HomeMy WebLinkAbout3338; Agua Hedionda & Calavera Creek Dredging; Calavera Hills Master Plan Phase II, Bridge Basin, District; 2001-01-25REVISED
BIOLOGICAL TECHNICAL REPORT
FOR THE
CALAVJERA Fma.S MASTER PLAN PHASE TI,
BRIDGE AND THOROUGHFARE DISTRICT,
AND DETENTION BASINS
CARLSBAD, CALIFORNIA
Prepared far
PLANNING SYSTEMS
CONTACT: PAUL KLUKAS
1530 FAILWAY AVENUE, SUITE 100
CIUUSBAD, CALIFORNIA 92008
WENDY Em--
BIOLOGIST
RECON NUMBER 3225B
JANUARY ,25,2001
t 927 Fi Avenue, Suite 200
San Diego, CA 92101
619 I 308-9333 fax 308-9334
TABLE OF CONTENTS
Summary of Findings
Introduction
Sumey Methods
Existing Conditions
A. Topography and Soils
B. Botany
C. zoology
D. Sensitive BioIogical Resources
E. Wetlands and Non-Wetland Jurisdictional Waters
Project Impacts
A. Plant CormnuIlities
B. Wildlife
C. Sensitive Biological Resources
D. Jurisdictional Wetlands and Waters of the U.S.
E. Wildlife Movement Corridors
Mitigation Measures
A. Sensitive Hant Communities
B. Sensitive
C. Jurisdictional Waters
References Cited
TABLE OFmCONTENTS (cont,)
FIGURES
Regional Locati0.n of the Project
Project Vicinity
Project Location
Existing Biological Resouroes: Master Plan Phase II
Existing Biological Resources: Bridge and Thoroughfare District and
Detention Basins
Existing Jurisdictional Waters of the U.S.
Project Impacts: Mkter PIan Phase II
Project Impacts: Bridge and Thoroughfare District and Detention Basins
Project Impacts to Jurisdictional Waters of the U.S.
Soil Types Within the Project Components
Vegetation Communities Within the Project Components
Sensitive Piant Species Observed w with the Potential for Occurrence
Sensitivity Codes
Sensitive Wildlife Species Known (or Potentially Occurring)
Impacts to Resources by Village Within the Master Plan Phase II
Project Component
Impacts to Resources Within the Bridge and Thoroughfare Disirict
Impacts to Resources Within the Detention Basins Project Component
Mitigation for Impacts to Resources Within the Master Han Phase I1 Project
Component
Mitigation for Impacts to Resources Within the Bridge and Thoroughfare
Diistrict -
1 1: Mitigation for Impacts to Resources Within tbe Detention Basins Project
Component
1: Plant Species Observed
2: W11dlife Species Observed
Summary of Findings
The Cdavera Hills Master Plan Phase I1 and Bridge and Thoroughfare District No. 4
project is located in the northeast quadrant of the city of Cadsbad. The study area
contains several sensitive plant communities including Diegan coastal sage scrub, riparian
woodland, native grassland, riparian scrub, riparian forest, cismontane alkali marsh,
cismontane alkali marsh (seasonal), and freshwater marsh. Two birds federally listed as
threatened or endangaed, the coastal California gnatcatcher and least Bell's vireo, and
one plant species Listed as endangered, thread-leaved brodiaea, were obswed omsite.
The property also contains jurisdidonal wetlands and non-wetland jurisdictional waters
of the U.S. Impacts to any of these sensitive resources would be significant and mitigation
would be required. me impact analysis and recommended mitigation ratios in this
document are based on the City of Carlsbad's Habitat Management Plan, which is
currently in the process of being approved by regulatory agencies and adopted by the City.
If this document is not approved as currently published or is not adopted by the City, the
required mitigation recommended in this document may have to be revised and the
project would be required to obtain applicable permits for impacts to listed species as per
Section 1qa) or Section 7 of the federal Endangered Species Act.
Introduction
The project site is located in the northeast quadrant of the city of Carlsbad (Figure 1) and
consists of three components: Calavera Hills Master Plan Phase II area, Bridge and
Thoroughfare District No. 4, and two proposed detention basins @~s 2 and 3). Tbe
Calavera Hills Master Plan area is bounded by State Route 78 (SR-78) on the north with
the southern boundary being an east-west line approximately one-half of a mile north of
the Rancho Carlsbad Mobile Home Park. Tbe Master Plan's western extent is near
Carlsbad Village Drive. Figure 3 also shows the proposed extensions of CoLIes
Boulevard and Cannon Road which are generally southeast of the Master Plan.
