Temecula City Council
May 24, 2022

Plant Species
The MSHCP lists 23 rare plant species that have a potential to occur in Riparian/Riverine and/or Vernal Pool habitats within the MSHCP Plan Area, which are listed below in Table 4, MSHCP Riparian/Riverine and Vernal Pool Plant Species. Of these, 17 species were determined to have no potential to occur within the study area based on geographic range, elevation range, and/or lack of suitable habitat on the study area. Although the study area is within the geographic range and supports potentially suitable habitat, Southern California black walnut (Juglans californica) is a conspicuous tree species and was not observed within the study area during any of the site visits. Of the remaining five species, smooth tarplant (Centromadia pungens ssp. laevis) was observed within Drainage A2.1 in the northern portion of the study area during the general biological survey. The remaining four species (Orcutt’s brodiaea [Brodiaea orcuttii], Prostrate navarretia [Navarretia prostrata], spreading [Navarretia fossalis], and vernal barley [Hordeum intercedens]) have a low potential to occur based on the presence of some wetland habitat (see Appendix F). A list of plant species observed during the field surveys is provided as Appendix A.

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21 Table 4

MSHCP RIPARIAN/RIVERINE AND VERNAL POOL PLANT SPECIES
Common Name Scientific Name Habitat
Brand’s phacelia Phacelia stellaris Sandy washes and/or benches in alluvial flood plains.

California Orcutt grass Orcuttia californica Vernal pools.

Coulter’s matilija poppy Romneya coulteri
Dry washes and canyons in
chaparral and coastal sage scrub
communities and disturbed areas.

Engelmann oak Quercus engelmannii Woodlands, mixed chaparral, and savannah grasslands.

Fish’s milkwort Polygala cornuta var. fishiae
Shaded, rocky places in canyons
associated with woodlands and
chaparral.
graceful tarplant Holocarpha virgata ssp.
elongata
Coastal mesas and foothills with
grassland habitats.
lemon lily Lilium parryi Moist montane meadows.

Mojave tarplant Deinandra mohavensis Drainages within arid montane chaparral.
mud nama Nama stenocarpum
Marshes, swamps, lake margins,
and riverbanks along muddy
embankments.
ocellated Humboldt lily Lilium humboldtii ssp. ocellatum Shaded montane canyons.

Orcutt’s brodiaea Brodiaea orcuttii
Vernally moist grasslands and
vernal pools; occasionally occurs
along stream embankments within
clay soils.

Parish’s meadowfoam Limnanthes gracilis var. parishii
Montane meadows with abundant
annual and herbaceous perennials
and lack of shrubs.
prostrate navarretia Navarretia prostrata Coastal sage scrub, valley and foothill grassland, and vernal pools.

San Diego button-celery Eryngium aristulatum var.
parishii Vernal pools.

San Jacinto Valley crownscale Atriplex coronata var. notatior Highly alkaline and silty-clay soils
associated with alkali sink scrub,
alkali playa, vernal pool, and annual
alkali grassland habitats.

San Miguel savory Clinopodium chandleri
Coastal sage scrub, chaparral,
cismontane woodland, riparian
woodland, and valley and foothill
grasslands.

Santa Ana River woolly-star Eriastrum densifolium spp.
sanctorum
Sandy soils on flood plains and
terraces within coastal scrub and
chaparral communities.
slender-horned spineflower Dodecahema leptoceras
Sandy soil associated with alluvial
scrub; is often found on stream
terraces and banks.
smooth tarplant Centromadia pungens ssp. laevis
Alkali scrubs, playas, and
grasslands; riparian woodland and
streams.

22 Table 4 (cont.)

MSHCP RIPARIAN/RIVERINE AND VERNAL POOL PLANT SPECIES
Common Name Scientific Name Habitat
spreading navarretia Navarretia fossalis Vernal pools, depressions, and ditches.
southern California black
walnut Juglans californica
Open savannahs, creek beds,
alluvial terraces, and north-facing
slopes.
thread-leaved brodiaea Brodiaea filifolia
Clay soils in vernally moist
grasslands and vernal pool
periphery are typical locales.
vernal barley Hordeum intercedens Saline flats and depressions in grasslands or vernal pools.

Source: Dudek (2003).

Animal Species
The MSHCP lists 12 sensitive animal species that have a potential to occur in Riparian/Riverine and/or Vernal Pool habitats within the MSHCP Plan Area, which are listed in Table 5, MSHCP Riparian/Riverine and Vernal Pool Animal Species. The MSHCP requires focused surveys to be conducted for projects that propose impacts to three invertebrates and three bird species, as described in detail below. The study area supports suitable habitat for two of the sensitive bird species (LBVI and SWFL).

Table 5

MSHCP RIPARIAN/RIVERINE AND VERNAL POOL ANIMAL SPECIES
Common Name Scientific Name Habitat
Riverside fairy shrimp Streptocephalus woottoni
Deep vernal pools and other
ephemeral basins that hold water for
typically 30 or more days.

Santa Rosa Plateau fairy shrimp Linderiella santarosae Limited to vernal pools within the Santa Rosa Plateau.
vernal pool fairy shrimp Branchinecta lynchi
Vernal pools and other ephemeral
basins within patches of grassland and
agriculture interspersed in coastal sage
scrub and chaparral.
arroyo toad Anaxyrus californicus Washes and intermittent streams with open-canopy riparian forest.

California red-legged frog Rana aurora draytonii Perennial streams with dense, shrubby riparian vegetation.
mountain yellow-legged frog Rana muscosa Perennial waterways, often within open riparian vegetation.

Santa Ana sucker Catostomus santaanae
Clear, cool perennial streams with
loose sand, gravel, cobble, and
boulders with algae, aquatic emergent
vegetation, macroinvertebrates, and
riparian vegetation.
bald eagle Haliaeetus leucocephalus Within close proximity to lakes or other water bodies.
least Bell’s vireo Vireo bellii pusillus Well-developed riparian scrub, woodland, or forest.

23 Table 5 (cont.)

MSHCP RIPARIAN/RIVERINE AND VERNAL POOL ANIMAL SPECIES
Common Name Scientific Name Habitat
peregrine falcon Falco peregrinus
Generally, areas with cliffs or tall
buildings near water where prey
(shorebirds and ducks) is concentrated.
southwestern willow flycatcher Empidonax traillii extimus Breeds within thickets of willows or
other riparian understory usually along
streams, ponds, lakes, or canyons.
western yellow-billed cuckoo Coccyzus americanus
occidentalis
Extensive stands of mature riparian
woodland.

Source: Dudek (2003).

Invertebrates
There are three sensitive fairy shrimp species that occur in the MSHCP Plan Area, including Riverside fairy shrimp (Streptocephalus woottoni), Santa Rosa Plateau fairy shrimp (Linderiella santarosae), and vernal pool fairy shrimp (Branchinecta lynchi). Vernal pool fairy shrimp occurs throughout the Central Valley and in several disjunct populations in the County. This species exists in vernal pools and other ephemeral basins, often located in patches of grassland and agriculture interspersed in coastal sage scrub and chaparral. Riverside fairy shrimp occurs in Riverside, Orange, and San Diego Counties as well as in northern Baja California, Mexico. This species is typically found in deeper vernal pools and other ephemeral basins that hold water for long periods of time (30 or more days). Santa Rosa Plateau fairy shrimp is limited to the Santa Rosa Plateau in the County.

The MSHCP requires focused surveys to be conducted for projects that propose impacts to suitable habitat for the three sensitive fairy shrimp species discussed above. The study area does not support suitable habitat for fairy shrimp species; therefore, no focused surveys were required.

Birds
Riparian/Riverine Areas within the MSHCP Plan Area provide suitable habitat for sensitive bird species, such as LBVI, SWFL, western yellow-billed cuckoo (Coccyzus americanus occidentalis), bald eagle (Haliaeetus leucocephalus), and peregrine falcon (Falco peregrinus). Typical habitat for LBVI consists of well-developed riparian scrub, woodland, or forest dominated by willows, mule fat, and Fremont cottonwood. LBVI will also use small patches of trees adjacent to dense, riparian habitat. Southwestern willow flycatcher and western yellow-billed cuckoo require mature riparian forest with a stratified canopy and nearby water. Both the bald eagle and peregrine falcon occur primarily in and adjacent to open water habitats, with peregrine falcon occurring in riparian areas.

The MSHCP requires focused surveys to be conducted for projects that propose impacts to suitable habitat for LBVI, southwestern willow flycatcher, and western yellow-billed cuckoo. The study area supports suitable habitat for LBVI and SWFL; therefore, focused surveys were required. As discussed in Section 3.6.2 above, four males and one pair of LBVIs were observed within suitable habitat on the study area. Focused surveys for SWFL were negative.

24 3.7.3 Narrow Endemic Plant Species Survey Area (MSHCP Section 6.1.3) The MSHCP requires focused plant surveys to be conducted for projects located within a Narrow Endemic Plant Species Survey Area (NEPSSA). There are 14 narrow endemic plant species that are associated with 10 different NEPSSAs located throughout the MSHCP Plan Area (see Table 6-1 in the MSHCP). The MSHCP requires a habitat assessment for projects located within a NEPSSA to determine whether the study area supports suitable habitat for plant species listed for the NEPSSA species.

Focused surveys for species listed for the NEPSSA must be conducted if suitable habitat is present. If focused surveys are positive, 90 percent of the property that supports habitat suitable for long-term conservation of the species must be avoided until conservation goals for the species are satisfied.

The study area is not within a NEPSSA; therefore, focused NEPSSA surveys were not required.

3.7.4 Additional Survey Needs and Procedures (MSHCP Section 6.3.2) The MSHCP requires additional surveys for projects that support suitable habitat for certain conditionally-covered species. The survey results provide species-specific information in order for the MSHCP to satisfy the Federal Endangered Species Act (FESA) issuance criteria. If focused surveys are positive for conditionally-covered species, 90 percent of the property that supports habitat suitable for long-term conservation of the species must be avoided until conservation goals for the species are satisfied. Additional survey requirements are discussed in detail below.

3.7.4.1 Criteria Area Species
Focused surveys for rare plant species must be conducted for projects located within a Criteria Area Species Survey Area (CASSA). There are 13 criteria area species, which are associated with eight CASSAs located throughout the MSHCP Plan Area (see Table 6-1 in the MSHCP). Prior to conducting focused surveys, a habitat assessment should be conducted to determine whether the study area supports suitable habitat for plant species listed for the CASSA. If suitable habitat is present, focused surveys for species listed for the CASSA should be conducted.

The study area is not within a CASSA; therefore, focused CASSA surveys were not required.

3.7.4.2 Amphibian Species
Focused surveys for arroyo toad (Bufo californicus), California red-legged frog (Rana draytonii), and mountain yellow-legged frog (Rana muscosa) must be conducted for projects located within an Amphibian Species Survey Area.

The study area is not within the Amphibian Species Survey Area; therefore, focused surveys were not required.

3.7.4.3 Bird Species
The study area is located within the BUOW Survey Area. Therefore, BUOW focused surveys were required in accordance with the County’s survey protocol (County 2006). As discussed in Section 3.6.2, no BUOWs or BUOW sign were observed during the focused surveys.

25 3.7.4.4 Mammal Species
Focused surveys for Aguanga kangaroo rat (Dipodomys merriami collinus), San Bernardino kangaroo rat (Dipodomys merriami parvus), and Los Angeles pocket mouse (Perognathus longimembris brevinasus) must be conducted for projects located within a Mammal Species Survey Area.

The study area is not within the Mammal Species Survey Area; therefore, focused surveys were not required.

4.0 REGIONAL AND REGULATORY CONTEXT
Biological resources located within the study area are subject to regulatory review by federal, state, and local agencies. Biological resources-related laws and regulations that apply to the project include the FESA, Migratory Bird Treaty Act (MBTA), CWA, California Endangered Species Act (CESA), and CFG Code.

4.1 FEDERAL REGULATIONS

4.1.1 Federal Endangered Species Act
Administered by the USFWS, the FESA provides the legal framework for the listing and protection of species (and their habitats) identified as being endangered or threatened with extinction. Actions that jeopardize endangered or threatened species and the habitats upon which they rely are considered a “take” under the FESA. Section 9(a) of the FESA defines take as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or attempt to engage in any such conduct.” “Harm” and “harass” are further defined in federal regulations and case law to include actions that adversely impair or disrupt a listed species’ behavioral patterns.

Sections 4(d), 7, and 10(a) of the FESA regulate actions that could jeopardize endangered or threatened species. Section 7 describes a process of federal interagency consultation for use when federal actions may adversely affect listed species. A biological assessment is required for any major construction activity if it may affect listed species. In this case, take can be authorized via a letter of biological opinion issued by the USFWS for non-marine related listed species issues. A Section 7 consultation is required when there is a nexus between federally listed species’ use of the site and impacts to USACE jurisdictional areas. Section 10(a) allows issuance of permits for “incidental” take of endangered or threatened species. The term “incidental” applies if the taking of a listed species is incidental to and not the purpose of an otherwise lawful activity. The MSHCP is the Section 10(a) permit for the City, which includes the study area.

4.1.2 Federal Clean Water Act, Section 404
Federal wetland regulation (non-marine issues) is guided by the Rivers and Harbors Act of 1899 and the CWA. The Rivers and Harbors Act deals primarily with discharges into navigable waters, while the purpose of the CWA is to restore and maintain the chemical, physical, and biological integrity of all waters of the U.S. Permitting for projects filling waters of the U.S., including wetlands and vernal pools, is overseen by USACE under Section 404 of the CWA. Projects may be permitted on an individual basis or may be covered under one of several approved Nationwide Permits. Individual Permits are assessed individually based on the type of action, amount of fill, etc. Individual Permits typically require

26 substantial time (often longer than six months) to review and approve, while Nationwide Permits are pre-approved if a project meets the appropriate conditions. A CWA Section 401 Water Quality Certification, which is administered by the State Water Resources Control Board, must be issued prior to any 404 Permit.

4.1.3 Migratory Bird Treaty Act
All migratory bird species that are native to the United States or its territories are protected under the Federal MBTA, as amended under the Migratory Bird Treaty Reform Act of 2004 (FR Doc. 05-5127). The MBTA is generally protective of migratory birds but does not actually stipulate the type of protection required. In common practice, the MBTA is used to place restrictions on disturbance of active bird nests during the nesting season, which is generally defined as March 1 to August 31. In addition, the USFWS commonly places restrictions on disturbances allowed near active raptor nests (January 15 to August 31).

4.1.4 Critical Habitat
As described by the FESA, critical habitat is the geographic area occupied by a threatened or endangered species essential to species conservation that may require special management considerations or protection. Critical habitat also may include specific areas not occupied by the species but that have been determined to be essential for species conservation.

Critical habitat does not occur on the study area. The nearest critical habitat to the study area includes San Diego ambrosia (Ambrosia pumila), which is approximately 0.8 mile to the south of the study area (USFWS 2021).

4.2 STATE REGULATIONS

4.2.1 California Environmental Quality Act
Primary environmental legislation in California is found in CEQA and its implementing guidelines (State CEQA Guidelines), which require that projects with potential adverse effects (i.e., impacts) on the environment undergo environmental review. Adverse environmental impacts are typically mitigated as a result of the environmental review process in accordance with existing laws and regulations.

4.2.2 California Endangered Species Act
The CESA is similar to the FESA in that it contains a process for listing species and regulating potential impacts to listed species. Section 2081 of the California ESA authorizes the CDFW to enter into a memorandum of agreement for take of listed species for scientific, educational, or management purposes. The MSHCP is the regional 2081 for this portion of the County, which includes the study area.

The golden eagle (Aquila chrysaetos) and white-tailed kite are considered state fully protected species.

Fully protected species may not be taken or possessed at any time, and no state licenses or permits may be issued for their take except for collecting the species necessary for scientific research and relocation of the bird species for the protection of livestock (Fish and Game Code Sections 3511, 4700, 5050, and 5515).

27 The Native Plant Protection Act (NPPA) enacted a process by which plants are listed as rare or endangered. The NPPA regulates the collection, transport, and commerce of plants that are listed. The California ESA followed the NPPA and covers both plants and animals that are determined to be endangered or threatened with extinction. Plants listed as rare under NPPA were designated threatened under the California ESA.

4.2.3 Protection of Raptor Species
Raptors (birds of prey) and owls and their active nests are protected by California Fish and Game Code Section 3503.5, which states that it is unlawful to take, possess, or destroy any birds of prey or to take, possess, or destroy the nest or eggs of any such bird unless authorized by the CDFW.

4.2.4 California Fish and Game Code, Section 1602
The California Fish and Game Code (Section 1600 et seq.) requires an agreement with the CDFW for projects affecting riparian and wetland habitats through the issuance of a Streambed Alteration Agreement.

4.3 LOCAL REGULATIONS

4.3.1 Multiple Species Habitat Conservation Plan Consistency The MSHCP is a comprehensive multi-jurisdictional effort that includes the City and multiple other cities throughout the western portion of the County. Rather than addressing sensitive species on an individual basis, the MSHCP focuses on the conservation of 146 species, proposing a reserve system of approximately 500,000 acres and a mechanism to fund and implement the reserve system (Dudek 2003). Most importantly, the MSHCP allows participating entities to issue take permits for listed species so that individual applicants need not seek their own permits from the USFWS and/or CDFW. The MSHCP was adopted on June 17, 2003, by the County Board of Supervisors. The Incidental Take Permit was issued by both the USFWS and CDFW on June 22, 2004. Section 3.6 above and Section 5.6 below demonstrate the project’s consistency with the MSHCP.

4.3.2 Stephens’ Kangaroo Rat Habitat Conservation Plan
The SKR HCP describes the conservation, mitigation, and monitoring measures that are implemented within core reserves. Within the HCP, there are seven core reserves, totaling 41,221 acres for conservation of SKR and associated habitat. The HCP provides a 30-year incidental take authorization for SKR on lands within its boundaries, which includes 533,954 acres within the County and the Cities of Corona, Hemet, Lake Elsinore, Moreno Valley, Murrieta, Perris, Riverside, and Temecula.

The study area is within the SKR HCP but is not located within any of the core reserves. Therefore, the project is required to pay a mitigation fee for incidental take authorization under the SKR HCP.

4.3.3 Protection of City Street Trees
The City has implemented regulatory measures to protect street trees. Ord. 09-05 § 1, Chapter 8.48 of the Temecula Municipal Code states “no person shall cut, remove, or relocate a Heritage Tree, or encroach into the protected zone of any Heritage Tree without first obtaining a Heritage Tree Removal

28 or Relocation Permit from the city in accordance with the provisions of this Ordinance.” Conditions of the permit may include the relocation or replacement of any trees removed. One or more trees of the same kind or type may be acceptable as replacement. Final permit conditions will be specified in the Heritage Tree Removal and/or Relocation Permit.

5.0 PROJECT EFFECTS
This section describes potential direct and indirect impacts associated with the proposed project. Direct impacts immediately alter the affected biological resources such that those resources are eliminated temporarily or permanently. Indirect impacts consist of secondary effects of a project, including noise, decreased water quality (e.g., through sedimentation, urban contaminants, or fuel release), fugitive dust, colonization of non-native plant species, animal behavioral changes, and night lighting. The magnitude of an indirect impact can be the same as a direct impact; however, the effect may take a longer time to become apparent.

The significance of impacts to biological resources present, or those with potential to occur, was determined based upon the sensitivity of the resource and the extent of the anticipated impacts. For certain highly sensitive resources (e.g., a federally listed species), any impact would be significant.

Conversely, other resources that are of low sensitivity (e.g., species with a large, locally stable population in the County but declining elsewhere) could sustain some impact with a less than significant effect.

According to Appendix G of the CEQA Guidelines, project impacts to biological resources would be considered significant if they would:
(a) Have a substantial adverse effect, either directly or 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 CDFW or USFWS.
(b) Have a substantial adverse effect on any riparian habitat or sensitive natural community identified by local or regional plans, policies, regulations, or by CDFW or USFWS. (c) Have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the CWA (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling hydrological interruption, or other means.
(d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident, or migratory wildlife corridors or impede the use of native wildlife nursery sites.
(e) Conflict with local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance.
(f) Conflict with provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.

29 5.1 SENSITIVE SPECIES

5.1.1 Rare Plant Species
Less than Significant with Mitigation Incorporated
A total of 17 of the 29 rare plant species recorded within the vicinity of the study area were not considered to have a potential to occur based on geographic range, elevation range, and/or lack of suitable habitat (see Appendix E). Of the remaining 12 species, nine of the species with a potential to occur are either fully or conditionally covered species under the MSHCP. The species include Coulter’s goldfields, little mousetail, long-spined spineflower, Orcutt’s brodiaea, Parry’s spineflower, prostrate vernal pool navarretia, San Diego ambrosia, spreading navarretia, and vernal barley. Since the study area is not located within a NEPSSA or CASSA, focused surveys were not warranted, and project impacts (if present) would be covered.

One Riparian/Riverine plant species (smooth tarplant) was observed within Drainage A2.1 in the northern portion of the study area. Smooth tarplant is a conditionally covered species under the MSHCP.

Surveys for this species are required if a project occurs within a CASSA 1, 2,3, or 4. Since the study area is not located within a CASSA, impacts to this species would be covered under the MSHCP.

Two species (alkali marsh aster and San Bernardino aster) are considered to have a low potential to occur on the study area and are not covered under the MSHCP. Alkali marsh aster is a CRPR 2B.2 species and San Bernardino aster is a CRPR 1B.2 species. Although potentially suitable habitat is present, these two species are not expected to occur since records within the vicinity of the study area are historical records from the early 1900s. There are no recent observations of alkali marsh aster in Riverside County.

The most recent observation of San Bernardino aster in Riverside County was 2015 in the San Jacinto Mountains, approximately 29 miles to the northeast of the project site.

5.1.2 Sensitive Animal Species
Less than Significant Impacts with Mitigation Incorporated Of the 29 sensitive animal species recorded within the vicinity of the study area, 15 species were considered to have no potential to occur on the study area due to lack of suitable habitat (see Appendix F). Therefore, no significant impacts to these sensitive wildlife species are anticipated by the project. Fourteen of the remaining 29 species (in addition to SWFL) were determined to have a potential to occur on the study area. Potential project impacts to these species are discussed in detail below.

Low Potential Species
Four species have a low potential to occur based on the presence of low quality and isolated habitat, limited acreage of habitat, surrounding development, and lack of recent observations within the immediate vicinity of the study area. These species include coast range newt, San Diego black-tailed jackrabbit, Swainson's hawk (foraging potential only), and western mastiff bat (foraging potential only).

30 Coast range newt, San Diego black-tailed jackrabbit, and Swainson’s hawk are fully covered species under the MSHCP. With payment of the MSHCP Local Development Mitigation Fee (LDMF), no additional mitigation is required for potential impacts to these species.

Western mastiff bat is not an MSHCP covered species and does not carry a federal or state listing as threatened or endangered. This species is listed as SSC by CDFW. The study area does not support suitable roosting habitat for this species. There is some potential for foraging habitat on the study area, although the habitat is considered low quality based on the presence of surrounding development. The nearest observation recorded on CNDDB was made in 2001, approximately 0.25 mile to the southeast of the study area (CDFW 2021). Based on the presence of surrounding development, lack of recent observations, and absence of suitable roosting habitat, no significant impacts to western mastiff bat are anticipated by the project.

Moderate Potential Species
Six species were determined to have a moderate potential to occur based on the presence of suitable habitat and recent observations within the vicinity of the study area. These include red diamond rattlesnake, Southern California legless lizard, southwestern pond turtle, SKR, two-striped gartersnake, and western spadefoot.

Red diamond rattlesnake, southwestern pond turtle, and western spadefoot are fully covered species under the MSHCP. With payment of the MSHCP Local Development Mitigation Fee (LDMF), no additional mitigation is required for potential impacts to these species.

SKR is a fully covered species under the MSHCP. In addition, the study area is located within the SKR HCP and is required to pay an SKR mitigation fee for incidental take authorization under the SKR HCP. See Section 5.6.7 below for a more detailed discussion.

Southern California legless lizard and two-striped gartersnake are SSC and are not covered species under the MSHCP. Although the study area supports potentially suitable habitat for these species, the habitat is considered low quality due to its small extent and heavily disturbed surrounding areas. The project would impact less than 0.5 acre of potentially suitable habitat, which overlaps with CDFW jurisdictional areas. Since the study area supports low quality habitat, the study area is not expected to support large populations of these species. If present, a loss of a few individuals would not be expected to reduce regional population numbers. Impacts to these species would be considered less than significant, and no mitigation measures are considered required.

High Potential Species
Coastal whiptail and white-tailed kite are fully covered species under the MSHCP. With payment of the MSHCP Local Development Mitigation Fee (LDMF), no additional mitigation is required for potential impacts to these species. Direct and/or indirect impacts to white-tailed kite during the nesting season (January 15 through August 31) would be avoided by implementing Measure Bio-4 (see Section 5.4.2 below).

31 Presumed Absent
BUOW and SWFL are conditionally covered species under the MSHCP. Focused surveys were conducted in 2020. Survey results were negative, and these species are presumed absent from the study area (Appendices G and I). Therefore, no direct or indirect impacts are anticipated to these species.

Since the study area supports suitable habitat for BUOW, focused surveys were conducted in accordance with the County’s survey protocol (2006). No BUOWs or BUOW sign were observed on the study area during the focused survey; therefore, BUOW is currently presumed absent from the study area. A measure requiring a pre-construction survey and avoidance of active nests and/or relocation of BUOW (if BUOWs are observed) is included as Measure BIO-1 below. With the implementation of Measure BIO-1, the project would not result in significant impacts to BUOW.

Presumed Present
LBVI is a federally and state endangered species and an MSHCP conditionally covered species. Since the study area supports suitable habitat, focused surveys were conducted during the 2020 season in accordance with USFWS’ survey protocol (2001). Four males and one pair were observed within the study area (Appendix H).

The project would not permanently or temporarily impact suitable LBVI habitat (Fremont cottonwood forest and woodland, arroyo willow thicket). However, LBVI was observed within the study area. Since project construction could have indirect impacts to LBVI that occupy habitat adjacent to Diaz Road, an avoidance/minimization measure is provided as Measure BIO-2 in Section 6.0 below, to avoid potential indirect impacts to LBVI during construction. The measure requires construction activities to be conducted outside of the LBVI nesting season (September 1 through March 14), as feasible. If construction activities are proposed within the nesting season (March 15 through August 31), weekly pre-construction surveys must be conducted ahead of project construction and a 300-foot avoidance buffer from occupied habitat must be established if LBVI are observed. If construction is proposed within the 300-foot buffer, a biological monitor would be required at all times and would have the authority to stop work. Additionally, daily noise monitoring would be required. Noise levels at the edge of occupied LBVI habitat may not exceed 60 A-weighted decibels (dBA), or an hourly average increase of 3 dBA if existing ambient noise levels already exceed 60 dBA. Please see Measure BIO-2 for more details. With the implementation of Measure BIO-2, the project would not result in significant impacts to LBVI.

5.2 SENSITIVE VEGETATION COMMUNITIES

5.2.1 California Department of Fish and Wildlife Sensitive Vegetation Communities/Habitats
Less than Significant with Mitigation Incorporated
The majority of permanent impacts are proposed within existing developed areas (25.28 acres; 79 percent; Table 6, Impacts to Vegetation and Land Uses; Figures 8a-h, Impacts to Vegetation). The majority of temporary impacts are proposed within areas that support upland mustards (0.16 acre; 80 percent). The project would entirely avoid permanent and temporary impacts within CDFW sensitive vegetation communities, including Fremont cottonwood forest and woodland and arroyo willow thicket.

Therefore, no mitigation is warranted.

32 Table 6

IMPACTS TO VEGETATION AND LAND USES
Vegetation Community/Land Use Temporary
Impacts (acres)1
Permanent
Impacts (acres)1
Arroyo Willow Thicket2 0.00 0.00
Fremont Cottonwood Forest and Woodland2 0.00 0.00
Riverwash 0.00 0.00
Developed 0.01 25.28
Disturbed 0.02 2.51
Eucalyptus Grove 0.01 0.49
Upland Mustards 0.16 3.69
TOTAL 0.20 31.97
1 Acreage is rounded to the nearest hundredth.
2 Sensitive habitats pursuant to CDFW’s Natural Communities List (2020).

5.2.2 California Department of Fish and Wildlife Riparian Habitat and Streambed
Less than Significant with Mitigation Incorporated
The JD survey area supports approximately 1.495 acres of jurisdictional streambeds pursuant to Section 1602 of the CFG Code as regulated by CDFW. The project would result in permanent impacts to approximately 0.265 acre and temporary impacts to 0.076 acre of CDFW jurisdiction on the study area (Table 7, Impacts to CDFW Jurisdiction; Figures 9a-f, Impacts to Jurisdictional Features and MSHCP Riparian/Riverine Areas). CDFW jurisdiction within Murrieta Creek would be entirely avoided.

Impacts to CDFW jurisdiction will require a Section 1602 Stream Alteration Agreement from the CDFW, as described in Measure BIO-3 included in Section 6.0 below. Compensatory mitigation for permanent impacts to CDFW jurisdiction would be required as part of subsequent Section 1602 permitting requirements. Permanent impacts to CDFW jurisdiction shall be mitigated through on-site or off-site enhancement, restoration, and/or creation of jurisdictional streambed at a ratio of no less than 2:1 as detailed in Measure BIO-3. With the implementation of Measure BIO-3, the project would not result in significant impacts to jurisdictional resources.

Table 7

IMPACTS TO CDFW JURISDICTION
Drainage Permanent
Impacts (acres)1
Temporary
Impacts (acres)1
Murrieta Creek 0.000 0.000
A1 0.000 0.000
A2 0.000 0.000
A2.1 0.064 0.026
B 0.000 0.000
C 0.027 0.005
D 0.027 0.006
E 0.036 0.009
F 0.000 0.000
G 0.021 0.006

33 Table 7 (cont.)

IMPACTS TO CDFW JURISDICTION
Drainage Permanent
Impacts (acres)1
Temporary
Impacts (acres)1
H 0.024 0.007
I 0.020 0.005
I1 0.010 0.001
J 0.016 0.006
K 0.020 0.005
TOTAL 0.265 0.076
1 Acreage is rounded to the nearest thousandth

5.3 U.S. ARMY CORPS OF ENGINEERS/REGIONAL WATER QUALITY

CONTROL BOARD JURISDICTION
Less than Significant with Mitigation Incorporated
The JD survey area supports approximately 0.096 acre of USACE/RWQCB non-wetland waters of the U.S. and 0.093 acre of wetlands pursuant to Sections 404/401 of the CWA as regulated by USACE and RWQCB, respectively. The project would result in permanent impacts to approximately 0.032 acre non- wetland waters of the U.S and 0.018 acre of wetlands (Table 8, Impacts to USACE/RWQCB Jurisdiction; Figure 9). The project would also require temporary impacts to approximately 0.005 acre of non- wetland waters of the U.S and 0.005 acre of wetlands.

