wildlife species of conservation concern. As described in Section 1.2.2, the CNDDB and USFWS were queried to detennine special-status wildlife species potentially present within the study area. Table 7.1 presents results of these queries that potentially occurring in the Study Area. Additional infonnation on these special-status species, as well as other species of interest in the study area, are presented in the sections below. The focus in the following sections is on wildlife species and habitats that could be affected by specific management actions being evaluated by Stanford University. Table 7.1 Listed Wildlife Species Potentially Occurring In Study Area Federal State Scientific Name Common Name Status Status EuphycJryas editha bayensis Bay checkerspot butterfly Threatened - Oncorhynchus mykiss1 steel head - central California coast DPS Threatened - Ambystoma califom/ense California tiger salamander Threatened Threatened Rana draytonii Califomla red-legged frog Threatened - Thamnophis slrtalis tetra taenia San Francisco garter snake Endangered Endangered Charadrius a/exandrinus western snowy plover Threatened nivosus - Laterallus jamaicensis California black rail Threatened cotum/culus - Ral/us long/rostris obso/etus California clapper rail Endangered Endangered Stemula antillarum brown; California least tern Endangered Endangered Reithrodontomys raviventris salt-marsh harvest mouse Endangered Endangered I Steelhead are addressed in Section 6. 7.1 Terrestriallnvertebrates One terrestrial invertebrate special-status species, the Bay checkerspot butterfly (Euphrydryas editha bayenis) is known to occur historically within grassland habitats in and around Stanford University (Stanford 2012). However, despite hundreds of hours of surveys, the Bay checkerspot butterfly has not been observed at Stanford since 1997. It is not expected to use any of the primary habitats that would be affected by management actions at Searsville Dam and is not discussed further in this document. Initial Technical Studies 44 - June 2013 Summary of Existing Biological Conditions Wildlife 7.2 Amphibians Amphibians within the study area primarily occur within riparian habitats including portions of the reservoir, the riparian area upstream of the reservoir, and creeks downstream of the dam. However, California tiger salamander (Ambystoma californiense), occurs within grassland habitats on Stanford campus and surrounding habitats and is not known or expected to use the riparian habitats or Searsville Reservoir (including Upper and Middle lakes). Within the riparian zone, western toad (Anaxyrus boreas), Sierran treefrog (Pseudacris sierra), bullfrog (Lithobates catesbeianus), California slender salamander (Batrachoseps attenuatus), rough-skinned newt (Taricha granulosa), California newt (Taricha lorosa), and arboreal salamander (Aneides lugubris) are expected to occur in the SF Creek watershed (H.T. Harvey and Associates 2001). Additionally, California red-legged frog (Rana draytonii) is known to occur in SF Creek downstream of Searsville Dam (Launer and Spain 1998). Black Salamanders (Aneides jlavipunctatus) are found along the creek just downstream of Searsville Dam (A. Launer, Stanford University. Conservation Program Manager, pers. comm., 2013). Yellow-eyed salamanders (Ensalina eschscholtzii xanthoptica) are also present in SF Creek watershed. including wetlands associated with Family Farm Road, upstream of Searsville Reservoir. There are some very old records of foothill yellow-legged (Rana boylil) frog from the watershed although they have not been observed for many years. Amphibians within Searsville Reservoir include western toad, Sierran treefrog. and bullfrog (H.T. Harvey and Associates 200 I). The following sections provide additional information on those amphibian species expected to be most relevant to the future evaluation of the effects on biological resources of specific management actions at Searsville Dam and reservoir. 7.2.1 California red-legged frog The California red-legged frog is federally listed as threatened. The species is distributed throughout 28 counties in California but occurs primarily between Santa Barbara and just north of San Francisco (Jennings and Hayes 1994, USFWS 2002). The largest areas of currently occupied habitat are in Monterey. San Luis Obispo. and Santa Barbara Counties (USFWS 2004). The California red-legged frog uses a variety of aquatic, riparian, and upland habitats up to an elevation of 4,921 feet (Jennings and Hayes 1994; Bulger et al. 2003; Stebbins 2003). The California red-legged frog typically inhabits permanent and semi-permanent water sources such as streams. lakes. marshes, natural and artificial ponds. and ephemeral drainages in valley bottoms and foothills. They breed between November and April in standing or slow-moving water that is at least 2.3 feet deep (Hayes and Jennings 1988). although tadpoles have been observed in shallower (0.8 - 1.6 feet deep) sections of streams not overrun by riparian vegetation (Reis 1999). Streams suitable for breeding typically contain shrubby riparian or emergent vegetation such as cattails (Typha sp.), tules (Scirpus sp.). and overhanging willows (Salix spp.) (Hayes and Jennings 1988). Egg masses containing 2,000 to 5.000 eggs are attached to vegetation below the surface of the water and hatch in 6 to 14 days (Storer 1925; Jennings and Hayes 1994). The fully aquatic larvae require approximately II to 20 weeks for development through metamorphosis. and metamorphosed frogs require appropriate upland refugia for aestivation during dry periods. Refuge for the California red-legged frog includes small Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 45 SearsvilJe Alternatives Study mammal burrows, downed logs or vegetation, and dense vegetation/litter layer (USFWS 2002). Within SF Creek, California red-legged frogs were once present downstream of Searsville Dam at several locations between Searsville Dam and just upstream of Interstate 280. The areas where concentrations of adult California red-legged frog were found are coincident with two of the areas in the creek where tadpoles were found. Figure 7.1 presents a summary of California red-legged frog occurrence data collected by Stanford University during surveys conducted on Stanford University property. During a 1997 study of California red-legged frogs in lower Corte Madera Creek and SF Creek, between 13 and 24 individual frogs were encountered (Launer and Spain 1998). Most sightings were concentrated in two areas: approximately 2,500-3,000 meters downstream from Searsville Dam and the other approximately 4,000 meters downstream of the Bear Creek/SF Creek confluence. Although Figure 7.1 shows occurrences of California red legged frog from downstream of the dam, they have not been seen in the Stanford portion of Corte Madera Creek or SF Creek since 2007. Although still present in the upper SF Creek watershed and at Lawler Ranch (across Sand Hill Road from the SLAC), Stanford staff observed a pronounced decline of this species in SF Creek in the late I 990s and early 2000s (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). Although likely present in the "Confluence Valley" that occupied the site of Sears ville Reservoir prior to construction of Searsville Dam, California red-legged frogs have not been detected in or around Searsville Reservoir, or in the wetland and riparian habitats upstream of the reservoir, within the limits of the historical extent of the reservoir (Middle and Upper Lakes and Corte Madera Creek delta). This may be in part due to the abundant nonnative predatory fishes (Section 6.1), crayfish (Section 6.3), and bullfrogs (Section 7.2.2) associated with Searsville Reservoir. Initial Technical Studies 46 - June 2013 Summary of Existing Biological Conditions Wildlife su ..... @ Rq:00Jtb0 ~_ ",,'" Bullfrog pnHnl o 1 9)(.l~ '," " 'r1OC! l ~J).A,)3 CJ Sal' F.;yosq,o.:o Ood Wi*>F.. h d o D s..F ~C ~Sr.I:>w,le rlh a ",."'" CJ Slar.l;rd pt;Ipfrty bou"IdaIy ·• mNO l2 C. llfornla ~d~ f9 ~ frog prtRni ." " 0 lml!¥.i8 ""- ...... ~ ...... lmi003 _." "- ,,",*~_..,_n-.:.:!O\ :t H __... _O""2;I<~~1O! l; ~ 1.0* ....., __ ~ 11 • ;g)I..2l"lI SummfIY 01 Existilg SiJmlMfY 01 Slafllord Univer5i1y Su1\'ey Rtsultr. Showi'l g FlgtJ'1 7.1 Biobgiclll LnIOfffiIlIion Preser.ce 01C alibllia Red-legged Irog$ ~d Bu I ~;!S Figure 7.1 Summary of Stanford University Survey Results Showing Presence of California Red-legged Frogs and Bullfrogs Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 47 Searsville Alternatives Study 7.2.2 Bullfrog Bullfrogs are an introduced species in California and are widespread throughout the state. A habitat generalist, they are adapted to a variety of lentic habitats and can consume nearly any animal that can fit in their mouths. Within SF Creek, adult bullfrogs were found to prey on small insects, other bullfrogs, crayfish, and even small birds (Launer and Holtgrieve 2000). Bullfrogs inhabit quiet waters of ponds, lakes, reservoirs, irrigation ditches, streams, marshes, and other permanent water (Stebbins 1954). Tadpoles overwinter and the species requires permanent water for breeding. Bullfrogs are known to negatively affect a variety of native species, including red-legged frogs (Snow and Witner 2010) and western pond turtles (Haws et al. 2012), through their voracious predatory behavior. In systems with nonnative predatory fish, this predation pressure has multiple consequences for California red-legged frog tadpoles. When the tadpoles respond to bullfrog presence by seeking deeper water, they can then be consumed by predatory fish. This interaction has been shown to have substantial effect on California red-legged frog tadpole survival to metamorphosis (Kiesecker and Blaustein 1997). This synergistic effect of bullfrogs and nonnative predatory fish may explain why California red-legged frog is not present in Searsville Reservoir. Bullfrogs evolved in the presence of predatory game fish and may not be palatable to fish (Kruse and Francis 1977), thereby conferring an advantage on bullfrogs over California native frogs when predatory fish are present. In the SF Creek watershed, bullfrogs are widely distributed. Figure 7.1 presents a summary of occurrence data for bullfrogs on Stanford University property collected by