The second major component of the project is the formation by the City of CarIsbad of a
Bridge and Thoroughfare District No. 4 for the extensions of College Boulevard armd
Cannon Rod College Boulevard would be extended from within the Calavera Kills
Master Plan at Cdsbad Village Drive to El Carnino Real. It should be recognized that the
Bridge and Thoroughfare District encompasses the reach of CoIIege Boulevard that lies
within the boundaries of the Calavera Hills Master Plan. Cannon Road would be
extended from El Carnino Real easterly to the city of Oceanside. Figures 2 and 3 shows
the limits of the District and the approximate alignments of both roadways. Two
alternative alignments for each roadway are also addressed in this report.
The third component of the project consists of the construction of two detention basins
(see Egwes 2 and 3) by the City of Carlsbad to control flooding impacts within CaIavera
Creek watershed. These basins have been recommended near the' northeast corner of the ,
Rancho Carlsbad Mobile Home Park Basin 'BJB" is located north of the Colfege
BoulevardfCannon Road intersection and would have an inundation area of
approximately 15 acres and a storage capacity of 49 a-feet. Basin "W is located
southeast of the College BoulevardCannon Road intersection and would have an
inundation area of approximately 8 acres with a storage volume of 48 acre-feet. The
basins are part of a larger drainage plan for the area, and are consistent with the 1994 City
of Carlsbad Master Drainage Plan.
A general biological swvey was conducted to map vegetation communities and to assess
the presence or potential for presence of sensitive floral and faunal species. In ation,
surveyx were conducted for the coastal Califomia gnatcatcher (Polwptih califomim
califomica) and least Bell's vireo (Vireo beUii pusillus) according to U.S. Fish and
Wildlife Service (LJSFWS) survey protocol. This report provides biological data and
background information required for environmental analysis by the California
Environmental Quality Act (CEQA). In addition, impacts were analyzed using
information provided in the City of Carlsbad's Draft Habitat Management Plan (HMP).
This document is currently in the process of being approved by regulatory agencies and
adopted by the City. If Ifs document is not approved as currently published or is not
adopted by the City, the required mitigation recommended in this document may have to
be revised and the project would be required to obtain applicable permits for impacts to
listed species as per Section 10(a) or Section 7 of the federal Endangered Species Act
Survey Methods
A general biological resources survey was conducted on November 22 and December 13,
1999, and January 5, 12, 17 and 19, 2000, by RECON biologists Wendy Loeffler,
Jennifer Hodge, and Cynthia Jones. Vegetation communities were assessed and mapped
for the three project components on a color aerial flown in 1999. The study area for the
Bridge and Thoroughfare District component includes a 500-foot corridor surrounding
the various alignment alternatives. The project components are not pgraphically
exclusive and overlap where the College Boulevard alignment falls within the Master
Plan boundary. Animal species observed directly or detected from calls, tracks, scat,
nests, or other sign were notad All plant species observed on-site were also noted, and
plants that could not k identified in the field were identified later using taxonomic keys.
The wildlife surveys include focused surveys for coastal California gna~atchers
conducted by RECON biologists Wendy bffler (permit number TS839084-2) and
Cynthia Jon- (TE-811615) according to the USFWS California gnatcatcher survey
guidelines (USFWS 1997a). Surveys were conducted on November 22 and December 13,
1999, and January 5,12, 17 and 19,2000 between the hours of 6:00 A.M. and 12:00 P.M.
Survey conditions were optimal for detecting coastal California gnatcarehers, with mild
temperatures and winds of 0 to 5 miles per hour.
Focused suweys for the southwestern willow flycatcher were conducted by Cynthia Jones
(TE-8 11615) on May 22, June 13, and June 23,2000, Suweys were conducted according
to the accepted survey protocol (Sogge et d. 1997), which requires at lemt one survey
between May 15 and 31, one survey between June 1 and 21, and one survey between
June 22 and July 10.
Focused surveys for least Bell's vireo were conducted on April 27; May 1 1 and 22;
June 4, 13, and 23; and July 5 and 14, 2000 by Amy EZsnic and Cynthia Jones. Survey
guidelines for these species require eight surveys, at least 10 days apart between April 1
and July 3 1 (USFWS 1999).
A wetland delineation was performed by RECON biologist Jennifer Hdge according to
the guidelines set forth by the U.S. Army Corps of Engineas (USACE 1987) on
December 13, 1999, and January 5, 17 and 19, 2000. A wetland delineation is used to
identify and map the extent of the wetlands and "waters of the U.S." found within the
proposed project boundary and provide information regarding both state and federal
jurisdictional issues.
Several previous surveys have been conducted on the Master Plan area and a portion of
the College Boulevard extension (RECON 1991 ; S weetwater Environmental Biologists,
kc. [SEB] 1995). me biological information gathered during these surveys is
incorporated into this report.