Impacts to USACE/RWQCB jurisdiction will require a Section 404 permit from USACE and a Section 401 permit from RWQCB, as described in Measure BIO-3 included in Section 6.0 below. Compensatory streambed mitigation for permanent impacts to USACE/RWQCB jurisdiction will be required as part of subsequent Section 404/401 permitting requirements. Permanent impacts to USACE/RWQCB jurisdiction shall be mitigated through on-site or off-site enhancement, restoration, and/or creation of jurisdictional streambed at a ratio of no less than 2:1 as required by Measure BIO-3. With the implementation of Measure BIO-3, the project would not result in significant impacts to jurisdictional resources.

Table 8

IMPACTS TO USACE/RWQCB JURISDICTION
Drainage
Permanent Impacts Temporary Impacts
Non-Wetland
(acres)1
Wetland (acres)1 Non-Wetland
(acres)1
Wetland (acres)1
A1 0.000 0.000 0.000 0.000
A2 <0.0002 0.000 0.000 0.000
A2.1 0.001 0.000 <0.0003 0.000
B 0.000 0.000 0.000 0.000
C 0.005 0.004 0.000 0.001
D 0.003 0.007 0.000 0.002
E 0.012 0.000 0.003 0.000
F 0.000 0.000 0.000 0.000
G 0.003 0.000 <0.0004 0.000

34 Table 8 (cont.)

IMPACTS TO USACE/RWQCB JURISDICTION
Drainage
Permanent Impacts Temporary Impacts
Non-Wetland
(acres)1
Wetland (acres)1 Non-Wetland
(acres)1
Wetland (acres)1
H 0.003 0.000 <0.0005 0.000
I 0.001 0.004 0.000 0.001
I1 0.002 0.000 <0.0006 0.000
J 0.002 0.000 <0.0007 0.000
K 0.000 0.003 0.000 0.001
TOTAL 0.032 0.018 0.005 0.005
1 Acreage is rounded to the nearest thousandth.
2 Actual acreage is 0.0004 acre.
3 Actual acreage is 0.0003 acre.
4 Actual acreage is 0.0004 acre.
5 Actual acreage is 0.0004 acre.
6 Actual acreage is 0.00003 acre.
7 Actual acreage is 0.0004 acre.

5.4 WILDLIFE MOVEMENT AND MIGRATORY SPECIES

5.4.1 Wildlife Movement
Less than Significant Impacts
The study area is located within Proposed Constrained Linkage 13, which consists of Murrieta Creek.

Regional wildlife movement is expected to occur within Murrieta Creek. However, the project would avoid Murrieta Creek and most of its tributaries. The proposed impacts within the project site are mostly restricted to existing developed areas. The project will implement Urban/Wildland Interface Guidelines to reduce potential indirect impacts to wildlife movement through Proposed Linkage 13, which includes Murrieta Creek. Therefore, the project will not significantly impact movement of wildlife or impede the use of native wildlife nursery sites.

5.4.2 Migratory Species
Less than Significant Impacts with Mitigation Incorporated Development of the proposed project could disturb or destroy active migratory bird nests, including eggs and young. Disturbance to or destruction of migratory bird eggs, young, or adults is in violation of the MBTA and is considered a potentially significant impact. Although suitable habitat for nesting birds on the study area is limited, herbaceous ground cover, shrubs, and trees located throughout the study area could provide habitat for protected nesting bird species. A mitigation measure is provided as Measure BIO-4 in Section 6.0 below, which would help ensure the project is in compliance with MBTA regulations. With implementation of Measure BIO-4, the project would not result in significant impacts to migratory bird species.

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35 5.5 CITY-PROTECTED TREES
Less than Significant with Mitigation Incorporated
The project will comply with the City’s Heritage Tree Ordinance (Section 8.48 of the City’s Municipal Code). The study area supports trees that may be subject to tree protection measures. In accordance with Measure BIO-5, prior to impacts, a tree survey will be conducted prior to construction. If protected trees are located within the project site and must be damaged or removed, a Heritage Tree Removal or Relocation Permit must be obtained. Therefore, implementation of MM BIO-5 would reduce any direct impacts to City-protected trees to less than significant.

5.6 ADOPTED HABITAT CONSERVATION PLANS
Less than Significant Impacts with Mitigation Incorporated As discussed in Section 3.7.1 above, the study area is within the Southwest Area Plan of the MSHCP. The following sections demonstrate the project’s compliance with MSHCP requirements.

5.6.1 MSHCP Reserve Assembly Requirements
The study area is located within the Subunit 1 (Murrieta Creek) of the Southwest Area Plan of the MSHCP. The study area includes portions of Criteria Cells 6656, 6781, 6782, 6783, 6890, 6891, 7021, and 7078 (Figure 7). The conservation requirements for these Criteria Cells are presented below in Table 3, Conservation Requirement of the MSHCP Criteria Cells. Although the study area is within several Criteria Cells, the project site is mostly within existing developed areas. The project site is not targeted for conservation or is an area that would contribute to the MSHCP reserve assembly.

Furthermore, Diaz Road is considered a “covered road” under the MSCHP. According to MSHCP Section

7.3.4, “safety improvements to other publicly maintained existing roadways within the Criteria Area are Covered Activities. The proposed road widening is considered a safety improvement and is, therefore, a “covered activity.” Implementation of the proposed project would avoid and minimize impacts to sensitive species and habitats adjacent to the existing roadway. To minimize and avoid impacts to sensitive species and habitats occurring adjacent to the project site, the project will comply with Best Management Practices (BMPs), as detailed in Section 7.5.3 and Appendix C of MSHCP. Ultimately, the project would not conflict with the MSHCP reserve assembly.

5.6.2 Riparian/Riverine Areas and Vernal Pools (MSHCP Section 6.1.2) The identification of MSHCP Riparian/Riverine resources is based on the potential for the habitat to support, or be a tributary to habitat that supports, Riparian/Riverine Covered Species. Riparian/Riverine Covered Species are identified in MSHCP Section 6.1.2. The MSHCP defines Riparian/Riverine habitat as “lands which contain Habitat dominated by trees, shrubs, or emergent mosses and lichens, which occur close to or which depend upon soil moisture from a nearby fresh water source; or areas with fresh water flow during all or a portion of the year” (Dudek 2003). The MSHCP defines Vernal Pools as “seasonal wetlands that occur in depression areas that have wetlands indicators of all three parameters (soils, vegetation, and hydrology) during the wetter portion of the growing season but normally lack wetlands indicators of hydrology and/or vegetation during the drier portion of the growing season” (Dudek 2003). Artificially created wetlands, except for those created intentionally to provide habitat or

36 resulting from the creation of open waters or alteration of natural stream courses, are not considered MSHCP Vernal Pools.

Riparian/Riverine Habitat
The MSHCP Riparian/Riverine Areas mapped on the study area are equivalent to CDFW jurisdiction.

Implementation of the proposed project would result in permanent impacts to approximately 0.256 acre of MSHCP Riparian/Riverine habitat and temporary impacts to 0.076 acre of Riparian/Riverine habitat (Figure 9; Table 9, Impacts to MSHCP Riparian/Riverine Areas; Table 9, Impacts to MSHCP Riparian Area Vegetation).

Since the project proposes impacts to Riparian/Riverine Areas, the project is required to prepare a Determination of Biologically Equivalent or Superior Preservation, which provides a detailed account of impacts and proposed mitigation to compensate for impacts. Mitigation for permanent impacts to the Riparian/Riverine Areas would be met by implementing required mitigation for impacts to CDFW jurisdiction. Mitigation would include off-site enhancement, restoration, and/or creation at a ratio of no less than 2:1, as required by Measure BIO-3 included in Section 6.0 below. With the implementation of Measure BIO-3, the project would not result in significant impacts to MSHCP Riparian/Riverine Areas.

Table 9

IMPACTS TO MSHCP RIPARIAN/RIVERINE AREAS
Drainage Permanent
Impacts (acres)1
Temporary
Impacts (acres)1
Murrieta Creek 0.000 0.000
A1 0.000 0.000
A2 0.000 0.000
A2.1 0.064 0.026
B 0.000 0.000
C 0.027 0.005
D 0.027 0.006
E 0.036 0.009
F 0.000 0.000
G 0.021 0.006
H 0.024 0.007
I 0.020 0.005
I1 0.010 0.001
J 0.016 0.006
K 0.020 0.005
TOTAL 0.265 0.076
1 Acreage is rounded to the nearest thousandth.

Riparian/Riverine and Vernal Pool Species
One Riparian/Riverine plant species (smooth tarplant) was observed within Drainage A2.1 in the northern portion of the study area. Smooth tarplant is a conditionally covered species under the MSHCP.

Surveys for this species are required if a project occurs within a CASSA 1, 2,3, or 4. Since the study area is not located within a CASSA, impacts to this species would be covered under the MSHCP. Four other

37 Riparian/Riverine plant species were determined to have a low potential to occur within the study area.

These species were not incidentally observed within the study area during field surveys.

Four males and one pair were observed within the study area. The project would not permanently or temporarily impact suitable LBVI habitat (Fremont cottonwood forest and woodland, arroyo willow thicket). However, project construction could have indirect impacts to LBVI that occupy habitat adjacent to Diaz Road. Indirect impacts to this species during the nesting season (March 1 through August 31) would be a significant impact. To avoid potential indirect impacts to LBVI, an avoidance/minimization measure is provided as Measure BIO-2 in Section 6.0 below. No other Riparian/Riverine animal species are expected to occur on the study area.

5.6.3 Narrow Endemic Plant Species (MSHCP Section 6.1.3) The study area is not located within a NEPSSA; therefore, no focused surveys were required, and the proposed project is consistent with Section 6.1.3 of the MSHCP.

5.6.4 Urban/Wildland Interface Guidelines (MSHCP Section 6.1.4) Proposed developments adjacent to MSHCP Conservation Areas may create edge effects that can impact conserved biological resources. The MSHCP provides several guidelines that address potential indirect effects from proposed developments that are in proximity to MSHCP Conservation Areas. These guidelines include measures addressing the quantity and quality of runoff generated by the development (i.e., drainage and toxics), night lighting, noise, non-native invasive plant species, barriers to humans and animal predators, and grading/land development encroachment.

The eastern portion of the study area is located within Proposed Constrained Linkage 13, which consists of Murrieta Creek. As discussed below, the project will comply with each applicable guideline to ensure consistency with MSHCP Section 6.1.4.

Drainage
The project will incorporate measures to avoid the discharge of untreated surface runoff into downstream waters. Measures will include those required for construction pursuant to the State Water Resources Control Board General Construction Storm Water Permit and the project Storm Water Pollution Prevention Program, while post-construction water quality measures will be implemented in compliance with the National Pollutant Discharge Elimination System, Municipal Storm Drain Permit requirements, and subsequent 401 Water Quality Certification from RWQCB for the project. The project will be designed to prevent the release of toxins, chemicals, petroleum products, exotic plant materials, or other elements that might degrade or harm biological resources or ecosystem processes downstream from the study area. In addition, post-construction BMPs are intended to help ensure that post-project hydrologic conditions remain consistent with pre-project conditions, therefore minimizing the potential for downstream erosion and/or sedimentation that could otherwise result from implementation of the proposed project.

Toxics
Land uses that use chemicals or generate bio-products that are potentially toxic or may adversely affect wildlife species, habitat, or water quality shall incorporate measures to ensure that application of such chemicals does not result in discharge into downstream waters. Measures such as those employed to

38 address drainage issues would be implemented by the proposed project to avoid the potential impacts of toxics.

Lighting
Temporary construction lighting and ambient lighting from the proposed development are required to be selectively placed, directed, and shielded away from the MSHCP Conservation Area. In addition, large spotlight-type lighting directed into conserved habitat will be prohibited.

Noise
Proposed noise generating land uses affecting the MSHCP Conservation Area shall incorporate setbacks, berms, or walls to minimize the effects of noise on MSHCP Conservation Area resources pursuant to applicable rules, regulations, and guidelines related to land use noise standards. For planning purposes, wildlife within the MSHCP Conservation Area should not be subject to noise that would exceed residential noise standards.

Temporary construction-related noise impacts will be reduced by the implementation of a number of measures, including the following:
• During all excavation and grading, the construction contractors shall equip all construction equipment, fixed or mobile, with properly operating and maintained mufflers, consistent with manufacturers’ standards to reduce construction equipment noise to the maximum extent possible. The construction contractor shall place all stationary construction equipment so that emitted noise is directed away from sensitive receptors nearest the study area. • The construction contractor shall stage equipment in areas that will create the greatest distance between construction-related noise sources and noise sensitive receptors nearest the study area during all project construction.
• All construction work shall occur during the daylight hours. The construction contractor shall limit all construction-related activities that would result in high noise levels according to the construction hours to be determined by the County.
• The construction contractor shall limit haul truck deliveries to the same hours specified for construction equipment. To the extent feasible, haul routes shall not pass through sensitive land uses or residential dwellings.

Invasives
The project shall not use invasive plants for erosion control, landscaping, wind rows, or other purposes.

Measure BIO-6 is provided in Section 6.0 below, which requires the project to comply with the MSHCP and avoid the use of invasive, non-native plants in accordance with MSHCP Table 6.2.

Barriers
Since the project consists of widening an existing road, barriers and signage are not necessary.

39 Grading/Land Development
Since the project consists of widening an existing road, manufactured slopes are not necessary.

5.6.5 Additional Surveys (MSHCP Section 6.3.2)
The study area is not within a CASSA or an Amphibian or Mammal Species Survey Area. No impacts to CASSA species or sensitive amphibian or mammal species are proposed.

The study area is within the MSHCP Burrowing Owl Survey Area, and the study area supports suitable habitat. Focused surveys were conducted in accordance with the County’s survey protocol. No burrowing owls or sign of burrowing owls were observed within the study area. Due to the presence of suitable habitat, a pre-construction survey is required within 30 days of ground disturbance pursuant to the MSHCP. A mitigation measure requiring a pre-construction survey, avoidance or replacement of burrowing owl habitat and individuals (if three or more pairs are observed), and avoidance of active nests and/or relocation of burrowing owl (if burrowing owls are observed) is included as Measure BIO-1 below.

As discussed above, the proposed project is consistent with MSHCP Section 6.3.2.

5.6.6 Fuels Management (MSHCP Section 6.4)
Because the proposed project consists of widening an existing road within a heavily developed portion of the City, a fuel modification zone is not incorporated into the proposed project. The proposed project is consistent with Section 6.4 of the MSHCP.

5.6.7 Multiple Species Habitat Conservation Plan and Stephens’ Kangaroo Rat Fees
In order for the project to participate in the MSHCP, the project proponent is required to pay an LDMF in order to finance the acquisitions of conservation areas to provide habitat for MSHCP covered species (County 2003). The LDMF must be paid prior to issuance of a building permit. The applicant shall pay the LDMF as determined by the County. Final fee credits shall be determined through coordination with the County.

The study area is also within the SKR HCP but is not located within any of the core reserves (County 1996). Therefore, the project is required to pay an SKR mitigation fee for incidental take authorization under the SKR HCP.

Measure BIO-7 is provided in Section 6.0, which requires the project proponent to pay the MSHCP LDMF and SKR HCP fees.

40 6.0 MITIGATION MEASURES
The following provides recommended measures intended to minimize or avoid impacts to biological resources:

BIO-1 Burrowing Owl: In compliance with the MSHCP, a pre-construction survey shall be conducted on the study area within 30 days prior to ground disturbance to determine presence of burrowing owls. If the pre-construction survey is negative and burrowing owl is confirmed absent, then ground-disturbing activities (i.e., earthwork, clearing, and grubbing) shall be allowed to commence and no further mitigation would be required.

If BUOW is observed during the pre-construction survey, active burrows shall be avoided by the project in accordance with the California Department of Fish and Wildlife’s (CDFW) Staff Report on Burrowing Owl Mitigation (2012) or CDFW’s most recent guidelines. The Project Proponent shall immediately inform the Western Riverside County Regional Conservation Authority (RCA) of BUOW observations. A BUOW Protection and Relocation Plan (plan) shall be prepared by a qualified biologist, which must be sent for approval by RCA prior to initiating ground disturbance. The RCA will coordinate directly with CDFW as needed to ensure that the plan is consistent with the MSHCP and CDFW guidelines. The plan shall detail avoidance measures that shall be implemented during construction and passive or active relocation methodology.

Relocation shall only occur outside of the nesting season (September 1 through January 31). The RCA may require translocation sites to be created within the MSHCP Conservation Area for the establishment of new colonies. If required, the translocation sites must take into consideration unoccupied habitat areas, presence of burrowing mammals, existing colonies, and effects to other MSHCP Covered Species in order to successfully create suitable habitat for BUOW. The translocation sites must be developed in consultation with RCA. If required, translocation sites would also be described in the agency-approved plan.

BIO-2 Least Bell’s Vireo: Due to presence of LBVI in the vicinity of the study area, the following avoidance and minimization measures shall be implemented to avoid potential impacts:
(1) To the extent feasible, construction activities (i.e., earthwork, clearing, and grubbing) shall occur outside of the nesting season for LBVI (September 1 through March 14).
(2) If construction activities are proposed within the LBVI nesting season (March 15 through August 31), the following measures (a. through g.) shall be implemented to avoid potential indirect impacts.
(a) At the start of each new stretch of construction, weekly limits will be identified by the contractor, and a qualified biologist will conduct weekly pre-construction surveys to determine the presence of LBVI nest-building activities, egg incubation activities, or brood-rearing activities within 300 feet of anticipated construction activities for the coming week. Surveys will be conducted more frequently if construction could progress beyond the limits of the weekly surveyed area.

41 (b) If nesting LBVI is observed during the weekly pre-construction surveys, a qualified biological monitor shall clearly delineate a 300-foot avoidance buffer around occupied habitat. The 300-foot avoidance buffer shall be clearly marked with flags and/or fencing prior to commencement of construction. No construction activities shall occur within the 300-foot buffer during the nesting season without the presence of a biological monitor.
(c) If construction activities (e.g., ground disturbance and canopy trimming) must occur within 300 feet of occupied habitat, the following measures shall be implemented:
(i) A biological monitor shall be present to perform daily surveys for LBVI and monitor construction activities. The biological monitor shall have the authority to stop work and notify the construction supervisor if the biologist feels construction activities could alter the birds’ normal behavior. The activities shall cease until additional minimization measures have been determined through coordination with CDFW and/or USFWS. (ii) A qualified acoustician shall also be retained to determine ambient noise levels and construction-related noise levels at the edge of occupied habitat.

Noise levels at the edge of the occupied habitat shall not exceed an hourly average of 60 dBA, or an hourly average increase of 3 dBA if existing ambient noise levels exceed 60 dBA. If project-related noise levels exceed the threshold described above, construction activities shall cease until additional minimization measures, such as visual and auditory barriers (e.g., sound wall), are taken to reduce project-related noise levels to below an hourly average of 60 dBA, or below an hourly average increase of 3 dBA if existing ambient noise levels exceed 60 dBA. If additional measures do not decrease project-related noise levels below the thresholds described above, construction activities shall cease until CDFW and/or USFWS are contacted to discuss alternative methods.
(d) All project personnel shall attend a Workers Environmental Awareness Program training presented by a qualified biologist prior to construction activities. The training program will inform project personnel about the life history of LBVI and all avoidance and minimization measures.
(e) The construction contractor shall only allow construction activities to occur during daylight hours.
(f) The construction contractor shall require functional mufflers on all construction equipment (stationary or mobile) used within or immediately adjacent to any 300-foot avoidance buffers to reduce construction equipment noise. Stationary equipment shall be situated so that noise generated from the equipment is not directed towards any occupied habitat for the LBVI.
(g) The construction contractor shall place staging areas as far as possible from any suitable occupied habitat for the LBVI.

42 (h) The biological monitor shall prepare written documentation of all monitoring activities at the completion of construction activities, which shall be submitted to CDFW and/or USFWS.

BIO-3 Jurisdictional Resources: Prior to issuance of a grading permit for impacts to jurisdictional resources, the City shall obtain regulatory permits from USACE, RWQCB, and CDFW (collectively, the “Resource Agencies”). Compensatory mitigation for permanent impacts to jurisdiction shall be required as part of subsequent permitting requirements. Permanent impacts to jurisdictional resources shall be mitigated through on-site or off-site enhancement, restoration, and/or creation of jurisdictional streambed at a mitigation-to-impact ratio of no less than 2:1. The following minimization measures will be implemented during construction:
• Use of standard BMPs to minimize the impacts during construction. • Construction-related equipment will be stored in developed areas, outside of drainages.
• Source control and treatment control BMPs will be implemented to minimize the potential contaminants that are generated during and after construction. Water quality BMPs will be implemented throughout the project to capture and treat potential contaminants.
• To avoid attracting predators during construction, the project shall be kept clean of debris to the extent possible. All food-related trash items shall be enclosed in sealed containers and regularly removed from the site.
• Employees shall strictly limit their activities, vehicles, equipment, and construction material to the proposed project footprint, staging areas, and designated routes of travel.
• Exclusion fencing should be maintained until the completion of construction activities.

BIO-4 Nesting Birds: To the extent possible, construction activities (i.e., earthwork, clearing, and grubbing) shall occur outside of the general bird nesting season for migratory birds, which is March 15 through August 31 for songbirds and January 15 to August 31 for raptors.

If construction activities (i.e., earthwork, clearing, and grubbing) must occur during the general bird nesting season for migratory birds (March 15 and August 31) and raptors (January 15 and August 31), a qualified biologist shall be retained to perform a pre- construction survey of potential nesting habitat to confirm the absence of active nests belonging to migratory birds and raptors afforded protection under the MBTA and CFG Code. The pre-construction survey shall be performed no more than seven days prior to the commencement of construction activities. The results of the pre-construction survey shall be documented by a qualified biologist. If construction is inactive for more than seven days, an additional survey shall be conducted.

43 If the qualified biologist determines that no active migratory bird or raptor nests occur, the activities shall be allowed to proceed without any further requirements. If the qualified biologist determines that an active migratory bird or raptor nest is present, no impacts within 300 feet (500 feet for raptors) of the active nest shall occur until the young have fledged the nest, and the nest is confirmed to no longer be active, or as determined by the qualified biologist. The biological monitor may modify the buffer as applicable for the specific bird species and type of work, or propose other recommendations to avoid indirect impacts to nesting birds.

BIO-5 Protected Trees: Prior to impacting any trees within the project site, a tree survey shall be conducted in accordance with the City of Temecula’s Heritage Tree Ordinance (Section 8.48 of the City’s Municipal Code). If trees subject to this ordinance must be damaged or removed within the project site, a Heritage Tree Removal or Relocation Permit must be obtained prior to damage or removal.

BIO-6 MSHCP Landscaping Restrictions: In accordance with MSHCP Section 6.1.4, no species listed in Table 6-2, Plants that Should Be Avoided Adjacent to the MSHCP Conservation Area, shall be used in the project landscape plans (including hydroseed mix used for interim erosion control).

BIO-7 Habitat Conservation Plan Fees: The City is subject to the MSHCP LDMF and the SKR HCP Fee, which shall be paid prior to issuance of any grading permit.

44 7.0 CERTIFICATION/QUALIFICATION
The following individuals contributed to the fieldwork and/or preparation of this report:

Ezekiel Cooley B.S., Natural Resources with an emphasis in Wildlife, Central Michigan University, 2004
Matthew Dimson B.S., Environmental Science and Policy, California State University Long Beach, 2017
Linda Garcia M.A., English, National University, 2012
B.A., Literatures in English, University of California, San Diego Erica Harris B.S., Biology, emphasis in Zoology, San Diego State University, 2009 Jessica Lee M.S., Biology with an emphasis in Wetland Ecology, California University, Long Beach, 2018
B.S., Marine Biology, Auburn University, 2013
Amir Morales B.S., Hydrological Sciences, Minor Geographic Information Systems, University of California Santa Barbara, 2001
Lauren Singleton M.S., Biology with an emphasis in Ecology and Entomology, California State University Long Beach, 2014
B.S., Biology with an emphasis in Ecology, California State University Long Beach, 2010
Daniel Torres B.S., Ecology and Natural Resources, Rutgers University, 2013

45 8.0 REFERENCES
American Ornithologists’ Union. 2020. AOU checklist of North and Middle America birds. Available from:
http://checklist.aou.org/taxa/ . Accessed February 5, 2021.

Baker, R.J., L.C. Bradley, R.D. Bradley, J.W. Dragoo, M.D. Engstrom, R.S. Hoffmann, C.A. Jones, F. Reid, D.W. Rice, and C. Jones. 2003. Revised checklist of North American mammals north of Mexico.

Occasional Papers of the Museum, Texas Tech University 223.

Baldwin, B.G., D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken, editors. 2012. The Jepson manual: Vascular plants of California. 2nd ed. University of California Press, Berkeley.

California Department of Fish and Wildlife. 2021. California Natural Diversity Database and Rarefind.

California Department of Fish and Wildlife: Sacramento, California. Available at:
https://www.wildlife.ca.gov/Data/CNDDB/Maps-and-Data . Accessed February 28, 2021. 2020. California natural community list. The Vegetation Classification and Mapping Program.

Wildlife & Habitat Data Analysis Branch. September 2020. Available from:
https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=153398&inline . Accessed February 5, 2021.
2009. Protocols for surveying and evaluating impacts to special status native plant populations and natural communities. State of California, California Natural Resources Agency. November 24, 2009.
2000. Guidelines for assessing the effects of proposed projects on rare, threatened, and endangered plants and natural communities. State of California, The Resources Agency.

December 9, 1983 revised May 8, 2000.

California Herps. 2021. A Guide to the Amphibians and Reptiles of California. Available from:
http://www.californiaherps.com . Accessed February 5, 2021.

California Native Plant Society. 2021. Inventory of rare and endangered plants of California. California Native Plant Society. Available at: http://www.rareplants.cnps.org/ . Accessed February 28, 2021.

Dudek and Associates. 2003. Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP) Final MSHCP Volume I. Prepared for County of Riverside, Transportation and Land Management Agency. Available at: http://www.rctlma.org/Portals/0/mshcp/index.html .

Emmel, T.C. and J.F. Emmel. 1973. The butterflies of Southern California. Natural History Museum of Los Angeles County, Science Series 26: 1-148.

Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Technical report Y-87-1. Vicksburg (MS): U.S. Army Engineer Waterways Experiment Station. 100 p. with Appendices.

46 Google Earth. 2020. Aerial imagery of the Diaz Road Improvement Project, 33.511203°, -117.164899°. Aerial Imagery from January 2020. Available at: https://earth.google.com/web/ .

Accessed January 8, 2021.

Grumbles, B.H. and J.P. Woodley, Jr. 2007. Memorandum: Clean Water Act jurisdiction following the U.S. Supreme Court’s Decision in Rapanos v. United States & Carabell v. United States. June 5. 12 p.

Historic Aerials. 1996. Aerial Imagery of the Diaz Road Improvement Project, 33.511203°, -117.164899°. Available at: https://www.historicaerials.com/viewer . Accessed July 16, 2020. 1978. Aerial Imagery of the Diaz Road Improvement Project, 33.511203°, -117.164899°. Available at: https://www.historicaerials.com/viewer . Accessed July 16, 2020.

Holland R.F. 1986. Preliminary descriptions of the terrestrial natural communities of California.

Nongame-Heritage Program, State of California, Department of Fish and Game, Sacramento. 156 pp.

Natural Resources Conservation Service. 2021. Web Soil Survey. United States Department of Agriculture (USDA). Available at: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.Aspx .

Accessed February 515, 2021.

Oberbauer, T. 1996. Terrestrial vegetation communities in San Diego County based on Holland’s descriptions, San Diego Association of Governments, San Diego, CA.

Riley, D.T. 2005. Ordinary High Water Mark. RGL No. 05-05. 4 p.

Riverside, County of. 2006. Burrowing owl survey instructions for the Western Riverside Multiple Species Habitat Conservation Plan Area. Environmental Programs Department. Available at:
https://www.rctlma.org/Portals/3/EPD/consultant/burrowing_owl_survey_instructions.pdf .

Accessed January 6, 2021.
2003. Ordinance 810.2. An Ordinance of the County of Riverside Amending Ordinance 810 to Establish the Western Riverside County Multiple Species Habitat Conservation Plan Mitigation Fee.
1996. Ordinance 663.10. An Ordinance of the County of Riverside Amending Ordinance 663 Establishing the Riverside County Stephens’ Kangaroo Rat Habitat Conservation Plan, Plan Fee Assessment Area, and Setting Mitigation Fees.

Sawyer, J.O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. 2nd Ed. Sacramento:

California Native Plant Society.

Sogge, M.K., Ahlers, D., and Sferra, S.J. 2010. A Natural History Summary and Survey Protocol for the Southwestern Willow Flycatcher: U.S. Geological Survey Techniques and Methods 2A-10.

47 Temecula, City of. 2009. Ord. 09-05 § 1 Chapter 8.48, of Temecula Municipal Code. Adopted August 2009. Available at: http://www.qcode.us/codes/temecula/?view=desktop&topic=8-8_48-i- 8_48_130. Accessed January 8, 2021.
1993. Temecula General Plan. Updated in 2005.

U.S. Army Corps of Engineers. 2008a. Regional supplement to the Corps of Engineers wetland delineation manual: Arid west region (Version 2.0). Ed. J.S. Wakeley, R.W. Lichvar, and C.V.

Noble. ERCD/EL TR-06-16. Vicksburg, MS: U.S. Army Engineer Research and Development Center.
2008b. A field guide to the identification of the ordinary high water mark (OHWM) in the Arid West region of the Unites States. Technical Report TR-08-12, Ed. R.W. Lichvar, S.M. McColley.

Hanover, New Hampshire: Cold Regions Research and Engineering Laboratory. 2007. Questions and Answers for Rapanos and Carabell Decisions. June 5. 21 pp. -- and EPA. 2007. Jurisdictional Determination Form Instructional Guidebook. May 30. 60 pp.

U.S. Fish and Wildlife Service. 2021a. Critical habitat mapping. GIS files provided by USFWS. Available at:
https://ecos.fws.gov/ecp/report/table/critical-habitat.html . Accessed January 6, 2021. 2021b. National Wetlands Inventory. Available at: https://www.fws.gov/wetlands/data/google- earth.html. Accessed January 6, 2021.
2001. Least Bell’s vireo survey guidelines. January 19. Available at:
https://www.fws.gov/ventura/docs/species/protocols/lbv/leastbellsvireo_survey- guidelines.pdf. Accessed January 6, 2021.

2000. Guidelines for conducting and reporting botanical inventories for federally listed, proposed and candidate plants. United States Fish and Wildlife Service. January 2000.

Western Riverside County Regional Conservation Authority. 2021. MSHCP information tool. Powered by ESRI. Available at:
http://wrcrca.maps.arcgis.com/apps/webappviewer/index.html?id=a73e69d2a64d41c29ebd3ac d67467abd. Accessed January 6, 2021.

