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4.4 Biological Resources
4.4 BIOLOGICAL RESOURCES
SCOPE AND METHODOLOGY
This section examines the potential for the proposed project to result in significant adverse impacts to
biological resources. The existence (or lack of) such resources in the City and immediate surroundings
were identified in a study performed by Envicom Corporation, in consultation with appropriate local,
state, and federal agencies, and through a review of the Natural Diversity Database.
A general survey of Azusa’s plants was performed by Envicom Corporation on November 30 and
December 2, 9, and 16, 1999, for the purpose of making contemporary observations of biological
conditions and to prepare related maps1 . A tabulation of vascular plants observed during the field
surveys, supplemented by a list of plants 2 of the San Gabriel Canyon from Morris Dam to Foothill
Boulevard is contained in Appendix E. A variety of biological surveys were utilized to characterize the
range of wildlife species (vertebrates) that are known, or reasonably expected to occur within the City
boundaries. The Draft Environmental Impact Report for Mountain Cove Residential Development
Project, October 1999 and the Monrovia Nursery Specific Plan Draft Environmental Impact Report,
October 2002 were also referenced.
ENVIRONMENTAL SETTING
Current Conditions
Vegetation. The majority of Azusa is urbanized. Relatively natural vegetation communities and habitats
for wildlife are largely limited to the remaining undeveloped floodplain of the San Gabriel River and
tributaries including Van Tassel Canyon, upper Fish Canyon, Roberts Canyon, and the upland foothill areas
of the San Gabriel Mountains that occur in the northern portion of the City.
The foothills, adjoining the Angeles National Forest, contain a variety of species depending primarily on
aspect and slope. The different habitats present in the foothills are displayed in Figure 4.4-1 and those in
the southern portion of the city in Figure 4.4-2. Steep, south-facing slopes on the north and west sides of
the San Gabriel River support rather sparse vegetation which would be classified as coastal sage scrub,
with the dominants being coastal sagebrush (Artemisia californica), California buckwheat (Eriogonum
fasciculatum), California brickellbush (Brickellia californica), Whipple’s yucca (Yucca whipplei ssp.
parishii), white sage (Salvia apiana), wishbone bush (Mirabilis californica) and local dense patches of
prickly-pear cactus (Opuntia littoralis), with scattered larger shrubs of laurel-leaf sumac (Malosma
laurina) and lemonadeberry (Rhus integrifolia ). In some locations, such as the slopes adjacent to the Fish
Canyon trailhead and quarry, the noxious castor bean (Ricinus communis) has severely invaded the dry
slopes.
On the north-facing slopes, especially on the north side of the Glendora Ridge and upper areas of Fish,
Van Tassel and Roberts Canyons, a denser, chaparral vegetation prevails. On these moderately moist
slopes, trees and larger shrubs can be found such as mountain mahogany (Cercocarpus betuloides), toyon
(Heteromeles arbutifolia ), Jim brush (Ceanothus oliganthus sorediatus), and scattered individuals of big
leaf maple (Acer macrophyllum) and big cone Douglas Fir (Pseudotsuga macrocarpa).
1
Field surveys conducted by Carl Wishner, Principal Biologist of Envicom Corporation.
White, Scott. Characterization of the San Gabriel River Wash, 1997, Scott White Biological Consulting.
2
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Figure 4.4-1
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The north facing slopes are also the known habitat of sensitive, endemic (occurring naturally in only a
particular region) species such as San Gabriel River dudleya (Dudleya cymosa crebrifolia ) and San
Gabriel Mountains dudleya (D. densiflora). Heretofore unreported is the extensive occurrence of
chaparral dominated by San Gabriel leather oak (Quercus durata gabrielensis) on the north slopes south
of Fish Canyon. This species is endemic to the San Gabriel Mountains. As reported by the California
Department of Fish and Game (1999b), the canyon bottoms of Van Tassel, Fish, and Roberts Canyons
support Southern Sycamore/Alder Riparian Woodland, the dominants being western Sycamore (Platanus
racemosa), white alder (Alnus rhombifolia), and probably also coast live oak (Quercus agrifolia) and
canyon live oak (Q. chrysolepis).