Limitations to the compiIation of a comprehensive floral checklist were imposed by
seasonal factors, such as blooming period and emergence of spring annual species. Faunal
species, such as birds and butterflies, that are only present during the breeding season of
late spring-to summer were not detected. Since surveys were performed during the day,
nocturnal anids were detected only by sign.
Fld nomenclature for common plants follows Hickman (1993). Plant community
classifications follows the Draft Habitat Management Plan for the Natural Communities
in the City of Carlsbad (City of Carlsbad 1999). Zoological nomenclature for birds is in
accordance with the American Ornithologists' Union Checklist (1998); for mammals,
Jones et al. (1982); and for amphibians and reptiles, Collins (1997). Assessments of the
sensitivity of species and habitats are based primarily on Skinner and Pavlik (1 9941, State
of California (1499% 1999b, 1999c, 2000), City of Carlsbad (1999), and Holland (1986).
Existing Conditions
Topography and Soils
Elevation of the entire site ranges from approximately 40 to 500 feet above mean sea
level (U.S. Geological Survey 1968). A small portion of Agua Hedionda Cmk-is present
within the College Boulevard extension south of the intersection with the proposed
Cannon Road. Several unnamed drainages flow north-south info Agua Hedionda Creek
The site contains several hills surrounding the flat agricultural fields. Several of the
hillslopes support rock outcrops.
There are 21 soil classifications present within the entire project area (U.S. Deparbnent of
Agriculture 1973). Table 1 presents the list of soil types and where within the three
projsct components each type is located. There are two different clay soil series press
on-site: Altamont clay and Diablo clay. There are 12 different loam soil series present,
which include Ioams, sandy loams, cobbly loams, and clay loarns. The loam soils are
represented by Huerhuexo lorn. The sandy loams are represented by many different soil
series: Bonsall sandy loam, Cieneba very mky coarse sandy loam, Cieneba-Fallbrook
rocky sandy loam, Escondido very fine sandy loam, Fallbrook rocky sandy loam, Friant
rocky fine sandy loam, Gaviota fine sandy loam, and Las Posas stony fine sandy loam.
The clay loam represented is Olivenhain cobbly loam and the clay loam is Salinas clay
loam. There are four sand and loamy sand soil series present on-site: Carlsbad &avellY
loamy sand, hs Flores Iomy fine sand, Marina loamy coarse sand, and Tujunga sand.
The remaining three soil types present are loamy alluvial land-Huerhuem complex,
riverwash, and steep gullied land.
Botany
Eleven vegetation communities were identified within the survey area! Diegan coastal
sage scrub, southern mixed and chamise chaparral, non-native grassland, ripariap
woodland, eucalyptus woodland, native grassland, riparian scrub, riparian forest,
cismontane alkali marsh, cismontane alkali marsh (seasonal), and freshwater marsh. The
rest of the site is agriculture, developed, or disturbed Table 2 presents the acreages of
each community within the project components. There is a total of 412.6 acres within the
Master Plan Phase II project component and a total of 421.2 acres within tbe Bridge and
Thoroughfare District and detention basin areas. This existing acreage for the roadways
reflects a survey area that includes a 500-foot corridor on both sides of the alignments.
These project components are not geographically exclusive and overlap where the
College Boulevard alignment fdIs within the Master Plan boundary. figure 4 illustrates
the locations of the plant communities within the Master Plan Phase II area and Figure 5
illustrates the vegetation within the Bridge and Thoroughfare District and detention basin
areas. A total pf 116 plant species were identified on the site (Attachment I). Of this total,
70 (60 percent)'are species native to southem California and 46 (40 percent) are
introduced species.
1 Diegan Coastal Sage Scrub
Diegan coastal sage scrub is the dominant vegetation community within the Master Plan
area and the Bridge and Thoroughfare Dislrict and detention basin areas. Them are
approximately 250.3 acres within the Master h phase 2 area and 137.3 acres within the
survey area of the Bridge and Thoroughfare DistricrlDetention Basins. Much of the
community is domid by California sagebrush (Artemisia calij'umica) and California
adolphia (Adolphia cuZij%mica). These areas tend to intergrade with areas dominated by
black sage (Salvia mellvera) and California buckwheat (Enbgonum fasicularm var.
fasciculm). Other areas, generally within or adjacent to the many small drainages on-
site, are dominated by coyote bush (Baccharis pilularis). Other common species include
laurel sumac (Malosma lauriraa.), lemonadeberry (Rhs iretegrifoia), common encelia
(Encelia califomica), blue elderberry (Sambmus nnexicana), and bladderpod (Isomeris
dorm). Understory species included both native and non-native species, such as purple
needlegrass (Nassella p ulch ra), slender stephomeria (Stephanomeri~ virgatu), coast
goldenbush (Isocoma mmiesii) , white- stemmed filaree (Erodiurn cicutarim), golden-
yamow (Enbphyllum cmfertiJIonun), wild oats (Aveuaa sp.), and California broom (Lotmcs
scuparius).