Stanford University staff. Most bullfrog activity is concentrated in Searsville Reservoir, with fewer bullfrogs found in the creeks (Launer and Spain 1998). Bullfrog distribution and abundance in the study area is dynamic; they are scattered throughout the SF Creek watershed and reproduction has occurred downstream of Searsville Dam, but so far none of the downstream reproduction episodes have resulted in areas of high local abundance (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). As discussed above, no California red-legged frogs are found in Searsville Reservoir and it is probable that red-legged frogs are unable to persist with the presence of both predatory game fish and an abundant, breeding population of bullfrogs 7.2.3 California Tiger Salamander California tiger salamander (Ambystoma californiense) (CTS) is listed as threatened under the ESA and CESA. CTS occur in the central Coast Ranges from Sonoma County to Santa Barbara County and eastward to the southern Central Valley and the foothills of the Sierra Nevada. Throughout the range ofthe species, suitable habitat has been converted to agricultural uses or developed. This trend has resulted in the direct elimination of populations as well as habitat degradation, resulting in unsustainable popUlations. CTS typically inhabit grassland and oak woodland habitats below 1,500 feet that have scattered ponds, intermittent streams, seasonal wetlands, vernal pools, or artificial impoundments such as stock ponds adjacent to upland areas. CTS spend much of their lives underground in burrows created by rodents, emerging after the first sustained rain Initial Technical Studies 48 - June 2013 Summary of Existing Biological Conditions Wildlife storms in November (Jennings and Hayes 1994) to migrate to breeding ponds. Adults will migrate up to 0.6 mile from upland sites to breeding ponds and juvenile salamanders have been detected as far as I mile from breeding sites. Currently, the USFWS regards all upland habitats within 1.3 miles (2 km) of known breeding sites as suitable upland habitat for CTS (Olah 2005). CTS are not known to occur within the study area. However, they do occur elsewhere on the Stanford campus; specifically the portion of the campus surrounding Lagunita to the north of Junipero Serra Boulevard (Stanford 2012). They are not known to breed within Searsville Reservoir or creeks in the study area. However, their expected range within the study area does include that portion ofthe campus on the south-eastern side of SF Creek, near the hospital and golf course. These areas are considered to be a population sink and CTS within this habitat is considered to be isolated from potential breeding habitat (Stanford 2012). Nonnative tiger salamanders (Ambysloma ligrinllm) are also sometimes found in the area, also not associated with the creek (A. Launer, Stanford University, Conservation Program Manager, pers. comm., 2013). 7.3 Reptiles The SF Creek watershed provides habitats for a number of reptile species, including two special-status species that could influence policy and management decisions related to actions at Searsville Dam and Reservoir (H.T. Harvey and Associates 200 I, Jones and Stokes 2004). These two species, western pond turtle (Aclinemys marmorata) and San Francisco garter snake (Thamnophis sirtalis tetrataenia), are addressed in the sections below. Wetland and riparian habitats that support these species also likely support western terrestrial garter snake (Thamnophis elegans). Upland areas in the SF Creek watershed provide habitat for a number of common reptiles. Table 7.2 lists common reptiles known as of recently from Stanford University properties. Some of these species, such as homed lizard (Phrynosoma coronaillm [blainvillii]) and whipsnake (Maslicophis ialeralis) may no longer be present due to a reduction in chaparral habitat, but are still present a few miles to the south (A. Launer, Stanford University, Conservation Program Manager, pers. comm .• 2013). Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 49 Searsville Alternatives Study Table 7.2 Common Reptiles Recently Occurring on Stanford University Properties Native Species western fence lizard Sce/oporus occidentalis coast homed lizard Phrynosoma corona tum (blainvillii) northern alligator lizard Elgaria coeru/ea southern alligator lizard Eigaria multicarinata westem skink Eumeces skiltonianus westem whiptail Aspidoscelis (Cnemidophorus) tigrus northern Pacific rattlesnake Crotalus viridis rubber boa Charina bottae western aquatic gartersnake Thamnophis atratus western terrestrial gartersnake Thamnophis e/egans red-sided gartersnake Thamnophis sirta/is common kingsnake Lampropeltis getula sharptailed snake Contia tenuis ringnecked snake Diadophis punctatus westem racer Coluber constrictor gopher snake Pituophis catenifer night snake Hypsiglena torquata chaparral whipsnake Masticophis lateralis westem pond turtle Actinemys (Clemmys) marmorata Nonnative Species red-eared slider Trachemys scripta elegans grey-banded kingsnake Lampropeltis altema Source: (A. launer. Stanford University. Conservation Program Manager. unpublished data. 2013) 7.3.1 Western Pond Turtle The western pond turtle, a California species of special concern, is the only freshwater turtle native to California. They are habitat generalists found in a variety of aquatic systems from slow-moving rivers and streams, lakes, ponds, and reservoirs, to permanent Initial Technical Studies 50 - June 2013 Summary of Existing Biological Conditions Wildlife and ephemeral wetlands, stock ponds, and marshes. Western pond turtles prefer aquatic habitat with refugia such as undercut banks, submerged vegetation, rocks, logs, and mud banks (Holland 1994). They also require suitable basking sites to thermoregulate their body temperatures, using sunny and protected mud banks, rocks, logs, root wads, and other opportunistic sites (Holland 1994, Bash 1999), and escaping to underwater refugia when threatened. Despite their name, western pond turtles regularly utilize terrestrial habitats throughout the year especially for nesting (females), mate-seeking (males), overwintering, and overland dispersal (Holland 1994, Reese 1996, Reese and Welsh 1997). Females will range anywhere from 3 to over 402 meters from a watercourse to find suitable nesting habitat (Holland 1994). Preferred nest sites are characteristically excavated in areas with sparse vegetation of short grasses or forbs, in hard-packed clay or silt soils, and along south- or west-facing slopes (Rathbun et al. 1992, Holland 1994, Reese and Welsh 1997). Western pond turtles were found in Searsville Reservoir in the past (H.T. Harvey and Associates 2001) and in SF Creek, downstream of Searsville Dam. However, they have not been observed in the reservoir since the mid-nineties (Stanford 2012). Surveys on Stanford University property reaching back to 1997 have documented these turtles at various locations along the creek, into the city of Palo Alto (Figure 7.2). In recent years most detections have been in the reach of SF Creek between Bear Creek and Los Trancos Creek. Only one hatchling WPT has been seen during Stanford's annual surveys of SF Creek since the mid-1990s (A. Launer, Stanford University, Conservation Program Manager, unpublished data, 2013). Threats to western pond turtle in the SF Creek watershed include introduced nonnative wildlife. Large adult bullfrogs and predatory game fish (e.g., largemouth bass) can prey on hatchling or young western pond turtles, though the extent of such predation is not well-documented (Haws et al. 2012). Red-eared sliders (Trachemys scripta e/egans) were observed within Jasper Ridge (specific location not described) in 2006, as well as in Lagunita and Webb Ranch in 2008 (Stanford 2012). The relationship between native western pond turtles and red-eared sliders is not fully understood, though there are some indications that they may compete (Bury et al. 2012). Loss and modification of upland habitat may also threaten western pond turtles. 7.3.2 San Francisco Garter Snake Habitats created by SF Creek and Searsville Reservoir may support intergrades of San Francisco garter snake. The San Francisco subspecies is state- and federally-listed as endangered; it is also designated a fully-protected species by the California Department ofFish and Wildlife (CDFW). As such, there is no mechanism to apply for take of the species to authorize otherwise lawful activities. San Francisco garter snake is one of 12 recognized subspecies of the common garter snake (T. sirtalis) (Rossman et al. 1996). The common garter snake ranges throughout much of the temperate regions of North America. In the greater San Francisco bay area, three subspecies occur: the San Francisco garter snake (T. s. tetralaenia), the California red-sided garter snake (T. s. infernalis), and the valley garter snake (T. s. jilchii). Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 51 Searsville Alternatives Study Wutlm Pond furlll ObSlrvltlons 0 0 ". 0 ,""...... > 0 • "'" \'lIlK boe, 0 "" • "'"WJ D s.,Fr~~~ I'i. Jenhed 0 "'" • l'J1O D s... F ranc;~~c-kSlb-W.1mhId:s I.-:,...,."" __...... , ... ..-.... __ <>«U• ..10_ """_ o S"n!:f~~ba..'I!:Dy _ ,'-_Oor. ~_O;'CClXl . l . r It -...~d>n~:xI1C.\.IRSlO l ' KulI'.,._ ...... ,..,."..