Appendix A
Plant Species Observed

Diaz Road Improvement Project
Appendix A

PLANT SPECIES OBSERVED
A-1
Family Scientific Name Common Name

GYMNOSPERMS
Pinus Cupressus sempervirens* Italian cypress
Pinus halepensis* Aleppo pine

ANGIOSPERMS - EUDICOTS
Anacardiaceae Schinus molle* Peruvian peppertree
Apocynaceae Nerium oleander* oleander
Asteraceae
Acourtia microcephala sacapellote
Ambrosia psilostachya ragweed
Artemisia douglasiana California mugwort
Artemisia tridentata big sagebrush
Baccharis salicifolia mule fat
Centaurea melitensis* tocalote
Cirsium vulgare* bull thistle
Dimorphotheca sinuate* African daisy
Heterotheca grandiflora telegraph weed
Helianthus annuus common sunflower
Hypochaeris glabra* smooth cat's ear
Isocoma menziesii Menzies' goldenbush
Lactuca serriola* prickly lettuce
Matricaria discoidea pineapple weed
Oncosiphon piluliferum* stinknet
Pseudognaphalium luteoalbum* everlasting cudweed
Silybum marianum* milk thistle
Sonchus oleraceus* common sow thistle
Taraxacum officinale* common dandelion
Artemisia dracunculus tarragon
Aizoaceae Mesembryanthemum nodiflorum* slender iceplant Boraginaceae
Amsinckia intermedia common fiddleneck
Cryptantha intermedia nievitas
Heliotropium curassavicum var. oculatum alkali heliotrope Pectocarya heterocarpa Chuckwalla combseed
Brassicaceae
Hirschfeldia incana* short-pod mustard
Lobularia maritima* sweet alyssum
Sisymbrium irio* London rocket
Caryophyllaceae Spergularia spp. sandspurry
Celastraceae Euonymus japonicus* Japanese spindletree
Chenopodiaceae
Atriplex semibaccata* Australian saltbush
Chenopodium murale* nettle leaf goosefoot
Salsola tragus* Russian thistle
Cistaceae Cistus incanus* hairy rockrose
Crassulaceae Crassula connata pigmy weed
Euphorbiaceae Croton californicus California croton

Diaz Road Improvement Project
Appendix A (cont.)

PLANT SPECIES OBSERVED
A-2
Family Scientific Name Common Name
Fabaceae
Acmispon americanus Spanish lotus
Acacia redolens* bank catclaw
Lupinus succulentus arroyo lupine
Melilotus indicus* annual yellow sweetclover
Robinia pseudoacacia* black locust
Trifolium hirtum* rose clover
Vicia villosa ssp. varia* winter vetch
Fagaceae Quercus agrifolia coast live oak
Geraniaceae Erodium botrys* long beaked filaree
Erodium cicutarium* redstem filaree
Lamiaceae Rosmarinus officinalis* rosemary
Malvaceae Malva parviflora* cheeseweed mallow
Myoporaceae Myoporum parvifolium* slender myoporum
Myrtaceae Eucalyptus camaldulensis* river red gum
Oleaceae Fraxinus uhdei* Shamel ash
Orobanchaceae Castilleja exserta purple owl's clover
Oxalidaceae Oxalis corniculate* creeping wood sorrel
Polygonaceae Eriogonum fasciculatum California buckwheat Rumex crispus* curly dock
Platanaceae Platanus × hispanica* London plane
Rosaceae
Heteromeles arbutifolia toyon
Pyracantha coccinea* scarlet firethorn
Pyrus calleryana* Callery pear
Rhaphiolepis indica* Indian hawthorn
Rubiaceae Galium aparine common bedstraw
Salicaceae
Salix exigua sandbar willow
Salix gooddingii Goodding's black willow
Salix lasiolepis arroyo willow
Solanaceae Nicotiana glauca* tree tobacco
Scrophulariaceae Leucophyllum langmaniae Texas sage
Tamaricaceae Tamarix ramosissima* saltcedar
Ulmaceae Ulmus pumila* Siberian elm
Urticaceae Urtica dioica stinging nettle

ANGIOSPERMS - MONOCOTS
Arecaceae Washingtonia robusta* Mexican fan palm
Cyperaceae Schoenoplectus acutus hardstem bulrush
Poaceae
Avena barbata* slender oat
Bromus diandrus* common ripgut grass
Bromus hordeaceus* soft brome
Hordeum murinum* hare barley
Bromus madritensis* red brome
Leptochloa fusca ssp. uninervia Mexican sprangletop
Polypogon monspeliensis* rabbitsfoot grass
Stipa pulchra purple needle grass
Vulpia myuros* foxtail fescue
Typhaceae Typha spp. cattail
* Non-native species

Appendix B
Animal Species Observed
or Detected

Diaz Road Improvement Project
Appendix B

ANIMAL SPECIES OBSERVED OR DETECTED
B-1
Order Family Scientific Name Common Name

INVERTEBRATES
Insects
Lepidoptera
Nymphalidae
Junonia coenia common buckeye
Nymphalis antiopa mourning cloak
Vanessa cardui painted lady
Papilionidae Papilio rutulus western tiger swallowtail
Pieridae Pontia protodice checkered white

VERTEBRATES
Reptiles
Squamata Phrynosomatidae Sceloporus occidentalis western fence lizard Uta stansburiana common side-blotched lizard
Birds
Accipitriformes Accipitridae
Accipiter cooperii Cooper's hawk
Buteo jamaicensis red-tailed hawk
Buteo lineatus red-shouldered hawk
Cathartidae Cathartes aura turkey vulture
Anseriformes Anatidae Anas platyrhynchos mallard
Spatula cyanoptera cinnamon teal
Apodiformes Trochilidae Calypte anna Anna's hummingbird Charadriiformes Charadriidae Charadrius vociferus killdeer Columbiformes Columbidae Streptopelia decaocto Eurasian collared dove Zenaida macroura mourning dove
Cuculiformes Cuculidae Geococcyx californianus greater roadrunner Falconiformes Falconidae Falco sparverius American kestrel Gruiformes Rallidae Fulica atra Eurasian coot
Fulica americana American coot
Passeriformes
Aegithalidae Psaltriparus minimus bushtit
Cardinalidae Passerina amoena lazuli bunting
Pheucticus melanocephalus black-headed grosbeak
Corvidae
Aphelocoma californica California scrub jay
Corvus brachyrhynchos American crow
Corvus corax common raven
Fringillidae
Haemorhous mexicanus house finch
Spinus psaltria lesser goldfinch
Spinus tristis American goldfinch
Hirundinidae Petrochelidon pyrrhonota cliff swallow
Stelgidopteryx serripennis northern rough-winged swallow Icteridae
Agelaius phoeniceus red-winged blackbird
Icterus bullockii Bullock's oriole
Icterus cucullatus hooded oriole
Icteria virens yellow-breasted chat
Molothrus ater brown-headed cowbird
Sturnella neglecta western meadowlark
Mimidae Mimus polyglottos northern mockingbird
Passerellidae Chondestes grammacus lark sparrow
Pipilo maculatus spotted towhee
Parulidae Cardellina pusilla Wilson's warbler
Geothlypis trichas common yellowthroat

Diaz Road Improvement Project
Appendix B (cont.)

ANIMAL SPECIES OBSERVED OR DETECTED
B-2

Order Family Scientific Name Common Name
Birds (cont.)
Passeriformes
(cont.)
Parulidae (cont.)
Melospiza melodia song sparrow
Melozone crissalis California towhee
Setophaga petechia yellow warbler
Ptiliogonatidae Phainopepla nitens phainopepla
Sturnidae Sturnus vulgaris European starling
Troglodytidae Cistothorus palustris marsh wren
Thryomanes bewickii Bewick's wren
Turdidae Turdus migratorius American robin
Tyrannidae
Empidonax traillii willow flycatcher
Myiarchus cinerascens ash-throated flycatcher
Sayornis nigricans black phoebe
Sayornis saya Say's phoebe
Tyrannus verticalis western kingbird
Vireonidae Vireo bellii pusillus Least Bell's Vireo
Vireo gilvus warbling vireo
Pelecaniformes Ardeidae
Ardea alba great egret
Ardea herodias great blue heron
Egretta thula snowy egret
Plegadis chihi white-faced ibis
Piciformes Picidae Colaptes auratus northern flicker
Dryobates nuttallii Nuttall's woodpecker
Mammals
Lagomorpha Leporidae Sylvilagus audubonii desert cottontail Rodentia Sciuridae Otospermophilus beecheyi California ground squirrel

Appendix C
Site Photographs

H:\PROJECTS\D\DEA-ALL\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix X_PhotosRepresentative Photos Appendix C
Diaz Road Improvement Project
Photo 1. View of disturbed land in northern portion of the study area, facing southwest. Non-native vegetation can be seen on the left and right.

Photo 2. View of southwestern willow scrub habitat in the central portion of the study area, facing northwest.

H:\PROJECTS\D\DEA-ALL\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix X_PhotosRepresentative Photos Appendix C
Diaz Road Improvement Project
Photo 3. View of developed land in the central portion of the study area, facing southwest. Diaz Road can be seen on the right.

Photo 4. View of the southern portion of the study area, facing south. Disturbed land can be seen on the lower right and non-native vegetation can be seen on the left. The intersection of Diaz Road and Rancho Way can be seen in the center.

Appendix D
Drainage Photographs

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 1: Photograph of Drainage A located in the northern portion of the study area, facing northwest.

Photograph 2: Photograph of Drainage A1 located in the northern portion of the study area, facing east.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 3: Photograph of Drainage A2 located in the northern portion of the study area, facing northwest.

Photograph 4: Photograph of Drainage A2.1 located in the northern portion of the study area, facing southwest.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 5: Photograph of Drainages B located in the central portion of the study area, facing northeast.

Photograph 6: Photograph of Drainage C located in the central portion of the study area, facing north.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 7: Photograph of Drainage D located in the central portion of the study area, facing northeast.

Photograph 8: Photograph of Drainage E located in the central portion of the study area, facing northeast.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 9: Photograph of Drainage F located in the central portion of the study area, facing east.

Photograph 10: Photograph of Drainage G located in the central portion of the study area, facing northeast.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 11: Photograph of Drainage H located in the southern portion of the study area, facing northeast.

Photograph 12: Photograph of Drainage I located in the southern portion of the study area, facing northeast.

H:\PROJECTS\D\DavidEvansAssoc_00207\DEA-12 Diaz Road\_Reports\GBRA\Appendices\Appendix D_Drainage PhotosDrainage Photos Appendix D
Diaz Road Improvement Project
Photograph 13: Photograph of Drainage J located in the southern portion of the study area, facing east.

Photograph 14: Photograph of Drainage K located in the southern portion of the study area, facing east.

Appendix E
Rare Plant Species Potential
to Occurs

Diaz Road Expansion Project
Appendix E
Rare Plant Species Potential to Occur1

E-1
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Abronia villosa var. aurita chaparral sand-verbena CRPR 1B.1 Annual herb. Occurs on sandy floodplains or flats in generally
inland, arid areas of sage scrub
and open chaparral. Elevation
range 0-1600 m. Flowering
period Mar-Aug.

None. The study area does not
support sage scrub or chaparral
habitats.

Almutaster pauciflorus alkali marsh aster CRPR 2B.2 Perennial herb. Occurs in meadows and seeps on alkaline
soil. Elevation range 200-700 m.

Flowering period Jun-Oct.

Low. The study area supports
highly disturbed mesic areas
with alkaline soils. Although the
study are supports disturbed
habitat, this species has not
been recorded in the region
since 1937.

Ambrosia pumila San Diego ambrosia FE
CRPR 1B.1
MSHCP Covered Species (b)
Perennial herb. Occurs on clay,
sandy loam, and sometimes
alkaline soils. Found in
grasslands, valley bottoms, and
dry drainages. Can occur on
slopes, disturbed places, in
coastal sage scrub and
chaparral. Elevation range 50-
600 m. Flowering period Apr-Jul.

High. The study area supports
suitable sandy loam and alkaline
soils, as well as disturbed habitat
for this species. This species was
recorded in CNDDB in 2010,
approximately 0.8 mile to the
southeast of the study area.

Arctostaphylos
rainbowensis
rainbow manzanita CRPR 1B.1
MSHCP Covered Species (e)
Shrub. Southern mixed
chaparral is preferred habitat
with a relatively dense canopy
from 6 to 8 feet. Elevation range
150-800 m. Flowering period
Jan-Feb.

None. The study area does not
support chaparral habitat.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-2
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Astragalus pachypus var.
jaegeri
Jaeger’s bush milk-
vetch
CRPR 1B.1

Perennial shrub. Occurs in sandy
or rocky soils. Found in
chaparral, cismontane
woodland, coast scrub, and
valley grassland habitats.

Elevation 365-975 m. Flowering
period Dec-Jun.

None. The study area does not
support chaparral habitat. The
study area is located outside oof
this species’ elevation range.

Brodiaea orcuttii Orcutt's brodiaea CRPR 1B.1
MSHCP Covered Species
Perennial herb. Occurs in
vernally moist grasslands, mima
mound topography, and vernal
pool periphery are preferred
habitat. Occasionally will grow
on streamside embankments in
clay soils. Elevation range 0-
1600 m. Flowering period Apr-
Jul.

Low. The study area supports
highly disturbed mesic areas,
including streamside
embankments with clay soils.

This species was recorded in
CNDDB in 2003, approximately

5.8 miles to the southeast of the
study area.

Brodiaea santarosae Santa Rosa basalt
brodiaea
CRPR 1B.2 Perennial herb. Occurs in soils
derived from Santa Rosa Basalt
within grassland habitat.

Elevation range 580-1045 m.

Flowering period May-Jun.

None. The study area is not
located on Santa Rosa Basalt.

The study area is located outside
of this species’ elevation range.

Chaenactis glabriuscula var.
orcuttiana
Orcutt’s pincushion CRPR 1B1 Annual herb. Occurs in sandy soils within coastal bluff scrub
and coastal dunes. Elevation
range 0-100 m. Flowering period
Apr-Jul.

None. The study area does not
support coastal bluff scrub or
coastal dune habitats. The study
area is located outside of this
species’ elevation range.

Calochortus weedii var.
intermedius
intermediate mariposa
lily
CRPR 1B.2
MSHCP Covered Species
Perennial herb. Occurs on dry,
rocky slopes within openings in
chaparral, coastal scrub, and
grassland habitats. Elevation
range 0-680 m. Flowering period
Jun-Jul.

None. The study area does not
support dry, rocky slopes.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-3
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Centromadia pungens ssp.
laevis
smooth tarplant CRPR 1B.1
MSHCP Covered Species (d)
Annual herb. Occurs within
valley and foothill grasslands,
particularly near alkaline locales.

Elevation range 90-500 m.

Flowering period Apr-Sep.

Present. The study supports
suitable habitat for this species.

This species was observed
during the general biological
survey.

Chorizanthe parryi var.
parryi
Parry's spineflower CRPR 1B.1
MSHCP Covered Species (e)
Annual herb. Occurs in sandy
soil on flats and foothills in
mixed grassland, coastal sage
scrub, and chaparral
communities. Elevation range
90-800 m. Flowering period
May-Jun.

Low. The study area supports
limited areas of highly disturbed
sandy soils. This species was
recorded on CNDDB in 2010,
approximately 4.8 miles to the
northeast of the study area.

Chorizanthe polygonoides
var. longispina
long-spined
spineflower
CRPR 1B.2
MSHCP Covered Species
Annual herb. Occurs within clay
lenses largely devoid of shrubs.

Can be occasionally seen on
vernal pool and even montane
meadows peripheries near
vernal seeps. Elevation range
30-1500 m. Flowering period
Apr-Jun.

Low. The study area supports
highly disturbed mesic areas.

This species was recorded on
CNDDB in 2015, approximately

3.3 miles to the northwest of the
study area within the Santa Rosa
Plateau.

Clinopodium chandleri San Miguel savory CRPR 1B.2
MSHCP Covered Species (b)
Perennial herb. Occurs on
Gabbro and metavolcanic soils
in interior foothills, chaparral,
and oak woodland. Elevation
range 0-1100 m. Flowering
period Mar-Jul.

None. The study area does not
support Gabbro or metavolcanic
soils.

Dudleya viscida sticky dudleya CRPR 1B.2
MSHCP Covered Species (f)
Perennial herb. Occurs on cliffs
and bluffs within chaparral,
coastal sage scrub, coastal bluff
scrub, and cismontane
woodland. Elevation range
below 450 m. Flowering period
May-Jun.

None. The study area does not
support cliffs or bluffs.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-4
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Eryngium aristulatum var.
parishii
San Diego button-
celery
FE/SE
CRPR 1B.1
MSHCP Covered Species
Annual or perennial herb.

Occurs in San Diego mesa
hardpan and clay pan vernal
pools, and southern interior
basalt flow vernal pools.

Elevation range 0-705 m.

Flowering period May-Jun.

None. The study area is not
within the geographic range of
this species.

Hordeum intercedens vernal barley CRPR 3.2
MSHCP Covered Species
Annual grass. Saline flats and
depressions in grasslands or in
vernal pool basins. Elevation
range 5-1000 m. Flowering
period Mar.-Jun.

Low. The study area supports
highly disturbed saline and
mesic habitat. This species was
recorded in the Consortium of
California Herbaria’s database in
2006, approximately 6.3 miles to
the northeast of the study area.

Horkelia cuneata var.
puberula
mesa horkelia CRPR 1B.1 Perennial herb. Occurs in sandy or gravelly areas within
chaparral, coastal sage scrub,
and coastal mesas. Elevation
range 70-870. Flowering period
Mar-Jul.

None. The study area does not
support chaparral, coastal sage
scrub, or coastal mesa habitats.

Juncus luciensis Santa Lucia dwarf rush CRPR 1B.2 Annual grass-like herb. Occurs in mesic sandy soils within seeps,
meadows, vernal pools,
streams, and roadsides.

Elevation 300-1900 m.

Flowering period Apr-Jul.

None. The study area supports
mesic areas. However, the
regional occurrences are limited
to the Santa Rosa Plateau,
approximately 2.75 miles to
west of the study area.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-5
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Lasthenia glabrata ssp.
coulteri
Coulter's goldfields CRPR 1B.1
MSHCP Covered Species (d)
Annual herb. Occurs in alkaline
soils, sinks, and grasslands.

Elevation range 0-1000 m.

Flowering period Apr-May.

Low. The study area supports
suitable mesic habitat with
alkaline soils, although these
areas are highly disturbed. This
species was recorded on CNDDB
in 1936, within a polygon that
includes a small area in the
southern portion of the study
area.

Mielichhoferia shevrockii Shevrock’s copper
moss
CRPR 1B.2

Moss. Occurs on rocks
containing heavy metals and
rocks along roadsides on mesic
sites within cismontane
woodland. Elevation range 750-
1400 m. Capsules mature Apr-
Jun. Flowering period N/A.

None. The study area is located
outside of this species’ the
elevation range.

Myosurus minimus ssp.
apus
little mousetail CRPR 3.1
MSHCP Covered Species (d)
Annual herb. Vernal pools and
alkaline marshes. This cryptic
species typically grows in the
deeper portions of vernal pool
basins, sprouting immediately
after the surface water has
evaporated. Elevation range 20-
640 m. Flowering period Mar-
Jun.

Low. The study area does not
support vernal pools but does
support potential wetland within
alkaline soils. This species was
recorded in CNDDB in 1990,
approximately 3.2 miles to the
northwest of the project site
within the Santa Rosa Plateau.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-6
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Navarretia fossalis spreading navarretia FT
CRPR 1B.1
MSHCP Covered Species (b)
Annual herb. Occurs in vernal
pools, vernal swales, or roadside
depressions. Population size is
strongly correlated with rainfall.

Depth of pool appears to be a
significant factor as this species
is rarely found in shallow pools.

Elevation range 30-1300 m.

Flowering period Apr-Jun.

Low. The study area supports
some areas of highly disturbed
roadside depressional areas with
soils. This species was recorded
in CNDDB in 1998,
approximately 2.9 miles to the
northwest of the study area.

Navarretia prostrata prostrate vernal pool
navarretia
CRPR 1B.1
MSHCP Covered Species (d)
Annual herb. Occurs in alkaline
floodplain, meadows, seeps, and
vernal pools within coastal scrub
and valley and foothill grassland.

Elevation range below 700 m.

Flowering period Apr-Jul.

Low. The study area supports
disturbed alkaline floodplain.

This species was recorded in
CNDDB in 2009, approximately

3.3 miles to the west of the
study area.

Orcuttia californica California Orcutt grass FE/SE
CRPR 1B.1
MSHCP Covered Species (b)
Annual herb. Occurs in or near
vernal pools. This species tends
to grow in wetter portions of
the vernal pool basin but does
not show much growth until the
basins become somewhat
desiccated. Elevation range 0-
700 m. Flowering period Apr-
Aug.

None. The study area does not
support vernal pools.

Pseudognaphalium
leucocephalum
white rabbit-tobacco CRPR 2B.2 Biennial or short-lived perennial herb. Occurs in sandy and
gravelly benches, dry stream
and canyon bottoms within
woodland, coastal scrub, and
chaparral. Elevation range
below 500 m. Flowering period
Jul-Oct.

None. The study area does not
support suitable dry streambed
habitat.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-7
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Scutellaria bolanderi ssp.
austromontana
southern mountain
skullcap
CRPR 1B.2 Perennial herb. Occurs within
gravelly soils along streambanks
in oak and pine woodlands.

Elevation 425-2000 m.

Flowering period Jun-Aug.

None. The study area does not
support suitable streambank oak
or pine woodlands. The study
area is located outside of this
species’ elevation range.

Symphyotrichum defoliatum San Bernardino aster CRPR 1B.2 Perennial herb. Occurs in vernally mesic soils within
cismontane woodland, coastal
scrub, lower montane
coniferous forest, meadows and
seeps, marshes and swamps,
grasslands, streams, springs, and
disturbed ditches. Elevation
range 0-2050 m. Flowering
period Jul-Nov.

Low. The study area does
support a limited area of
roadside depressional areas and
disturbed ditches draining into
Murrieta Creek. However, this
species has not been recorded in
the vicinity of the study area
since 1923.

Tetracoccus dioicus Parry’s tetracoccus CRPR 1B.2

Shrub. Occurs on stony,
decomposed gabbro and dry
slopes within chaparral and
coastal scrub. Elevation below
1000 m. Flowering period Apr-
May.

None. The study area does not
support chaparral or coastal
sage scrub habitats.

Diaz Road Improvements Project
Appendix E (cont.)
Rare Plant Species Potential to Occur

E-8
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3
Tortula californica California screw-moss CRPR 1B.2

Moss. Occurs in sandy soils
within chenopod scrub and
grasslands. Elevation 10-1460
m. Flowering Period N/A
None. The study area does not
support chenopod scrub or
grasslands.

Source: HELIX (2021)
1 Sensitive species reported within the Murrieta and Temecula quadrangles based on a database search conducted on CNDDB and CNPS. 2 Listing is as follows: F = Federal; S = State of California; E = Endangered; T = Threatened.

CRPR = California Rare Plant Rank: 1A – presumed extinct; 1B – rare, threatened, or endangered in California and elsewhere; 2A – rare, threatened, or endangered in California and elsewhere; 2B – rare, threatened, or endangered in California but more common elsewhere. Extension codes: .1 – seriously endangered; .2 – moderately endangered; .3 – not very endangered. MSHCP Conditionally Covered Species (a) through (f): (a) surveys may be required for species as part of wetland mapping (MSHCP Section 6.1.2); (b) surveys may be required for species within Narrow Endemic Plant Species Survey Area (MSHCP Section 6.1.3); (c) surveys may be required for species within locations shown on survey maps (MSHCP Section 6.3.2); (d) surveys may be required for species within Criteria Area Species Survey Area (MSHCP Section 6.3.2); (e) covered species will be considered to be covered species adequately conserved when conservation requirements identified in species-specific conservation objectives have been met (MSHCP Table 9-3); and (f) covered species will be conserved covered species adequately conserved when a Memorandum of Understanding is executed with the Forest Service that addresses management for these species on Forest Service Land (MSHCP Table 9-3). 3 Potential to Occur is assessed as follows: None: Habitat suitable for species survival does not occur on the study area, the study area is not within geographic range of the species, and/or the study area is not within the elevation range of the species; Low: Suitable habitat is present on the study area but of low quality and/or small extent. The species has not been recorded recently on or near the study area. Although the species was not observed during surveys for the current project, the species cannot be excluded with certainty; Moderate: Suitable habitat is present on the study area and the species was recorded recently near the study area; however, the habitat is of moderate quality and/or small extent. Although the species was not observed during surveys for the current project, the species cannot be excluded with certainty; High:

Suitable habitat of sufficient extent is present on the study area and the species has been recorded recently on or near the study area, but was not observed during surveys for the current project. However, focused/protocol surveys are not required or have not been completed; Presumed Present: The species was observed during focused surveys for the current project and is assumed to occupy the study area; Presumed Absent: Suitable habitat is present on the study area but focused surveys for the species were negative.

Appendix F
Sensitive Animal Species Potential
to Occur

Diaz Road Improvements Project
Appendix F
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-1
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Insects
Bombus crotchii Crotch bumble bee --/SCE Coastal California east to the Sierra- Cascade crest and south into Mexico.

Species’ food genera include
Antirrhinum sp., Phacelia sp., Clarkia
sp., Dendromecon sp., Eschscholzia
sp., and Eriogonum sp.

None. The study area does not
support chaparral or coastal sage
scrub habitat.

Euphydryas editha
quino
quino checkerspot
butterfly
FE/--
MSHCP Covered Species
Open, sunny areas within chaparral
and coastal sage scrub. Host plants
are Plantago spp., Antirrhinum
coulterianum, and Cordylanthus
rigidus.

None. The study area does not
support chaparral or coastal sage
scrub habitat.

Invertebrates
Branchinecta lynchi vernal pool fairy shrimp FT
MSHCP Covered Species (a)
Most commonly found in swale,
earth slump, or basal-flow depression
pools in unplowed grasslands.

Requires cool-water pools.

None. The study area does not
support vernal pools.

Branchinecta
sandiegonensis
San Diego fairy shrimp FE Vernal pools. Endemic to mesas in San Diego and Orange Counties.

None. The study area does not
support vernal pools.

Streptocephalus
woottoni
Riverside fairy shrimp FE
MSHCP Covered Species (a)
Typically requires deep vernal pools
and seasonal wetlands at least 30
centimeters deep.

None. The study area does not
support vernal pools.

Fish
Gila orcuttii arroyo chub SSC
MSHCP Covered Species
Prefers slow moving streams or
backwaters with sand or mud
bottoms. Streams are typically
deeper than 40 centimeters (16
inches). Primary food source is
aquatic vegetation and invertebrates.

None. The study area does not
support perennial stream habitat.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-2
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Amphibians
Spea hammondii western spadefoot SSC
MSHCP Covered Species
Occurs in open coastal sage scrub,
chaparral, and grassland, along sandy
or gravelly washes, floodplains,
alluvial fans, or playas; requires
vernal pools for breeding and friable
soils for burrowing; generally
excluded from areas with bullfrogs
(Rana catesbiana) or crayfish
(Procambarus spp.)
Moderate. The study area supports
limited areas of floodplain habitat
within Murrieta Creek. However,
there are no observations of this
species recorded on CNDDB within
Murrieta Creek. This species was
recorded in CNDDB in 2017,
approximately 0.8 mile to the west
of the study area.

Taricha torosa Coast Range newt SSC
MSHCP Covered Species
Breeds in ponds, reservoirs, and
slow-moving stream pools; often
found in riparian forest, woodlands,
chaparral, or grassland within one
kilometer of breeding habitat.

Low. The study area supports limited
areas of habitat within Murrieta
Creek. However, there are no
observations of this species recorded
in CNDDB within Murrieta Creek.

This species was recorded in CNDDB
in 2001, approximately 5.0 miles to
the northwest of the study area
within Cole Canyon.

Reptiles
Anniella stebbinsi Southern California
legless lizard
SSC Occurs in moist, warm, loose soil with
plant cover. May be found in coastal
sand dunes, chaparral, pine-oak
woodlands, desert scrub, sandy
washes, and stream terraces with
sycamores, cottonwoods, or oaks.

Moderate. The study area supports
suitable moist soils with plant cover
and sandy wash habitat. This species
was recorded in CNDDB in 2000,
approximately 5.4 miles to the
northeast of the project site.

Arizona elegans
occidentalis
California glossy snake SSC Most common in desert habitats, but also occurs in chaparral, arid scrub,
and annual grassland. Associated
with sandy open areas with sparse
shrub cover, but can also occur in
rocky habitats.

None. The study area does not
support chaparral, grassland, or
scrub habitat.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-3
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Aspidoscelis tigris
stejnegeri
coastal whiptail SSC
MSHCP Covered Species
Open coastal sage scrub, chaparral,
and woodlands. Frequently found
along the edges of dirt roads
traversing its habitats. Important
habitat components include open,
sunny areas, shrub cover with
accumulated leaf litter, and an
abundance of insects, spiders, or
scorpions.

High. The study area supports
suitable habitat within the southern
willow scrub and cottonwood-willow
riparian habitats. This species was
recorded in CNDDB in 2001,
approximately 1.9 miles the
southeast of the study, at the
confluence of Murrieta Creek and
the Santa Margarita River.

Crotalus ruber red diamond
rattlesnake
SSC
MSHCP Covered Species
Occurs in chaparral, coastal sage
scrub, along creek banks, particularly
among rock outcrops or piles of
debris with a supply of burrowing
rodents for prey.

Moderate. The study area supports
suitable habitat within the southern
willow scrub and southern
cottonwood-willow riparian forest.

The nearest occurrence recorded in
CNDDB is an undated collection
made approximately 2.5 miles to the
southeast of the study area.

Actinemys pallida southwestern pond
turtle
SSC
MSHCP Covered Species
Almost entirely aquatic; occurs in
freshwater marshes, creeks, ponds,
rivers and streams, particularly where
basking sites, deep water retreats,
and egg laying areas are readily
available.

Moderate. The study area supports
suitable aquatic habitat for this
species. There is an occurrence
recorded in CNDDB in 2015 located
adjacent to the study area,
downstream of the intersection of
Diaz Road and Rancho California
Road.

Phrynosoma blainvillii coast horned lizard SSC
MSHCP Covered Species
Coastal sage scrub and open areas in
chaparral, oak woodlands, and
coniferous forests with sufficient
basking sites, adequate scrub cover,
and areas of loose soil; require native
ants, especially harvester ants
(Pogonomyrmex spp.), and are
generally excluded from areas
invaded by Argentine ants
(Linepithema humile).