2. Southern Mixed and Chamise Chaparral
Chaparral is present on approximately 66.6 acres of the Master Plan area and
approximately 24.8 acres of the Bridge and Thoroughfare District and detention basin
areas. The majority of the chaparral is dominated by laurel sumac, lernonadek~~y, coast
blue lilac (Ceanothus tomentosus), chamise (Ademstom califomica), toyon
(HeteromeIw ~rbutfolia), and black sage. Several areas of chapd were dominated by
chamise. Much of the understory consists of typical coastal sage scrub species, such as
California adolphia, California sagebrush, coyote bush, and California buckwheat. The
soils that underlie this community are primarily loam and sandy loans. The site does not
contain the sandstone soils required to support southern maritime chaparral (City of
Carlsbad 1999).
3. Non-Native Grassland
Approximately 20.2 acres of the Master Plan area and approximately 16.3 acres of the
Bridge and Thoroughfare District and detention basin areas are covered with non-native
grassland This plant community is dominated by non-native grasses such as wild oat,
ripgut grass (Bromus diandnrs), foxtail chess (B. madritensis ssp. rubens), and smooth
brome (B. Rordmeus). Herbaceous species, such as black mustard (Brassica nigra),
white-stemmed filaree (Erodim cicutarim), and western ragweed (Ambrosia
psilostachya) were also common in these amas.
Riparian Woodland
Approximately 0.2 acre of riparian woodland is pment within the Master Plan area and
approximately 15.1 acres are present within the Bridge and Thoroughfare Disaict and
detention basin areas. These areas are lcated along a portion of ~alavera Agua
Hedon& Creek, and an unnamed drainage. Western sycamom (Plafartus racema)
dominate the plant community with understory species composed of the native mugwort
(Artemisia duuglasiaPza) and jimson weed (Dafum wrighiii), d ncm-native plants,
including giant red (Arundo donax), horehound (Mamrbim vulgare), castor bean
(Ricinus communis), and poison hemlock (Conim maculattm).
*.i .
5. Eucalyptus Woodland
Eucalyptus woodland is present on approximately 9.9 acres of Village H in the Master
PIan asea and scattered in a few small patches totaling 5.0 acres within the Bridge and
Thoroughfare District area. This plant community is dominated by eucalyptus irees
(Earca&tus spp.) and has a groundcover ?hat ranges hrn bam to mhhd cover with
non-native grasses, such as wild oats, ripgut grass, and smooth brome.
Native Grassland
Native grasslands are comprised of native perennial bunch grasses. This plant community
has been mainly converted to non-native annual grassIands due to the invasion of exotic
annual gasses. Native grasslands often have s large component of noo-n'atlve grasses but
are distinguished as native when the cover by native grass species is 10 percent or greater.
Native grassland was primarily found in Village H of the Master Plan area on
appmxirnately 9.3 acres.
Riparian Scrub
Approximately 7.2 acres of riparian scrub are present within the Master Plan area and 3.3
acres are present within the Bridge and Thoroughfare District detention basin areas. Tbe
community designation includes both mule fat scrub and southern willow scrub habitats
found along many of the drainages on-site. Mule fat (Baccharis saIicifolia) and coyote
bush dominate with giant red, pampas gass (Cortadenb jubnta), and curiy-dock (Rumex
crispus) commonly presenL The southern willow scrub is dominated by amyo willow
(Sdk hiolepis), which forms a canopy with variable density throughout the site. Other
associated trees include red willow (Salk lmvigata), black willow (S. gooddingii),
wcstem sycamore and Mexican fan palm (Washingtonia robusta). The understory
includes mule fat, tdl yellow evening primrose (Oenothera elata ssp. himtissim), giant
wild rye (Le~s con&nsams), tall flatsedge (Cypems eragrostis), rue (JURCUS sp.), and
curly dock.
8. Riparian Forest
Riparian forest, defined as southern coast live oak riparian forest, is a habitat that is found
in drainage bottoms often intergrading with riparian scrub and woodland habitats.
Approximately 2.0 acres of this habitat is locd dong the creek the flows within the
Cannon Road alignment of the Bridge and Thoroughfare District. The dominant tree is
the coast live oak (Quercus agrifolia), with a variable understory of freshwater marsh
habitat, as described below, and other species that include poison oak (Tox*coddrm
diversiloburn), coyote bush, and toyon.