For the San Gabriel River, the extent of natural vegetation is restricted west of the levee, as it exits from
the mouth of San Gabriel Canyon. The vegetation near the mouth of the canyon consists of alluvial scrub
and woodland, wherein the dominant species are those typical of coastal sage scrub and riparian habitats,
namely coastal sagebrush, brittlebush (Encelia farinosa), golden aster (Heterotheca sessiliflora),
California buckwheat, scalebroom (Lepidospartum squamatum), laurel-leaf sumac, lemonadeberry,
mulefat (Baccharis salicifolia), and willow (Salix spp.). In the lower-most reach, upstream from the
Foothill Boulevard Bridge, the invasive giant reed (Arundo donax) is prevalent, whereas, in the upstream
portions, the native specie s dominate, with increasing amounts of Whipple’s yucca imparting a unique
appearance to the alluvial scrub there. The plants and their location described are summarized in Table
4.4-1.
TABLE 4.4-1: HABITATS
Location
Vegetation Association
Dominant Species
South Facing Slope
South Slope Coastal Sage Scrub
North Facing Slope
North Slope Chapparal
River and/or Tributaries
Alluvial Scrub and Woodland
Canyon Bottom
Southern Sycamore/Alder
Riparian Woodland
coastal
sagebrush,
California
buckwheat,
California brickellbush, Whipple’s yucca, white
sage, wishbone bush, prickly-pear cactus, laurelleaf sumac, and lemonadeberry, castor bean*
mountain mahogany, toyon, Jim brush, big leaf
maple, big cone Douglas fir, San Gabriel River
dudleya, San Gabriel Mountains dudleya
coastal sagebrush, brittlebush, golden aster,
California buckwheat, scalebroom, laurel-leaf
sumac, mulefat, willow, giant reed*
Sycamore, white alder, coast live oak, canyon live
oak
*Non-native, invasive species
SOURCE: Envicom Corporation, 1999.
Wildlife
Table 4.4-2 states in general terms the habitat in which the various animals exist and includes wildlife
species commonly found in Azusa. Different animals use different amounts of space to fulfill their need
for food, water, and cover. Small mammals, such as a mouse, need a limited area in which to survive
while larger mammals like a fox, coyote, or bear will roam larger amounts of territory in search of
essentials. Depending on the time of year, there may be more species present in the City. In the spring,
fall, and during yearly migrations, a greater number of birds are present in the City’s habitats. In
addition, although not mentioned as a specific habitat in the table below, inactive quarries in the northern
part of the City filled with open water, serve as a groundwater recharge area and provide habitat for
wildlife, especially waterfowl.
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TABLE 4.4-2: WILDLIFE FOUND IN AZUSA
Species Group and Habitat
Fishes occurring in the San Gabriel River and
surrounding reservoirs
Amphibians occurring the San Gabriel River and
tributaries
Amphibians occurring in north slope chaparral and
canyon bottoms
Reptiles occurring in coastal sage scrub and chaparral
Typically Occurring Species
Rainbow trout, green sunfish, large mouth bass, carp
Pacific slender salamander, black-bellied salamander,
Pacific and California treefrogs
Pacific slender salamander and Pacific treefrog
Birds occurring in coastal sage scrub and chaparral
Birds occurring in native woodlands
Mammals occurring in coastal sage scrub and chaparral
Western fence lizard, side-blotched lizard, western skink,
California whipsnake, gopher snake, western
rattlesnake, southern alligator lizard, common kingsnake,
Gilbert skink, San Diego banded gecko, rosy boa,
western whiptail, ringneck snake, racer, western patchnosed snake
California towhee, spotted towhee, wrentit, bushtit,
Bewick’s wren, Cactus wren, California quail, Anna’s
hummingbird, western scrub-jay, Northern mockingbird,
California thrasher, black phoebe, house finch
Northern flicker, mourning dove, acorn woodpecker,
house wren, Hutton’s vireo, lesser goldfinch, American
crow, common raven
Audubon’s cottontail, California ground squirrel, Botta’s
pocket gopher, deer mouse, desert woodrat, Pacific
kangaroo rat, ornate shrew, California mouse, duskyfooted wood rat, black-tailed jack rabbit, raccoon, coyote,
striped skunk, gray fox, bobcat, mountain lion, American
black bear
SOURCE: Bon Terra Consulting as cited in the Draft Environmental Impact Report for Mountain Cov e Residential Development Project and Glenn
Lukos Associates, October 1999. Biological Technical Report Monrovia Nursery Development Project Los Angeles County, California, September
2002, as cited in the Monrovia Nursery Specific Plan and Project Draft Environmental Impact Report, October 2002.