~_ """ :>or) Summery 01 Emlilg Sum mery 01 Stanlol'd UnMH sity Survey FijJU"81.2 BiologiCllllnlOlmDtion Results S/KIwing Pfesel)CO of Western Pond Turtle Figure 7.2 Summary of Stanford University Survey Results Showing Presence of Western Pond Turtle Initial Technical Studies 52 - June 2013 Summary of Existing Biolog ical Conditions Wildlife The San Francisco garter snake occurs primarily in San Mateo County. Red-sided garter snakes occur in the south bay, east bay, and north bay. The valley garter snake occurs in the Central Valley and throughout much of the rest of California. The contact zone between San Francisco garter snakes and California red-sided garter snakes is widely regarded to be an intergrade region, where T. sirtalis exhibit a color morphology intermediary between the clean lateral red and black stripes of a T. s. tetralaenia and the even checkering of a T. s. infernalis (Barry 1976). T. sirtalis are known to occur on Stanford Linear Accelerator Center (SLAC) lands (Sieb and Pappenfuss 1981) and in SF Creek (H.T. Harvey and Associates 2001). These snakes are highly aquatic. During the spring, summer and much of fall, they are found near the margins of sag ponds, freshwater marshes, or other aquatic habitats with sufficient emergent vegetation. In the winter, they retreat to winter hibernacula, usually rodent burrows in adjacent upland areas above the waterline. They are frog specialists, preferring California red-legged frogs, though they will eat bullfrog tadpoles and Siearran treefrogs. Suitable habitat is likely present in SF Creek and in Searsville Reservoir and associated wetland habitats. The T. sirtalis in the study area are within the purported intergrade zone, along the boundary of San Mateo and Santa Clara counties (Barry 1976). Barry (1976) reports that all of the snakes he found on the Stanford University campus and at Lagunita were T. s. infernalis, but the former presence of intergrades was well-documented. In a review of museum specimens, Sieb and Pappenfuss (1981) found the T. sirtalis collected from the Stanford area to be a mix of T. s. infernalis, and T. sirtalis intergrades. T. s. lelrataenia were also present, though rare. Some genetic analyses have been conducted on the T. sirtalis complex (Janzen et al. 2002, Lim et al. 2009) that may provide reference populations to compare the purported Stanford intergrade snakes to, but the existing data are not conclusive. See Section 8 for recommendations related to clarifying the status of T. sirlalis populations on Stanford University properties. 7.4 Birds Overall, the study area contains a wide variety of bird habitats, species assemblages, rare species, and numerous bird "Species of Special Concern" to the State of California. This section summarizes the review of existing materials, including: published bird studies from JRBP, technical reports prepared by consultants since 2000, CNDDB records for the region, unpublished bird survey data, California Bird Species ofSpecial Concern, and other relevant documents. Habitats upstream of Sears ville Dam (open water, freshwater emergent vegetation, and the regionally unique willow-dominated riparian forest) are treated separately from downstream habitats (riparian forest, urban riparian, and tidal marsh). 7.4.1 Searsville Reservoir and Corte Madera Creek Delta For the purposes of describing bird habitat associated with Searsville Reservoir, a distinction is made in this section between open water and wetland habitat associated with Searsville, Middle, and Upper lakes, and the riparian habitat associated with the Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 53 Searsville Alternatives Study portion of Corte Madera Creek that flows across the sediment delta within the historical limits of Sears ville Reservoir. These habitats are addressed separately below. 7.4.1.1 Sears ville Reservoir, Middle Lake, and Upper Lake Open water habitat in the study area is restricted to Searsville Reservoir, Middle Lake, and Upper Lake. Open water habitats contain a wide variety of food resources which in tum attracts a diversity of foraging birds, including raptors, ducks, and passerines. Nesting habitat, mainly stands of tule and cattail, and to a lesser degree fringing riparian vegetation, rings open water habitat. Food resources include exotic fish, amphibians, aquatic vegetation, algae, and aquatic insects. Due to the diversity of prey and forage items, a wide diversity of bird species are able to forage within the open water habitat (Stanford, unpublished data). Typical piscivores include bird species such as double-crested cormorant (Phalacrocorax aurilus), scaup (Aylha sp.), osprey (Pandion haliaelus), and great blue heron (Ardea herodias). Aquatic omnivores, such as mallard (Anas platyrhynchos), American coot (Fulica americana), and ruddy duck (Oxyursjamaicensis) may also be found foraging on aquatic vegetation or aquatic insects. Freshwater emergent vegetation and riparian habitat along the fringes support nesting habitat for numerous species, and also provide perching habitat for species documented to breed in JRBP such as the belted kingfisher (Megacery/e alcyon). Bird-hunting birds, such as peregrine falcon (Falco peregrinus) and Cooper's hawk (Accipiter cooperii) actively forage in the area, attracted to the diversity of avian prey. Nesting habitat is restricted to stands of cattail and rush, and to a lesser degree, riparian vegetation. Passerines such as red-winged blackbird (Agelaius phoeniceus), song sparrow (Melaspiza meladia), and common yellowthroat (Geolhlypis Irichas) would be expected to nest in emergent vegetation surrounding open water. Resident open-water species likely to nest in aquatic vegetation include pied-billed grebe (Podilymbus podiceps), mallard, and American coot (DeSante 1971). California Species of Special Concern with potential to nest in emergent vegetation include salt marsh common yellowthroat (Geolhlypis Irichas sinuosa) and tricolored blackbird (Agelaius tricolor). Nesting records indicate that a tricolored blackbird colony last nested at Searsville Reservoir in 1960 (Fee et at. 1996). Despite the long-term absence of a nesting colony, individual tricolored blackbirds continue to be detected at Searsville Reservoir, most likely after post-breeding dispersal (Stanford, unpublished data; Shuford and Gardali, 2008). Unlike the tricolored blackbird, the salt marsh common yellowthroat appears to be a consistent breeder at Searsville Reservoir. The most recent records available for this subspecies indicate that as of 1996, 22 males were detected singing in freshwater emergent vegetation (Fee et at. 1996). Though unlikely that each singing male indicates an active nest, it is reasonable to assume that this subspecies currently breeds at Searsville Reservoir. Given the consistently high density of breeding pairs of salt marsh common yellowthroat, Searsville Reservoir is likely an important regional resource for this subspecies. Initial Technical Studies 54 - June 2013 Summary of Existing Biological Conditions Wildlife 7.4.1.2 Corte Madera Creek Delta An expansive and mature willow-dominated riparian forest extends south and west of Searsville Reservoir. Unlike riparian habitat downstream of Sears ville Dam, which is largely restricted to narrow creek and stream corridors, this riparian forest is first and foremost distinguished by covering a wide flat delta composed of sediments transported by Corte Madera Creek (DeSante 1971). The riparian forest itself contains unique vegetative associations not encountered in the more typical riparian habitat seen downstream of the dam. Mature willow and cottonwood dominate the upper canopy. The mid-canopy is dominated by dogwood, box-elder, and young willows. Ground cover is sparse and shrubby. Marsh habitat within or abutting the riparian forest boundaries are typically dominated by dense stands of cattail and tule, and open water pools. Species such wood duck (Aix sponsa), may nest in tree cavities surrounding ponds within denser riparian habitat. Nesting habitat within the riparian forest is generally expected to be of very high quality. The riparian forest itself is surrounded by upland and open water, so nesting birds have access to a wide-range of foraging habitats. In addition to typical California riparian species, less common nesting riparian-obligate species have been documented within the riparian forest, such as Wilson's warbler (Cardellina pusi/la), warbling vireo (Vireo gilvus), Swainson's thrush (Ca/harus ustufatus), and Cassin's vireo (Vireo cassinil) (Stanford, unpublished data). Long-term point-count data provide an excellent baseline for bird diversity and habitat use within the Preserve and nearby natural areas (Bonebrake et al. 2006). Nest predation by exotic predators such as feral cats and nonnative rats is expected to be less significant than downstream riparian edge habitat (generally downstream of Los Trancos Creek confluence), where these types of predators are both more numerous and have better access to active bird nests. Exotic avian species such as European starlings (Sturnus vulgaris) and brown-headed cowbird (Mofothrus ater), though present, are not dominant species in the forest itself. Therefore, nesting success is likely increased due to reduced predation and nest parasitism, and increased nest cavity availability, among other factors. Overall, the riparian forest is a regionally significant nesting location for resident and migratory riparian-obligate native bird species. The only California Species of Special Concern with potential to nest in the riparian forest is the yellow warbler (Dendroica petechia). Nesting records indicate that this species commonly nested within the riparian habitat surrounding Searsville Reservoir (including the riparian forest) in the 1960's (DeSante 1971, 1972a and b), but has gradually diminished such that only a single pair was recorded nesting in 1996 (Fee et al. 1996). More recent records from 2006 indicate that only a single yellow warbler was detected during surveys between 1999 and 2005. In addition to yellow warbler, other species of neotropical migrants that historically bred in the riparian forest have likewise undergone a significant decline over time, likely due to broad changes in regional development, and habitat loss along historical migration pathways, among other factors (Anderegg 2008). Because recent records indicate that yellow warbler is still an occasional nester, the riparian forest should be considered important habitat for this species. Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 55 Searsville Alternatives Study 7.4.2 San Francisquito Creek to San Francisco Bay SF Creek is a significant ecological resource for birds because it provides riparian nesting habitat for a wide variety of species, and is an important migratory corridor between San Francisco Bay and upland habitats that begin, generally, west of Interstate 280. Where SF Creek occurs inside JRBP and nearby, nesting and foraging habitat quality should generally be considered high. The upper reaches of SF Creek support typical California riparian species, such as Stellar's jay (Cyanocitta stellerl), chestnut backed chickadee (Poecile ru!escens), red-breasted merganser (Mergus serrator), Wilson's warbler, yellow-rumped warbler (Setophaga coronata), fox sparrow (Passerella Waca) and Cooper's hawk. As SF Creek meets urban Palo Alto, the nature of the riparian corridor becomes more typical of creeks in heavily urban areas. Riparian vegetation begins to be replaced by a combination of native and exotic tree species, such as yellow wattle acacia and eucalyptus. Foraging habitat is reduced compared to the upstream reaches of the creek, where a mix of upland and riparian habitats create a diversity of foraging niches. Nesting and foraging habitat is present, and urban sections of SF Creek presumably provide important habitat for many of the same species found in the upper reaches. However, the quality and abundance of nesting habitat downstream is degraded due to greater presence of edge-habitat predators, such as feral cats; nest competition with introduced species such as European starling; and anthropogenic disturbance (Anderegg 2008). Based on a review of aerial imagery, SF Creek transitions from a riparian dominated urban creek to a brackish marsh and eventually tidal marsh vegetation dominated channel. This transition zone occurs at approximately the location where U.S. Highway 101 crosses the creek. Historically, the creek emptied into a broad tidal marsh delta, where it met San Francisco Bay (SFEI 2009). Currently, SF Creek empties directly into San Francisco Bay, bypassing most of the surrounding tidal marsh habitat. Narrow strips of tidal marsh vegetation occur on the lower edges of the levees that separate SF Creek from the Palo Alto bay lands to the north, and the Palo Alto Airport, to the south. These narrow, linear tidal marsh habitat fragments may provide limited nesting and foraging habitat for the federally listed California clapper rail (Rallus longirostris obsoletus) and California Species of Special Concern Alameda song sparrow (Melospiza melodia pusillula). Though these species have limited potential to occur or breed in the fringing tidal marsh habitat found near the mouth of SF Creek, project activities are not anticipated to result in impacts to California clapper rail, California black rail, or Alameda song sparrow. Nesting and foraging habitat for western snowy plover (Charadrius alexandrinus nivosus) and California least tern (Sternula antillarum browni) is functionally absent from the study area. Typical habitat for western snowy plover consists of unvegetated sandy or rocky substrates such as beaches and salt ponds (Ehrlich et al 1988). California least tern prefers to nest colonially in open unvegetated habitat near shallow water (Zeiner et al. 1988). Common species expected to occur include willet (Tringa semipalmata), least sandpiper (Calidris minutilla), Canada goose (Branta canadensis), and mallard. Initial Technical Studies 56 - June 2013 Summary of Existing Biological Conditions Wildlife 7.5 Mammals Within the study area, mammal species include riparian and woodland oriented species, species more suited to grassland and chaparral habitats, species that thrive in urbanized habitats, and species that depend on salt marsh habitats where SF Creek meets San Francisco Bay. A biotic assessment of upper Searsville Reservoir and the lower floodplain of Corte Madera Creek concluded that the floodplain above Searsville Reservoir supports relatively few mammal species (Fee et al. 1999). Although burrowing mammals are likely limited by the seasonal inundation and high water table, this area is important to some species including the San Francisco dusky-footed wood rat, which is known to occur in wooded areas around Searsville Reservoir, particularly the riparian area upstream of the lake. Evidence of bobcat activity was also observed in the riparian forest on the Corte Madera Creek sediment delta upstream of Searsville Reservoir during the reconnaissance visits (Figure 7.3). The riparian zone of SF Creek and immediate area supports a number of mammal species - both seasonal visitors and year-round residents. Deer, opossum, raccoon, deer mice, Botta's pocket gopher, tree squirrels, San Francisco dusky-footed woodrat, California vole, coyote, gray fox, bobcat, striped skunk, and the nonnative red fox have been observed along creeks of the SF Creek watershed (Stanford 2012). Recently, muskrats (Ondatra zibethicus) have been observed in wetlands associated with Searsville Reservoir (P. Cohen, Stanford University, Jasper Ridge Biological Preserve, Executive Director, pers. comm., 2013). Raccoon are common throughout the watershed. Mountain lions are also present in the watershed and have been seen as far downstream as the Junipero Serra Boulevard Bridge (Launer and Spain 1998). Sightings, however, are rare; the watershed is probably only part of a single lion's or possibly two lions' expansive home range. The tidally influenced portion of SF Creek contains breeding populations of salt marsh harvest mouse (Young et al. 2003). San Francisco dusky-footed woodrat, salt marsh harvest mouse, and bats are discussed further below because these taxa are managed by federal and state agencies and may warrant special consideration when considering the effects of specific management actions at Searsville Dam and reservoir. Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 57 Sears ville Alternatives Study Figure 7.3 Bobcat markings on a tree growing on the sediment delta of Corte Madera Creek, photographed November 11 , 2012 7.5.1 San Francisco Dusky-footed Wood rat The Sail Francisco dusky-footed woodrat (NeolOma macrotis luciana), a California Species of Special Concern, is one ofeleyen woodrat subspecies recognized throughout their range. Woodrats generall y inhabit dense chaparral, oak and riparian wood lands, and mixed coniferous forests with well-developed undergrowth. Wood rats exhibit high site fidelity and conslnlct multichambered stick nests (middens) elcyated in trces or at ground-level in dense brush. Such nests may last and be inhabited for tens of years by succcssive wood rat generations. Woodrats are generali st herbi vores and liYe in loosely cooperative societies. San Francisco dusky-footed woodrats are present with in the SF Creek watershed. They appear to be ycry common within the riparian habitat on the sediment delta upstream of Searsvill e Reservoir, based on observations of num erous wood rat middens during reconnaissance visits to the area. San Francisco dusky-footed woodrats arc expected to occur in woodland habitats th roughout the study area, but they may occur at higher densities in riparian habitats within the historical extent of Sears ville Reservoir. They are very abundant in wooded areas throughout the Stanford portion of the watershed (A. Launer, Stanford Uni versity, Conservation Program Manager, pefS. comm ., 20 13). Initial Technical Studies 56 - June 2013 Summary of Existing Biological Conditions Wildlife 7.5.2 Salt marsh harvest mouse The salt-marsh harvest mouse (Reilhrodonlomys rav;venlris) is endemic to the marshes of San Francisco Bay, and has been Federally listed as endangered primarily because of destruction and modification of its habitat (Geissel et al 1988). They are primarily nocturnal, however, some crepuscular activity has also been observed (USFWS 1984). They are active year round, and are good swimmers and climbers. They do not use burrows; instead they build a grass nest or use abandoned birds' nest during breeding season from spring to fall. They presumably feed on seeds, grasses, forbs, pickleweed, and salt grass. They require freshwater but are known to consume brackish or even seawater. Approximately 80% of historical tidal marshes have been destroyed and most of those that remain only support a few to no mice due to backfilling, subsidence, or changes in vegetation (Shellhammer 1982). Salt marsh harvest mice are critically dependent on dense cover, and their preferred habitat is pickleweed (USFWS 2008). They also move into adjoining grasslands during the highest winter tides. Salt marsh harvest mouse is known to occur within the tidal marsh habitat at the mouth of SF Creek and would be limited to the salt marsh habitat downstream of Highway 101 in the Palo Alto baylands (NHC 2004). 7.5.3 Bats A number of bat species are known or expected to occur in the SF Creek watershed, several of which are special-status species managed by the CDFW. Bats playa vital ecological role as the primary predators of nocturnal insects and help to control populations of agricultural pests (McCracken 1996). After several decades of alarming population reductions, by 2004 56% of all bat species in the US were currently listed or in consideration for listing under the ESA, a larger proportion than any other taxonomic group (Bogan et aI., 1996). Primary reasons for the decline of bat species include urbanization and habitat reduction. Bat species within California typically utilize woodland habitats for roosting and forage over open water and other open spaces where insects congregate. Due to the presence of abundant foraging and roosting habitat, including two horizontal adits dug during dam construction utilized as caves near the right abutment of Searsville Dam (Figure 7.4), JRBP and habitats associated with Searsville Reservoir are particularly valuable for bats. Bat populations have been the subject of several studies at JRBP. These include a study in 1994 to identify the species present at JRBP, Lebacqz et ai, acoustically identified several other species and an extensive study was conducted through 2000 (Evelyn et al. 2004). More recent studies have been conducted by Mudd (2007) to determine species present with JRBP. As many as 11 species of bats are known to use or have used JRBP for foraging and roosting (Mudd et al. 2007), several of which are California Species of Special Concern (Table 7.3). In addition to roosting habitat provided by the caves near Searsville Dam (created incidentally by geotechnical exploration during construction of Searsville Dam), many of these species are known to roost in trees within JRBP (Evelyn et al. 2000). Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 59 Searsville Alternatives Study Figure 7.4 The entrance to one of two caves created by geotechnical exploration during construction of Searsville Dam During the most recent study. eight species were identified (Mudd 2007). The most common species detected during this study were of the gen us Myotis, most likely Yuma myotis (Myolis Yllmanensis) or California myot is (MYO fis califomicus), both of which have been co llected from JRBP in the past. Also recorded frequently were the Mexican free -tai led bat (Tadarido brasiliensis) and the sil ver-haired bal (Lasionyclerh noctivagans). The big brown bat (EptesicusjllsclIs) and the hoary bat (Lasilll"lls cinerellj') were recorded less frequently. Two olher species identified during the Mudd study were identified less frequently: fringed myolis (Myotis thysonodes) and red bat (L{ISillrlls blossevillil). The fringed myotis was not identified at JRBP pri or to the most recent study, and the red bat was the species recorded least ofte n (M udd 2007). Two other species not identified using acousti c monitoring in the most recent study may also be present: the pallid bat (Al1Irozolis pallid/ls) whi ch was collected during mist net surveys at JRB P (Evelyn et al. 2004), and Townscnd 's big-cared bal (COfYl1orhifws towlIselldii), which was obscrved in 1994. Thesc two spec ies may be present but havc never been recorded at Searsvil le Reservoir (Mudd 2007). One other species, the western pipestre lte (Pipestrelllls hesperus) is listed by BCI (Bat Conservation Intern ational, Inc.) as "may not exist in our area but may have been found there" (Mudd 2007). Initial Technical Studies 60 -June 2013 Summary of Existing Biological Conditions Wildlife Table 7.3 Possible bat species identified at Jasper Ridge Federal State Common Name Scientific Name Observation Notes Status Status Pallid bat Antrozous pallidus Netted but call never recorded S SSC Townsend's Big- Corynorhinus townsend;; Observed once but call never S SSC eared bat recorded silver-haired bat Lasionycteris noctivagans Recorded less frequently -- western red bat Lasiurus blossevillii Least recorded S SSC hoary bat Lasiurus cinereus Recorded less frequently - - long-legged myotis Myotis volans Call recorded - - California myotis Myotis califomicus Most common, call signature and -- SSC netted western small Myotis ci/iolabrum BCI source suggest that this bat - - footed myotis may exist in the area. Yuma myotis Myotis yumanensis Most common, call signature and - - netted little brown bat Myotis lucifugus Not seen but BCI source suggest - - that this bat may exist in the area. fringed myotis Myotis thysanodes Not seen but BCI source suggest - - that this bat may exist in our area. western long- Myotis evotis BCI source suggest that this bat -- - eared myotis may exist in our area. big brown bat Eptesicus fuscus Recorded less frequently -- -- western pipestrelle Pipistreflus hesperus BCI source suggests this bat may - - not exist in our area but may have been found there Mexican free- Tadarida brasiliensis Recorded less frequently - - tailed bat western mastiff bat Eumops perotis BCI source suggest that this bat - SSC may exist in the area. S =USFWS Sensitive Species SSC =CDFW Species of Special Concern Initial Technical Studies Surnrnary of Existing Biological Conditions June 2013 - 61 Sears ville Alternatives Study 8 Recommendations This section identifies additional information that could be useful when evaluating the potential effects of various management actions on biological resources in the study area. The recommendations for additional information are intended to support evaluation of alternatives and selection of preferred alternatives. Additional studies may be required to support an Environmental Impact Report and permitting for a preferred alternative but that is not the focus of this section. 8.1 San Francisco Garter Snake The San Francisco garter snake is a protected taxon with very limited distribution. Currently, snakes in and around the study area are identified as intergrades between the protected and common taxa. Determining whether the Stanford snakes are more closely related to the protected or common garter snakes could have important management implications. The analysis of alternatives and potential modification of habitats that may currently support this listed species brings to question: what taxonomic entity are the snakes on Stanford's property and where do they occur? The answers to these questions are critical to the determination of whether these snakes are protected under regulatory processes, and could have substantial bearing on the Searsville Alternatives Study. A field study would allow biologists to determine the distribution of Thamnophis sirlatis in the watershed and provide an opportunity to collect genetic samples. Ultimately, the taxonomic determination of T. sirtalis on Stanford properties will be dependent on either a careful study of the color morphology, a genetic analysis, or a combination of both. Some genetic analyses have been conducted on the T. sirlalis complex (Janzen et al. 2002, Lim et al. 2009) that may provide reference populations for comparison with Stanford's snakes. Analysis of T. sirtalis color morphology and/or genetic analysis may provide data that will inform agencies and managers on the best alternative to pursue, balancing the protections of endangered species with differing habitat requirements. 8.2 Benthic Macroinvertebrates Stanford has expressed interest in differences in BMI communities in the different aquatic habitats in the study area, and how those communities could change with implementation of different actions. The BMI may be important to the diverse bird and bat fauna that occur in association with Searsville Reservoir. Baseline invertebrate collections targeting the aquatic phase of BMIs in the various habitats in the study area during spring time when day length, stream flow, food supply, and temperature combine to increase the in-stream activity ofBMls may provide a better picture ofBMI diversity and abundance among the aquatic habitats in the study area. These baseline data would provide additional information useful to evaluating potential effects of specific actions, and would also provide a pre project baseline that could be used to monitor changes that may occur if a specific project is later implemented. Initial Technical Studies 62 - June 2013 Summary of Existing Biological Conditions Recommendations 8.3 Steel head Although steelhead are known to be present in SF Creek, little is known about the size or timing of this run. Given the importance of evaluating the potential effects of specific management actions on steel head, a study targeted at learning more about the existing run of steelhead in the SF Creek watershed may be appropriate. Similar to BMI, additional information regarding the existing steel head run in SF Creek could facilitate the evaluation of the potential effects of specific actions, and would help establish basel ine conditions against which the effects of future actions could be monitored. Although not addressed in this technical memorandum, fish passage options at Searsville Dam are being evaluated by URS for Stanford in another technical memorandum. Additional knowledge of steelhead in SF Creek could also be useful in relation to the fish passage evaluation, as the timing, size, and location of the existing steel head run is relevant to the fish passage evaluation. 8.4 Wetlands There are extensive potential jurisdictional wetlands and non-wetland waters of the u.S. in the project area. Many of these wetlands are hydrologically dependent on Searsville Reservoir. A jurisdictional wetland delineation in areas that would be hydrologically affected by the alternatives would allow wetland biologists to accurately determine the wetland impacts for permitting and mitigation purposes. Based on the results, they would be able to compare the alternatives and the potential mitigation required to offset their effects. Since wetland mitigation is typically one of the largest project implementation cost items, this information would be very beneficial for the effective evaluation of the alternatives. The extent to which additional detail regarding wetlands in the study area would facilitate alternatives analysis should be weighed against the effort of conducting extensive surveys in areas where precise wetland boundaries may not be needed for project implementation or permitting, since approximations based on existing data presented in this TM also would inform alternatives analyses. Additionally, non-jurisdictional wetlands are of potential interest for Stanford and Jasper Ridge Biological Preserve. Non-jurisdictional wetlands could be surveyed as part of the vegetation alliance assessment recommended below. 8.5 Vegetation The Jasper Ridge Biological Preserve includes numerous examples of sensitive and rare plant communities. Many ofthese communities surrounding Searsville Reservoir and its tributaries are dependent on the ground water table, micro-climate and moisture regime provided by the lake. Currently, CDFW requires a vegetation alliance level assessment of impacts based on the 2nd edition of the Manual of California Vegetation (Sawyer et. al. 2008) classification. While the available detailed vegetation map of the Preserve provides an accurate depiction of the vegetation present, and provides some information on vegetation alliances, it does not provide the riparian scrub and forest detail required for a permit level evaluation of impacts (as noted in the legend on the map). At this time it is assumed that existing information is sufficient for an alternatives analysis, although additional information may be required to permit any selected alternative. Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 63 Searsville Alternatives Study 9 References Anderegg, W.R. 2008. The Butterfly Effect: The response of riparian bird diversity to climate change and human development. Honors Thesis. Stanford University. May 27, 2008. Baldwin, B. G., D. H. 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Conversations with Jonathan Stead, URS Project Ecologist, during information sharing phase of Searsville Initial Technical Studies Project. Launer, A. E. 2013. Stanford University, Conservation Program Manager, personal communication. Comments from Stanford University on draft Summary of Existing Biological Conditions Technical Memorandum provided to URS via email. Initial Technical Studies 68 - June 2013 Summary of Existing Biological Conditions References Leidy, R.A., O.S. Becker, B.N. Harvey. 