9. Cismontane Alkali Marsh
Two small patches of cismontane alkali marsh totaling 1.0 acre are present within the
Bridge and Thoroughfare District. This habitat is characterized by the pmsence of wetland
species, such as spiny rush (Jmus acutus ssp. Ieopoldir*), yerba mansa (Anempsis
califomica), salt grass (Distichlis spicata), spikmsh (Eleocharis sp.), and alkali heath
(Frunkenia salim). I
10. Cismontane Aikali Marsh (seasonal)
Seasonal cismontane alkali marsh defines small patches of vegetation that are currently '
dry but are dominated by wetland plants. These areas are generally located at the upper
end of small erosional drainages. There are several small patches totaling 05 acre within
the Cannon Road alignment within the Bridge and Thoroughfare District and one 0.1-a-
patch within the Master Plan area. The dominant plants include several species of rush .
(Juncus spp.).
11. Freshwater Marsh
Approximately 0.5 acre of freshwater marsh is present in a drainage within the Master
Plan area and an approximately 0.2-acre patch is present within the alignment of College
Boulevard just below El Carnino Red. There is also a small isolated patch of freshwater
marsh at the approximate intersection between the College and Cannon road alignments.
This community is dominatd by broad-leaved cattails (Typha latifolk), including also
rush, pampas grass, giant reed, and tall flatsedge.
12. Agriculture
Much of the Bridge and Thoroughfare District area is under cultivhon. These fields
account for approximately 133.6 acres of the survey area.
This designation is used for the approximately 25.8 acres in the Master Plan area and 54.1
acres in the Bridge and Thoroughfare District detention basins area. Developed includes
the lnss converted to housidg, pgved roads, a other structures. These amm contain some
landscaping, including palm treg and Hottentot fig (Carpobronrs em*j).
14. Disturbed
This designation is used primarily for areas that have been graded or are dominated by
non-native weedy +a. The plants present here include fennel (Foeniculm vulgare),
black mustard, ripgut grass, smooth brome, bristly ox-tongue (Plcris echioides), and
Bermuda grass (Cynodon &ctylon). There are approximately 22.5 acres in the Master
Plan area and 28.0 acres in the Bridge and Thoroughfare DistrictlDetention Basins area
C. zoology
Overall, the project m and vicinity provides high value habitat for wildlife species.
Much of the site contains moderate to high-quality coast$ sage and chaparral habitat and
high-quality riparian habitats, which provide cover, foraging, and breeding habitat for a
variety of native wildlife species. A complete list ' of the wildlife species detected is
provided in Attachment 2. Sensitive species potentially occurring on-site are discussed in
the Sensitive Biological Resources section.
1. Amphibians
Most amphibians quire moisture for at least a portion of their life cycle, with many
requiring a permanent water source for habitat and reproduction. Terrestrial amphibians
have adapted to more arid conditions and are not completely dependent on a perennial or
standing source of water. These species avoid desiccation by burrowing beneath the soil
or leaf litter during the day and during the dry season.
Pacific treefrogs (&la regilla) were-heard within the drainages and wetlands throughout
the Pwem-
2. Reptiles
The diversity and abundance of reptile species varies with hfiitat type. Many reptiles are
restricted, to cdn vegetation communities and soil types although some of these species
will also forage in adjacent communities. Other spies are more ubiquitous using a
variety of vegetation types for foraging and shelter.
No reptiles were observed on-site during the current surveys. A number of species have
been identified previously on the site including San Diego gopher snake (Pimophis
catenveer mnecterts), San Diego horned lizaxd (Phynosoma coronam blainvillii),
westem fence' Iizkd (SceZoponis orcidcn frrlis), side-blotched lizard (Utrr stiansbun'm),
and Belding's orangethroat whiptail (Cnernidophorus hyperytkrtrs beldingi) WON
1991; SEE 1995).
3. Birds
The diversity of bird spe.cies varies with rapect to the character, quality, and diversity of
vegetation communities. Due to the variety of habitats present on the property, the bird
diversity is fairly high. .- .
Birds commonly obswved within the Diegm coastal sage scrub and southern mixed and
chamise chap& include Bewick's wren (Thyronmes bewickii), bushtit (Psdtripalzrs
mihimus minim), yellow-rumped warbler (Dendroica coronata), wrentit (Chumaea
fmciafa), Anna's hummingbird (Calypte annu), California towhee (Peilo misscalis),
spotted towhee (P. rnuculatw), and California quail (CdlipepLa caZifbmica).
Birds commonly found in the riparian habitats include lesser goldfinch (Carduelis tristis
salic-1, Nuttall's woodpecker (Dsndrocopos nunallii), bushtit, common
yellowthroat (Geothlypis m'ckas), song sparrow (Melospiza melodia), and yellow-rumped
warbler.