Sensitive Species and Habitats
The “sensitive” or “special” label denotes that a species is state or federally listed as threatened or
endangered, is a potential candidate for state or federal listing as threatened or endangered, or, though not
listed, may be near extirpation or extinction, and is being monitored. The California Natural Diversity
Database Rarefind application was run for the City and surrounding area (Azusa and Baldwin Park
quadrangles) in June 1999 and updated as of May 2003.
The State and federal classifications for sensitive species include the following:
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SA Special Animal (tracked by California Natural Diversity Database)
CE California listed as Endangered
CT California listed as Threatened
CP California Protected
CFP California Fully Protected
CSC California Special Concern Species
FE Federally listed as Endangered
FPE Federally proposed for listing as Endangered
FT Federally listed as Threatened
FSC Federal Special Concern species
CNPS 1 B California Native Plant Society “plant rare, threatened, or endangered in California and
elsewhere”
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CNPS 2 California Native Plant Society “plant rare, threatened, or endangered in California and
but more common elsewhere”
MNBMC Migratory Nongame Birds of Management Concern (US Fish and Wildlife Service)
The list of sensitive species in and around the near vicinity of Azusa is composed of 95 sensitive
butterfly, fish, amphibian, reptile, bird, mammal, plant species and certain habitats, all of which are
designated as one or more of the above classifications. Six of the species are federally endangered. They
are the Quino checkerspot butterfly, the southern steelhead trout, the unarmored threespine stickleback
(fish), the Least Bell’s vireo (bird), and two plant species, Braunton’s milkvetch and slender-horned
spineflower. Other species among the list, though not federally protected, are fully protected under
California state law. For a complete listing of the sensitive species including the most recent update, see
Appendix E of this EIR.
SIGNIFICANCE CRITERIA
The proposed project would result in a significant impact if it results in any of the following:
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A substantial adverse impact, either directly or indirectly through habitat modifications, on any species
identified as a candidate, sensitive, or special status species in local or regional plans, policies, or
regulations, or by the California Department of Fish and Game or United States Fish and Wildlife
Service;
A substantial adverse effect on any riparian habitat or other sensitive natural community identified in
local or regional plans, policies, regulations or by the California Department of Fish and Game or the
U.S. Fish and Wildlife Service;
A substantial adverse effect on federally protected wetlands, as defined by Section 404 of the Clean
Water Act, (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal,
filling, hydrological interpretation, or other means;
Substantial interference with the movement of any native resident or migratory fish, wildlife species,
established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery
sites;
A conflict with any local policies or ordinances protecting biological resources, such as a tree
preservation policy or ordinance; or
A conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community
Conservation Plan, or other approved local, regional, or state habitat conservation plan.
ENVIRONMENTAL IMPACTS
The Azusa General Plan Update sets forth numerous policies to protect the vegetation and habitats that
are part of the City. The first goal of the General Plan Open Space and Biological Resources section is to
“conserve and protect nature.” The associated policies, 1.1 and 1.2, include the establishment of a
biological resource database, including types of habitats and the creation of a detailed Biological
Resource Area (BRA) Overlay Zone map.