2005. Historical distribution and current status ofsteelheadlrainbow trout (Oncorhynchus mykiss) in streams ofthe San Francisco Estuary, California. Center for Ecosystem Management and Restoration, Oakland, CA. Lichvar, R.W., and S.M. McColley. 2008. A Field Guide to the Identification ofthe Ordinary High Water Mark (OHWM) in the Arid West Region ofthe Western United States. A Delineation Manual. USACE, Engineering Research and Development Center, Vicksburg, Mississippi. Lim T.L., K.S. Swaim, E.J. Routman. 2009. A Phylogeography ofthe San Francisco Garter Snake, Thamnophis sirtatis tetrataenia, San Francisco State University. Lindquist, S. B., and M. D. Bachmann. 1980. Feeding behavior ofthe tiger salamander, Ambystoma tigrinum. Herpetologica 36:144-158. Mateos, D.M. 2013. David Moreno Mateos, Stanford University Postdoctoral Research fellow, Biology (School of Humanities and Sciences). Personal communication. Email correspondence and transmittal of unpublished data with Jon Stead, URS Corporation. February 13, 2013. McCracken, O. F., 1996. Bats aloft: a study ofhigh altitude feeding. Bats 14, 7-10. Moyle, P. B., 2002. Inland Fishes ofCalifornia. University of California Press, Berkeley, California. Mudd, T. 2007. Assessment ofthe status ofbats at Jasper Ridge, preliminary draft. Jasper Ridge State of the Preserve Assessment. NHC. Northwest Hydraulic Consultants and Jones & Stokes Associates. 2004. San Francisquito Creek Watershed, Existing Conditions Analysis, Final Report. San Francisquito Creek Joint Powers Authority. 27 p and Appendices. NMFS (National Marine Fisheries Service), 2005. Endangered and Threatened Species; Designation of Critical Habitat for Seven Evolutionarily Significant Units of Pacific Salmon and Steel head in California; Final Rule. 50 CFR Part 226 Vol. 70 (170): 52488-52627. National Oceanic and Atmospheric Administration's National Marine Fisheries Service. Olah, R. 2005. Personal communication between Ryan Olah at the USFWS and Lorena Sol6rzano-Vincent, URS biologist. Olberding Environmental, Inc. 2007. U.S. Army Corps of Engineers Jurisdictional Delineation for the Corte Madera Creek Restoration Project Area. Prepared for Stanford Management Company. September. Initial Technical Studies Summary of Existing Biological Conditions June 2013 - 69 Searsville Alternatives Study Rathbun, Galen B., Nancy Siepel, and Dan Holland. 1992. Nesting Behavior and Movements of Western Pond Turtles, Clemmys marmorata. The Southwestern Naturalist. 37(3): pp 319- 324. Reece, P.F., and J. S. Richardson. 2000. Benthic macro invertebrate assemblages of coastal and continental streams and large rivers ofsouthwestern British Columbia, Canada. Hydrobiologia 439: 77-89. Reese, Devin A. 1996. Comparative Demography and Habitat Use 0/ Western Pond Turtles in Northern California: The Effects 0/ Damming and Related Alterations. Unpublished PhD Dissertation: University of California at Berkeley. 253 pp. 26 Reese, Devin A. and Hartwell H. Welsh. 1997. Use o/Terrestrial Habitat by Western Pond Turtles, Clemmys marmorata: Implications/or Management. In: Van Abbema, J. (ed). Proceedings: Conservation, Restoration, and Management of Tortoises and Turtles-An International Conference. New York Turtle and Tortoise Society. pp 352-357. Reis, O.K. 1999. Habitat characteristics of California red-legged frogs (Rana aurora draytonii): Ecological differences between eggs, tadpoles, and adults in a coastal brackish and freshwater system. M.S. Thesis. San Jose State University. 58 pp Rossman DA, Ford NB, Seigel RA (1996) The garter snakes: evolution and ecology. University of Oklahoma Press. SFEI (San Francisco Estuary Institute). 2009. Historical Ecology 0/ Lower San Francisqllito Creek Phase 1. Technical memorandum accompanying project GIS data. Prepared for San Francisquito Creek Joint Powers Authority. March 2009. Sawyer, J., T. Keeler-Wolf, and J. Evans. 2009. A Manualo/California Vegetation. Second Edition. The California Native Plant Society, Sacramento, California. Shaffer, H. B., R. N. Fisher, and S. E. Stanley. 1993. Status report: the California tiger salamander (Ambystoma californiense). Final report to the California Department ofFish and Game, Inland Fisheries Division, Rancho Cordova California, under Contracts (FG9422 and 1383). Shellhammer, H.S., R. Jackson, W. Davilla, A. Gilroy, H. T. Harvey, and L. Simons. 1982. Habitat preferences 0/ salt marsh harvest mice, Reithrodontomys raviventris. Shuford, W.O. and Gardali, T., editors. 2008. California Bird Species o/Special Concern: A ranked assessment o/species, subspecies, and distinct populations 0/ Initial Technical Studies 70 - June 2013 Summary of Existing Biological Conditions References birds of immediate conservation concern in California. Studies of Western Birds I. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento. Sieb, Robert L. and Theodor J. Papenfuss, Survey ofSLAC Landsfor San Francisco Garter Snake. November 1981. Smith, J.1., and D.R. Harden. 2001. Adult Steelhead Passage in the Bear Creek Watershed. Prepared for the San Francisquito Watershed Council. July. Snow, N.P., and G. Witner. 2010. American Bullfrogs as Invasive Species: A Review of the Introduction, Subsequent Problems, Management Options, and Future Directions. Proc. 24th Vertebr. Pest Control. Stanford University. 2012. Habitat Conservation Plan. Riparian Woodland and Creeks. http://hcp.stanford.edulriparian.html. Accessed : February 19, 2013. Stanford University. No date. Bird species occurrences from Jasper Ridge Biological Preserve. Unpublished data. Stebbins, Robert C. 2003. Western Reptiles and Amphibians. Third Edition. Peterson Field Guides. Houghton Mifflin Company, Boston. 533 pp. Stebbins, R.C. 1954. Amphibians and reptiles of western North America. New York: McGraw-Hili Book Company, Inc. Stoecker, M. 2010. San Francisquito Creek Watershed Council's Salmonid Migration Barrier Spreadsheet. Updated from "Salmonid migration barriers/impediments in the San Francisquito Creek Watershed, San Francisco Bay, CA", M. Stoecker (2000-2002). April 7. Storer, Tracy I. 1925. A Synopsis of the Amphibia of California University ofCalifonia Publications in Zoology. Volume 27. University of California Press. Stuber, R.1., G. Gebhart, and O.E. Maughan. 1982. Habitat Suitability Index Models: Largemouth Bass. US Department of the Interior, Washington DC, USA Swanson, J. L. 20 II. Benthic macroinvertebrates response to the restoration ofa hypereutrophic midwestern reservoir. Dissertation and Theses in Natural Resources. Paper 21. May I, 20 II. Initial Technical Studies Summary of Existing Biological Conditions June 2013 -71 Searsville Alternatives Study USDAINRCS 2013. Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed February 13, 2013. USFWS (United State Fish and Wildlife Service), 1984. Salt marsh harvest mouse and California clapper rail Recovery Plan. Portland Oregon. November 6, 1984. USFWS. 2002. Recovery Plan for the California Red-legged Frog (Rana aurora draytonil). U.S. Fish and Wildlife Service, Portland, Oregon. viii + 173 pp. USFWS. U.S. Fish and Wildlife Service. 2008. Endangered and Threatened Wildlife and Plants; Initiation of 5-Year Reviews of 58 Species in California and Nevada; A vailability of Completed 5-Year Reviews in California, Nevada and Southern Oregon. Federal Register 73: 11945-11950 USFWS 2009. U.S. Fish and Wildlife Service. National Wetland Inventory online geodatabase. Available at http://www.fws.gov/wetlandslDataiMapper.html. USFWS 20 13a. U.S. Fish and Wildlife Service. List of Federally Endangered and Threatened Species. Accessed Sacramento Fish and Wildlife Office on January 24, 2013. Available online at http://www.fws.gov/sacramento/es_species/Lists/es_species -' ists-form.cfm USFWS. 20 13b. Sacramento Fish and Wildlife Office Species Profiles. Online: http://www.fws.gov/sacramento/es_species/Lists/es_species_lists-form.cfm Western Regional Climate Center. 2013. Historical Climatological Data Summary for Palo Alto, CA. Website: http://www.wrcc.dri.eduiCLIMATEDATA.html. Accessed in 2013. You Tube. 2013. San Francisquito Creek Steelhead Trout. Website: http://www.youtube.com/watch?v=B-JWIZP8rYO. Accessed June 18, 2013. Young, S., R. McMurty, M. Stanley-Jones, and A. Ringer. 2003. Watershed Assessment Report. Chapter 5: Assessment ofSan Francisquito Watershed. CALFED Bay Delta Program. February 2003. Zeiner, D.C., W.F. Laudenslayer, Jr., K.E. Mayer, and M. White, eds. 1988-1990. California's Wildlife. Vol. I-III. California Department ofFish and Game, Sacramento, California. Initial Technical Studies 72 - June 2013 Summary of Existing Biological Conditions Appendix A CNDDB Species List California Department of Fish and Game Natural Diversity Database CNDDB Wide Tabular Report for Stanford Searsville Dam Alternatives Study Palo Alto, Mlndego Hili, Woodside, and Mountain Vlow '''ement Occ Ran Population Status- ..... Presence CNDDB Total Historic Recent Pres. Poss. Name (ScientifiC/Common) Ranks Other Lists Listing Status EO's A B C D X U >20yr <=20yr Extant ExtIrp. ExtIrp. Acanthomfntha duttonfl G1 CNPS: 1B.1 Fed: Endangered 5 0 1 0 1 1 0 1 2 2 0 1 San Mateo Ihom-mint S1 Cal: Endangered S:3 Allfum penfnsulare vaT. franclscanum G5T2 CNPS: 1B.2 Fed: None 14 0 0 1 0 0 4 4 1 5 0 0 Franciscan onion S2.2 Cal: None S:5 Ambystoma calffomiense G2G3 CDFG: SC Fed: Threatened 1054 0 1 0 0 3 1 3 2 2 1 2 California tiger salamander S2S3 Cal: Threatened S:5 Antrozous pall/dus G5 CDFG: SC Fed: None 402 0 0 0 0 0 3 3 0 3 0 0 pallid bat S3 Cal: None S:3 Arctostaphylos andelSonf/ G2 CNPS: 1B.2 Fed: None 40 0 0 0 0 0 5 5 0 5 0 0 Anderson's manzanita S2? Cal: None S:5 Arctostaphylos reglsmontana G2 CNPS: 1B.2 Fed: None 15 2 0 3 1 0 6 5 7 12 0 0 Kings Mountain manzanita S2.2 Cal: None S:12 As/ootus G5 CDFG: SC Fed: None 40 0 0 0 0 0 1 1 0 1 0 0 long·eared owl S3 Cal: None S:1 Astragalus pycnostachyus var. G2T2 CNPS: 1B.2 Fed: None 25 0 0 0 0 0 1 1 0 1 0 0 pycnostachyus S2.2 Cal: None S:1 coastal marsh milk-vetch Astragalus tener var. tener G2T2 CNPS: 1B.2 Fed: None 65 0 0 0 0 1 0 1 0 0 1 0 alkali milk-vetch S2 Cal: None S:1 Athene cunlcu/aria G4 CDFG: SC Fed: None 1823 0 0 0 11 1 3 4 11 14 1 0 burrowing owl S2 Cal: None S:15 Callclna minor G1 CDFG: Fed: None 2 0 0 0 0 0 1 1 0 1 0 0 Edgewood blind harvestman S1 Cal: None S:1 Centromadla parryl ssp. congdonl/ G4T2 CNPS: 1B.2 Fed: None 91 0 0 1 1 0 0 0 2 2 0 0 Congdon's larplant S2 Cal: None S:2 Charadrlus alexandrlnus nlvosus G4T3 CDFG: SC Fed: Threatened 120 0 1 0 0 1 1 1 2 2 1 0 western snowy plover S2 Cal: None S:3 Chloropyron maritimum ssp. palustre G4?T2 CNPS: 1B.2 Fed: None 61 0 0 0 0 2 0 2 0 0 2 0 Point Reyes bird's-beak S2.2 Cal: None S:2 Chorizanthe cusp/data vaT. cusp/data G2T2 CNPS: 1B.2 Fed: None 20 0 0 0 0 0 1 1 0 1 0 0 San Franclsco Bay spinenower S2.2 Cal: None S:1 Commerclal Version - Dated November 02. 