None. The study area does not
support chaparral, oak woodlands,
or coniferous forest habitats.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-4
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Thamnophis
hammondii
two-striped
gartersnake
SSC Occurs in or near permanent fresh
water bordered by dense riparian
vegetation. Occasionally occurs in
artificially created aquatic habitats,
such as manmade lakes or stock
ponds.

Moderate. The study area supports
suitable aquatic habitat and riparian
vegetation.

Birds
Aquila chrysaetos golden eagle SFP
MSHCP Covered Species
Typical foraging habitat includes
grassy and open, shrubby habitats.

Generally nests on remote cliffs;
requires areas of solitude at a
distance from human habitation.

None. The study area does not
support suitable open space for this
species or remote cliffs for nesting.

Athene cunicularia burrowing owl SSC
MSHCP Covered Species (c)
Typical habitat is grasslands, open
scrublands, agricultural fields, and
other areas where there are ground
squirrel burrows or other areas in
which to burrow.

Presumed Absent. The study area
supports some limited areas of
suitable habitat. Focused surveys
performed in 2020 were negative.

Buteo swainsoni Swainson's hawk ST
MSHCP Covered Species
Breeds in open grassland with
scattered trees or groves within
agricultural/ranch lands. Forages for
small mammals, reptiles, birds, and
insects in adjacent grassland and
agricultural fields.

Low. The study area supports a small
amount of suitable foraging habitat
for this species. This species is not
known to nest in southern California
with the exception of populations in
the Antelope Valley and Mojave
Desert. An observation of this
species was recorded in eBird in
2015, approximately 2.6 miles to the
southwest of the study area within
Temecula Creek.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-5
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Coccyzus americanus western yellow-billed
cuckoo
FT/SE
MSHCP Covered Species (a)
Generally occurs along larger river
systems, where it nests in riparian
forest dominated by willows (Salix
sp.) and cottonwoods (Populus sp.).

None. Small patches of riparian
forest habitat exist on the study area
within Murrieta Creek. However, this
habitat is patchy and does not
support perennial water. This
species has not been recorded on
CNDDB within the vicinity of the
study area since 1950.

Elanus leucurus white-tailed kite SFP
MSHCP Covered Species
Nests in trees with dense canopies
within open grasslands, woodlands,
and marshes. Forages for small
mammals within lightly
grazed/ungrazed pastures and
grasslands.

High. The study area supports a
small amount of suitable nesting
habitat within the southwestern
willow scrub, southern cottonwood-
willow riparian forest, and
eucalyptus woodland. An
observation of this species within
the study area was recorded in eBird
in 2021.

Empidonax traillii
extimus
southwestern willow
flycatcher
FE/SE Nests within thickets of willows or
other riparian understory usually
along streams, ponds, lakes, or
canyons. Migrants may be found
among other shrubs in wetter areas.

Presumed Absent. The study area
supports potentially suitable riparian
habitat. Focused surveys performed
in 2020 were negative.

Polioptila californica
californica
coastal California
gnatcatcher
FT/SSC
MSHCP Covered Species
Occurs in coastal sage scrub and very
open chaparral.

None. The study area does not
support coastal sage scrub or
chaparral.

Vireo bellii pusillus least Bell's vireo FE/SE
MSHCP Covered Species (a)
Inhabits riparian woodland and is
most frequent in areas that combine
an understory of dense, young
willows or mule fat with a canopy of
tall willows.

Presumed Present. The study area
supports suitable southern willow
scrub habitat. Focused surveys
performed in 2020 detected four
males and one pair within or
adjacent to the study area.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-6
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Mammals
Chaetodipus
californicus femoralis
Dulzura pocket mouse SSC Primarily associated with mature chaparral. It has, however, been
trapped in mule fat scrub and is
known to occur in coastal sage scrub.

None. The study area does not
support chaparral, mule fat scrub, or
coastal sage scrub.

Chaetodipus fallax
fallax
northwestern San
Diego pocket mouse
SSC
MSHCP Covered Species
Herbaceous openings within coastal
sage scrub, chaparral, grasslands, and
desert scrub. Often associated with
sandy, rocky, or gravelly substrates.

None. The study area does not
support coastal sage scrub,
chaparral, grasslands, or desert
scrub.

Dipodomys merriami
parvus
San Bernardino
kangaroo rat
FE/SSC
MSHCP Covered Species (c)
Generally associated with alluvial fan
sage scrub, but also occurs in sage
scrub, chaparral, and grassland in
proximity to alluvial fan sage scrub
habitats.

None. The study area does not
support alluvial fan sage scrub.

Dipodomys stephensi Stephens' kangaroo rat FE/ST
MSHCP Covered Species
Primarily occurs in sparsely vegetated
areas within grassland habitats, but
also found in open coastal scrub
habitat. Feeds on filaree (Erodium
sp.) and brome (Bromus sp.) seeds.

Dig burrows in firm soil or use
abandoned pocket gopher burrows.

Moderate. The study area supports
suitable sparsely vegetated areas for
this species. The nearest observation
of this species was recorded in
CNDDB in 1994, approximately 1.5
miles to the southeast of the study
area.

Eumops perotis
californicus
western mastiff bat SSC Roosts under exfoliating rock slabs on cliff faces and occasionally in large
boulder crevices and building cracks.

Forages in a variety of open areas,
including washes, floodplains,
chaparral, coastal sage scrub,
woodlands, ponderosa pine forests,
grassland, and agricultural areas.

Low. The study area does not
support suitable roosting habitat but
does support foraging habitat. This
species was recorded on CNDDB in
2001, less than 0.3 mile to the
southeast of the study area.

Lepus californicus
bennettii
San Diego black-tailed
jackrabbit
SSC
MSHCP Covered Species
Occurs primarily in open habitats
including coastal sage scrub,
chaparral, grasslands, croplands, and
open, disturbed areas if there is at
least some shrub cover present.

Low. The study area supports a
limited amount of suitable disturbed
habitat with some shrub cover. This
species was recorded on CNDDB in
2007, approximately 1.4 miles to the
north of the study area.

Diaz Road Improvements Project
Appendix F (cont.)
SENSITIVE ANIMAL SPECIES POTENTIAL TO OCCUR1
F-7
Species Name Common Name Status2 Habitat, Ecology, and Life History Potential to Occur3 Perognathus
longimembris
brevinasus
Los Angeles pocket
mouse
SSC
MSHCP Covered Species (c)
Sandy, gravelly, or stony soils within
coastal scrub, alluvial sage scrub, and
grassland habitats.

None. The study area does not
support suitable habitat for this
species.

Source: HELIX (2021)
1 Sensitive species reported within the Murrieta and Temecula quadrangles based on a database search conducted on CNDDB. 2 Listing is as follows: F = Federal; S = State of California; E = Endangered; T = Threatened; CE = Candidate Endangered; CT = Candidate Threated; FP = Fully Protected; SSC = State Species of Special Concern. MSHCP Conditionally Covered Species (a) through (f): (a) surveys may be required for species as part of wetland mapping (MSHCP Section 6.1.2); (b) surveys may be required for species within Narrow Endemic Plant Species Survey Area (MSHCP Section 6.1.3); (c) surveys may be required for species within locations shown on survey maps (MSHCP Section 6.3.2); (d) surveys may be required for species within Criteria Area Species Survey Area (MSHCP Section 6.3.2); (e) covered species will be considered to be covered species adequately conserved when conservation requirements identified in species-specific conservation objectives have been met (MSHCP Table 9- 3); and (f) covered species will be conserved covered species adequately conserved when a Memorandum of Understanding is executed with the Forest Service that addresses management for these species on Forest Service Land (MSHCP Table 9-3). 3 Potential to Occur is assessed as follows. None: Species is so limited to a particular habitat that it cannot disperse across unsuitable habitat (e.g. aquatic organisms), and habitat suitable for its survival does not occur on the study area; Not Expected: Species moves freely and might disperse through or across the study area, but suitable habitat for residence or breeding does not occur on the study area (includes species recorded during surveys but only as transients); Low: Suitable habitat is present on the study area but of low quality and/or small extent. The species has not been recorded recently on or near the study area. Although the species was not observed during surveys for the current project, the species cannot be excluded with certainty; Moderate: Suitable habitat is present on the study area and the species was recorded recently near the study area; however, the habitat is of moderate quality and/or small extent. Although the species was not observed during surveys for the current project, the species cannot be excluded with certainty; High: Suitable habitat of sufficient extent for residence or breeding is present on the study area and the species has been recorded recently on or near the study area, but was not observed during surveys for the current project. However, focused/protocol surveys are not required or have not been completed; Presumed Present: The species was observed during biological surveys for the current project and is assumed to occupy the study area; Presumed Absent: Suitable habitat is present on the study area but focused/protocol surveys for the species were negative.

Appendix G
Burrowing Owl Focused
Survey Report

HELIX Environmental Planning, Inc.
16485 Laguna Canyon Road, Suite 150
Irvine, CA 92618
949.234.8792 tel.
619.462.0552 fax
www.helixepi.com

October 15, 2020 DEA-12
Mr. Gavin Powell
David Evans and Associates, Inc.
41951 Remington Avenue, Suite 220
Temecula, CA 92590
Subject: 2020 Burrowing Owl (Athene cunicularia) Survey Report for the Diaz Road Expansion Project
Dear Mr. Powell:

This letter report presents the results of the 2020 focused burrowing owl (Athene cunicularia; BUOW) survey conducted by HELIX Environmental Planning, Inc. (HELIX) for the Diaz Road Expansion Project (project) located in the City of Temecula, Riverside County (County), California. The survey was conducted in accordance with the County’s Burrowing Owl Survey Instructions for the Western Riverside Multiple Species Habitat Conservation Plan (MSHCP; County of Riverside [County] 2006). This survey was conducted to meet applicable conditions under the MSHCP, which was approved in 2003 (Dudek and Associates [Dudek] 2003). The MSHCP is a comprehensive planning effort that includes the County of Riverside and multiple cities. As part of the MSHCP implementation, enrolled jurisdictions are required to impose terms of the MSHCP, including appropriate surveys in accordance with Volume 1, Section 6.

The project site is located within the MSHCP BUOW Survey Area; therefore, surveys are required if suitable habitat is present (County 2006). This letter report describes the methods used to perform the survey and the survey results.

STUDY AREA LOCATION
The project site is located within the City of Temecula in Riverside County, California (Figure 1, Regional Location). It lies within Township 7 South, Range 3 West and Township 8 South, Range 3 West, on the U.S. Geological Survey (USGS) 7.5-minute Murrieta and Temecula quadrangle maps (Figure 2, USGS Topography). The project proposes to improve an approximately 2.2-mile segment of Diaz Road located west of Interstate (I-) 15, approximately between Cherry Street and Rancho California Road (Figure 3, Aerial Photograph). The survey area includes the project site plus an additional 500 feet (Figure 3).

PROJECT DESCRIPTION
The proposed project is for the development and improvement of Diaz Road.

Letter to Mr. Gavin Powell Page 2 of 5
October 15, 2020

PROJECT SITE DESCRIPTION
The topography of the study area is mostly flat with elevations on the study area range from approximately 1,016 feet (310 meters) above mean sea level (AMSL) near the northern boundary to a high of approximately 1,037 feet (316 meters) AMSL near the northern boundary. Representative photographs of the project site are depicted in Attachment A, Site Photographs.

Eight soil types are mapped on the project site, including Chino silt loam (drained, saline-alkaline), Domino silt loam (strongly saline-alkaline), Grangeville fine sandy loam (drained, 0 to 5 percent slopes), Grangeville fine sandy loam (saline-alkali, 0 to 5 percent slopes), Grangeville sandy loam (sand substratum, drained, 0 to 5 percent slopes), Riverwash, Willows silty clay (deep, saline-alkaline), Willows silty clay (deep, strongly saline-alkaline
Surrounding land uses include commercial development with some undeveloped parcels to the southwest. A park and Murrieta Creek exist along the northeast boundary of the study area. The western portion is bound by Diaz Road and commercial developments. (Figure 3). The project site is located approximately 2.5 miles east of the Santa Rosa Plateau Ecological Reserve.

METHODS
A Step I Habitat Assessment and Step II Locating Burrows and Burrowing Owls were conducted on the project site by HELIX biologists, Matthew Dimson and Daniel Torres between June 5 and August 6, 2020, in accordance with the County’s survey protocol (County 2006). The specific survey information is provided in Table 1, Survey Information. The habitat assessment and focused burrow and BUOW surveys are described in detail below.

Table 1

SURVEY INFORMATION
Site
Visit
Survey
Date Biologists Start/Stop
Time
Start/Stop
Weather Conditions Survey Results
11 06/05/20 Matthew Dimson 0515-0735 61F, wind 0-1 mph, 0% clouds 75F, wind 0-1 mph, 10% clouds
Suitable habitat and
burrows observed;
no BUOW detected.
2 07/08/20 Matthew Dimson 0545-0745
65F, wind 1-2 mph, 100%
clouds
66F, wind 1-2 mph, 100%
clouds
No BUOW detected.
3 07/21/20 Matthew Dimson 0550-0750 67F, wind 1-2 mph, 50% clouds 69F, wind 0-1 mph, 50% clouds No BUOW detected.
4 08/06/20 Daniel Torres 0605 - 0800
59 F, wind 1-2 mph, 100%
clouds
61F, wind 3-4 mph, 95% clouds
No BUOW detected.
1 This visit included the habitat assessment, focused burrow survey, and first focused burrowing owl survey.

Step I – Habitat Assessment

Letter to Mr. Gavin Powell Page 3 of 5
October 15, 2020

The project site is located within an MSHCP BUOW survey area; therefore, a Step I Habitat Assessment was conducted to determine whether the project site supports suitable BUOW habitat. The habitat assessment was conducted prior to commencement of the Step II surveys described below. The assessment was conducted on the project site and within a 150-meter (approximately 500-foot) buffer zone around the periphery of the project site (collectively, the survey area). The survey area was slowly walked and assessed for suitable BUOW habitat, including:
• disturbed low-growing vegetation within grassland and shrublands (less than 30 percent canopy cover);
• gently rolling or level terrain;
• areas with abundant small mammal burrows, especially California ground squirrel burrows (Otospermophilus beecheyi);
• fence posts, rocks, or other low perching locations; and • man-made structures, such as earthen berms, debris piles, and cement culverts.

Inaccessible areas of the survey area and buffer zone were visually assessed using binoculars.

Step II – Locating Burrows and Burrowing Owls
Since suitable habitat was observed during the habitat assessment, Step II surveys were conducted within the survey area. Step II surveys, which consist of a focused burrow survey (Part A) and four focused BUOW surveys (Part B), were conducted to determine whether the survey area supports suitable burrows and/or BUOW. The focused burrow survey was conducted concurrently with the first BUOW survey.

All potential burrows were checked for signs of recent owl occupation. Signs of occupation include:
• pellets/casting (regurgitated fur, bones, and/or insect parts); • white wash (excrement); and/or
• feathers.

Since suitable burrows were observed within the survey area, three additional BUOW surveys were conducted. The biologists walked transects spaced no greater than 30 meters apart (approximately 100 feet) to allow for 100 percent visual coverage of all suitable habitat within the survey area. The biologists walked slowly and methodically, closely checking suitable habitat within the survey area for suitable burrows, BUOW diagnostic sign (e.g., molted feathers, pellets/castings, or whitewash at or near a burrow entrance), and individual BUOW. Inaccessible areas of the survey area were visually assessed using binoculars. All suitable burrows, burrow surrogates, BUOW sign, and/or BUOW observations were recorded using a handheld Global Positioning System unit (Figure 4, Suitable Burrow and Transect Locations).

RESULTS
Suitable BUOW habitat was observed within the survey area, including disturbed habitat and non-native grasslands (Attachment A). Suitable burrows that could potentially be used by BUOW were observed within and adjacent to the survey area. No BUOW or sign of BUOW occupation were observed during

Letter to Mr. Gavin Powell Page 4 of 5
October 15, 2020

the four focused surveys. Therefore, BUOW does not currently occupy the survey area. Observed burrow locations and transects walked are shown on Figure 4.

CONCLUSION
No BUOWs were observed or detected within the survey area during the focused surveys. Burrows with potential to support BUOW were noted in the survey area, but no sign of BUOW occupation was observed. A pre-construction survey is required 30 days prior to ground disturbance pursuant to the County’s survey protocol (County 2006). If ground-disturbing activities are delayed more than 30 days after the pre-construction survey has been completed, the survey area must be resurveyed.

If you have any questions regarding the information presented in this letter report, please contact Ezekiel Cooley ([email protected]) or Lauren Singleton ([email protected]) at (949) 234-8770.

Sincerely,

Matthew Dimson Daniel Torres
Biologist Biologist

Attachments:

Figure 1: Regional Location
Figure 2: USGS Topography
Figure 3: Aerial Photograph
Figure 4: Suitable Burrow and Transect Locations
Attachment A: Site Photographs

Letter to Mr. Gavin Powell Page 5 of 5
October 15, 2020

REFERENCES
Dudek and Associates. 2003. Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP) Final MSHCP Volume I. Prep. for County of Riverside, Transportation and Land Management Agency.

Riverside, County of. 2006. Environmental Programs Department. Burrowing Owl Survey Instructions for the Western Riverside Multiple Species Habitat Conservation Plan Area. Retrieved from:
http://www.wrc-
rca.org/species/survey_protocols/Birds/Burrowing%20Owl%20Survey%20Instructions%20compl ete.pdf. March 29. Accessed August 20, 2019.

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Regional LocationH:\GIS\PROJECTS\D\DEA-All\DEA-12\Map\BUOW\Fig1_Regional.mxd DEA-12 10/13/2020 - SABSource: Base Map Layers (ESRI, 2013)K Diaz Road Expansion
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H:\GIS\PROJECTS\D\DEA-All\DEA-12\Map\BUOW\Att_A_SitePhotos1-4.indd DEA-12 10/09/20 -ECRepresentative Site Photographs Attachment A
Source: HELIX 2020
Photograph 1: View of a non-native grassland in the southern portion of the project site, facing southeast.

Photograph 3: View of disturbed habitat in the northern portion of the project site, facing north.

Photograph 2: View of a suitable burrow in the center of the project site, facing east.

Photograph 4: View of an open culvert in the center of the project, facing west.

Appendix H
Least Bell’s Vireo Focused
Survey Report

HELIX Environmental Planning, Inc.
16485 Laguna Canyon Road
Suite 150
Irvine, CA 92618
949.234.8792 tel.
619.462.0552 fax
www.helixepi.com

August 27, 2020 DEA-12

Ms. Stacey Love
U.S. Fish and Wildlife Service
2177 Salk Avenue, Suite 250
Carlsbad, CA 92008

Subject: 2020 Least Bell’s Vireo (Vireo bellii pusillus) Survey Report for the Diaz Road Expansion Project
Dear Ms. Love:

This letter presents the results of a U.S. Fish and Wildlife Service (USFWS) protocol presence/absence survey for the federally endangered least Bell’s vireo (Vireo bellii pusillus; LBVI) conducted by HELIX Environmental Planning, Inc. (HELIX) for the Diaz Road Expansion Project (project). This letter describes the survey methods and results and is being submitted to the USFWS in accordance with protocol survey guidelines.

PROJECT LOCATION
The project is located in the City of Temecula, Riverside County, California (Figure 1, Regional Location).

It is depicted within unsectioned lands in Township 7 South, Range 3 West and Township 8 South, Range 3 West, on the U.S. Geological Survey (USGS) 7.5-minute Murrieta and Temecula quadrangle maps (Figure 2, USGS Topography). The project proposes to improve an approximately 2.2-mile segment of Diaz Road located west of Interstate (I-) 15, approximately between Cherry Street and Rancho California Road (Figure 3, Aerial Photograph). The project study area includes the project site plus an additional 500 feet (Figure 3). The study area does not occur within or adjacent to USFWS-designated critical habitat for the species.

METHODS
The survey consisted of eight site visits conducted by HELIX biologists Erica Harris, Ezekiel Cooley, Daniel Torres, and Lauren Singleton between April 28 and July 27, 2020 (Table 1, Survey Information), in accordance with the current USFWS survey protocol 1. The LBVI survey area included all suitable habitat

1 U.S. Fish and Wildlife Service (USFWS). 2001. Least Bell’s Vireo Survey Guidelines. January 19.

Letter to Ms. Stacey Love Page 2 of 11
August 27, 2020

located within study area. Approximately 28.0 acres of the suitable LBVI habitat surveyed was composed of southern willow scrub located along Murrieta Creek, as well as southern cottonwood-willow riparian forest located in a tributary to Murrieta Creek (Figure 4, 2020 Least Bell’s Vireo Survey Results).

The surveys were conducted by walking along the edges of, as well as within, potential LBVI habitat in the survey area while listening for LBVI and viewing birds with the aid of binoculars. The survey route was designed to ensure complete survey coverage of habitat potentially occupied by LBVI.

A portion of the surveys were conducted on the same days as the protocol surveys for the southwestern willow flycatcher (Empidonax traillii extimus; SWFL). During these survey visits, a permitted biologist for SWFL surveyed the entire survey area for both SWFL and LBVI; however, the surveys were not conducted concurrently. The LBVI survey was conducted sequentially after the SWFL survey. The surveyor surveyed for SWFL as they walked one direction along/within suitable SWFL habitat, and then surveyed for LBVI as they walked back the other direction. A separate survey report is being submitted for the SWFL surveys (HELIX in preparation).

Table 1, Survey Information, details the survey dates, times, weather conditions, and survey results.

Letter to Ms. Stacey Love Page 3 of 11
August 27, 2020

Table 1

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
1 4/28/20 Ezekiel
Cooley 0700/1030 28.0 ac/

8.0 ac per hr.
60°F, wind 0-1 mph, 0% clouds
78°F, wind 0-1 mph, 0% clouds
• Male, presumably same male belonging
to Pair No. 1, heard singing within
northern portion of the study, approx.
1,100 feet northeast of Dendy Parkway.
• Male (Male No. 1) heard singing in
northern portion of the study area
approx. 730 feet northeast of Dendy
Parkway and 370 feet south of male
from Pair No. 1
• Male No. 2 heard singing to east of
intersection of Diaz Road and Dendy
Parkway and approx. 820 feet south of
Male No. 1.
• Male No. 3 singing to east of Diaz Road
approx. 1,300 feet north of Winchester
Avenue., to south of confluence of Santa
Gertrudis Creek and Murrieta Creek.
• Male No. 4 heard to east of Diaz Road
approx. 765 feet southeast of
Winchester Road.
0 Letter to Ms. Stacey Love Page 4 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
2 5/9/20 Lauren
Singleton 0730/1100 28.0 ac/

8.0 ac per hr.
60°F, wind 2-3 mph, 30% clouds
72°F, wind 4-5 mph, 20% clouds
• Male and female from Pair No. 1
detected. Male heard singing in same
general area. Female heard scolding
and observed foraging with male within
understory.
• Male No. 1 heard singing in same
general area at northern portion of site.
• Male No. 2 heard singing in same
general within northern portion of site.
• Male No. 3 singing in same general
areas near confluence of Santa
Gertrudis Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area to southeast of
Winchester Road.
4 Letter to Ms. Stacey Love Page 5 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
3 5/21/20 Erica
Harris2 0930/1100 28.0 ac/

18.7 ac per hr.
60°F, wind 0-1 mph, 0% clouds
68°F, wind 0-1 mph, 0% clouds
• Male from Pair No. 1 heard singing in
same general area within northern
portion of study area. Counter-singing
with Male. No. 1.
• Male No. 1 heard singing in same
general area in northern portion of
study area. Counter-singing with the
male from Pair No. 1 and Male No. 2.
• Male No. 2 heard singing in same
general area in northern portion of
study area. Counter-singing with Male
No. 1.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area southeast of Winchester
Road.
6 Letter to Ms. Stacey Love Page 6 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
4 6/4/20 Erica
Harris2 0900/1100 28.0 ac/

14.0 ac per hr.
76°F, wind 0-1 mph, 55% clouds
88°F, wind 1-3 mph, 70% clouds
• Male and female from Pair No. 1
detected. Male heard singing in same
general area. Female heard scolding
and observed foraging with male within
understory.
• Male No. 1 heard singing in same
general area in northern portion of
study area. Counter-singing with the
male from Pair No. 1 and Male No. 2.
• Male No. 2 heard singing in same
general area in northern portion of
study area. Counter-singing with Male
No.1.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area southeast of Winchester
Road.
7 Letter to Ms. Stacey Love Page 7 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
5 6/19/20 Erica
Harris2 0930/1100 28.0 ac/

18.7 ac per hr.
65°F, wind 0-1 mph, 100% clouds
73°F, wind 1-2 mph, 10% clouds
• Male from Pair No. 1 heard singing in
same general area within northern
portion of study area. Counter-singing
with Male. No. 1.
• Male No. 1 heard singing in same
general area in northern portion of
study area. Counter-singing with the
male from Pair No. 1 and Male No. 2.
• Male No. 2 heard singing in same
general area in northern portion of
study area. Counter-singing with Male
No. 1.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area southeast of Winchester
Road.
1 Letter to Ms. Stacey Love Page 8 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
6 7/2/20 Erica
Harris2 0930/1100 28.0 ac/

18.7 ac per hr.
67°F, wind 0-1 mph, 100% clouds
73°F, wind 0-1 mph, 80% clouds
• Male from Pair No. 1 heard singing in
same general area within northern
portion of study area. Counter-singing
with Male. No. 1.
• Male No. 1 heard singing in same
general area in northern portion of
study area. Counter-singing with the
male from Pair No. 1 and Male No. 2.
• Male No. 2 heard singing in same
general area in northern portion of
study area. Counter-singing with Male
No. 1.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area southeast of Winchester
Road.
3 Letter to Ms. Stacey Love Page 9 of 11
August 27, 2020

Table 1 (cont.)

SURVEY INFORMATION
Site Survey Biologist Time Approx. Acres Weather Conditions Survey Results Visit Date (Start/Stop) Surveyed/
Acres Per Hour
(Start/Stop) Least Bell’s Vireo (LBVI) Brown-Headed
Cowbird1
7 7/13/20 Erica
Harris2 0930/1100 28.0 ac/

18.7 ac per hr..
84°F, wind 0-1 mph, 0% clouds
89°F, wind 1-3 mph, 30% clouds
• Male from Pair No. 1 heard singing in
same general area within northern
portion of study area. Counter-singing
with Male. No.1.
• Male No. 1 heard singing in same
general area in northern portion of
study area. Counter-singing with the
male from Pair No. 1 and Male No. 2.
• Male No. 2 heard singing in same
general area in northern portion of
study area. Counter-singing with Male
No. 1.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area south of Winchester Road.
3 8 7/27/20 Daniel
Torres 0645/1020 28.0 ac/

7.8 ac per hr.
59°F, wind 1-2 mph, 0% clouds
72°F, wind 4-5 mph, 0% clouds
• Male No. 1 heard singing in same
general area in northern portion of
study area.
• Male No. 3 singing in same general area
near confluence of Santa Gertrudis
Creek and Murrieta Creek.
• Male No. 4 heard singing in same
general area south of Winchester Road.
0 1 Number of brown-headed cowbird (Molothrus ater) detected during survey. 2 Southwestern willow flycatcher (Empidonax traillii extimus) biologist; Conducted surveys on same day as the flycatcher surveys.

Letter to Ms. Stacey Love Page 10 of 11
August 27, 2020

SURVEY RESULTS
One vireo pair and four single male vireos were detected within the study area during the 2020 survey effort, though not all individuals were detected during each survey visit (Figure 4). One vireo pair (Pair No. 1) was observed within the northern portion of the study area, three male vireos were detected northwest of Winchester Road (Male No. 1, Male No. 2, and Male No. 3), and one male vireo was detected southeast of Winchester Road (Male No. 4) No banded individuals were observed during the survey; however, not all individuals were directly observed. A detailed description of LBVI locations and observations is included below.

One vireo pair (Pair No. 1) was detected within the northern portion of the study area, approximately 1,100 feet north of Dendy Parkway. Only the male was heard singing within the area during the first survey visit. The male and female were both observed foraging together during the second survey visit.

A male was heard singing during the third survey visit in the same general area and was counter-singing with another male vireo (Male No. 1) to the south. Both the male and female were observed foraging together during the fourth survey visit; both individuals were observed to be unbanded. The male was heard singing during the fifth through seventh survey visits, often heard simultaneously with Male No. 1, but was not detected during the eighth survey.

A single, unbanded male vireo (Male No. 1) was detected in the northern portion of the study area, approximately 730 feet northeast of Dendy Parkway and 370 feet south of Pair No. 1 (Figure 4). The male was heard singing within the area during all eight survey visits, and was often heard simultaneously singing with the male from Pair No. 1 to the north and another male vireo (Male No. 2) to the south. The male was visually observed during the fourth survey and was confirmed to be unbanded.

A single, unbanded male vireo (Male No. 2) was detected in the northern portion of the study area, east of the Diaz Road and Dendy Parkway intersection and approximately 820 feet south of Male No. 1 (Figure 4). The male was heard singing within the area during the first seven survey visits, often heard simultaneously with the Male No. 1 to the north, but was not detected during the eight survey. The male was visually observed during the fourth survey and was confirmed to be unbanded.

A single male vireo (Male No. 3) was detected within the central portion of the study area, approximately 1,300 feet north of Winchester Avenue and south of the confluence of San Gertrudis Creek and Murrieta Creek (Figure 4). The male was heard singing on both the east and west banks of the creek during all eight survey visits.

A single male vireo (Male No. 4) was detected in the central portion of the study area approximately 765 feet southeast of Winchester Road (Figure 4). The male was heard singing during all eight survey visits.

The brown-headed cowbird (Molothrus ater; BHCO), a nest parasite of the LBVI, was detected during six of the eight surveys along Murrieta Creek (Figure 4). Observations of BHCO included singing and calling males, calling females, and individuals observed in courtship displays.

Letter to Ms. Stacey Love Page 11 of 11
August 27, 2020

CERTIFICATION
I certify that the information in this survey report and attached exhibits fully and accurately represents our work. Please contact Shelby Howard or us at (619) 462-1515 should you have any questions.

Sincerely,

Erica Harris Ezekiel Cooley
Senior Scientist Biologist

Lauren Singleton Daniel Torres
Biologist Biologist

Attachments:

Figure 1: Regional Location
Figure 2: USGS Topography
Figure 3: Aerial Photograph
Figure 4: 2020 Least Bell’s Vireo Survey Results

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Appendix I
Southwestern Willow Flycatcher
Survey Report

HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
La Mesa, CA 91942
619.462.1515 tel
619.462.0552 fax
www.helixepi.com

August 27, 2020 DEA-12

Ms. Stacey Love
U.S. Fish and Wildlife Service
2177 Salk Avenue, Suite 250
Carlsbad, CA 92008

Subject: 2020 Southwestern Willow Flycatcher (Empidonax traillii extimus) Survey Report for the Diaz Road Expansion Project
Dear Ms. Love:

This letter presents the results of a U.S. Fish and Wildlife Service (USFWS) protocol presence/absence survey for the federally listed southwestern willow flycatcher (Empidonax traillii extimus; SWFL) conducted by HELIX Environmental Planning, Inc. (HELIX) for the Diaz Road Expansion Project (project).