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Figure 4.4-3 BRA’s
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A map of the potential BRA’s is shown in Figure 4.4-3. The BRA’s would ideally connect at some part
to form wildlife corridors so that wildlife could move through uninterrupted tracts of land. Within many
of the BRA’s, City Nature Preserves would also be created. Additionally, the City would seek, where
possible, to restore habitats within nature preserves for rare, threatened and/or endangered species that are
believed to have gone extinct within the City and/or Sphere of Influence as stated in Policy 2.3.
Open Space and Biological Resources policies related to preservation include the following:
1.1
Ensure that the City has accurate, current data and information on biological resources, including
the types of habitats, individual species, and their locations.
1.2
Create a detailed Biological Resource Area (BRA) Overlay Zone Map using Figure Bio-3 as a
guide.3 Biological Resource Areas include 1) Van Tassel Canyon and Ridgelines, 2) Fish Creek,
Fish/Roberts Ridge, 3) Glendora Ridge 4) San Gabriel Canyon Floodplain, 5) RV Park, 6)
Northern Recharge Ponds, and 7) San Gabriel River and Floodway. The BRA’s purpose is to
ensure maintenance of ecological integrity, including connections between habitats for wildlife
movement and dispersal, and to concentrate development in areas that are the least biologically
sensitive, and absent of protected and other sensitive species, etc.
2.1
Establish, by working with conservation and educational organizations and state and federal
agencies, a multitude of City Nature Preserves. These City Nature Preserves should consist of
contiguous and diverse habitat areas within identified undeveloped areas. Areas of high priority
include 1) Van Tassel Canyon and Ridgelines, 2) Fish Creek, Fish/Roberts Ridge, 3) Glendora
Ridge, 4) San Gabriel Canyon Floodplain, 5) RV Park, 6) Northern Recharge Ponds, and 7) San
Gabriel River and Floodway.
2.3
Coordinate with the California Department of Fish and Game and the United States Fish and
Wildlife Service to determine the feasibility of restoring habitats within nature preserves for
rare, threatened, and/or endangered species and those species of wildlife that are believed to
have gone extinct in the Planning Area.
According to the proposed land use map, the growth of Azusa over the next 25 years would occur in
already developed areas, limiting habitat modification of the remaining undisturbed lands. Specific
policies of the proposed General Plan under the Open Space and Biological Resources section as well as
the Recreation and Cultural and Historic Resources sections provide for the protection of the San Gabriel
River and watershed. The riparian habitat of the San Gabriel River would be enhanced and maintained
for its ecologic, natural aesthetic, cultural and recreational value.
Policies specific to the San Gabriel River include:
5.1
3
Continue and expand the City’s leadership role in protecting and enhancing the San Gabriel River
and Watershed through the establishment of nature centers and educational and interpretative
programs, exotic weedy species control, sponsorship and participation in environmental
education, and other activities such as habitat restoration, flood and fire prevention, recreation
planning.
Figure Bio-3 is part of the proposed City of Azusa General Plan. It is not included in this document.
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Recreation
5.1
Enhance local foothills and river areas because of their inherent environmental, ecological,
and/or aesthetic contributions to the community and the region.
Cultural and Historic Resources
2.1
Combine historically and culturally significant sites such as those on the proposed landmarks list
with recreational learning opportunities. Examples may include the Santa Fe Depot, the
Woman’s Club, the citrus processing buildings, and the Durrell Building.
3.2
Incorporate natural resources such as the San Gabriel River drainage into development when
appropriate as a means of understanding and appreciating the history of the site or the area. This
may include the mining activities and any prehistoric sites that may be encountered during
subsequent studies of drainage.
The proposed General Plan would not conflict with any Habitat Conservation or Natural Community
Conservation Plans because none is currently in place. Since the policies and programs of the proposed
General Plan promote the preservation of Azusa’s biological resources, no impact is anticipated.
MITIGATION MEASURES
Since no impact to biological resources is anticipated, no mitigation measures are recommended.
LEVEL OF IMPACT AFTER MITIGATION
No significant impacts to biological resources are anticipated.
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