2012 - Biogeographic Data Branch Page 1 Report Printed on Thursday, January 24,2013 Information Explros 0510212013 California Department of Fish and Game Natural Diversity Database CNDDB Wide Tabular Report for Stanford Soarsville Dam Alternatives Study Palo Alto, Mlndego Hili, WoodSide, and Mounteln VIew -Iement Occ Ran "opulatlon Statu&- -Presence CNDDB Total Historic Recent Pres. P08S. Name (Scientific/Common) Ranks Other Lists Ustlng Status EO's A B C D X U >20yr <=20yr Extant Extlrp. Extlrp. C/rr:us eyaneus G5 CDFG: 5C Fed: None 43 0 1 0 0 0 2 2 1 3 0 0 northern harrier S3 cal: None 5:3 C/rs/um fontlnale var. fontlnalo G2T2 CNP5: 1B.1 Fed: Endangered 5 0 0 3 0 1 0 1 3 3 1 0 founlaln thistle 51 Cal: Endangered 5:4 Clrslum praettlrfens GX CNP5: 1A Fed: None 1 0 0 0 0 1 0 1 0 0 1 0 lost thistle SX Cal: None C/arlc/a eonelnna ssp. autom/xa G5?T3 CNP5: 4.3 Fed: None 20 0 0 0 0 0 2 2 0 2 0 0 5anla Clara red ribbons S3.3 Cal: None 5:2 Coll/nsia multle%r G2 CNP5: 1B.2 Fed: None 25 1 0 0 0 0 1 1 1 2 0 0 5an Francisco collinsla 52.2 Cal: None 5:2 D/podomys venustus venuslus G4T1 CDFG: Fed: None 14 0 0 0 0 0 3 3 0 3 0 0 5anta Cruz kangaroo rat 51 Cal: None 5:3 D/rr:a oee/dentsl/s G2G3 CNP5: 1B.2 Fed: None 52 0 2 2 0 0 7 6 5 11 0 0 western leatherwood 5253 Cal: None 5:11 Egretta thu/a G5 CDFG: Fed: None 15 0 0 0 0 0 1 0 1 1 0 0 snowy egret 54 Cal: None 5:1 Emys mannorats G3G4 CDFG: 5C Fed: None 1134 0 3 1 0 0 2 2 4 6 0 0 westem pond turtle 53 Cal: None 5:6 Erfogonum nudum var. decumms G5T2 CNP5: 1B.1 Fed: None 5 0 0 0 0 0 1 1 0 1 0 0 Ben Lomond buckwheat 52.1 Cal: None 5:1 Erfophyllum /atl/obum Gl CNP5: 1B.l Fed: Endangered 4 0 0 0 0 0 1 1 0 1 0 0 San Mateo woolly sunflower 51 Cal: Endangered 5:1 Eryng/um arfstulatum VaT. hooverl G5T2 CNP5: lB.l Fed: None 10 0 0 0 0 2 0 2 0 0 2 0 Hoover's button-celery 52.1 Cal: None 5:2 Euphydryas edltha bayensls G5T1 CDFG: Fed: Threatened 24 0 1 0 0 2 0 1 2 1 1 1 Bay checkerspot butterfly 51 Cal: None 5:3 Frlll//aria IiIlBelJa G2 CNP5: lB.2 Fed: None 69 1 2 0 0 0 1 4 0 4 0 0 fragrant fritillary 52 Cal: None 5:4 GIJothlyPIs trfehas slnuosa G5T2 CDFG: 5C Fed: None 111 0 3 0 0 0 7 7 3 10 0 0 saltmarsh common yellowthroat 52 cal: None 5:10 Commercial Version - Dated November 02.2012 - BiogeographIc Data Branch Page 2 Report Printed on Thursday. January 24.2013 Information Expires 0510212013 California Department of Fish and Game Natural Diversity Database CNDDB Wide Tabular Report for Stanford Searsville Dam Alternatives Study Palo Alto, Mlndego Hili, Woodside, and Mountain View Element Occ Ran" Population Status- ~Presence CNOCB Total Historic Recent Pres. Pass. Name (Scientific/Common) Ranks Other Lists Listing Status EO's A B C 0 X U >20yr <=20 yr Extant Extlrp. ExtIrp. Hssperollnon congsslum G2 CNP8: lB.l Fed: Threatened 27 1 1 2 0 1 0 3 2 4 0 1 Marin westem flax 82 Cal: Threatened 8:5 Hydrochara rlckseckerl G1G2 CDFG: Fed: None 13 0 0 0 0 0 1 1 0 1 0 0 Ricksecker's water scavenger beeUe 81S2 Cal: None 8:1 Laslurus clnefflus G5 CDFG: Fed: None 235 0 0 0 0 0 6 6 0 6 0 0 hoary bat 84? Cal: None 8:6 Lateral/us jamalcensls cotumlculus G4T1 CDFG: Fed: None 241 0 2 0 0 0 1 0 3 3 0 0 California black rail 81 Cal: Threatened 8:3 Legeneffl IImoSB G2 CNP8: lB.l Fed: None 78 0 0 0 0 0 1 1 0 1 0 0 legenere 82.2 Cal: None 8:1 Lesslngla arachnoldea Gl CNP8: lB.2 Fed: None 9 0 0 0 0 0 1 0 1 1 0 0 Crystal 8prings lesslngla 81.2 Cal: None 8:1 Malacothamnus arcuatus G2Q CNPS: lB.2 Fed: None 21 0 0 1 1 0 4 4 2 6 0 0 arcuate bush-mallow 82.2 Cal: None 8:6 Malacothamnus davldsonll Gl CNPS: lB.2 Fed: None 40 0 0 0 0 0 1 1 0 1 0 0 Davidson's bush-mallow 81.1 Cal: None S:l Malacothamnus hallli G2Q CNP8: lB.2 Fed: None 37 0 0 0 0 0 1 1 0 1 0 0 Hall's bush-mallow 82 Cal: None 8:1 Melosplza melodla pusll/ula G5T2? CDFG: SC Fed: None 38 0 4 0 0 0 6 6 4 10 0 0 Alameda song sparrow 82? Cal: None 8:10 Mlcroclna edgewoodensls G1 CDFG: Fed: None 1 0 0 0 0 0 1 1 0 1 0 0 Edgewood Park micro-blind harvestman 81 Cal: None Monolopla gracI/ens G2G3 CNP8: 1B.2 Fed: None 45 0 0 0 0 0 6 4 2 6 0 0 woodland woollythreads 8283 Cal: None 8:6 N. Central Coast Calif. G? Fed: None 2 0 1 0 0 0 0 1 0 1 0 0 RoachlStlcklebacklStHlhead Stream 8NR Cal: None 8:1 Neotoma fusc/pes anneclens G5T2T3 CDFG: SC Fed: None 11 0 0 1 0 0 1 0 2 2 0 0 San Francisco dusky-footed woodrat 8283 Cal: None S:2 North Central Coast StHlhead/Sculpln G? Fed: None 1 0 1 0 0 0 0 1 0 1 0 0 Stream 8NR Cal: None Commercial Version - Dated November 02.2012 - Biogeographic Data BranCh Page 3 Report Printed on Thursday. January 24. 2013 Information expires 0510212013 California Department of Fish and Game Natural Diversity Database CNDDB Wide Tabular Report for Stanford Searsville Dam Alternatives Study Palo Alto, Mlndego Hili, Woodside, and Mountain View Element Occ Ran Population Status- r-Presence CNDDB Total Historic Recent Pres. Poss. Name (SCientifiC/Common) Ranks Other Lists Llstlng Status EO's A B C D X U >20yr <=20yr Extant Extlrp. Extirp. Northern Coastal Salt Marsh G3 Fed: None 53 0 1 0 0 0 2 3 0 3 0 0 53.2 Cal: None 5:3 Oncorhynchus myklss Indeus G5T2Q CDFG: Fed: Threatened 38 0 2 0 0 0 2 2 2 4 0 0 steelhead - central California coast DP5 52 Cal: None 5:4 Pedlculans dudley/ G2 CNP5: 1B.2 Fed: None 12 0 1 0 0 0 1 1 1 2 0 0 Dudley's lousewort 52.2 Cal: Rare 5:2 Pentachaeta bellldiflol'B Gl CNP5: lB.l Fed: Endangered 14 1 0 0 0 0 1 1 1 2 0 0 white-rayed pentachaeta Cal: Endangered 5:2 51 - Plperia candida G3? CNP5: 1B.2 Fed: None 53 0 0 0 0 0 2 2 0 2 0 0 white-flowered rein orchid 52 Cal: None 5:2 Plagloboth'YS chonsianus var. G3T2Q CNP5: 1B.2 Fed: None 12 0 0 0 0 0 1 1 0 1 0 0 Chorls' popcornflower 52.2 Cal: None 5:1 Ral/us longlrostns obso/stus G5Tl CDFG: Fed: Endangered 92 3 3 0 0 0 5 5 6 11 0 0 California dapper rail 51 Cal: Endangered 5:11 Rana dl'Bytonli G4T2T3 CDFG: 5C Fed: Threatened 1327 1 8 3 1 0 5 1 17 18 0 0 California red-legged frog 5253 Cal: None 5:18 Relthrodontomys I'Bv/ventrls G1G2 CDFG: Fed: Endangered 137 2 3 3 0 0 7 14 1 15 0 0 salt-marsh harvest mouse 5152 Cal: Endangered 5:15 SefIHJnUne Bunchgl'BSS G2 Fed: None 22 1 0 0 0 0 1 2 0 2 0 0 52.2 Cal: None 5:2 SI/ene vSllIcunda ssp_ vSlflCunda G5T2 CNP5: 1B.2 Fed: None 12 0 0 0 0 1 0 1 0 0 1 0 5an Francisco campion 52.2 Cal: None 5:1 SOIllX vagrans ha//coetss G5Tl CDFG: 5C Fed: None 12 0 0 0 0 1 3 4 0 3 0 1 salt-marsh wandering shrew 51 Cal: None 5:4 Speyeria ad/asts adiaste G1G2T1 CDFG: Fed: None 2 0 0 0 0 0 1 1 0 1 0 0 unsilvered fritillary 51 Cal: None 5:1 Sternula antlliarum browni G4T2T3Q CDFG: Fed: Endangered 67 0 0 0 0 1 2 3 0 2 0 1 California least tern 5253 Cal: Endangered 5:3 Commercial Version - Dated November 02. 2012 - Biogeographic Data Branch Page 4 Report Printed on Thursday. January 24.2013 Information Expires 0510212013 California Department of Fish and Game Natural Diversity Database CNDDB Wide Tabular Report for Stanford Searsvllle Dam Alternatives Study Palo Alto, Mlndego Hili, Woodside, and Mountain View "Iement Occ Ran "opulatlon Sta -Presence CNDDB Total Historic Recent Pres. Poss. Name (SclentHIclCommon) Ranks Other Lists LIsting Status EO's A B C 0 X U >20yr <=20yr Extant ExtIrp. ExtIrp. Stuckonla flllformis G5 CNP5: 2.2 Fed: None 21 0 0 0 0 0 1 1 0 1 0 0 slender-leaved pondweed 5152 Cal: None 5:1 Suatlda callfom/ca G1 CNP5: 1B.1 Fed: Endangered 17 0 0 0 0 0 1 1 0 1 0 0 Califomia seablite 51 Cal: None 5:1 Tax/dea taxus G5 CDFG: 5C Fed: None 454 0 0 0 0 0 2 2 0 2 0 0 American badger 54 Cal: None 5:2 Thamnophls s/rtalls tetrataen/a G5T2 CDFG: Fed: Endangered 38 1 3 2 0 0 0 4 2 6 0 0 San Francisco garter snake 52 Cal: Endangered S:6 Trifolium amoenum G1 CNPS: 1B.1 Fed: Endangered 26 0 0 0 0 0 1 1 0 1 0 0 showy rancheria dover S1 Cal: None 5:1 Tryon/a Imitator G2G3 CDFG: Fed: None 33 0 0 0 0 0 1 1 0 1 0 0 mimic tryonia (=Califomia brackishwater 5253 Cal: None S:1 snail) Usnea longlsslma G4 CNPS: Fed: None 206 0 0 0 0 2 0 1 1 0 1 1 long-beard lichen 54.2 Cal: None 5:2 Valley Oak Woodland G3 Fed: None 91 0 0 0 0 0 1 1 0 1 0 0 52.1 Cal: None 5:1 Commercial Version -- Dated November 02,2012 - Biogeographic Data Branch Page 5 Report Printed on Thursday, January 24, 2013 Information Expires 0510212013 Appendix B USFWS Species List Sacr:lI11e!Uo Fi sh & Wildlife omec Species Lisl United States Department of the Interior FISH AND WILDLIFE SERVICE Sacramento Fish and Wildlife Office 2800 Cottage Way, Room W-2605 Sacramento, California 95825 January 24, 2013 Document Number: 130124111232 Norm Ponferrada URS Corporation 1333 Broadway, Suite BOO Oakland, CA 94612 Subject: Species List for Stanford Searsville Dam Alternatives Study Dear: Mr. Ponferrada We are sending this official species list in response to your January 24, 2013 request for information about endangered and threatened species. The list covers the California counties and/or U.S. Geological Survey 7'h minute quad or quads you requested. Our database was developed primarily to assist Federal agencies that are consulting with us. Therefore, our lists include all of the sensitive species that have been found In a certain area and also ones that may be affected by projects In the area. For example, a fish may be on the list for a quad If it lives somewhere downstream from that quad. Birds are included even if they only migrate through an area. In other words, we include all of the species we want people to consider when they do something that affects the environment. Please read Important Information About Your Species List (below). It explains how we made the list and describes your responsibilities under the Endangered Species Act. Our database is constantly updated as species are proposed, listed and delisted. If you address proposed and candidate species in your planning, this should not be a