This report describes the methods used to perform the survey and the results. It is being submitted to the USFWS as a condition of HELIX’s Threatened and Endangered Species Permit TE-778195-14.

PROJECT LOCATION
The project is located in the City of Temecula, Riverside County, California (Figure 1, Regional Location).

It is depicted within unsectioned lands in Township 7 South, Range 3 West and Township 8 South, Range 3 West, on the U.S. Geological Survey (USGS) 7.5-minute Murrieta and Temecula quadrangle maps (Figure 2, USGS Topography). The project proposes to improve an approximately 2.2-mile segment of Diaz Road located west of Interstate (I-) 15, approximately between Cherry Street and Rancho California Road (Figure 3, Aerial Photograph). The project study area includes the project site plus an additional 500 feet (Figure 3). The study area does not occur within or adjacent to USFWS-designated critical habitat for the species.

METHODS
The survey consisted of five site visits conducted by HELIX biologist Erica Harris (TE-778195-14) in accordance with the current USFWS approved survey protocol 1. The SWFL survey area included all

1 Sogge, Mark K., Ahlers, Darrell, and Sferra, Susan J. 2010. A Natural History Summary and Survey Protocol for the Southwestern Willow Flycatcher: U.S. Geological Survey Techniques and Methods 2A-10.

Letter to Ms. Stacey Love Page 2 of 5
August 27, 2020

suitable habitat located within the study area. Approximately 28.0 acres of potential SWFL habitat surveyed was composed of southern willow scrub located along Murrieta Creek, as well as southern cottonwood-willow riparian forest located in a tributary to Murrieta Creek (Figure 4, 2020 Southwestern Willow Flycatcher Survey Results).

Survey protocol requires that five survey visits be conducted at least five days apart, between the hours of sunrise and 10:30 a.m., within the three specified survey periods. One survey was conducted during Survey Period 1 (May 15 to 31), two surveys were conducted during Survey Period 2 (June 1 to 24), and two surveys were conducted during Survey Period 3 (June 25 to July 17).

The surveys were conducted by walking within and along the perimeter of suitable SWFL habitat present within the study area. Surveys were conducted with binoculars to aid in bird detection. Recorded SWFL vocalizations were played every 20 to 30 meters followed by a one-minute silent period to listen for a response. The survey route was arranged to ensure complete survey coverage of habitat with potential for occupancy by SWFL.

The surveys were conducted on the same days as the protocol surveys for the least Bell’s vireo (Vireo bellii pusillus; LBVI). The permitted biologist for SWFL surveyed the entire survey area for both SWFL and LBVI; however, the surveys were not conducted concurrently. The LBVI survey was conducted sequentially after the SWFL survey. The surveyor surveyed for SWFL as they walked one direction along/within suitable SWFL habitat, and then surveyed for LBVI as they walked back the other direction.

A separate survey report is being submitted for the LBVI surveys (HELIX in preparation).

Table 1, Survey Information, details the survey dates, times, weather conditions, and survey results.

Letter to Ms. Stacey Love Page 3 of 5
August 27, 2020

Table 1

SURVEY INFORMATION
Survey
Period1
Site
Visit
Survey
Date Biologist Start/Stop
Time
Approx. Acres
Surveyed/
Acres Per Hour
Start/Stop
Weather Conditions Survey Results
1 1 5/21/20 Erica Harris2 0730/0930 28.0 ac/

14.0 ac per hr.
60°F, wind 0-1 mph, 0% clouds
68°F, wind 0-1 mph, 0% clouds
• Single WIFL (Male No. 1) heard singing on
eastern bank of Murrieta Creek between
Dendry Parkway and Winchester Road
near confluence of Santa Gertrudis Creek
and Murrieta Creek.
2 2 6/4/20 Erica Harris2 0730/0930 28.0 ac/

14.0 ac per hr.
70°F, wind 0-1 mph, 90% clouds
76°F, wind 0-1 mph, 55% clouds No flycatchers observed
2 3 6/19/20 Erica Harris2 0730/0930 28.0 ac/

14.0 ac per hr.
61°F, wind 0-1 mph, 100% clouds
65°F, wind 0-1 mph, 100% clouds No flycatchers observed 3 4 7/2/20 Erica Harris2 0730/0930 28.0 ac/

14.0 ac per hr.
64°F, wind 0-1 mph, 100% clouds
67°F, wind 0-1 mph, 100% clouds No flycatchers observed 3 5 7/13/20 Erica Harris2 0730/0930 28.0 ac/

14.0 ac per hr.
70°F, wind 0-1 mph, 0% clouds
84°F, wind 0-1 mph, 0% clouds No flycatchers observed
1 Survey Period 1 (May 15 to 31), Survey Period 2 (June 1 to 24), Survey Period 3 (June 25 to July 17). 2 USFWS Permit TE-778195-14

Letter to Ms. Stacey Love Page 4 of 5
August 27, 2020

SURVEY RESULTS
No breeding southwestern willow flycatchers were detected during the survey effort. One willow flycatcher (Empidonax traillii; WIFL) was detected during the first survey in May. A single, male WIFL (Male No. 1) was heard signing along the eastern bank of Murrieta Creek, between Dendry Road and Winchester Road, near its confluence with Santa Gertrudis Creek (Figure 4). As noted below, the male could not be identified to subspecies. The male was not detected during the subsequent four surveys and no other WIFLs were detected during any of the surveys. The single observation of a male WIFL is presumed to be a migrating individual.

The first survey period represents a time when other migratory subspecies of WIFL are moving through southern California, particularly northern breeding subspecies Empidonax traillii brewsteri and E.t. adastus, though migrants could still be travelling through the region during the second survey period. By the third survey period (beginning June 22nd), SWFL should be the only subspecies remaining within the southern California region, as the non-migrant period is generally considered from about June 15 to July 20 2. The detection of the single WIFL within study area occurred on May 21 during the first survey window and no other WIFL were detected during subsequent surveys. Therefore, it can be concluded that this individual most likely represents a migratory individual. No breeding SWFL were documented within the Diaz Road study area. Furthermore, no documented breeding occurrences of southwestern willow flycatcher occur along Murrieta Creek 3,4.

A Willow Flycatcher Survey and Detection Form has been completed and is included as Attachment A, Willow Flycatcher Survey and Detection Form.

CERTIFICATION
I certify that the information in this survey report and attached exhibits fully and accurately represents our work. Please contact Shelby Howard or me at (619) 462-1515 should you have any questions.

Sincerely,

Erica Harris
Senior Scientist

2 Unitt, P., 1987, Empidonax traillii extimus: an endangered subspecies: Western Birds, v. 18, no. 3, p. 137-162. 3 California Department of Fish and Wildlife. 2020. RareFind Database Program, Version 5. 4 U.S. Fish and Wildlife Service. 2020. Occurrence Information for Multiple Species within Jurisdiction of the Carlsbad Fish and Wildlife Office (CFWO). Retrieved from: http://www.fws.gov/carlsbad/gis/cfwogis.html

Letter to Ms. Stacey Love Page 5 of 5
August 27, 2020

Attachments:

Figure 1: Regional Location
Figure 2: USGS Topography
Figure 3: Aerial Photograph
Figure 4: 2020 Southwestern Willow Flycatcher Survey Results Attachment A: Willow Flycatcher Survey and Detection Form

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S O L A N A WAY VIANORTE

Di ion
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Willow Flycatcher Sighting*
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Figure 4

Willow Flycatcher (WIFL) Survey and Detection Form (revised April, 2010) Site Name: Diaz Road Expansion Project State: CA County: San Diego USGS Quad Name: Murrieta/Temecula Elevation: 310 (meters) Creek, River, or Lake Name: Murrieta Creek
Is copy of USGS map marked with survey area and WIFL sightings attached (as required)? Yes X No Survey Coordinates: Start: E 485622 N 3706614 UTM Datum: WSG84 (See instructions) Stop: E 483335 N 3709136 UTM Zone: 11N
If survey coordinates changed between visits, enter coordinates for each survey in comments section on back of this page. **Fill in additional site information on back of this page** Nest(s)
Found?
Y or N
If Yes,
number of
nests
Survey # 1 # Birds Sex UTM N
Observer(s): 1 M 3708791
Erica Harris
Survey # 2 # Birds Sex UTM N
Observer(s):

Erica Harris
Survey # 3 # Birds Sex UTM N
Observer(s):

Erica Harris
Survey # 4 # Birds Sex UTM N
Observer(s):

Erica Harris
Survey # 5 # Birds Sex UTM N
Observer(s):

Erica Harris
Yes No X

10.00 483756
Survey #
Observer(s) (Full
Name)
Date (m/d/y)
Survey Time
Number of
Adult
WIFLs
Estimated
Number of
Pairs
Estimated
Number of
Territories
Comments (e.g., bird behavior; evidence of
pairs or breeding; potential threats [livestock,
cowbirds, Diorhabda spp.]). If Diorhabda
found, contact USFWS and State WIFL
coordinator.

GPS Coordinates for WIFL Detections (this
is an optional column for documenting individuals, pairs, or groups of birds found on
each survey). Include additional sheets if necessary.

Date:

N
Total survey hrs.: 0 0 0 0 If yes, report color combination(s) in the comments section on back of form and report to USFWS.

2.00 Date:
0 Total Nests
N
UTM E
00 0
1 0
5/21/2020
Be careful not to double count individuals.

Overall Site Summary
Totals do not equal the sum of each
column. Include only resident adults. Do
not include migrants, nestlings, and
fledglings.

Start:
7:30
9:30
Total hrs.:

2.00 7/13/2020

2.00 6/4/2020
0 0
n/a
n/a
N
UTM E
0 9:30
0 Date:
7:30
9:30
0 Total Adult
Residents Total Pairs Total
Territories
9:30
Total hrs.:

Start:

Date:
0 6/19/2020
0 N
Start:

2.00 Total hrs.:
0 Total hrs.:
7:30
Were any WIFLs color-banded?
7:30
Stop:
9:30
Start:

2.00 7/2/2020
N
Stop:

Stop: n/a
n/a
Stop:

Date:

Male singing from east side of Murrieta Creek.

Passively monitored individual for
approximately 15 minutes during which the
male continued to vocalize with short breaks.

Only detected aurally. Not detected during
subsequent survey visits. Presumed to be a
migrating individual. Brown-headed cowbird
present along Murrieta Creek.

UTM E
Total hrs.:

UTM E
UTM E
Start:
7:30
Stop: 0
Reporting Individual: Erica Harris Date Report Completed: 8/27/2020 US Fish & Wildlife Service Permit #: TE-778195-14 State Wildlife Agency Permit #:

Submit form to USFWS and State Wildlife Agency by September 1st. Retain a copy for your records.

X
Fill in the following information completely. Submit form by September 1 st . Retain a copy for your records.

Reporting Individual Erica Harris Phone # 619-462-1515
Affiliation HELIX Environmental Planning, Inc. E-mail [email protected] Site Name Diaz Road Expansion Project Date report Completed Was this site surveyed in a previous year? Yes____ No__X__ Unknown____ 8/27/2020
Did you verify that this site name is consistent with that used in previous yrs? Yes No Not Applicable X If name is different, what name(s) was used in the past? N/A If site was surveyed last year, did you survey the same general area this year? Yes No If no, summarize below.

Did you survey the same general area during each visit to this site this year? Yes No If no, summarize below.

Management Authority for Survey Area: Federal Municipal/County X State Tribal Private Name of Management Entity or Owner (e.g., Tonto National Forest) City of Temecula/Riverside County Flood Control and Water Conseration District Length of area surveyed: 3.5 (km)
Vegetation Characteristics: Check (only one) category that best describes the predominant tree/shrub foliar layer at this site:

Native broadleaf plants (entirely or almost entirely, > 90% native) Mixed native and exotic plants (mostly native, 50 - 90% native) Mixed native and exotic plants (mostly exotic, 50 - 90% exotic) Exotic/introduced plants (entirely or almost entirely, > 90% exotic) Identify the 2-3 predominant tree/shrub species in order of dominance. Use scientific name.

Salix lasiolepis, Schoenoplus acutus, Tamarix sp., Salix gooddingii Average height of canopy (Do not include a range): 4.5 (meters) Attach the following: 1) copy of USGS quad/topographical map (REQUIRED) of survey area, outlining survey site and location of WIFL detections; 2) sketch or aerial photo showing site location, patch shape, survey route, location of any detected WIFLs or their nests; 3) photos of the interior of the patch, exterior of the patch, and overall site. Describe any unique habitat features in Comments.

Comments (such as start and end coordinates of survey area if changed among surveys, supplemental visits to sites, unique habitat features.

Attach additional sheets if necessary.

Stretch of Murrieta Creek between Cherry Street and Rancho California Road.

Territory Summary Table. Provide the following information for each verified territory at your site.

Territory Number All Dates Detected UTM E UTM N
Pair
Confirmed?
Y or N
Nest
Found?
Y or N
Description of How You Confirmed
Territory and Breeding Status
(e.g., vocalization type, pair interactions,
nesting attempts, behavior)
No territories present
Attach additional sheets if necessary

Diaz Road Extension Project
Cultural Resources Survey
January 2022 | 00207.00012.001
Submitted to:

City of Temecula
41000 Main Street
Temecula, CA 92590
Prepared for:

David Evans and Associates, Inc.
41951 Remington Ave., Suite 220
Temecula, CA 92590
Prepared by:

HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
La Mesa, CA 91942
Mary Robbins-Wade
Cultural Resources Group Manager

Diaz Road Extension Project

Cultural Resources Survey

Submitted to:

City of Temecula
41000 Main Street
Temecula, CA 92590

Prepared for:

David Evans and Associates, Inc.
41951 Remington Ave., Suite 220
Temecula, CA 92590

Prepared by:

HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
La Mesa, CA 91942

January 2022 | 00207.00012.001

National Archaeological Database Information

Authors: Mary Robbins Wade, M.A., RPA and James Turner, M.A., RPA with contributions by Theodore G. Cooley, M.A., RPA

Firm: HELIX Environmental Planning, Inc.

Client/Project: David Evans and Associates, Inc. / Diaz Road Expansion Project

Report Date: January 2022

Report Title: Cultural Resources Survey for the Diaz Road Extension Project, Temecula, California
Submitted to: City of Temecula

Type of Study: Cultural Resources Survey

New Sites: None

Updated Sites: None
USGS Quad: Murrieta 7.5' Quadrangle
Acreage: Approximately 2.2 linear miles

Key Words: Temecula; Riverside County; Township 7 South, Range 3 West; Township 8 South, Range 3 West; Murrieta Creek; Diaz Road; archaeological survey; no archaeological resources found

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i

TABLE OF CONTENTS
Section Page

EXECUTIVE SUMMARY ............................................................................................................................. ES-1

1.0 INTRODUCTION ................................................................................................................................ 1

1.1 Project Location .................................................................................................................. 1

1.2 Project Description ............................................................................................................. 1

1.3 Regulatory Framework ....................................................................................................... 1

1.3.1 Federal ................................................................................................................... 2

1.3.2 State ....................................................................................................................... 2

1.3.3 City of Temecula .................................................................................................... 3

1.3.4 Native American Heritage Values .......................................................................... 4

1.4 Area of Potential Effects ..................................................................................................... 5

1.5 Project Personnel ................................................................................................................ 5

2.0 PROJECT SETTING ............................................................................................................................. 5

2.1 Natural Setting .................................................................................................................... 5

2.2 Cultural Setting ................................................................................................................... 6

2.2.1 Prehistoric Period .................................................................................................. 6

2.2.2 Ethnohistory......................................................................................................... 10

2.2.3 Historical Background .......................................................................................... 11

3.0 ARCHIVAL RESEARCH AND CONTACT PROGRAM .......................................................................... 14

3.1 Records Search .................................................................................................................. 14

3.1.1 Previous Surveys .................................................................................................. 14

3.1.2 Previously Recorded Resources ........................................................................... 15

3.2 Other Archival Research ................................................................................................... 17

3.3 Native American Contact Program ................................................................................... 17

4.0 SURVEY METHODOLOGY AND RESULTS ........................................................................................ 19

4.1 Survey Overview ............................................................................................................... 19

4.1.1 Methods and Results ........................................................................................... 19

5.0 SUMMARY AND MANAGEMENT RECOMMENDATIONS ................................................................ 22

5.1 Management Recommendations ..................................................................................... 22

6.0 REFERENCES ................................................................................................................................... 24

ii
TABLE OF CONTENTS (cont.)

LIST OF APPENDICES

A Resumes
B Records Search Results (Confidential, bound separately) C Native American Correspondence (Confidential, bound separately)

LIST OF FIGURES

No. Title Follows Page

1 Regional Location ............................................................................................................................. 2 2 USGS Topography ............................................................................................................................ 2 3 Project Area .................................................................................................................................... 2

LIST OF TABLES

No. Title Page

1 Previous Studies Within or Adjacent to the Project Area .............................................................. 14 2 Previously Recorded Resources Within One Mile of the Project Area .......................................... 16 3 Native American Contact Program Responses .............................................................................. 18

iii

ACRONYMS AND ABBREVIATIONS
AB Assembly Bill
APE Area of Potential Effects
APN Assessor’s Parcel Number

BP Before Present

CCR California Code of Regulations
CEQA California Environmental Quality Act
CFR Code of Federal Regulations
CHRIS California Historical Resources Information System CRHR California Register of Historical Resources

EIC Eastern Information Center

HELIX HELIX Environmental Planning, Inc.

NAHC Native American Heritage Commission
NHPA National Historic Preservation Act
NRHP National Register of Historic Places

OHP Office of Historic Preservation

PRC Public Resources Code

SHPO State Historic Preservation Officer

TCP Traditional Cultural Properties
TCR Tribal Cultural Resources

USGS U.S. Geological Survey

iv

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Cultural Resources Survey for the Diaz Road Extension Project | January 2022 ES-1

EXECUTIVE SUMMARY
HELIX Environmental Planning, Inc. (HELIX) was contracted by David Evans and Associates, Inc. to provide cultural resources services for the Diaz Road Expansion Project (project) in the City of Temecula, Riverside County, California. The project is a proposed approximately 2.2 linear miles of city infrastructure improvements associated with the widening and/or construction of Diaz Road between Cherry Street and Rancho California Road. A cultural resources study including a records search, Sacred Lands File search, Native American outreach, a review of historic aerial photographs and maps, and a pedestrian survey was conducted for the Project Area of Potential Effects (APE). This report details the methods and results of the cultural resources study and has been prepared to comply with the California Environmental Quality Act (CEQA) and Section 106 of the National Historic Preservation Act (NHPA), as amended.

The records search obtained from the Eastern Information Center (EIC) on September 8, 2020 indicated that 138 previous cultural resources studies have been conducted within one mile of the project area, 17 of which overlap with the project area. The records search results also indicated that a total of 16 cultural resources have been previously recorded within one mile of the project area; however, no sites have been recorded within the project alignment.

The field investigations included intensive pedestrian survey of the study area by a HELIX archaeologist and a Native American monitor on May 28, 2020. The survey did not result in the identification of any cultural material within the project area.

Based on the results of the current study, no historic resources, per CEQA, or historic properties, per NHPA, will be affected by the Diaz Road Expansion Project and no impacts to cultural resources are anticipated. However, the Sacred Land File search results provided by the NAHC were returned with positive results. Due to these concerns, it is recommended that grading activities be monitored by a qualified archaeologist and a Native American monitor.

Should the project limits change to incorporate new areas of proposed disturbance, an archaeological survey of these areas will be required.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 ES-2

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Cultural Resources Survey for the Diaz Road Extension Project | January 2022 1 1.0 INTRODUCTION
HELIX Environmental Planning, Inc. (HELIX) was contracted by David Evans and Associates, Inc. to provide cultural resources services for the Diaz Road Expansion Project (project) in the City of Temecula (City), Riverside County, California. The project proposes 2.2 linear miles of City infrastructure improvements associated with the widening and/or construction of Diaz Road between Cherry Street and Rancho California Road. A cultural resources study including a records search, Sacred Lands File search, Native American outreach, a review of historic aerial photographs and maps, and a pedestrian survey was conducted for the Project Area of Potential Effects (APE). This report details the methods and results of the cultural resources study and has been prepared to comply with the California Environmental Quality Act (CEQA) and Section 106 of the National Historic Preservation Act (NHPA) of 1966, as amended.

1.1 PROJECT LOCATION
The project is located in the City of Temecula in southwestern Riverside County (Figure 1, Regional Location). The project is located south of the Interstate (I-)215 and I-15 interchange and west of I-15, within Township 7 South, Range 3 West and Township 8 South, Range 3 West of the Temecula Land Grant, on the U.S. Geological Survey (USGS) 7.5' Murrieta quadrangle (Figure 2, USGS Topography). The approximately 2.2-linear mile project site consists of the existing Diaz Road corridor and is bordered by Rancho California Road to the south, Cherry Street to the north, and Murrieta Creek to the east (Figure 3, Aerial Photograph). The Assessor’s Parcel Numbers (APNs) identified as being associated with the project site include segments of Diaz Road (APNs 909-120-006 and APN 909-370-050), the walking/biking pathway adjoining northeast of Diaz Road (APNs 921-740-004 & -005, and 909-120-016, - 021, -040, -051 & -055), and several small walled/fenced enclosures containing utility and water company infrastructure along the northeast side of Diaz Road at several locations between Rancho California Road and Cherry Street (APNs 909-370- 051, 909-120-044 & -056, and 921-740-002).

1.2 PROJECT DESCRIPTION
The project proposes to improve Diaz Road to meet the roadway classification requirements of a major arterial with four divided lanes, as specified by City Standard No. 101, between Cherry Street and Rancho California Road. The standards call for a 100-foot minimum right-of-way, a 76-foot roadway with a 14-foot raised median, and 12-foot parkways on each side of the road. The approximately 2.2-mile long segment would be improved on its current horizontal alignment and as depicted in the City’s General Plan, Circulation Element, Figure C-2 Roadway Plan. As such, the proposed project would widen the existing Diaz Road segment and extend the northwestern end of Cherry Street. The project would complete the City’s only existing north-south corridor west of Murrieta Creek. North of Cherry Street, this north-south corridor is planned to continue as Washington Avenue within the City of Murrieta.

1.3 REGULATORY FRAMEWORK
Cultural resources are defined as buildings, sites, structures, or objects, each of which may have historical, architectural, archaeological, cultural, and/or scientific importance. Significant resources are those resources which have been found eligible to the California Register of Historical Resources (CRHR) or National Register of Historic Places (NRHP), as applicable.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 2 1.3.1 Federal
Federal regulations that would be applicable to the project if there is a federal nexus, such as permitting by a federal agency, consist of the National Historic Preservation Act (NHPA) and its implementing regulations (16 United States Code 470 et seq., 36 Code of Federal Regulations [CFR] Part 800).

Section 106 of the NHPA requires Federal agencies to take into account the effects of their undertakings on “historic properties”, that is, properties (either historic or archaeological) that are listed on or eligible for listing on the NRHP. To be eligible for the NRHP, a property must be significant at the local, state, or national level under one or more of the following four criteria:

A. associated with events that have made a significant contribution to the broad patterns of our history;
B. associated with the lives of persons significant in our past; C. embodies the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction; and/or D. has yielded or may be likely to yield, information important in prehistory or history.

1.3.2 State
The California Environmental Quality Act (CEQA), Public Resources Code (PRC) 21084.1, and California Code of Regulations (CCR) Title 14 Section 15064.5, address determining the significance of impacts to archaeological and historic resources and discuss significant cultural resources as “historical resources,” which are defined as:
• resource(s) listed or determined eligible by the State Historical Resources Commission for listing in the CRHR (14 CCR Section 15064.5[a][1]);
• resource(s) either listed in the NRHP or in a “local register of historical resources” or identified as significant in a historical resource survey meeting the requirements of Section 5024.1(g) of the PRC, unless “the preponderance of evidence demonstrates that it is not historically or culturally significant” (14 CCR Section 15064.5[a][2]); and • resources determined by the Lead Agency to meet the criteria for listing on the CRHR (14 CCR Section 15064.5[a][3]).

For listing in the CRHR, a historical resource must be significant at the local, state, or national level under one or more of the following four criteria:

1. It is associated with events that have made a significant contribution to the broad patterns of local or regional history, or the cultural heritage of California or the United States;

2. It is associated with the lives of persons important to local, California, or national history;

3. It embodies the distinctive characteristics of a type, period, region, or method of construction, or represents the work of a master or possesses high artistic values; and/or

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Cultural Resources Survey for the Diaz Road Extension Project | January 2022 3 4. It has yielded or has the potential to yield information important to the prehistory or history of the local area, California, or the nation.

Under 14 CCR Section 15064.5(a)(4), a resource may also be considered a “historical resource” for the purposes of CEQA at the discretion of the lead agency.

All resources that are eligible for listing in the NRHP or CRHR must have integrity, which is the authenticity of a historical resource’s physical identity evidenced by the survival of characteristics that existed during the resource’s period of significance. Resources, therefore, must retain enough of their historic character or appearance to be recognizable as historical resources and to convey the reasons for their significance. Integrity is evaluated with regard to the retention of location, design, setting, materials, workmanship, feeling, and association. In an archaeological deposit, integrity is assessed with reference to the preservation of material constituents and their culturally and historically meaningful spatial relationships. A resource must also be judged with reference to the particular criteria under which it is proposed for nomination. Under Section 106 of the NHPA, actions that alter any of the characteristics that qualify a property for eligibility for listing in the NRHP “in a manner that would diminish the integrity of the property’s location, design, setting, materials, workmanship, feeling, or association” (36 CFR 800.5[a]) constitute an adverse effect to the historic property.

1.3.3 City of Temecula
The City’s General Plan (2005) includes the following goal and related policies regarding cultural and historical resources as part of the Open Space and Conservation Element (City of Temecula 2005:

OS-29-OS-28):

Goal 6: Preservation of significant historical and cultural resources.

Policies

6.1: Maintain an inventory of areas with archaeological/paleontological sensitivity, and historic sites in the Planning Area.

6.2: Work to preserve or salvage potential archaeological and paleontological resources on sites proposed for future development through the development review and mitigation monitoring processes.

6.3: Preserve and reuse historical buildings in accordance with the Old Town Specific Plan.

6.4: Assist property owners in seeking State and/or federal registration and appropriate zoning for historic sites and assets.

6.5: Pursue the acquisition and preservation of historical buildings for public facilities in accordance with the Old Town Specific Plan when appropriate.

6.6: Ensure compatibility between land uses and building designs in the Old Town Specific Plan Area and areas adjacent to Old Town.

6.7: Encourage use of California’s Historic Building Code when preserving/rehabilitating historic structures.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 4 6.8: Support an integrated approach to historic preservation in coordination with other affected jurisdictions, agencies, and organizations for areas within the Planning Area and surrounding region that seeks to establish linkages between historic sites or buildings with other historic features such as roads, trails, ridges, and seasonal waterways.

6.9: Encourage the preservation and re-use of historic structures, landscape features, roads, landmark trees, and trails.

6.10: Work with the Pechanga Band of Luiseño Indians to identify and appropriately address cultural resources and tribal sacred sites through the development review process.

6.11: Encourage voluntary landowner efforts to protect cultural resource and tribal sacred sites consistent with State requirements.

1.3.4 Native American Heritage Values
Federal and state laws mandate that consideration be given to the concerns of contemporary Native Americans with regard to potentially ancestral human remains, associated funerary objects, and items of cultural patrimony. Consequently, an important element in assessing the significance of the study site has been to evaluate the likelihood that these classes of items are present in areas that would be affected by the proposed project.

Potentially relevant to prehistoric archaeological sites is the category termed Traditional Cultural Properties (TCP) in discussions of cultural resource management performed under federal auspices.

According to Patricia L. Parker and Thomas F. King (1998), “Traditional” in this context refers to those beliefs, customs, and practices of a living community of people that have been passed down through the generations, usually orally or through practice. The traditional cultural significance of a historic property, then, is significance derived from the role the property plays in a community’s historically rooted beliefs, customs, and practices. Cultural resources can include TCPs, such as gathering areas, landmarks, and ethnographic locations, in addition to archaeological districts. Generally, a TCP may consist of a single site, or group of associated archaeological sites (district or traditional cultural landscape), or an area of cultural/ethnographic importance.

In California, the Traditional Tribal Cultural Places Bill of 2004 requires local governments to consult with Native American Tribes during the project planning process, specifically before adopting or amending a General Plan or a Specific Plan, or when designating land as open space for the purpose of protecting Native American cultural places. The intent of this legislation is to encourage consultation and assist in the preservation of Native American places of prehistoric, archaeological, cultural, spiritual, and ceremonial importance. State Assembly Bill (AB) 52, effective July 1, 2015, introduced the Tribal Cultural Resource (TCR) as a class of cultural resource and additional considerations relating to Native American consultation into CEQA. As a general concept, a TCR is similar to the federally defined TCP; however, it incorporates consideration of local and state significance and the required mitigation under CEQA. A TCR may be considered significant if included in a local or state register of historical resources; or determined by the lead agency to be significant pursuant to criteria set forth in PRC §5024.1; or is a geographically defined cultural landscape that meets one or more of these criteria; or is a historical resource described in PRC §21084.1, a unique archaeological resource described PRC §21083.2; or is a non-unique archaeological resource if it conforms with the above criteria.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 5 1.4 AREA OF POTENTIAL EFFECTS
Pursuant to 36 CFR 800.4(a)(1), the APE is the geographic area within which an undertaking may directly or indirectly alter the character or use of historic properties. For the purposes of this report, the project APE consists of the 2.2-linear mile segment of Diaz Road from Rancho California Road in the south to Cherry Road in the north (see Figure 3).

1.5 PROJECT PERSONNEL
A cultural resources survey was conducted by HELIX in 2020 to assess whether the project would have any effects on cultural resources. Mary Robbins-Wade, M.A., RPA served as the principal investigator and report co-author, Julie Roy, B.A. conducted the field survey, James Turner, M.A., RPA is report co- author, and Theodore G. Cooley, M.A., RPA served as report contributor. Resumes of key HELIX personnel are included as Appendix A. A Native American monitor from the Pechanga Band of Luiseño Mission Indians (Pechanga) participated in the survey. This report addresses the methods and results of the cultural resources survey, which included a records search, Sacred Land File search, Native American outreach, historic archival research, and an intensive pedestrian field survey.

2.0 PROJECT SETTING

2.1 NATURAL SETTING
The project area lies within the foothills of the Temecula Valley at the eastern base of the Santa Ana and Elsinore mountains, and the Santa Rosa Plateau. The project alignment lies on the Elsinore Fault Zone and is situated just west of Murrieta Creek.