Mouming dove (Zkmida mcacroura marginella), kingbird (Tyrannus sp.), house finch
(Carpodc~cus mexicanus frontalis), and western meadowlark (Sturnella negteeta) were
commonly observed within the native and non-native grasslands.
Raptors observed on-site include . red-tailed hawk (Buteo jamaicensis), red-shouldered
hawk (Buteo liiwatus eiegans), northern harrier (Circus cymeus hudsonius), turkey
vulture (Catharta aura), white-Wed kite (Ehw leucurus), American kestrel (Falco
spawerim), and Cooper's hawk (Accipiter coopcrii). A common barn ow1 (Tyfo ah
pmtincoh) carcass was found in the coastal sage scrub in Village H. Nesting habitat is
present on-site for these species and other raptm in the riparian habitats.
Coastal sage scrub, chaparral, woodland, and riparian cornmumties typically provide
cover and foraging opportunities for a variety of mammal species. Many mammal species
are nocturnal and must be detected during daytime surveys by observing their sign, such
as tracks, sc* and burrows.
Cottontail rabbit (SyIvilagw audubonii), southern pocket gapher (Tkomrnys umbnitus),
woodrat (Neotoma sp.), and coyote (Canis btrans) were observed either directly m
througb sign. San Diego black-tailed jackrabbit (Lapus califimicus bennem'i?) was also
observed during previous surveys (RECON 199 1; SEB 1 W5).
D. Sensitive Biological Resources
State and federal agencies mgulate sensitive species and require an assessment of their
presence or potential presence to be conducted on-site prior to the approval of any
proposed development on a property. For purposes of this report, species will be
considered sensitive if they m: (1) listed or proposed for listing by state or federal
agencies as threatened or endangered; (2) on List 1B (considered endangered throughout
its mge) or List 2 (considered endangered in California but more common elsewhere) of
the California Native Plant Society's (CNPS) Inventory of Rare ad Endwagered
Vascular Plants of California (Skinner and Pavlik 1994); (3) included on the Draft
Habitat Management Plan @IMP) or Multiple Habitat Conservation Program (MHCP) list
of species evaluated for coverage or list of narrow endemic plant species; or
(4) considered fully protected, sensitive, rare, endangered, or threatened by the State of
California (1999a, 1999b, 1999~) and Natural Diversity Data Base (NDDB) (State of
California 2000), or other local conservation organizations or specialists. California fully
protected is a designation adopted by the State of California prior to the creation of the
State Endangered Species Act and is intended as protection from harm or harassment.
Noteworthy plant species are considered to be those which rn on List 3 ' (more
information about the plant's distribution d rarity needed) and List 4 (piants of limited
distribution) of the CNPS Inventory. Sensitive habitat types are those identified by the
NDDB (State of California 2000), Holland (1986) andlor those considered sensitive by
other resome agencies.
The MHCP is a comprehensive, multi-jurisdictional habitat conservation plan currently
being drafted far northwestern San Diego County (San Diego Man of
Governments [SANDAG] 1998). In addition to the City of CPdsb.4, participating '
jurisdictions include the cities of Oceanside, Vista, San Marcos, Escondido, Encinitas,
and Solana Beach. The City of CarIsbad has drafted the Draft Habitat Management Plan
for Natural Communities in the City of Carlsbad (HMP), a subarea plan of the MHCP
(City of Carlsbad 1999). The City's Draft EMF designates a natural habitat preseme
system and provides a regulatory framework for determining impacts and designating
mitigation associated with proposed projects. In the event the Draft HMP is not formally
approved and adopted, all projects would be required ta obtain applicable permits for
impacts to listed species as per Section 1qa) or Section 7 of the federal Endangered
Species Act.
The multi-jurisdictional MHCP draft document identifies a series of focused planning
areas within which some lands will be dedicated for preservation of native habitats. These
ms contain both %ad line" areas which will be preserved as open space and "soft line"
areas which will include both development and open space to be determined through the
planning process. Mitigation requirements for impacts to the biological resources are
based on ratios provided by the Draft HMP (City of Carlsbad 1999). If this plan is not
formally adopted, these mitigation requirements may need to be revised.
Determination of the potential occurrence for listed, sensitive, or noteworthy species me
based upon known ranges and habitat preferences for the species @kine1 et al. 1988%
1988b, 1990; Skinner and Pavlik 194; Reiser 1994); species occurrence records from the
NDDB (State of California 20); and species occurrence recd from other sites in the
vicinity of the project site.