problem. However, we recommend th Please contact us if your project may affect endangered or threatened species or if you have any questions about the attached list or your responsibilities under the Endangered Species Act. A list of Endangered Species Program contacts can be found here. Endangered Species Division tl1tp: llwww.fw s .gov fs.acrnnJ(:nlo/c s_s pcci..: sl Li s l sfc s_ s pccic s~ li s l s~auto- l ellcr.cfm ll f2 4 12 013 10: 18: II AM 1 Sacramento Fish & Wildlife Office Species List Page I of5 u.s. Fish It Wildlife Service Sacramento Fish & Wildlife Office Federal Endangered and Threatened Species that Occur in or may be Affected by Projects in the Counties and/or U.S.G.S. 7 1/2 Minute Quads you requested Document Number: 130124111232 Database Last Updated: September 18, 2011 Quad Lists Listed Species Invertebrates Euphydryas editha bayensis bay checkerspot butterfly (T) Critical habitat, bay checkers pot butterfly (X) Lepidurus packardi vernal pool tadpole shrimp (E) Fish Acipenser medlrostris green sturgeon (T) (NMFS) Eucydogobius newberryi tidewater goby (E) Hypomesus transpacificus delta smelt (T) Oncorhynchus kisutch coho salmon - central CA coast (E) (NMFS) Critical habitat, coho salmon - central CA coast (X) (NMFS) Oncorhynchus mykiss Central California Coastal steelhead (T) (NMFS) Central Valley steelhead (T) (NMFS) Critical habitat, Central California coastal steelhead (X) (NMFS) Oncorhynchus tshawytscha Central Valley spring-run chinook salmon (T) (NMFS) winter-run chinook salmon, Sacramento River (E) (NMFS) Amphibians Ambystoma californiense California tiger salamander, central population (T) Rana draytonii California red-legged frog (T) Critical habitat, california red-legged frog (X) Reptiles Thamnophis sirtalis tetra taenia San Francisco garter snake (E) Birds http://www.fws.gov/sacramento/es_species/Lists/es_species_I ists.cfm 1124/2013 Sacramento Fish & Wildlife Office Species List Page 2 of5 Brachyramphus marmoratus Critical habitat, marbled murrelet (X) marbled murrelet (T) Charadrlus alexandrlnus nivosus western snowy plover (T) Pelecanus occidentalls califomicus California brown pelican (E) Rallus /onglrostris obso/etus California clapper rail (E) Sternula antillarum (=Sterna, =albifrons) browni California least tern (E) Mammals Reithrodontomys raviventris salt marsh harvest mouse (E) Plants Acanthomintha duttonii San Mateo thommint (E) Cirsium fontinale var. fontinale fountain thistle (E) Eriophyllum latilobum San Mateo woolly sunflower (E) Hesperollnon congestum Marin dwarf-flax (=western flax) (T) Pentachaeta bellidlflora white-rayed pentachaeta (E) Suaeda californica California sea blite (E) Trifolium amoenum showy Indian clover (E) Quads Containing Listed, Proposed or Candidate Species: MOUNTAIN VIEW (428A) PALO ALTO (4286) MINDEGO HILL (428C) WOODSIDE (429A) ------~.~-~------County Lists No county species lists requested. Key: (E) Endangered - Usted as being in danger of extinction. (T) Threatened - Usted as IIkelv to become endangered within the foreseeable future. (P) Proposed - Officially proposed in the Federal Register for listing as endangered or threatened. (NMFS) Species under the Jurisdiction of the National OceaniC & Atmospheric Administration Fisheries Service. Consult with them directly about these species. Critical Habitat - Area essential to the conservation of a species. http://www .fws.gov/sacramento/es_ species/Listsles_species -'ists.cfm 1/24/2013 Sacramento Fish & Wildlife Office Species List Page 3 of5 (PX) Proposed Critical Habitat - The species is already listed. Critical habitat Is being proposed for it. (C) Candidate - Candidate to become a proposed species. (V) Vacated by a court order. Not currently In effect. Being reviewed by the Service. (X) Critical Habitat designated for this species Important Information About Your Species List How We Make Species Lists We store information about endangered and threatened species lists by U.S. Geological Survey 7Y2 minute quads. The United States is divided into these quads, which are about the size of San Francisco. The animals on your species list are ones that occur within, or may be affected by projects within, the quads covered by the list. • Fish and other aquatic species appear on your list if they are in the same watershed as your quad or if water use in your quad might affect them. • Amphibians will be on the list for a quad or county if pesticides applied in that area may be carried to their habitat by air currents. • Birds are shown regardless of whether they are resident or migratory. Relevant birds on the county list should be considered regardless of whether they appear on a quad list. Plants Any plants on your list are ones that have actually been observed in the area covered by the list. Plants may exist in an area without ever having been detected there. You can find out what's in the surrounding quads through the California Native Plant Society's online Inventory of Rare and Endangered Plants. Surveying Some of the species on your list may not be affected by your project. A trained biologist and/or botanist, familiar with the habitat requirements of the species on your list, should determine whether they or habitats suitable for them may be affected by your project. We recommend that your surveys include any proposed and candidate species on your list. See our Protocol and Recovery Permits pages. For plant surveys, we recommend using the Guidelines for Conducting and Reporting Botanical Inventories. The results of your surveys should be published in any environmental documents prepared for your project. Your Responsibilities Under the Endangered Species Act All animals identified as listed above are fully protected under the Endangered Species Act of 1973, as amended. Section 9 of the Act and its implementing regulations prohibit the take of a federally listed wildlife species. Take is defined by the Act as "to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect" any such animal. Take may include significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding, or shelter (50 CFR §17.3). Take incidental to an otherwise lawful activity may be authorized by one of two procedures: • If a Federal agency is involved with the permitting, funding, or carrying out of a project that may http://www.fws.gov/sacramento/es_species/Lists/es_species _Iists.cfm 1/24/2013 Sacramento Fish & Wildlife Office Species List Page 4 of5 result in take, then that agency must engage in a formal consultation with the Service. During formal consultation, the Federal agency, the applicant and the Service work together to avoid or minimize the impact on listed species and their habitat. Such consultation would result in a biological opinion by the Service addressing the anticipated effect of the project on listed and proposed species. The opinion may authorize a limited level of incidental take. • If no Federal agency is involved with the project, and federally listed species may be taken as part of the project, then you, the applicant, should apply for an incidental take permit. The Service may issue such a permit if you submit a satisfactory conservation plan for the species that would be affected by your project. Should your survey determine that federally listed or proposed species occur in the area and are likely to be affected by the project, we recommend that you work with this office and the California Department of Fish and Game to develop a plan that minimizes the project's direct and indirect impacts to listed species and compensates for project-related loss of habitat. You should include the plan in any environmental documents you file. Critical Habitat When a species is listed as endangered or threatened, areas of habitat considered essential to its conservation may be deSignated as critical habitat. These areas may require special management considerations or protection. They provide needed space for growth and normal behavior; food, water, air, light, other nutritional or physiological requirements; cover or shelter; and sites for breeding, reproduction, rearing of offspring, germination or seed dispersal. Although critical habitat may be designated on private or State lands, activities on these lands are not restricted unless there is Federal involvement in the activities or direct harm to listed wildlife. If any species has proposed or deSignated critical habitat within a quad, there will be a separate line for this on the species list. Boundary descriptions of the critical habitat may be found in the Federal Register. The information is also reprinted in the Code of Federal Regulations (50 CFR 17.95). See our Map Room page. Candidate Species We recommend that you address impacts to candidate species. We put plants and animals on our candidate list when we have enough scientific information to eventually propose them for listing as threatened or endangered. By considering these species early in your planning process you may be able to avoid the problems that could develop if one of these candidates was listed before the end of your project. Species of Concern The Sacramento Fish & Wildlife Office no longer maintains a list of species of concern. However, various other agencies and organizations maintain lists of at-risk species. These lists provide essential information for land management planning and conservation efforts. More info Wetlands If your project will impact wetlands, riparian habitat, or other jurisdictional waters as defined by section 404 of the Clean Water Act and/or section 10 of the Rivers and Harbors Act, you will need to obtain a permit from the U.S. Army Corps of Engineers. Impacts to wetland habitats require site specific mitigation and monitoring. For questions regarding wetlands, please contact Mark Littlefield of this office at (916) 414-6520. http://www.fws.gov/sacramento/es_specieslLists/es_species_I ists.cfm 1/24/2013 Sacramento Fish & Wildlife Office Species List Page 50f5 Updates Our database is constantly updated as species are proposed, listed and delisted. If you address proposed and candidate species in your planning, this should not be a problem. However, we recommend that you get an updated list every 90 days. That would be April 24, 2013. http://www .fws.gov/sacramento/es _ species/Lists/es_species_I ists.cfm 1/24/2013