The climate of western Riverside County is characterized as a semi-arid environment with low humidity and rainfall. Almost all rainfall occurs in the winter, but the region can also experience rare, intense summer thunderstorms. Wind is also a strong feature of this climatic regime, with dry winds in excess of 25 miles per hour in the late winter and early spring (National Oceanic and Atmospheric Administration [NOAA] 2014). The project area is characterized predominantly by urban development comprised of freeway infrastructure. Areas immediately surrounding the project area include transportation infrastructure and residential, large-scale recreational/commercial, and industrial development. The Murrieta Creek is located immediately to the east of the project area.

Geologically, the project area is underlain by late Pleistocene and early Holocene age alluvial channel deposits consisting of fluvial sediments deposited on canyon floors. Within the project area, these deposits consist of relatively young valley alluvium deposits, containing unconsolidated sand, silt, and clay deposits (Kennedy and Morton n.d.). Older alluvial flood plain deposits line both the eastern and western sides of the Murrieta Creek—these deposits contain brown sandstone containing sparse cobbles and boulders. The nearby foothills of Santa Ana and Elsinore mountains are underlain by the Pauba formation; however, the mountains themselves mostly consist of granitic rocks dating to the Cretaceous Period and metavolcanics and metasedimentary rocks dating to the Jurassic Period (Kennedy and Morton n.d.; Tan and Kennedy 2000). Seven soil series are mapped for the project area: Chino silty loam (0 to 2 percent slopes, drained); Domino silty loam (0 to 2 percent slopes); Grangeville sandy loam, sandy substratum (0 to 5 percent slopes, drained); Grangeville fine sandy loam (0 to 2 percent slopes, drained); Grangeville fine sandy loam (0 to 5 percent slopes); Riverwash (0 to 8 percent slopes,

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 6 excessively drained); and Willows silty clay (0 to 2 percent slopes, deep, saline-alkali). The Chino silty loam represents the majority of the soils in the area (Web Soil Survey 2019). Prehistorically, these soil series likely sustained native grassland species.

Prehistorically, the natural vegetation in the project area likely consisted of riparian vegetation along the Murrieta Creek drainage, coastal sage scrub and native grasslands in adjacent hill areas, and chaparral in the upper elevations of the adjacent mountains. Prior to historic and modern activities, well-watered drainages such as Murrieta Creek likely contained stands of riparian communities with plants such as western sycamore (Platanus racemosa), Fremont cottonwood (Populus fremontii), coast live oak (Quercus agrifolia) and willow (Salix sp.). Native grassland plants include Stipa, Elymus, Poa, and Muhlenbergia sp. Plants of the coastal sage scrub community include California sagebrush (Artemisia californica), white sage (Salvia apiana), flat-top buckwheat (Eriogonum fasciculatum), broom baccharis (Baccharis sarothroides), wild onion (Allium haematochiton), laurel sumac (Malosma laurina), San Diego sunflower (Bahiopsis laciniata), golden-yarrow (Eriophyllum confertiflorum), sawtooth goldenbush (Hazardia squarrosa), yucca (Yucca schidigera, Hesperoyucca whipplei), prickly pear cactus (Opuntia sp.), and scrub oak (Quercus dumosa) (Hall 2007; Munz 1974). Major wildlife species found in this environment prehistorically were coyote (Canis latrans); mule deer (Odocoileus hemionus); grizzly bear (Ursus arctos); mountain lion (Puma concolor); desert cottontail (Sylvilagus audubonii); jackrabbit (Lepus californicus); and various rodents, the most notable of which are the valley pocket gopher (Thomomys bottae), California ground squirrel (Ostospermophilus beecheyi), and dusky footed woodrat (Neotoma fuscipes) (Head 1972). Desert cottontails, jackrabbits, and rodents were very important to the prehistoric diet; deer were somewhat less significant for food, but were an important source of leather, bone, and antler. Many of the plant and animal species naturally occurring in the project vicinity are known to have been used by native populations for food, medicine, tools, ceremonial and other uses (Bean and Shipek 1978; Hedges and Beresford 1986; Luomala 1978; Sparkman 1908).

2.2 CULTURAL SETTING

2.2.1 Prehistoric Period
Moratto (1984) has previously defined eight archaeological regions and 16 subregions for California. The location of the project places it within the boundary of the San Diego subregion of the Southern Coast Region, but it is also located adjacent to the boundary with the Colorado River subregion of the Desert Region (Moratto 1984: 148, Figure 4.13). The following culture history briefly describes the known prehistoric cultural Traditions and chronology of archaeological sites in the vicinity of the project. The approximately 10,000 years of documented prehistory of the region has often been divided into three periods: Early Prehistoric Period, Archaic Period, and Late Prehistoric Period.

Prior to 1984, when Moratto defined the San Diego subregion, little archaeological investigation had occurred in the westernmost Riverside and San Bernardino counties portion of this subregion. This paucity of archaeological information limited the ability of researchers to assess the cultural and temporal associations for the archaeological resources in this part of the subregion. One of the few early studies to occur in this area prior to 1984 was conducted near Temecula in the early the 1950s at a site identified as the ethnohistoric village of Temeku (McCown 1955). The investigation produced a substantial, primarily Late Prehistoric Period, artifact assemblage, but with some possible late Archaic materials as well. Another study, conducted in the 1970s, for the construction of the Perris Reservoir (O’Connell et al. 1974, eds.), consisted of investigations at several sites and was, perhaps, the most extensive study conducted in the area prior to 1984. The results, which included several radiocarbon

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 7 dates, indicated a predominance of occupation at the sites during the Late Prehistoric Period, AD 1500, but with some limited evidence for occupation as early as 380 BC (Bettinger 1974:159-162). During the last approximately 35 years since 1984, several substantial archaeological studies have occurred that have served to substantially augment the archaeological record for the area (e.g., Applied Earth Works, Inc. 2001; Grenda 1997). Based on the information provided by these and other subsequent studies in the area, Sutton and Gardner (2010) and others have recently begun to define the prehistory of this area of the San Diego subregion and how it fits in with the previously better-known areas of the subregion.

The three chronological periods defined for the prehistory of the San Diego subregion are described below.

2.2.1.1 Early Prehistoric Period
The Early Prehistoric Period represents the time of the entrance of the first known human inhabitants into California. In some areas of California, it is referred to as the Paleo-Indian period and is associated with the big-game-hunting activities of the peoples of the last Ice Age, occurring during the Terminal Pleistocene (pre-10,000 years ago) and the Early Holocene (beginning circa 10,000 years ago) (Erlandson 1994, 1997; Erlandson et al. 2007). In the western United States, the most substantial evidence for the Paleo-Indian or Big-Game-Hunting peoples, derives from finds of large fluted spear and projectile points (Fluted-Point Tradition) at sites in places such as Clovis and Folsom in the Great Basin and the Desert Southwest (Moratto 1984:79–88). In California, most of the evidence for the Fluted-Point Tradition derives principally from areas along the western margins of the Great Basin including the eastern Sierras and the Mojave Desert, and in the southern Central Valley (Dillon 2002; Rondeau et al. 2007). Elsewhere in California, with the exception of a site in the north coast ranges in northwestern California, CA-LAK-36, only isolated occurrences of fluted spear points have occurred, scattered around the state (Dillon 2002; Rondeau et al. 2007). These isolated occurrences have, however, included two fluted points or fluted point fragments discovered relatively recently in, or in close proximity to, the San Diego subregion; one in the mountainous eastern area of San Diego County approximately 35 miles to the southeast of the project area (Kline and Kline 2007) and another along the coast approximately 40 miles to the northwest of the project area in adjacent Orange County (Fitzgerald and Rondeau 2012). Two examples have also been discovered to the south in Baja California (Des Lauriers 2008; Hyland and Gutierrez 1995). Despite these isolated occurrences of fluted points in the San Diego subregion and Baja California, to date none have been found in the western Riverside or San Bernardino counties area (Dillon 2002; Rondeau et al. 2007).

The earliest sites in the San Diego subregion, documented to be over 9,000 years old, belong to the San Dieguito Tradition (Warren et al. 1998; Warren and Ore 2011). The San Dieguito Tradition, with an artifact assemblage distinct from that of the Fluted Point Tradition, has been documented mostly in the coastal and near coastal areas in San Diego County (Carrico et al. 1993; Rogers 1966; True and Bouey 1990; Warren 1966; Warren and True 1961), as well as in the southeastern California deserts (Rogers 1939, 1966; Warren 1967). The content of the earliest component of the C.W. Harris Site (CA-SDI- 149/316/4935B), located along the San Dieguito River in San Diego County, formed the basis upon which Warren and others (Rogers 1966; Vaughan 1982; Warren 1966, 1967; Warren and True 1961) identified the “San Dieguito complex,” which Warren later reclassified as the San Dieguito Tradition (1968). This Tradition is characterized by an artifact inventory consisting almost entirely of flaked stone biface and scraping tools, but lacking the fluted points associated with the Fluted-Point Tradition. Diagnostic artifact types and categories associated with the San Dieguito Tradition include elongated bifacial knives; scraping tools; crescentics; and Silver Lake, Lake Mojave, and leaf-shaped projectile points (Knell and Becker 2017; Rogers 1939; Warren 1967).

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 8 Some researchers interpret the San Dieguito Tradition/complex as having a primarily, but not exclusively, hunting subsistence orientation, sufficiently hunting-oriented as to be distinct from the more gathering-oriented complexes of traits that were to follow in the Archaic Period (Warren 1968; Warren et al. 1998). Other researchers see the San Dieguito subsistence system as less focused on hunting and more diversified, therefore, possibly ancestral to, or a developmental stage for, the subsequent, predominantly gathering-oriented Encinitas Tradition, denoted in the San Diego area as the “La Jolla/Pauma complex” (cf. Bull 1983, 1987; Ezell 1987; Gallegos 1987, 1991; Koerper et al. 1991).

While little definite evidence for the San Dieguito Tradition has been discovered in other coastal and near-coastal areas of southern California outside of San Diego County, some evidence for it has been discovered relatively recently in the eastern Mountains of San Diego County (Pigniolo 2005) and in a coastal area to the north, in Los Angeles County (Sutton and Grenda 2012).

2.2.1.2 Archaic Period
During the subsequent Archaic Period, artifact assemblages of the Milling Stone Horizon/Encinitas Tradition occur at a range of coastal and adjacent inland sites, and, in contrast to those of the previous Early Prehistoric Period, are relatively common in the study area region. These assemblages appear to indicate that a relatively stable, sedentary, predominantly gathering complex, possibly associated with one people, was present in the coastal and immediately inland areas of southern California for more than 7,000 years (Grenda 1997; Sutton and Gardner 2010; Warren 1968; Warren et al. 1998).

Warren has proposed that, during the Archaic Period in the south coastal region, the Encinitas Tradition began circa 8,500 years ago and extended essentially unchanged until circa 1,500 years ago (Warren 1968:2; Warren et al. 1998). Also, during the Archaic Period in the coastal region, beginning somewhere north of San Diego and extending to Santa Barbara, a fourth cultural assemblage, variously described as the intermediate Horizon (Wallace 1955) or Campbell Tradition (Warren 1968), has been delineated and distinguished, following the Milling Stone Horizon/Encinitas Tradition. This assemblage is distinguished from earlier Archaic assemblages by the presence of large projectile points and milling tools such as the mortar and pestle. The time period of this assemblage is viewed as beginning circa 4,800 years ago and continuing to as late as 1,300 years ago (Warren 1968). While still a matter of some debate, Warren and others (1998) have subsequently termed the time period encompassing the extent of the intermediate/ Campbell cultural assemblage in the southernmost coastal region as the Final Archaic Period.

In the western Riverside County area, archaeological investigations conducted in Perris Valley for the Perris Reservoir project produced a single radiocarbon date of circa 2200 years before present (BP) and a few diagnostic artifacts as the only evidence for a late Archaic Period occupation at the archaeological sites investigated (Bettinger 1974:159-162). More recently, large-scale archaeological investigations have been conducted for the Eastside Reservoir (Diamond Valley Lake) Project, located approximately 12 miles northeast of the study area. This project involved construction, within the adjacent Domenigoni and Diamond valleys, of the Diamond Valley Lake reservoir and the associated Eastside Reservoir Project (Goldberg 2001; Robinson 2001). Based on the results from this project, the researchers developed a local chronology specific to the Domenigoni and Diamond valleys based on projectile point style changes and associated radiocarbon dates (Robinson 2001). The terminology in this chronology resembles that already presented above, with the period from 9,500 to 7,000 years ago designated as the Early Archaic period, the period from 7,000 to 4,000 years ago as the Middle Archaic, and the period from 4,000 to 1,500 years ago as the Late Archaic. In the Eastside Reservoir Project, only two components could be firmly dated to the Early Archaic, but sparse evidence of Early Archaic activity was noted in six other localities. One site did, however, produce two radiocarbon dates of 9190±50 BP and 9310±60 BP

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 9 (McDougall 2001). For the Middle Archaic, firm evidence was documented in 14 locations, with traces at four other sites. During the Late Archaic, a profusion of activity and occupation was evident, with 23 firmly dated site components and sparse evidence at eight other localities (Goldberg 2001:524).

Another archaeological investigation conducted in the general vicinity of the project area has also produced evidence for prehistoric occupation in the western Riverside County region during the earliest part of the Archaic Period. This investigation occurred at Lake Elsinore, located approximately 14 miles to the northwest of the study area (Grenda 1997). This natural lake is situated in a fault-created basin whose principal source of water in prehistoric times was the San Jacinto River (Grenda 1997:3).

Archaeological investigations conducted at a site located along the old lake shoreline indicated occupation as early as 8,500 years ago (Grenda 1997). Thus, prehistoric occupation during the Archaic Period in the study area vicinity is documented to have occurred possibly as early as 9,300 years ago, and remained present to the end of the period, approximately 1,500 years ago. While this temporal extent correlates with Warren’s original proposed extent of the Encinitas Tradition, refinement of his characterization of the Tradition as being a relatively stable, sedentary, predominantly gathering complex, possibly associated with one people, and with an extent mostly restricted to the San Diego County area, may now, based on new information available, be subject to some revision (cf. Sutton and Gardner 2010).

2.2.1.3 Late Prehistoric Period
The beginning of the Late Prehistoric Period, circa 1,500 years ago, is seen as marked by a number of rather abrupt changes. The magnitude of these changes and the short period of time within which they took place are reflected in significant alteration of previous subsistence practices and the adoption of significant new technologies. As discussed further below, some of this change may have been as a result of significant variations in the climatic conditions. Subsistence and technological changes that occurred include a shift from hunting using atlatl and dart to the bow and arrow; a de-emphasizing of shellfish gathering along some areas of the coast (possibly due to silting-in of the coastal lagoons); and an increase in the storage of crops, such as acorns and pinyon nuts. Other new traits introduced during the Late Prehistoric Period include the production of pottery and cremation of the dead, and, locally, in the western Riverside County area, a shift in settlement pattern is apparent (cf. Wilke 1974).

This shift in settlement is first noted during the early part of the period from 1,500 to 750 years ago, and is evidenced, locally, in the results from the Eastside Reservoir Project by a rather sudden decline in occupation in the local area during the initial part of the period. This 750-year period was termed by the Eastside Reservoir researchers as the Saratoga Springs Period, following Warren’s (1984) desert terminology. This period can also be seen to partially coincide with a warm and arid period known as the Medieval Warm Period, documented to have occurred between approximately 1,100 and 600 years ago (Jones et al. 1999; Kennett and Kennett 2000; Stine 1994). During this period, at least two episodes of severe drought have also been demonstrated, the first calibrated to between 1060 and 840 BP and the second between 740 and 650 BP (Goldberg 2001; Stine 1994). Goldberg (2001) hypothesized that the Medieval Warm Period could account for the decline in sites occurring in the Eastside Reservoir Project area during the Saratoga Springs Period (1500 to 750 BP), claiming that desert and inland areas of western Riverside County, such as where the Eastside Reservoir Project and the current study area are located, would no longer be suitable to support residential bases. Goldberg (2001) further hypothesized that settlements would possibly be clustered at more suitable water sources during this time, such as at the coast, Lake Cahuilla, or Lake Elsinore (cf. Wilke 1974). While a decline was noted during the initial part of the Saratoga Springs Period, subsequently, during the latter part of the period, during the time of

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 10 the Medieval Warm Period, a reoccupation began to occur (Goldberg 2001:578). According to Goldberg “When components dating to the Medieval Warm segment of the Saratoga Springs Period are segregated and combined with Medieval Warm components from the Late Prehistoric Period, it shows that the frequency of refuse deposits and artifact and toolstone caches during the Medieval Warm is slightly higher than during the Late Archaic and much higher than during the later portion of the Late Prehistoric Period” (2001:578).

In the Eastside Reservoir Project, the Late Prehistoric Period was defined as extending from the end of the Saratoga Springs Period (750 BP) to 410 BP. A subsequent Protohistoric Period was also defined as extending from 410 to 150 BP. The Late Prehistoric (750–410 BP) was characterized by the presence of Cottonwood projectile points, although research indicated that Cottonwood points had actually begun to appear in the Eastside Reservoir Project study area as early as 950 BP. Ceramics and abundant obsidian begin to appear around the time of the Cabrillo exploration in AD 1542; thus this date (i.e., circa 410 BP), until the establishment of the mission system in the late 1700s, was defined as the Protohistoric Period (Robinson 2001). It should also be noted that the end of the Saratoga Springs Period and the beginning of the Late Prehistoric Period, 750 BP, also coincides with the onset of the Little Ice Age, generally dated from 750 to 150 BP (Goldberg 2001; Sutton et al. 2007). During this period, the climate was cooler and moister, and the sites identified within the Eastside Reservoir Project study area reflected a substantial increase in number and diversity, longer occupation periods, and more sedentary land use. Similar intensification of land use also occurred during this time in neighboring San Gorgonio Pass (Bean et al. 1991) and Perris Valley (Wilke 1974).

2.2.2 Ethnohistory
The project area is within the traditional territory of the Luiseño people (Kroeber 1925: Plate 57; Pechanga Tribal Government n.d.), although some ethnographers place the area of the project in proximity to a transitional area between the Luiseño and a related cultural group, the Cahuilla (Bean 1972, 1978; Bean and Shipek 1978). The Luiseño and Cahuilla, along with the Gabrielino, Juaneño, and Cupeño, comprise the Cupan group of the Takic subfamily of the Uto-Aztecan linguistic stock (Bean and Vane 1979; Miller 1986; Shipley 1978).

The name Luiseño derives from Mission San Luis Rey de Francia and has been used to refer to the Native people associated with the mission. The Luiseño followed a seasonal gathering cycle, with bands occupying a series of campsites within their territory (Bean and Shipek 1978; White 1963). The Luiseño lived in semi-sedentary villages usually located along major drainages, in valley bottoms, and also on the coastal strand, with each family controlling gathering areas (Bean and Shipek 1978; Sparkman 1908; White 1963). True (1990) indicated that the predominant determining factor for placement of villages and campsites was locations where water was readily available, preferably on a year-round basis. While most of the major Luiseño villages known ethnographically were located closer to the coast along the Santa Margarita River Valley and the San Luis Rey River Valley (Bean and Shipek 1978; Kroeber 1925; White 1963), Kroeber does indicate general locations for three Luiseño villages in more inland areas. He places the village of Panache in proximity to Lake Elsinore and the confluence of the San Jacinto River and Temescal Creek, approximately 15 miles to the northwest of the project area, and the villages of Temeku and Meha in the vicinity of the confluence of the upper Santa Margarita River, Murrieta Creek, and Temecula Creek, approximately two miles to the south of the project area (Kroeber 1925: Plate 57; McCown 1955:1).

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 11 It must be noted that interpretation by archaeologists and linguistic anthropologists may differ from the beliefs and traditional knowledge of the Luiseño people. The Luiseño creation story indicates that the Luiseño people have always been here, not migrating from elsewhere. The creation story of the Pechanga people tells that the world was created at Temecula. “The Káamalam [first people] moved to a place called Nachíivo Pomíisavo, but it was too small, so they moved to a place called ‘exva Teméeku,’ this place you know now as Temeku. Here they settled while everything was still in darkness (DuBois 1908)” (Masiel-Zamora 2013:2). A traditional Luiseño story tells of a great flood, and the people went to higher ground, where they were saved. The San Luis Rey Band say that this higher ground where the people were saved is Morro Hill. Some Luiseño informants indicated the place in this story is a hill just east of Highway 395 in the San Luis Rey River Valley (Cupples and Hedges 1977).

2.2.3 Historical Background

2.2.3.1 Spanish Period
While Juan Rodriguez Cabrillo visited San Diego briefly in 1542, the beginning of the historic period in the San Diego region is generally given as 1769. In the mid-eighteenth century, Spain had escalated its involvement in California from exploration to colonization (Weber 1992) and in that year, a Spanish expedition headed by Gaspar de Portolá and Junípero Serra established the Royal Presidio of San Diego.

Portolá then traveled north from San Diego seeking suitable locations to establish military presidios and religious missions in order to extend the Spanish Empire into Alta California.

The first documented Spanish contact in what is now Riverside County was by Spanish military captain Juan Bautista de Anza who led expeditions in 1774 and 1775 from Sonora to Monterey (Bolton 1930).

Anza embarked on the initial expedition to explore a land route northward through California from Sonora, with the second expedition bringing settlers across the land route to strengthen the colonization of San Francisco (Rolle 1963). Anza’s route led from the San Jacinto Mountains northwest through the San Jacinto Valley, which was named “San José” by Anza. Little documentation exists of Anza’s route being used after the two expeditions, although it was likely used to bring Spanish supplies into the newly colonized Alta California (Lech 2004). In 1781, the Spanish government closed the route due to uprisings by the Yuman Indians. However, by that time, the missions were established and self- sufficient; thus, the need for Spanish supplies from Sonora had begun to diminish.

Although Riverside County proved to be too far inland to include any missions within its limits, Missions San Juan Capistrano and San Luis Rey de Francia, established in 1776 and 1798 respectively, claimed a large part of southwestern Riverside County. The Spanish missions did not have as direct an effect on the inland tribal groups as they did on the Native people who lived along the coast (Bean 1978). On the coast, the Luiseño were moved into the Mission environment, where living conditions and diseases promoted the decline of the Luiseño population (Bean and Shipek 1978). However, throughout the Spanish Period, the influence of the Spanish progressively spread further from the coast and into the inland areas of southern California as Missions San Luis Rey and San Gabriel extended their influence into the surrounding regions and used the lands for grazing cattle and other animals.

In the 1810s, ranchos and mission outposts called asistencias were established, increasing the amount of Spanish contact in the region. An asistencia was established in Pala in 1818 and in San Bernardino in 1819. Additionally, Rancho San Jacinto was established for cattle grazing in the San Jacinto Valley (Bean and Vane 1980; Brigandi 1999). In 1820, Father Payeras, a senior mission official, promoted the idea that the San Bernardino and Pala asistencias be developed into full missions in order to establish an inland

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 12 mission system (Lech 2004). However, Mexico won its independence from Spain in 1821, bringing an end to the Spanish Period in California.

2.2.3.2 Mexican Period
Although Mexico gained its independence from Spain in 1821, Spanish patterns of culture and influence remained for a time. The missions continued to operate as they had in the past, and laws governing the distribution of land were also retained in the 1820s. Following secularization of the missions in 1834, large ranchos were granted to prominent and well-connected individuals, ushering in the Rancho Era, with the society making a transition from one dominated by the church and the military to a more civilian population, with people living on ranchos or in pueblos. With the numerous new ranchos in private hands, cattle ranching expanded and prevailed over agricultural activities.

In order to obtain a rancho, an applicant submitted a petition containing personal information and a land description and map (diseño). In 1840, Pio Pico secured a provisional grant to Rancho Temecula (Gerstbacher 1994). The Rancho ultimately was granted to Felix Valdes, a Mexican army officer, in December 1844. He would later sell Rancho Temecula to his attorney, Luis Vignes in 1846 (Gerstbacher 1994).

2.2.3.3 American Period
American governance began in 1848, when Mexico signed the Treaty of Guadalupe Hidalgo, ceding California to the United States at the conclusion of the Mexican–American War.

California’s acquisition by the United States substantially increased the growth of the population in California. The California gold rush, the end of the Civil War, and the passage of the Homestead Act implementing the United States’ manifest destiny to occupy and exploit the North American continent brought many people to California after 1848. While the American system required that the newly acquired land be surveyed prior to settlement, the Treaty of Guadalupe Hidalgo bound the United States to honor the land claims of Mexican citizens who were granted ownership of ranchos by the Mexican government (Lech 2004). The Land Act of 1851 established a board of commissioners to review land grant claims, and land patents for the land grants were issued from 1876 to 1893.

In November 1851, Antonio Garra of Cupa (now Warner Springs) attempted to unite all of the Native American tribes of Southern California to drive out the Americans. This outbreak of violence, known as the Garra revolt, was attributed to the levying of taxes upon converted Indians by the San Diego County Sherriff (Bibb 1991). Garra was ultimately captured by Juan Antonio, chief of the Cahuilla, and was turned over to the Americans.

The Treaty of Temecula was signed on January 5, 1852 at the Apis Adobe in Temecula. This treaty created a reservation for the Temecula Indians in order to protect them and their lands from American and Californio incursions. It also forced them to cede all other land to the government, though it did provide assistance to the Indians to establish agriculture for subsistence (Bibb 1991). Signed by President Zachary Taylor, the treaty was ultimately rejected by the U.S. Senate in response to lobbying by land speculators and settlers (Bibb 1991; Gerstbacher 1994; Van Horn 1974).

Southern California was developed by Americans and other immigrants who migrated to the western frontier in pursuit of gold and other mining, agriculture, trade, and land speculation (Lech 2004). Initially southern California was divided into only two counties: Los Angeles and San Diego. In 1853, San

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 13 Bernardino County was added, placing what is now Riverside County primarily within San Diego County and partially within San Bernardino County. Orange County divided from Los Angeles County in 1889.

Riverside County was created on March 11, 1893, when California Governor Markham signed a bill that combined a small portion of San Bernardino County and a large portion of San Diego County (Gerstbacher 1994).

In 1859, the 26,608.54-acre Rancho Temecula was granted to Luis Vignes by the U.S. Land Office (Gerstbacher 1994). The rancho would later be purchased in 1875 by Juan Murrieta, Domingo Pujol, and Francisco Zanjuro. Murrieta and Zanjuro were part of an 1875 posse formed by the San Diego County Sheriff to evict the Temecula Indians from Little Temecula Rancho, located south of the project area (Gerstbacher 1994).

In 1857, John Butterfield won a six year, $600,000-a-year federal contract to transport mail between St. Louis, Missouri and San Francisco twice a week within 25 days, stopping in Temecula at the Magee Store. Although lack of water and conflicts with Native Americans plagued the mail line, it was a success; almost without exception, the mail was transported in the required amount of time (Helmich 2008). By May 1859, Temecula saw the establishment of its first post office, the second ever in the state of California (Brigandi n.d.; City of Temecula n.d.).

The railroad connecting National City to Temecula was completed in January 1882. This not only allowed Temecula residents access to San Diego, but also began a minor business boom in Temecula. A year later, the line was extended to San Bernardino. A series of floods in the late 1880s washed out the tracks, causing the railroad to be abandoned (Brigandi n.d.; City of Temecula n.d.).

During the latter decades of the nineteenth century, the granite and cattle industries kept the fledgling community alive (Brigandi n.d.). Granite from nearby hills was sent to San Diego, Los Angeles, and San Francisco; however, due to the increased usage of cement in the early 1900s, the quarries were forced to shut down. In 1905, Walter Vail, a Canadian cattle rancher, purchased land in the Temecula Valley— his goal was to build a cattle empire. This goal was short lived, however, as Vail died in a Los Angeles streetcar accident in 1906 (Ammenheuser 2011a; Brigandi n.d.). Mahlon Vail, the son of Walter Vail, took over the family industry.

By the 1940s, Vail Ranch had become a massive cattle operation—hoping to grow more of their own feed, the Vails decided to dam Temecula Creek and create an irrigation system for the ranch. The dam, and Lake Vail, was finished in 1948 (Ammenheuser 2011a; Brigandi n.d.).

Vail Ranch was sold to developers in the early 1960s, who announced plans for a master planned community called Rancho California (Brigandi n.d.). It was not until the early 1980s, however, that the area began to grow due to the construction of I-15. The City of Temecula was incorporated nine years later in 1989, when the citizens voted to officially name the city Temecula (Brigandi n.d.).

The 1967 and 1978 historic aerials depict what appeared to be an airport adjacent to the project area.

Originally located just west of the project area, the Rancho California Airport was developed in the late 1960s by the developers of the Rancho California master plan community, who would travel to the area by air (Ammenheuser 2011b). Plagued by “terrifying” crosswinds, the owners of the airport, Kaiser- Aetna, shut it down in May 1976. It reopened under the direction of Riverside County a short time later (Ammenheuser 2011b; Sack 2007). The airport operated from the late 1960s to 1989, when it shut down after the new French Valley Airport opened, approximately five miles northeast of the project area (Ammenheuser 2011b; Sack 2007).

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 14 3.0 ARCHIVAL RESEARCH AND CONTACT PROGRAM

3.1 RECORDS SEARCH
HELIX requested a record search of the California Historical Resources Information System (CHRIS) from the Eastern Information Center (EIC) on April 23, 2020. Due to COVID-19, the University of California, Riverside campus was closed, causing a delay in processing records searches by EIC staff. The records search results were received on September 9, 2020. The records search covered a one-mile radius around the project alignment and included the identification of previously recorded cultural resources and locations and citations for previous cultural resources studies. A review of the California Historical Resources and the state Office of Historic Preservation (OHP) historic properties directories, and Local Register was also conducted. The records search summary and maps are included as Appendix B (Confidential Appendices, bound separately).

3.1.1 Previous Surveys
The records search results identified 138 previous cultural resource studies within the record search limits, 17 of which occurred within or overlap the project alignment (Table 1, Previous Studies Within or Adjacent to the Project Area). Nine of the studies were noted as archaeological assessments and five were surveys; the remaining studies include a geoarchaeological evaluation, a monitoring program, and a cultural resource study.

Table 1

PREVIOUS STUDIES WITHIN OR ADJACENT TO THE PROJECT AREA Report
Number (RI-) Year Author Report Title
00238 1986 Brown, Steve Archaeological Assessment Form, Riverside County Planning Department, TPM 21383
01013 1978 Hammond, Stephen R. Cultural Resources Survey of Two Materials Sources, Murrieta Creek and the Joe Deleo, Jr. Property,
Riverside County, California
01048 1980 White, Christopher W. Cultural Resource Inventory and Impact Assessment for the KACOR/Rancho California Property
01382 1981 Scientific Resource
Surveys, Inc.