1. Sensitive Plant Communities and Habitats
The following communities identifisd on-site are considered sensitive by the City of
Carlsbad (19991, NDDB (State of California 20001, Holland (19861, ador state and
federal resource agencies: Diegan coastal sage scrub, native grassland, riparian woodland,
riparian scrub, riparian forest, cismontane alkali marsh, cismontane alkali marsh
(seasonal), and freshwater marsh.
I
a. Diegah Coastal Sage Scrub
Diegan coastal sage scrub is restricted to the coastal areas of southern CaLifd and
northern Baja California. Development and other human-relatd activities have seriously
impacted this plant community and its associated plant and wildlife species. It is
estimated that 70-90 percent of the presettlement southern California coastal sage scrub
has been destroyed, with the losses accelerating rapidly within the last &ade moss et d.
1995; Sawyer and Keeler-Wolf 1995). Diegan coastal sage scrub is considered sensitive
by federal and state resource agencies, most southem CaIifornia jurisdictions, lccal
conservation organizations, and the City of Carlsbad. This plant community is occupied
by the coastal California gnatcatcher based on biological studies conducted in 1992, +
1995, and 1999 that have noted the presence of this species within the Master Plan
Phase II, Bridge and Thoroughfare District survey areas, and the Calavera Nature
Preserve WON 1991; SEB 1995).
b. Native Grassland
Native grasslands are. considered sensitive because of the extensive Im of this
community throughout the state. Native grasslands are listed as sensitive by the City of
Carlsbad (19991, Holland (1986), and NDDB (State of California 2000) and it is
estimated that only 0.1 percent of the native grasslands in California remain (Keeley
1990). Tbe loss of native grasslands is attributed to development, agriculture, grazing,
and invasion by non-native, annual grasses and other non-native plant species. The
invasion of native grasslands by non-native species including brome grasses (Brow
spp.), wild oats, and mustards h+s degraded native grasslands to the extent that it is rare to
find any that have not been invaded by these species. Grasslands that have 10 percent
cover by native grasses such as needlegrass are classified hue as native grasslands.
c. Riparian Woodland, Riparian Scrub, and Riparian Forest
AU riparian communities are coAsidem3 sensitive by the City of Carlsbad and are
regulated as sensitive wetland habitats by the California Department of Fish and Game
(CDFG) and U.S. Army Corps of Engineers (USACE). These plant communities are
found along rivers, streams, and intermittent drainages throughout southern California.
ChanneIization of rivers, streams, and drainages for flood control and land development
has resulted in curnulatiqe losses of these habitat types tbroughout the state. The loss of
riparian habitats in southern California has been estimated at greater than 95 percent
Cr:aber et al. 1989). Riparian scrub, in particular, potentially supports several endangered
and otherwise sensitive wildlife species.
d. Cismontane Alkali Marsh and Cismontane Alkali Marsh (Seasonal)
Cismontane alkali marshes are typically low-lying areas with a high water table that have
alkaline soils. Evaporation of ponded water often results in salts remaining on the surface.
This plant community is identified as sensitive by the City of Carlsbad (1999), Holland
(19861, and NDDB (State of California 2000), and is considered a sensitive wetland
community by USACE and CDFG. Wetland communities have been greatly reduced
throughout their entire range and continue to decline as a result of urbanization. State and
federal resource agencies consider wetland communities to be sensitive plant
communities.
Freshwater Marsh
Freshwater marsh vegetation occurs in open bodies of fresh water with little current flow,
such as ponds, and to a lesser extent around seeps and springs. This plant community is
identified as sensitive by the City of Carlsbad (1999), Holland (1986), and NDDB (State
of California 2000), and is considered sensitive as a wetland community by USACE and
CDFG. Freshwater marsh communities, as with all wetland habitats, have been greatly
reduced throughout their entire range and continue to decline as a result of urbanization
and are considered sensitive by state and federal resource agencies.
2. Sensitive Plants
Seven sensitive plant species were observed on-site during the most recent surveys
conducted by RECON in 1999 and during previous surveys conducted in 1991,1992, and
1995 (RECON 199 1, SEB 1995). One plant that is federally and state listed, three
sensitive plant species, and three noteworthy plant species were observed on-site: thread-
leaved brodiaea (Brodiaea ftlifolia), Nuttall' s scrub oak (Quercus dumscm), California
adolphia, Palmer's grapplinghook (Harpugonella pahri var. paLmeri), spiny rush
(Juncus mtus ssp. le~~~dii),' western dichondm (Dichondr. orcidentdis), and ashy
spike-moss (Selaginella cimruscerrs). figures 4 and 5 show the locations of thread-leaved
brodiaea, Palmer's grapphghoo~ and Nuttall's smb o& California adolpbia, spiny
rush, and ashy spike-moss were common within their respective habitats throughout the
sik and were not mapped.