Archaeological Assessment Form (PM 4646)
01824 1984 Drover, Christopher E. An Archaeological Assessment of Parcel Maps 19580 and 19626 In Temecula, California
02318 1987 Keller, Jean S. An Archaeological Assessment of Los Cerritos Ranch, Riverside County, California
02502 1989 Wade, Sue A., and
Susan M. Hector
An Archival and Limited Field Archaeological Survey
of the Temescal Wash and Rice Canyon Pipeline
Alternatives for the Regional Water Reclamation
Facility at Rancho California
02509* 1989 Drover, Christopher E. An Archaeological Assessment of Tentative Parcel Maps 24085 and 24086, Riverside County, California
03279 1991 Drover, Christopher E. Environmental Impact Evaluation: An Archaeological Assessment of the West Side Parkway Project,
Temecula, California

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 15 Report
Number (RI-) Year Author Report Title
3280* 2000 Love, Bruce, Leslie
Quintero, Thomas A.

Wake, Harry M. Quinn,
Kathryn J. W. Bouscaren,
and Michael Hogan
Archaeological Survey, Testing, & Monitoring at
Tentative Parcel Map No. 28657, City of Temecula,
Riverside County, California
3496 1992 Jones & Stokes
Associates, Inc
Archaeological Survey Report for Riverside County
Murrieta Creek Flood Control Project
4770* 2004 Hoover, Anna M., and
Kristie R. Blevins
A Phase I Archaeological Survey Report on the
Temecula Education Complex Property, APN 909-
370-002, City of Temecula, Riverside County,
California
4877 2003 Peak & Associates, Inc. Cultural Resources Assessment of the Proposed Temecula Valley Regional Water Reclamation
Facility Effluent Pipeline, Riverside County,
California
6731* 2006 Austerman, Virginia and
Curt Duke
Archaeological Monitoring Program, Temecula
Education Center, City of Temecula, Riverside
County, California
6877 2006 Onken, Jill, Kerry D. Cato,
Anne Q. Stoll, and
Michael K. Lerch
Geoarchaeological Evaluation for the Murrieta Creek
Flood Control and Ecosystem Restoration Project,
Riverside County, California
8387 2009 Brunzell, David Letter Report: Cultural Resources Assessment of the Distributed Antennae Communications System
Project in the Cities of Temecula and Murrieta,
Riverside County, California (BCR Consulting Project
No. SYN0903)
9747 2014 Ramirez, Robert, Jennifer
Peterson, and Kevin
Hunt
Eastern Municipal Water District Temecula Valley
Recycled Water Pipeline Project Cultural Resources
Study
* Adjacent to Project Area.

3.1.2 Previously Recorded Resources
The EIC has a record of 16 previously recorded cultural resources within a one-mile radius of the project alignment, but none have been recorded within the project area itself (Table 2, Previously Recorded Resources within One Mile of the Project Area). Three resources were recorded as Native American village sites, including two described as historic Indian villages. Other prehistoric/Native American resources within the search radius consist of bedrock milling features (one mortar and one slick), a rock enclosure with associated lithic scatter, artifact scatters, and isolated artifacts. Historic period resources include two twentieth century residences, a historic gravesite, a rock ring of unknown use, a wooden fence post, and a historic artifact scatter.

While no resources have been recorded within or adjacent to the project alignment, the three sites noted as “villages” are recorded in relative proximity to one another but on opposite sides of the project alignment and opposite sides of Murrieta Creek, suggesting that the entire area was at one time part of an overall village complex, much of which has apparently been destroyed be development.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 16 Table 2

PREVIOUSLY RECORDED RESOURCES WITHIN ONE MILE OF THE PROJECT AREA Primary
Number
(P-33-#)
Trinomial
(CA-RIV-#) Age Description Recorder, Date
000237 237 Prehistoric Possible village site consisting of lithic and ceramic artifacts
and dark midden soils.

McCown, 1952; Bowles,
1982; Keller 1987;
Drover and Smith, 1991;
Austerman, 2006
000644 644H Historic Native
American
Historic Indian village site with
midden containing a “great
amount” of cultural debris
Humbert and
Hammond, 1973
000717 717H Historic Native
American
Historic Indian village. Based
on informant data not physical
evidence, although undated
site form lists projectile points.

Noted in 1984 as destroyed by
construction.

Smith, 1974; Unknown,
n.d.; Crotteau, 1984
001382 1382H Historic Historic gravesite consisting of
a 6-foot by 20-inch by 8-inch
pile of rock with a wooden
lattice head marker.

Pettus 1976;
Drover 1984
001384 1384 Prehistoric Bedrock mortar and grinding
slick.

Morin, Welch, and
Pettus, 1976;
Drover, 1984
001727 1727H Historic Large wooden post with
several tangled strands of
barbed wire.

Graham, 1979
001730 1730 Prehistoric Processing area with a light
scatter of artifacts.

Graham, 1979;
Apple, 1981
002134 2134 Prehistoric Secondary reduction lithic site. Bowles, 1982; Bonner, 1986
004786 4786 Prehistoric Small scatter of lithic debitage and the proximal end of a
projectile point.

Drover and Smith, 1991
004986 4986 Prehistoric Rock enclosure with a lithic
scatter.

Drover and Smith, 1991
007447 -- Historic Historic residence built in the
Provincial Revival architectural
style around 1932.

Oxendine, 1983
013511 -- Prehistoric Isolate: single mano. Bowles, 1982 013712 -- Prehistoric Isolate: a mano and a
hammerstone.

Bowles, 1982
013726 -- Historic Circle of large rocks. Morin and Welch, 1976 019848 -- Historic Historic residence built around
1955, contains an irregular
plan and five Roman Doric
columns.

White, 2011

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 17 Primary
Number
(P-33-#)
Trinomial
(CA-RIV-#) Age Description Recorder, Date
024683 12214 Historic Historic trash scatter
consisting of bottles and bottle
fragments, ceramic fragments,
metal scraps, butchered bone,
and burned rocks.

Bruce, 2015

3.2 OTHER ARCHIVAL RESEARCH
Various additional archival sources were also consulted, including historic topographic maps and aerial imagery. These include historic aerials from 1938, 1947, 1967, and 1978 (NETR Online 2020) and several historic USGS topographic maps, including the 1901 Elsinore, 1947 Santa Ana, and 1960 Santa Ana (1:125,000), the 1943 Murrieta (1:62,500), and the 1953 and 1973 Murrieta (1:24,000) topographic maps. The purpose of this research was to identify historic structures and land use in the area.

No buildings appear in the project area on the 1901 USGS 30' Elsinore quadrangle, but there are a few dirt roads present, and the “Southern California RR San Bernardino and Temecula Line” is shown along the west edge of the project area on this map. The street grids and some buildings are shown in the location of Murrieta to the north on the 1901 map. The 1947 USGS 30' Santa Ana quadrangle displays U.S. Route 395 (US 395) bordering the eastern edge of the project area–this route is present on the 1960 Santa Ana quadrangle as well.

Both the 1943 15' Murrieta (1:62,500) and the 1953 7.5' Murrieta (1:24,000) USGS topographic maps show the project area bordered by the Murrieta Creek to the east. Neither map shows any buildings or structures within or near the project area. The 1973 7.5' Murrieta (1:24,000) USGS topographic map shows Diaz Road, along with the Rancho California Airport and several buildings located around the project area.

The historic aerials from 1938 and 1947 show US 395 running north-south to the east of the project area; neither of these aerials show any development along what would later become Diaz Road.

However, the 1967 and 1978 aerials show the development of the Rancho California Airport west of the project alignment, from a single dirt airstrip with no buildings to a functional airport with buildings and aircraft hangers, near modern-day Rancho California Road and Business Park Drive (NETR Online 2020).

By the time the 1996 aerial photograph was taken, the area had been developed to the extent seen in the 2016 aerial photograph, with the airport being replaced by commercial and industrial development (NETR Online 2020).

3.3 NATIVE AMERICAN CONTACT PROGRAM
HELIX contacted the Native American Heritage Commission (NAHC) on April 24, 2020 for a Sacred Lands File search and list of Native American contacts for the project area. The NAHC indicated in a response dated April 27, 2020 that the results were positive and that the Pechanga Band of Luiseño Indians should be contacted. Also provided was a list of 15 Native American tribal contacts who may have knowledge of cultural resources in the project area. Letters were sent on May 7, 2020 to Native American representatives and interested parties identified by the NAHC. Two responses have been received to date (Table 3, Native American Contact Program Responses). The Rincon Band of Luiseño

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 18 Indians (Rincon) stated that, while the project area is within the territory of the Luiseño people and Rincon’s “specific area of Historic interest,” they have no knowledge of any cultural resources within the project area. The Quechan Indian Tribe responded stating that they do not wish to comment on the project and defer to local Tribes. If any additional responses are received, they will be forwarded to City staff. Native American correspondence is included as Appendix C (Confidential Appendices, bound separately).

Table 3

NATIVE AMERICAN CONTACT PROGRAM RESPONSES
Contact/Tribe Response
Juaneño Band of Mission Indians Responded to AB 52 notification on July 21, 2020; indicated that the Band yields to the recommendations of the Pechanga Band.

Pechanga Band of Luiseño Indians Responded to AB 52 notification on July 15, 2020; formally requested to begin consultation. Indicated that the project is located within a Traditional Cultural Property. Provided minor comments/revisions to cultural resources mitigation measures in the IS/MND; these have been incorporated.

Quechan Indian Tribe Responded on June 9, 2020; do not wish to comment on this project; as such, they defer to local tribes.

Responded to AB 52 notification on July 17, 2020; indicated that they do not wish to comment on project and defer to local Tribes.

Rincon Band of Luiseño Indians Responded on May 18, 2020; the project area is within the territory of the Luiseño people and is within Rincon’s specific area of Historic interest.

Rincon has no knowledge of cultural resources within the project area; however, they believe that the potential exists for cultural resources to be identified during further research and survey work. They request a copy of this report and a copy of the records search results.

Responded to AB 52 notification on July 17, 2020; formally requested to begin consultation. Indicated that the project is located within the Band’s Area of Historic Interest.

Soboba Band of Luiseño Indians Responded to AB 52 notification on July 16, 2020; requested to defer to the Pechanga Band.

Agua Caliente Band of Cahuilla
Indians
Responded to AB 52 notification on September 22, 2020; defer to other tribes in the area.

The City of Temecula provided formal notification for the proposed project under AB 52 on June 30, 2020 to 17 tribal contacts. Responses were received from six tribes; Pechanga and Rincon both formally requested to begin consultation (Table 3). The Juaneño Band of Mission Indians and the Soboba Band of Luiseño Indians both deferred to Pechanga. The Quechan Indian Tribe and the Agua Caliente Band of Cahuilla Indians deferred to local tribes without naming a specific tribe (Table 3). During AB 52 consultation, the draft of this cultural resources study was provided to Pechanga and Rincon for review and comment, as was the Initial Study/Mitigated Negative Declaration (IS/MND). Rincon indicated they agreed with the mitigation measures and had no further comments. Pechanga provided minor comments/revisions to the detailed mitigation measures in the IS/MND; their comments have been incorporated.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 19 Principal Investigator Mary Robbins-Wade contacted Pechanga in April 2020, as recommended by the NAHC, and on May 26, 2020, Ms. Robbins-Wade spoke with Ebru Ozdil of the Pechanga Cultural Resources Department about the project. Ms. Ozdil stated that, while Pechanga had no record of archaeological sites within the project area itself, the area surrounding the project is part of the Luiseño village of Qengva, and is regarded as a TCR and TCP. She reiterated information from the 1974 site record for CA-RIV-717: “A Temecula resident claims that when young (approximately 50 years ago) an old woman in Temecula told him that the site had been a Luiseño village, inhabited in 1874. He has seen many surface artifacts there” (Smith 1974). Ms. Ozdil also noted that human remains and sacred items have been found in proximity to the project area; additionally, there is a Luiseño place name near Dendy Parkway and another near Winchester Road. The area is important to the Luiseño people due to the amount of water in the area.

4.0 SURVEY METHODOLOGY AND RESULTS

4.1 SURVEY OVERVIEW
A pedestrian survey of the project site was conducted on May 28, 2020 by HELIX staff archaeologist Julie Roy and Chris Yearyean from the Pechanga Cultural Resources Department. The project survey area is located along Diaz Road from Rancho California Road in the south to Cherry Street to the north. Where possible, the survey area covered 25 feet on each side the direct impact area shown in Figure 3; however, for the most part, the west side of the 25-foot buffer consists of commercial and industrial development, where there was no open ground. The eastern edge of the survey area is bordered by the Murrieta Creek. The entire project survey area was walked in transects spaced approximately 3 to 5 meters apart.

4.1.1 Methods and Results
The northern edge of the project alignment was highly disturbed due to recent trenching for an underground pipeline (Plate 1). The eastern edge of Diaz Road was also disturbed; ground visibility in this area was less than 10 percent, due to development of a concrete or asphalt bike/walking path with landscaped vegetation, sod, grass, weeds, and bark/mulch (Plates 2 and 3). Some open areas were available for visual inspection, though these areas had visibility less than 35 percent, due to cut weeds and grasses. Trenching was also occurring at the southern end of the alignment–this area was also heavily disturbed by the creation of manufactured slopes and planted trees, as well as recent trenching (Plates 4 and 5).

All visible ground within the project boundary was visually inspected; no cultural material was observed.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 20 Plate 1. Overview of the APE at the north end, view to the south. Trenching visible on right of road.

Plate 2. Overview of the east side of Diaz Road, with bike path on the right; view to the northwest.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 21 Plate 3. Overview of the east side of Diaz Road, with bike path on the left; view to the southeast.

Plate 4. Overview of the southern end of Diaz Road, view to the north.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 22 Plate 5. Overview of the southern end of Diaz Road, view to the south.

5.0 SUMMARY AND MANAGEMENT

RECOMMENDATIONS
A study was undertaken to identify cultural resources that are present in the Diaz Road Expansion Project alignment and to determine the effects of the project on historical resources per CEQA and historic properties per the NHPA. The cultural resources survey did not identify any archaeological resources within the project area. Although the project alignment is within a TCR/TCP, no physical manifestations of cultural activities have been identified within the project area; therefore, no impacts to cultural resources are anticipated.

While the project area and immediate vicinity remained relatively undeveloped until the late 1960s, when the Rancho California Airport was constructed, it has since been highly disturbed by commercial development, utility installations, and road formation. Additionally, the results of the survey indicated that the project area had been highly disturbed due to recent trenching for underground utilities, as well as the creation of manufactured slopes and planting of trees. However, as addressed below, the project is in an alluvial setting where there is a potential for buried cultural resources to be present.

5.1 MANAGEMENT RECOMMENDATIONS
Based on the results of the current study, no historical resources (per CEQA) or historic properties (per the NHPA) will be affected by the Diaz Road Expansion Project. However, while no archaeological resources have been identified within the APE, as noted by the NAHC, the area is sensitive for cultural resources. The Pechanga Band of Luiseño Indians indicated that several cultural sites and Luiseño place names are located within close proximity to the project area and that the area is part of a TCR/TCP.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 23 Because the project site was covered by fill material and transportation infrastructure, the original ground surface could not be observed in most areas. Additionally, the project site is located within alluvial soils, where there is a potential for buried cultural resources.

Based on these factors, it is recommended that an archaeological and Native American monitoring program be implemented for grading or other ground disturbing activities (e.g., trenching for utilities).

The monitoring program would include attendance by the archaeologist and Pechanga Native American monitor at a preconstruction meeting with the grading contractor and the presence of archaeological and Pechanga Native American monitors during initial ground disturbing activities on site. Both archaeological and Native American monitors would have the authority to temporarily halt or redirect grading and other ground-disturbing activity in the event that cultural resources are encountered. If the monitors determine that the project area has been too disturbed by past activities for cultural material to be present, monitoring would be discontinued. If significant cultural material is encountered, the project archaeologist would coordinate with Pechanga and City of Temecula staff to develop and implement appropriate mitigation measures.

In the event that human remains are discovered, the County Coroner shall be contacted. If the remains are determined to be of Native American origin, the Most Likely Descendant, as identified by the NAHC, shall be contacted in order to determine proper treatment and disposition of the remains. All requirements of Health & Safety Code §7050.5 and PRC §5097.98 shall be followed.

Should the project limits change to incorporate new areas of proposed disturbance, archaeological survey of these areas will be required.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 24 6.0 REFERENCES
Ammenheuser, Maura
2011a A Look Back: Vail Ranch Covered Temecula Area. The Press-Enterprise. Electronic document available at: https://www.pe.com/2011/03/26/a-look-back-vail-ranch- covered-temecula-area/, accessed September 30, 2020.
2011b Temecula: Rancho California Airport a Distant Memory. The Press-Enterprise. Electronic document available at: https://www.pe.com/2011/10/15/temecula-rancho-california- airport-a-distant-memory/, accessed May 29, 2020.

Applied Earth Works, Inc.
2001 Metropolitan Water District of Southern California, Eastside Reservoir Project, Final Report of Archaeological Investigations. Volumes I to V. General editor, Susan K.

Goldberg. Report prepared for the Metropolitan Water District of Southern California, Los Angeles.

Bean, Lowell John
1972 Mukat’s People: The Cahuilla Indians of Southern California. University of California Press, Berkeley and Los Angeles.
1978 Cahuilla. In California, edited by Robert F. Heizer, pp. 575-587. Handbook of North American Indians, vol. 8. William C. Sturtevant, general editor. Smithsonian Institution, Washington, D.C.

Bean, Lowell John, and Florence C. Shipek
1978 Luiseño. In California, edited by Robert F. Heizer, pp. 550-563. Handbook of North American Indians, vol. 8. William C. Sturtevant, general editor. Smithsonian Institution, Washington, D.C.

Bean, Lowell J., and Sylvia B. Vane (editors)
1979 Native Americans of Western Riverside County California and the Devers-Mira Loma 500 kV Transmission Line Route (Lamb-Canyon-Mira Loma Section). Prepared by Cultural Systems Research, Inc., Menlo Park, California, for Southern California Edison Company, Rosemead, California.
1980 The Ethnography and History of the Devers to Lamb Canyon Transmission Corridor Area, Riverside County, California. Prepared by Cultural Systems Research, Inc., Menlo Park, California, for Southern California Edison Company, Rosemead California.

Bean, Lowell J., Sylvia B. Vane, and Jackson Young
1991 The Cahuilla Landscape: The Santa Rosa and San Jacinto Mountains. Ballena Press, Menlo Park, CA.

Bettinger, Robert L.
1974 Dating the Perris Reservoir Assemblages. In Perris Reservoir Archaeology, edited by James F. O’Connell, Philip J. Wilke, Thomas F. King, and Carol L. Mix, pp. 159–162.

California Department of Parks and Recreation Reports No. 14. Sacramento

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 25 Bibb, Leland E.
1991 Pablo Apis and Temecula. The Journal of San Diego History. 37(4). Electronic document available at: https://sandiegohistory.org/journal/1991/october/temecula-3/ , accessed May 29, 2020.

Bolton, Herbert E.
1930 Anza’s California Expeditions, Vols. I–IV. University of California Press, Berkeley.

Brigandi, Phil
1999 The Outposts of Mission San Luis Rey. Journal of San Diego History 45(2):106–112. n.d. A Short History of Temecula, California. Electronic document, available at:
https://www.temeculahistoricalsociety.org/html2/Temecula_History.html , accessed September 30, 2020.

Bull, Charles S.
1983 Shaking the Foundations: The Evidence for San Diego Prehistory. Casual Papers: Cultural Resource Management 1(3):15-64. Cultural Resource Management Center, San Diego State University.
1987 A New Proposal: Some Suggestions for San Diego Prehistory. In San Dieguito-La Jolla:

Chronology and Controversy, edited by Dennis Gallegos, pp. 35-42. San Diego County Archaeological Society, Research Paper 1.

Carrico, Richard L., Theodore G. Cooley, and Joyce M. Clevenger 1993 Archaeological Excavations at the Harris Site Complex, San Diego County, California.

Prepared by Ogden Environmental and Energy Services, San Diego. Report on file at the South Coastal Information Center, San Diego State University.

City of Temecula
2005 City of Temecula General Plan.
n.d. History of Temecula. Temecula.gov. Electronic document available at:
https://www.temeculaca.gov/150/History-of-Temecula , accessed September 30, 2020.

Cupples, Sue Ann, and Ken Hedges
1977 San Luis Rey River Basin: Overview of Cultural Resources. San Diego State University Foundation. Prepared for US Army Corps of Engineers. Electronic document, available at: http://www.dtic.mil/dtic/tr/fulltext/u2/a146300.pdf . Accessed June 2, 2020.

Des Lauriers, Matthew R.
2008 A Paleoindian Fluted Point from Isla Cedros, Baja, California. Journal of Island & Coastal Archaeology 3:271–276.

Dillon, Brian D.
2002 California Paleo-Indians: Lack of Evidence, or Evidence of a Lack? In Essays in California Archaeology: A Memorial to Franklin Fenenga. Edited by William J. Wallace and Francis A. Riddell. Contributions of the University of California Archaeological Research Facility, No. 60. Berkeley, California.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 26 DuBois, Constance
1908 The Religion of the Luiseño Indians of Southern California. University of California Publications in American Archaeology and Ethnology 8(3):69-186.

Erlandson, Jon M.
1994 Early Hunter-Gatherers of the California Coast. New York, Plenum Press. 1997 The Middle Holocene along the California Coast. In Archaeology of the California Coast during the Middle Holocene, edited by J.M. Erlandson and M.A. Glassow. pp. 61–72.

Perspectives in California Archaeology, Vol. 4, J.E. Arnold, series editor. Institute of Archaeology, University of California, Los Angeles.

Erlandson, Jon M., Torben C. Rick, Terry L. Jones, and Judith F. Porcasi 2007 One If by Land, Two If by Sea: Who Were the First Californians? In California Prehistory:

Colonization, Culture, and Complexity, edited by Terry L. Jones and Kathryn A. Jones, pp. 53–62. Altamira Press, Lanham, Maryland.

Ezell, Paul H.
1987 The Harris Site – An Atypical San Dieguito Site, or Am I Beating a Dead Horse? In San Dieguito–La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 15-22.

San Diego County Archaeological Society Research Paper Number 1. San Diego.

Fitzgerald, Richard T., and Michael F. Rondeau
2012 A Fluted Projectile Point from Crystal Cove State Park, Orange County, Alta California.

California Archaeology 4(2):247-256.

Gallegos, Dennis R.
1987 A Review and Synthesis of Environmental and Cultural Material for the Batiquitos Lagoon Region. In San Dieguito-La Jolla: Chronology and Controversy, edited by Dennis Gallegos, pp. 23-34. San Diego County Archaeological Society, Research Paper 1. 1991 Antiquity and Adaptation at Agua Hedionda, Carlsbad, California. In Hunter-Gatherers of Early Holocene Coastal California, edited by J.M. Erlandson and R.H. Colten., pp. 19–42.

Perspectives in California Archaeology, Vol. 1, J.E. Arnold, series editor. Institute of Archaeology, University of California, Los Angeles.

Gerstbacher, Emily
1994 Temecula History: A Chronology, 1797-1993. Friends of the Temecula Library, Temecula, California.

Goldberg, Susan
2001 Land Use, Mobility, and Intensification Evaluation and Refinement of the Model. In Metropolitan Water District of Southern California, Eastside Reservoir Project, Final Report of Archaeological Investigations, Volume IV: Prehistoric Archaeology Synthesis of Findings, edited by Susan K. Goldberg, Chapter 14. Report prepared by Applied Earthworks, Hemet, California for Metropolitan Water District of Southern California, Los Angeles.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 27 Grenda, Donn R.
1997 Continuity & Change: 8,500 Years of Lacustrine Adaptation on the Shores of Lake Elsinore. Statistical Research, Inc. Technical Series 59, Tucson.

Hall, Clarence A., Jr.
2007 Introduction to the Geology of Southern California and its Native Plants. University of California Press, Berkeley.

Head, W.S.
1972 The California Chaparral: An Elfin Forest. Naturegraph, Healdsburg, California.

Helmich, Mary
2008 The Butterfield Overland Mail. California Department of Parks and Recreation. Electronic document available at: https://www.parks.ca.gov/?page_id=25444 , accessed September 3, 2020.

Hedges, Ken, and Christina Beresford
1986 Santa Ysabel Ethnobotany. San Diego Museum of Man Ethnic Technology Notes No. 20.

Hyland, Justin R., and Maria De La Luz Gutierrez
1995 An Obsidian Fluted Point from Central Baja California. The Journal of California and Great Basin Anthropology 17(1): 126–128.

Jones, Terry L., Gary M. Brown, L. Mark Raab, Janet L. McVicker, W. Geoffrey Spaulding, Douglas J.

Kennett, Andrew York, and Phillip L. Walker
1999 Environmental Imperatives Reconsidered. Demographic Crisis in Western North America during the Medieval Climatic Anomaly. Current Anthropology 40:137–170.

Kennedy, M.P. and D.M. Morton
n.d. Preliminary Geologic Map of The Murrieta 7.5' Quadrangle Riverside County, California.

Version 1.0. Digital database by Rachel M. Alvarez and Greg Morton. U.S. Department of the Interior, U.S. Geological Survey, and the California Geological Survey.

Kennett, Douglas J., and James P. Kennett
2000 Competitive and Cooperative Responses to Climatic Instability in Coastal Southern California. American Antiquity 65:379–395.

Kline, George E., and Victoria L. Kline
2007 Fluted Point Recovered from San Diego County Excavation. Proceedings of the Society for California Archaeology 20:55–59.

Knell, Edward J., and Mark S. Becker
2017 Early Holocene San Dieguito Complex Lithic Technological Strategies at the C.W. Harris Site, San Diego, California. Journal of California and Great Basin Anthropology 37(2):183-201.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 28 Koerper, Henry C., Paul E. Langenwalter II, and Adella Schroth 1991 Early Holocene Adaptations and the Transition Phase Problem: Evidence from the Allan O. Kelly Site, Agua Hedionda Lagoon. In Hunter-Gatherers of Early Holocene Coastal California, edited by J. M. Erlandson and R. H. Colton, pp. 43–62. Perspectives in California Archaeology, vol. 1, J.E. Arnold, series editor. Institute of Archaeology, University of California, Los Angeles.

Kroeber, A.L.
1925 Handbook of California Indians. Bulletin 78 of the Bureau of American Ethnology of the Smithsonian Institution.

Lech, Steve
2004 Along the Old Roads: A History of the Portion of Southern California That Became Riverside County, 1772–1893. Steve Lech, Riverside, California.

Luomala, Katherine
1978 Tipai-Ipai. In California, edited by Robert F. Heizer, pp. 592-609. Handbook of North American Indians, vol. 8. William C. Sturtevant, general editor. Smithsonian Institution, Washington, D.C.

Masiel-Zamora, Myra Ruth
2013 Analysis of ‘Éxva Teméeku, A Luiseño Indian Village Site Named Temeku, Located in Temecula, California. Master’s thesis, Department of Anthropology, San Diego State University.

McCown, B.E.
1955 Temeku. A Page from the History of the Luiseño Indians. Archaeological Survey Association of Southern California Paper No. 3.

McDougall, Dennis P.
2001 CA-RIV-5086/H. In Metropolitan Water District of Southern California, Eastside Reservoir Project, Final Report of Archaeological Investigations, Volume II: Archaic and Late Prehistoric Occupation Sites, edited by Susan K. Goldberg, Chap. 9. Prepared by Applied Earthworks, Hemet, California for Metropolitan Water District of Southern California, Los Angeles.

Miller, Wick R.
1986 Numic Languages. In Great Basin, edited by W. L. D’Azevedo, pp. 98–112. Handbook of North American Indians, Vol. 11. William C. Sturtevant, general editor. Smithsonian Institution, Washington, D.C.

Moratto, Michael J.
1984 California Archaeology. Academic Press, Orlando.

Munz, Philip A.
1974 A Flora of Southern California. University of California Press, Berkeley.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 29 National Oceanic and Atmospheric Administration (NOAA) 2014 Electronic document available at: http://forecast.weather.gov/ MapClick.php?zoneid=CAZ048#.VGlzkP0tA1U, accessed in June 2020.

NETR Online
2020 Historic Aerials. Nationwide Environmental Title Research, LLC. Electronic document available at: http://www.historicaerials.com , accessed May 29, 2020.

O’Connell, James F., Philip J. Wilke, Thomas F. King and Carol L. Mix, editors. 1974 Perris Reservoir Archaeology: Late Prehistoric Demographic Change in Southeastern California. Report prepared by the Archaeological Research Unit, Department of Anthropology, University of California, Riverside, California, for the State of California Department of Parks and Recreation.

Parker, Patricia L., and Thomas F. King
1998 Guidelines for Evaluating and Documenting Traditional Cultural Properties. National Park Service, Washington, D.C.

Pigniolo, Andrew R.
2005 A Different Context: San Dieguito in the Mountains of Southern California. Proceedings of the Society for California Archaeology 18:255-262.

Robinson, Mark C.
2001 Units of Analysis. In Metropolitan Water District of Southern California, Eastside Reservoir Project, Final Report of Archaeological Investigations, Volume IV: Prehistoric Archaeology Synthesis of Findings, edited by Susan K. Goldberg, Chapter 4. Prepared by Applied Earthworks, Hemet, California for Metropolitan Water District of Southern California, Los Angeles.

Rogers, Malcolm J.
1939 Early Lithic Industries of the Lower Basin of the Colorado River and Adjacent Desert Areas. San Diego Museum of Man Papers No. 3. San Diego Museum of Man. 1966 Ancient Hunters of the Far West. Union-Tribune Publishing Company, San Diego.

Rolle, A.F.
1963 California: A History. Thomas Y. Crowell Company, New York, New York.

Rondeau, Michael F., James Cassidy, and Terry L. Jones. 2007 Colonization Technologies: Fluted Projectile Points and the First Californians. In California Prehistory: Colonization, Culture, and Complexity, edited by Terry L. Jones and Kathryn A. Klar. AltaMira Press, Lanham, Maryland.

Sack, Nicole
2007 Airport Gone, Not Forgotten; Historical Society Plaque Project Recalls Dangerous Strip.

San Diego Union Tribune. Electronic document available at:
https://www.sandiegouniontribune.com/sdut-airport-gone-not-forgotten-historical- society-2007apr06-story.html, accessed May 29, 2020.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 30 Shipley, William F.
1978 Native Languages of California. In California, edited by Robert F. Heizer, pp. 80-90.

Handbook of North American Indians, Vol. 8, William C. Sturtevant, general editor, Smithsonian Institution, Washington, D.C.

Smith, Joan R.
1974 Letter to Society for California Archaeology, part of archaeological site record for P-33- 000717/CA-RIV-717. Site record on file at Eastern Information Center, University of California Riverside.

Sparkman, Philip Stedman
1908 The Culture of the Luiseño Indians. University of California Publications in American Archaeology and Ethnology 8(4):187-234.

Stine, S.
1994 Extreme and Persistent Drought in California and Patagonia during Mediaeval Time.

Nature 369:546–549.

Sutton, Mark Q., and Jill K. Gardner.
2010 Reconceptualizing the Encinitas Tradition of Southern California. Pacific Coast Archaeological Society Quarterly, 42(4)1–64. Costa Mesa.