Previously observed plant locations are expected to still be valid data becaux the sd and
vegetation has not been substantially altered during the interim. The extent of plant
populations in density and area can fluctuate from year to year based on environmental
conditions; however, species are still expected to be present at their previously recorded
locations.
a. Observed
Plant observations are from both the current and previous surveys (RECON 199 1; SEB
1995).
Thd-leaved brodiaea (BroGiaea @$oh). Thread-leaved brodiaea is a state
endangem and a federal threatened listed species, a Draft HMP and MHCP covered
species, and a CNPS List 1B species. This perennial corm typically occurs on hillsides or
valleys in grassland communities with clay, loamy sand, w alkaline silty-clay soils
(USFWS 1994). Tbe blooming period for thread-leaved brodiaea is from May to June. A
population of this species is present within the grassland and sage scrub habitat on tbe
northern portion of Village H, Approximately 300 individuals within 1,700 square meters
was originally mapped by RECON biologists in 1991 (RECON 1991). The population
was reidentifid in 1995 when 200 individuals were observed (State of California 2000).
This decrease in flowering plants does not show a decline in the number of individuals
present. Year to year variations in numbers of individual flowering can occur due ta
changes in environmental conditions (e.g., rainfall).
Nuttall's scrnb oak (Qwrcus dumosa). Nuttall's scrub oak, a Draft HMP and MHCP
covered species and a CNPS List 1B species, is a coastal chaparral shrub that can occur
witb an open canopy or in dense stands. It is identifiable all year, as it is an evergreen.
The geographic range of Nuttall's scrub oak spans from a few locations in southem
Orange County south to he middle of Baja California. Urban development along the
coast is the primary cause of its decline in San Diego County. This shrub was idensed in
the southern mixed and chamise chaparral habitat in the Calavera Nature Preserve within
the Master Plan area during the 1W9-2000 surveys.
California adolphia (AdoIphia califomica). This shrub is a CNPS list 2 species that
generally occurs in Diegan coastal sage scrub, often associated with California buckwheat
and California sagebrush. It is apparent all year by its unique spiny stems. Its geographic
range includes San Diego County south into Baja California. California adolphia is
present and often a dominant species within the Diegan coastal sage scrub and southem
mixed and chamise chaparral throughout the Master Plan and Bridge and Thoroughfhre 4
Districtareas.
Palmer's grapplinghook (Haqagonsk pahen var. palPnm3. Palmer's grapplinghook
is a CNPS List 2 specie. This small herbaceous annual is found iq day soils in caastal
sage scrub, chaparral, and valley grasslands in southern Califha, including Lus
Angeles, Orange, Riverside, and San Diego Counties, into Baja California, Arizona, and
Sonora, Mexico. It is an inconspicuous plant that can be easily overlooked The flowering
period is hm March through April. The species is threatened by development. Palmer's
ppplinghook was observed in two small patches in Diegan coastal sage scrub within the
open space north of Village U of the Master Plan area (RECON 1991).
Spiny rush (Juncw ucutacs ssp. kopoU3. Spiny rush is a CMPS List 4 species. It is a
large bushy rush commonly found in marsh habitats throughout San Diego County. It can
be found in a variety of soil types at low elevations wherever ponded water or saturated
soils are present, and is apparent year-round. Its range includes areas in Santa Barbma,
Orange, San Diego, and Riverside Counties, into mainland Mexico and Baja California.
This species is common in the cismontane alkali marsh habitat within the Cannon Road
alignment aad detention basins survey areas.
Western dichondra (Dikhnlkrr ace&&). Westem dichondra is a CMlPS List 4 '
species usually found growing under brush or trees in coastal sage scrub, chapand, or
oak woodland areas. It grows primarily in dry sandy soils ranging from Orange County
south into Baja California, Mexico. It is apparent from March to May. The numbers of
western dichondra are in a slow decline in southern California. This species was observed .
in several place in the Master Plan area and on the College Boulevard alignment Wng
previous smeys (RECON 1991; SEB 1995).
Ashy spike-moss (SelaginetCa cinermcens). This species is a CNPS List 4 promate
perennial that is apparent yea-round. Its range includes Orange and San Diego Counties
in California, south into Baja California. Ashy spikemoss is declining due to urban
development. It was identified throughout the site in the Diegan coastal sage scrub and
the charnise-dominant patches of the southern mixed and charnise chaparral within the
Master Plan Phase II area and Bridge and Thoroughfare District areas.
b, Not Observed
Several other sensitive species are known to occur in the vicinity of the project site and
are considered as potentially occurring on-site based on vegetation communities
identified. Table 3 summarizes the status, habitats, and results of the botanical swey for
each of these potentially occurring species, with codes explained in Table 4. Many of