Sutton, Mark Q., and Don R. Grenda.
2012 Defining Level 1 at Malaga Cove (CA LAN-138), Alta California. California Archaeology 4(1): 123–144.

Tan, Siang S., and Michael P. Kennedy.
2000 Geologic Map of the Temecula 7.5' Quadrangle San Diego County, California: A Digital Database. Version 1.0. Digital database by Brad Nelson and Gary Patt. California Department of Conservation, California Geological Survey.

True, D.L.
1990 Site Locations and Water Supply: A Perspective from Northern San Diego County, California. Journal of New World Archaeology 7(4):37–60.

True, D.L., and Paul D. Bouey.
1990 Gladishill: A Probable San Dieguito Camp Near Valley Center, California. Journal of New World Archaeology 7(4): 1-28.

Van Horn, David M.
1974 Tempting Temecula. The Journal of San Diego History. 20(1). Electronic document available at: https://sandiegohistory.org/journal/1974/january/temecula/ , accessed May 29, 2020.

Vaughan, Sheila J.
1982 A Replicative Systems Analysis of the San Dieguito Component at the C.W. Harris Site.

Master’s thesis, Department of Anthropology, University of Nevada, Las Vegas.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 31 Wallace, William J.
1955 A Suggested Chronology for Southern California Coastal Archaeology. Southwestern Journal of Anthropology 11:214-230.

Warren, Claude N.
1967 The San Dieguito Complex: A Review and Hypothesis. American Antiquity 32:168-185. 1968 Cultural Tradition and Ecological Adaptation on the Southern California Coast. In Archaic Prehistory in the Western United States, edited by C. Irwin-Williams, pp. 1–14. Eastern New Mexico Contributions in Anthropology 1(3). Portales, New Mexico. 1984 The Desert Region. In California Archaeology, edited by Michael J. Moratto, pp. 339– 430. Academic Press, Orlando, Florida.

Warren, Claude N. (editor)
1966 The San Dieguito Type Site: M.J. Rogers’ 1938 Excavation on the San Dieguito River. San Diego Museum Papers No. 5. San Diego Museum of Man.

Warren, Claude N., and D.L. True.
1961 The San Dieguito Complex and Its Place in San Diego County Prehistory. Archaeological Survey Annual Report, 1960-1961, pp. 246-291. University of California, Los Angeles.

Warren, Claude N., and H.T. Ore
2011 The Age of the San Dieguito Artifact Assemblage at the C. W. Harris Site. Journal of California and Great basin Anthropology 31(1):81-97.

Warren, C.N., G. Siegler, and F. Dittmer
1998 Paleoindian and Early Archaic Periods. In Prehistoric and Historic Archaeology of Metropolitan San Diego: A Historic Properties Background Study. Prepared for the Metropolitan Wastewater Department, City of San Diego. ASM Affiliates, Encinitas, California.

Web Soil Survey.
2019 Natural Resource Conservation Service. United States Department of Agriculture.

Electronic document, available at:
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx , accessed June 2, 2020.

Weber, David
1992 The Spanish Frontier in North America. Yale University Press.

White, Raymond C.
1963 Luiseño Social Organization. University of California Publications in American Archaeology and Ethnology 48(2):91-194.

Wilke, Philip
1974 Settlement and Subsistence at Perris Reservoir: A Summary of Archaeological Investigations. In Perris Reservoir Archaeology, edited by J.F. O’Connell, P.J. Wilke, T.F. King, and C.L. Mix, pp. 20–30. California Department of Parks and Recreation Reports No. 14. Sacramento.

Cultural Resources Survey for the Diaz Road Extension Project | January 2022 32 This page intentionally left blank

Appendix A
Resumes

Mary Robbins-Wade, RPA
Cultural Resources Group Manager

Summary of Qualifications
Ms. Robbins-Wade has 41 years of extensive experience in both archaeological research and general environmental studies. She oversees the management of all archaeological, historic, and interpretive projects; prepares and administers budgets and contracts; designs research programs; supervises personnel; and writes reports.

Ms. Robbins-Wade has managed or participated in hundreds of projects under the California Environmental Quality Act (CEQA), as well as numerous archaeological studies under various federal jurisdictions, addressing Section 106 compliance and National Environmental Policy Act (NEPA) issues. She has excellent relationships with local Native American communities and the Native American Heritage Commission (NAHC), as well as has supported a number of local agency clients with Native American consultation under State Bill 18 and assistance with notification and Native American outreach for Assembly Bill 52 consultation. Ms. Robbins-Wade is a Registered Professional Archaeologist (RPA) and meets the U.S. Secretary of the Interior's Professional Qualifications for prehistoric and historic archaeology.

Selected Project Experience

12 Oaks Winery Resort. Project Manager/ Principal Investigator for a cultural resources survey of approximately 650 acres for a proposed project in the County of Riverside. Oversaw background research, field survey, site record updates, Native American coordination, and report preparation. Met with Pechanga Cultural Resources staff to discuss Native American concerns. Worked with applicant and Pechanga to design the project to avoid impacts to cultural resources. Work performed for Standard Portfolio Temecula, LLC.

28th Street between Island Avenue and Clay Avenue Utilities Undergrounding Archaeological Monitoring. Project Manager/Principal Investigator for a utilities undergrounding project in a historic neighborhood of East San Diego. Responsible for project management; coordination of archaeological and Native American monitors; coordination with forensic anthropologist, Native American representative/Most Likely Descendent, and City staff regarding treatment of possible human remains; oversaw identification of artifacts and cultural features, report preparation, and resource documentation. Work performed for the City of San Diego.

Archaeological Testing F11 Project. Project Manager for a cultural resources study for a proposed mixed-use commercial and residential tower in downtown San Diego.

Initial work included an archaeological records search and a historic study, including assessment of the potential for historic archaeological resources. Subsequent work included development and implementation of an archaeological testing plan, as well as construction monitoring and the assessment of historic archaeological resources encountered. Work performed for the Richman Group of Companies.

Education
Master of Arts,
Anthropology, San
Diego State
University, California,
1990
Bachelor of Arts,
Anthropology,
University of
California, Santa
Barbara, 1981

Registrations/
Certifications
Caltrans,
Professionally
Qualified Staff-
Equivalent Principal
Investigator for
prehistoric
archaeology,
, Bureau of Land
Management
Statewide Cultural
Resource Use Permit
(California), permit
#CA-18-35,
, Register of
Professional
Archaeologists
#10294, 1991
County of San Diego,
Approved CEQA
Consultant for
Archaeological
Resources, 2007
, Orange County
Approved
Archaeologist 2016

Mary Robbins-Wade, RPA
Cultural Resources Group Manager

2 Blended Reverse Osmosis (RO) Line Project. Project Manager/ Principal Investigator for cultural resources monitoring during construction of a 24-inch recycled water pipeline in the City of Escondido.

Oversaw monitoring program, including Worker Environmental Awareness Training; responsible for Native American outreach/coordination, coordination with City staff and construction crews, and general project management. Work performed for the City of Escondido.

Buena Sanitation District Green Oak Sewer Replacement Project. Project Manager/Principal Investigator for a cultural resources testing program in conjunction with a proposed sewer replacement project for the City of Vista. Oversaw background research, fieldwork, site record update, Native American coordination, and report preparation. Work performed for Harris & Associates, Inc., with the City of Vista as the lead agency.

Cactus II Feeder Transmission Pipeline IS/MND. Cultural Resources Task Lead for this project in the City of Moreno Valley. Eastern Municipal Water District proposed to construct approximately five miles of new 30-inch to 42 inch-diameter pipeline; the project would address existing system deficiencies within the City and provide supply for developing areas. Oversaw background research, field survey, and report preparation. Responsible for Native American outreach for cultural resources survey. Assisted District with Native American outreach and consultation under AB 52. Work performed under an as-needed contract for Eastern Municipal Water District.

Dale 2199C Pressure Zone Looping Pipeline Project. Cultural Resources Task Lead for this project in Moreno Valley. Eastern Municipal Water District proposed construction of a new pipeline to connect two existing pipelines in the District’s 2199C Pressure Zone. The pipeline would consist of an 18-inch- diameter pipeline between Kitching Street and Alta Vista Drive that would connect to an existing 12-inch- diameter pipeline in the northern end of Kitching Street and to an existing 18-inch-diameter pipeline at the eastern end of Alta Vista Drive. The project will improve reliability and boost the Dale Pressure Zone’s baseline pressure and fire flow availabilities. Four potential alignments were under consideration; three of these bisect undeveloped land to varying degrees, while the other is entirely situated within developed roadways. Oversaw background research and field survey. Responsible for Native American outreach for cultural resources survey and co-authored technical report. Work performed under an as-needed contract for Eastern Municipal Water District.

Downtown Riverside Metrolink Station Track & Platform Project. Cultural Resources Task Lead for this project involving changes to and expansion of the Downtown Riverside Metrolink Station.

Overseeing records search and background information, archaeological survey, and report preparation.

Responsible for coordination with Native American Heritage Commission, Riverside County Transportation Commission (RCTC), and Federal Transportation Authority (FTA) on Native American outreach. Work performed for Riverside County Transportation Commission as a subconsultant to HNTB Corporation.

Emergency Storage Pond Project. Project Manager/Principal Investigator for a cultural resources testing program in conjunction with the Escondido Recycled Water Distribution System - Phase 1. Two cultural resources sites that could not be avoided through project design were evaluated to assess site significance and significance of project impacts. Work included documentation of bedrock milling

Mary Robbins-Wade, RPA
Cultural Resources Group Manager

3 features, mapping of features and surface artifacts, excavation of a series of shovel test pits at each site, cataloging and analysis of cultural material recovered, and report preparation. The project is located in an area that is sensitive to both the Kumeyaay and Luiseño people, requiring close coordination with Native American monitors from both groups. Work performed for the City of Escondido.

Escondido Brine Line Project. Project Manager/Principal Investigator for cultural resources monitoring during construction of approximately 2.3 miles of a 15-inch brine return pipeline in the City of Escondido.

The project, which is part of the City’s Agricultural Recycled Water and Potable Reuse Program, enables discharge of brine recovered from a reverse osmosis facility that is treating recycled water; it is one part of the larger proposed expansion of Escondido's recycled water distribution to serve eastern and northern agricultural land. The project is located in an area that is sensitive to both the Kumeyaay and Luiseño people, requiring close coordination with Native American monitors from both groups. Oversaw monitoring program, including Worker Environmental Awareness Training; responsible for Native American outreach/coordination, coordination with City staff and construction crews, and general project management. Work performed for the City of Escondido.

Hacienda del Mar EIR. Senior Archaeologist for a proposed commercial development project for a senior care facility in Del Mar. Assisted in the preparation of associated permit applications and an EIR. Oversaw background research, updated records search and Sacred Lands File search, monitoring of geotechnical testing, coordination with City staff on cultural resources issues, and preparation of updated report. Prior to coming to HELIX, served as Cultural Resources Task Lead for the cultural resources survey for the project, conducted as a subcontractor to HELIX. Work performed for Milan Capital Management, with the City of San Diego as the lead agency.

Lilac Hills Ranch. Project Manager/Principal Investigator of a cultural resources survey and testing program for an approximately 608-acre mixed-use development in the Valley Center area. Oversaw background research, field survey, testing, recording of archaeological sites and historic structures, and report preparation. Responsible for development of the research design and data recovery program, preparation of the preservation plan, and Native American outreach and coordination. The project also included recording historic structures, development of a research design and data recovery program for a significant archaeological site, and coordination with the Native American community and the client to develop a preservation plan for a significant cultural resource. The project changed over time, so additional survey areas were included, and a variety of off-site improvement alternatives were addressed. Work performed for Accretive Investments, Inc. with County of San Diego as the lead agency.

Moulton Niguel Water District Regional Lift Force Main Replacement. Cultural Resources Task Lead/Principal Investigator for the replacement of a regional lift station force main operated by Moulton Niguel Water District (MNWD). The project comprises an approximately 9,200 linear foot alignment within Laguna Niguel Regional Park in Orange County, in an area that is quite sensitive in terms of cultural resources. HELIX is supporting Tetra Tech throughout the preliminary design, environmental review (CEQA), and final design, including permitting with applicable state and federal regulatory agencies. The cultural resources survey will inform project design, in order to avoid or minimize potential impacts to cultural resources. Oversaw background research and constraints analysis, Native American

Mary Robbins-Wade, RPA
Cultural Resources Group Manager

4 coordination, cultural resources survey, coordination with MNWD and Tetra Tech, and report preparation. Work performed for MNWD, as a subconsultant to Tetra Tech.

Murrieta Hot Springs Road Improvements Project. Principal Investigator/Cultural Resources Task Lead for cultural resources survey in support of an Initial Study/Mitigated Negative Declaration (IS/MND) for the widening of Murrieta Hot Springs Road in the City of Murrieta. The project would widen or restripe Murrieta Hot Springs Road between Winchester Road and Margarita Road from a 4-lane roadway to a six-lane roadway to improve traffic flow, as well as provide bike lanes in both directions along this segment. A new raised median, light poles, signage, stormwater catch basins, retaining walls, and sidewalks would also be provided on both sides of the roadway, where appropriate. The project area is in a location that is culturally sensitive to the Native American community. The cultural resources study included tribal outreach and coordination to address this cultural sensitivity.

Park Circle - Cultural Resources. Project Manager/Principal Investigator of a cultural resources survey and testing program for a proposed 65-acre residential development in the Valley Center area of San Diego County. The project is located along Moosa Creek, in an area that is culturally sensitive to the Luiseño people. Oversaw background research, historic study, field survey, testing, recording archaeological sites and historic structures, and report preparation. Responsible for Native American outreach and coordination. The cultural resources study included survey of the project area, testing of several archaeological sites, and outreach and coordination with the Native American community, as well as a historic study that addressed a mid-20th century dairy barn and a late 19th century vernacular farmhouse. Work performed for Touchstone Communities.

Peacock Hill Cultural Resources. Project Manager/Principal Investigator of a cultural resources study update for a residential development in Lakeside. Oversaw updated research, fieldwork, lab work, analysis by forensic anthropologists, report preparation, and Native American coordination. In the course of outreach and coordination with the Native American (Kumeyaay) community, possible human remains were identified, prompting additional fieldwork, as well as coordination with the Native American community and forensic anthropologists. Work performed for Peacock Hill, Inc.

Sky Canyon Sewer Environmental Consulting. Cultural Resources Task Lead for this project adjacent to the City of Murrieta in southwestern Riverside County. Eastern Municipal Water District (District) proposed to implement the Sky Canyon Sewer Main Extension Project to construct approximately 6,700 linear feet of new gravity-fed 36-inch-diameter sewer main to provide additional sewer capacity for planned development. The proposed 36-inch-diameter sewer main would extend the existing 36-inch- diameter French Valley Sewer at Winchester Road further downstream to Murrieta Hot Springs Road.

Oversaw background research and field survey. Responsible for Native American outreach for cultural resources survey and co-authored technical report. Assisted District with Native American outreach and consultation under AB 52. Work performed under an as-needed contract for Eastern Municipal Water District.

James Turner, RPA
Staff Archaeologist

Summary of Qualifications
Mr. Turner is a Registered Professional Archaeologist (RPA) with a Master's degree in Anthropology and field and college-level teaching experience in archaeology. He is experienced in Section 106, the Native American Graves Protection and Repatriation Act (NAGPRA), and writing detailed reports. Mr. Turner has archaeological research and fieldwork expertise throughout southern California. He has also received training in identifying and analyzing animal remains in archaeological contexts, historic artifact identification, and technical writing. Mr. Turner’s experience meets the Secretary of the Interior’s Professional Qualification Standards for archaeology.

Selected Project Experience
eTS 43472 “Gold Mine” Monitoring (2020). Archaeologist for an erosion control and repair project in the community of Julian. Conducted cultural resource monitoring and report preparation. Work performed for San Diego Gas & Electric.

Aliso Creek Canyon Restoration Project (2020). Archaeologist for an erosion repair project in Lake Forest. Conducted a field survey of the project area, performed background research, and produced a cultural resources report. Work performed for the Orange County Department of Public Works.

Broadway Channel Improvements - Phase A (2020 - ). Archaeologist for an earthen channel improvement project in the city of El Cajon. Performed background research and prepared cultural resource survey report. Work performed for City of El Cajon.

Clairemont Community Plan Update EIR Ph1 (2020). Archaeologist for the Clairemont Community Plan Update. Performed background research and assisted with preparing the Community Plan Update cultural resources section. Work performed for the City of San Diego.

Cordial Road Pipeline (2020). Archaeologist for a pipeline replacement project in the unincorporated portion of the City of El Cajon. Performed background research and field survey. Other responsibilities included the production of a letter report detailing the methods and results of the survey, as well as the completion of a site record update to submit to the South Coastal Information Center. Work performed for the Padre Dam Municipal Water District.

Carmel Mountain Road Life Sciences Project (2020). Archaeologist for a proposed commercial development project in the Torrey Hills Community Plan area.

Education
Master of Arts,
Anthropology, San
Diego State
University, 2018
Bachelor of Arts,
Biology and
Anthropology, San
Diego State
University, 2015

Registrations/
Certifications
Registered
Professional
Archaeologist #17338

Professional
Affiliations
Society for Historical
Archaeology
Society for California
Archaeology

James Turner, RPA
Staff Archaeologist

2 Responsibilities included performing background and archival research and producing an archaeological resources report. Work performed for Allen Matkins Leck Gabme Mallory & Natsis, LLP.

Draft EIS/Overseas EIS - Disposal of Decommissioned, Defueled Ex-Enterprise (CVN 65) & Associated Naval Reactor Plants (2020 - ). Archaeologist for the Draft EIS for the disposal of the Navy ex-Enterprise. Responsible for background research and citation management and assisted with document preparation. Work performed for the United States Navy as a subconsultant to ManTech.

Eastlake Village Park (2020). Archaeologist for a telecommunication project in the community of Eastlake in the City of Chula Vista. Conducted cultural resource monitoring for the drilling of a cassion hole. Work performed for Terracon.

General Coatings (2020). Archaeologist for a due diligence project for the possible future expansion of the General Coatings property. Conducted background research, which included analyzing a records search and viewing historic maps and aerial photographs of the project area. Additional responsibilities included performing a field survey of the project area and producing a cultural resources due diligence report.

Work performed for General Coatings.

Lake Rancho Viejo Environmental Consulting (2020). Archaeologist for a cultural resources survey for a proposed housing development in the community of Fallbrook in northern San Diego County. Conducted background research and report preparation. Work performed for Q Technology Direct LLC with County of San Diego as the lead agency.

Mtn View Connector Pipeline - Cultural (2020). Archaeologist for a waterline replacement project in the community of Alpine. Conducted cultural resource monitoring and prepared the final monitoring report. Work performed for Padre Dam Municipal Water District.

Salt Bay Design District Specific Plan EIR (2020). Archaeologist for a mixed-use development project, which proposes to include wholesale/retail shopping and light industrial uses. Participated in an archaeological testing program and produced artifact tables for report. Work performed for M & A Gabaee.

Santa Ysabel Trail (2020 - ). Staff Archaeologist for a proposed 3 mile hiking trail in the unincorporated community of Julian. Performed background research, participated in the cultural resource survey, and contributed to the cultural resources survey report. Work performed for the County of San Diego Parks and Recreation Department.

Julie A. Roy
Archaeologist

Summary of Qualifications
Ms. Roy has over 20 years of experience as an archaeologist, field lead, and supervisor on more than 130 projects throughout California, Nevada, Arizona, and Guam. Conducted archaeological studies for a wide variety of development and resource management projects including work on military installations, energy and transmission projects, commercial and residential developments, historic archaeology projects, and water projects. Competent in all areas of archaeology and efficient in report preparation for a range of cultural resource studies including monitoring projects and archaeological Phase I, II and III studies. Ms. Roy is proficient in laboratory activities including artifact preparation, cataloging, identification, and illustration. Accomplished in the initiation, coordination and completion of field assignments including survey, site testing, dry and wet screening, and data recovery projects. She is also knowledgeable in the preparation of proposals and report writing and research, client, contractor and subcontractor correspondence, laboratory, computer software including Microsoft, Adobe, Geographic Information System (GIS)/ArcView, Computer-Aided Design and Drafting (CADD), Global Positioning System (GPS) and total-station operations, as well as in the illustration of archaeological features, artifacts, and burials. Ms. Roy is established as a qualified archaeological monitor for the City and the County of San Diego. Her experience includes working closely with representatives of San Diego County Parks and Recreation for the past 10 years and she has received accolades from numerous county representatives for her work at park facilities. For the past 4 four years, she has served as the monitoring coordinator for the San Diego Gas & Electric Company (SDG&E) Fire Resource Mitigation Initiative (FiRM) project, where she regularly provided effective communication between field monitors, construction managers/foremen, and Principal Investigators for construction projects and assisted in scheduling and tracking of project progress.

Selected Project Experience
Blythe to Eagle Mountain TLRR Survey (2017). Field Director on this Southern California Edison (SCE) Survey project, which included supervising two crews during a period of two weeks. Conducted survey, mapping, recording new cultural resources and updating previously recorded sites along the transmission line corridor. Other responsibilities included report writing and completion of site records for distrib ution to SCE and the South Coastal Information Center (SCIC).

On-call Archaeological Services (Present). Archaeologist and Field Lead for SDG&E infrastructure operations and transmission line maintenance activities for over 12 years. Projects include survey, testing, excavations, and data recovery of both historic and prehistoric resources including Native American burial sites. Approved to monitor for City projects throughout San Diego and Imperial counties. Other duties include records search, survey, archaeological documentation and investigations, and Education
Master of Arts,
Archaeology,
University of
Leicester, England,
In progress

Bachelor of Arts,
Anthropological
Archaeology,
University of
California San Diego,
2002

Associate of Arts,
Psychology, San
Diego City College,
2000

Registrations/
Certifications
OSHA 30-hour
Construction Safety
Training Certification

Competent Person
Certification

Professional
Affiliations
Society for California
Archaeology

Society for American
Archaeology

Association of
Environmental
Professionals

Julie A. Roy
Archaeologist

2 preparation of reports under California Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA) guidelines.

Fire Resource Cultural Resources Mitigation (Present). Monitoring Coordinator and Lead Archaeologist on this FiRM project for SDG&E. Monitoring Coordinator duties consist of close communication with SDG&E supervisors and staff, liaisons, and contractors in conjunction with the coordination of FiRM project activities associated with cultural and Native American archaeological and monitoring efforts throughout San Diego and Imperial Counties. Archaeological Supervisor duties consists of record search, survey, archaeological site documentation, testing, excavations, and data recovery projects, and preparing reports following CEQA and NEPA guidelines.

Archaeological Monitoring, Bird Rock Avenue Utility Undergrounding Project (2005).

Archaeological Monitor for the undergrounding of residential utilities in the Bird Rock community of La Jolla. The project was conducted under CEQA and the City of San Diego guidelines while working closely with San Diego Gas and Electric Company and the construction contractor. No cultural resources were identified during this project.

Archaeological Monitoring and Data Recovery, Princess Street Utility Undergrounding Project (2005 - 2006). Archaeological Monitor/Crew Chief for utility undergrounding proj ect, which included trenching through a major prehistoric and ethnohistoric Indian village site (the Spindrift Site/CA-SDI-39) in La Jolla. Crewmembers worked closely with Native American representatives during the recovery of human remains. A concurrent data recovery program incorporated all cultural material recovered from the trenching activities. This project was conducted pursuant to CEQA and City of San Diego guidelines while working closely with San Diego Gas & Electric Company and the construction contractor.

Environmental Impact Statement, Southern Nevada Supplemental Airport (2007 - 2009).

Archaeologist on this project that included survey and recordation of the northern portion of Ivanpah Valley from the California state line to Henderson, Clarke County, Nevada. Cultural sites located within the project area included a section of the pacific railroad, historic roads, camps, railroad and construction debris, transmission lines, trash scatters and prehistoric sites and features. The project was surveyed and recorded in compliance with the Nevada State Historic Preservation Office (SHPO) and Bureau of Land Management (BLM) guidelines.

Monitoring, Genesis Solar Power Project (2011 - 2012). Supervisor-in-Charge of over 20 cultural monitors on this solar power project located in Blythe, California. Responsible for conducting safety meetings and coordinating cultural monitors to all areas of the project site, as well as leading test excavations of discovered resources during construction activities. Also responsible for representing firm during onsite meetings with Nextera officials, Bureau of Veritas, BLM, and safety liaisons for the project.

Communicated directly with Native American supervisors and monitors on a daily basis. Recorded and collected artifacts located during construction activities with the use of Global Positioning Satellite technology. Completed daily field notes and collection logs for all collected artifacts, and reviewed all staff monitoring logs prior to daily submission to the California Energy Commission (CEC). Work performed for Nextera.

Survey and Monitoring, Palen Solar Power Project (2009 - 2010). Archaeologist for survey and cultural monitoring in Desert Center, California. Monitored contract and personnel activities during traveling to and from proposed project sites, including trenching and testing within the proposed project areas. Work performed for Solar Millennium.

Julie A. Roy
Archaeologist

3 Ridgecrest Solar Power Project (2009 - 2010). Archaeologist for surveys of the project area undertaken to determine if cultural resources are present and if there would be any project effects on these resources. Monitored contractor activities during the testing phase of the project to ensure that sites were not impacted during work activities. The project was located in Ridgecrest and work was performed for Solar Millennium.

On-Call Archaeological Services (Present). Archaeologist and Field Lead for County Parks infrastructure and maintenance activities for San Diego County Department of Parks and Recreation.

Responsible for communication with County supervisors and contractors, and the coordination of project activities with cultural and Native American monitors for projects throughout San Diego and Imperial Counties. Other duties include records search, field survey, archaeological documentation and investigations including testing, excavations and data recovery projects and preparation of reports following CEQA and NEPA guidelines.

Pacifica Street Utility Undergrounding Project (2006). Archaeological Monitor/Crew Chief for residential utility undergrounding project in the community of Pacific Beach in San Diego. Trenches and cultural materials were documented in conjunction with a concurrent data recovery program. The project included working with Native American representatives and the discovery of human remains. The project was conducted under CEQA and City of San Diego guidelines while working closely with the construction contractor.

Archaeological Monitoring, 20A Julian Conversion Project (2006). Archaeological Monitor for undergrounding of utilities in the City of Julian. The project was conducted under the County of San Diego guidelines while working closely with the construction contractor.

Data Recovery, Hill Street Utility Undergrounding Project (2006). Archaeological Monitor participated in the data recovery for this residential utility undergrounding project in the community of Point Loma in San Diego. The project was conducted under CEQA and City of San Diego guidelines while working closely with the construction contractor.

Archaeological Monitoring, 30th Street Utility Undergrounding Project (2006). Archaeological Monitor for residential utility undergrounding project in the community of South Park in San Diego. The project was conducted under CEQA and City of San Diego guidelines while working closely with the construction contractor.

DRAFT-1GEOTECHNICAL DESIGN REPORT

PROPOSED DIAZ ROAD EXPANSION PROJECT
(PW17-25)

CITY OF TEMECULA, CALIFORNIA
Prepared for
DAVID EVANS AND ASSOCIATES, INC.
41951 Remington Avenue, Suite 200
Temecula, CA 92590
Project No. 12502.001
July 6, 2020

DRAFT-1July 6, 2020
Project No. 12502.001
David Evans and Associates, Inc.
41951 Remington Avenue, Suite 200
Temecula, CA 92590
Attention: Mr. Gavin Powell, PE, Project Manager
Subject: Geotechnical Design Report
Proposed Diaz Road Expansion Project (PW17-25)
City of Temecula, California
In accordance with your request, we are pleased to present herewith the results of our geotechnical evaluation for the subject project.Based on the results of our evaluation and review, it is our opinion that the proposed roadway improvements are generally feasible from a geotechnical perspective provided the recommendations included in this report are implemented during design and construction phases.Please note that further testing and/or field verification should be performed to confirm the actual site/subgrade conditions exposed during construction and provide additional recommendations,when warranted.

The opportunity to be of service is sincerely appreciated. If you should have any questions, please do not hesitate to call our office.

Respectfully submitted,
LEIGHTON CONSULTING, INC.

Simon I. Saiid, GE 2641
Principal Engineer
Robert F. Riha, CEG 1921
Senior Principal Geologist
Distribution: (1) Addressee (PDF)

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001 - i -

TABLE OF CONTENTS
Section Page

1.0 INTRODUCTION ......................................................................................... 1

1.1 PURPOSE AND SCOPE OF WORK ........................................................................... 1

1.2 SITE DESCRIPTION / EXISTING IMPROVEMENTS ...................................................... 1

1.3 STREET DESIGNATION ......................................................................................... 2

1.4 PROJECT IMPROVEMENTS .................................................................................... 2

2.0 FIELD EXPLORATION AND LABORATORY TESTING ......... 3

2.1 FIELD EXPLORATION ............................................................................................ 3

2.2 LABORATORY TESTING ......................................................................................... 3

3.0 SUMMARY OF GEOLOGIC FINDINGS ........................................... 4

3.1 REGIONAL GEOLOGIC SETTING .............................................................................4

3.2 SUBSURFACE CONDITIONS / EARTH MATERIALS ..................................................... 4

3.3 OBSERVED PAVEMENT CONDITION .......................................................................5

3.4 SURFACE AND GROUNDWATER AND POOR RIDE QUALITY ......................................... 5

4.0 CONCLUSIONS AND RECOMMENDATIONS ..............................6

4.1 GENERAL ............................................................................................................ 6

4.2 GENERAL EARTHWORK CONSIDERATIONS .............................................................6

4.3 SUBGRADE PREPARATION AND REMEDIAL EARTHWORK .......................................... 6

4.4 FILL MATERIALS .................................................................................................. 7

4.5 SHRINKAGE .........................................................................................................7

4.6 UTILITY TRENCHES .............................................................................................. 7

4.7 PRELIMINARY PAVEMENT DESIGN ......................................................................... 8

4.8 REHABILITATION OF EXISTING PAVEMENT ..............................................................9

4.9 RETAINING WALLS / CULVERTS ............................................................................. 9

4.10 CORROSION POTENTIAL ..................................................................................... 10

4.11 PERCOLATION/INFILTRATION TESTING .................................................................11

4.12 CONSTRUCTION OBSERVATION ........................................................................... 11

5.0 LIMITATIONS ............................................................................................ 12 REFERENCES .............................................................................................................. 13

LIST OF TABLES
TABLE 1. EXISTING PAVEMENT THICKNESS ..................................................................................... 5 TABLE 2. DEPTHS TO GROUNDWATER ............................................................................................ 5 TABLE 3. PRELIMINARY PAVEMENT DESIGN .................................................................................... 8

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

- ii -

LIST OF FIGURES
Figure 1 – Site Location Map
Figure 2 – Regional Geologic Map
Figure 3 – Regional Fault Map
Figure 4 – Boring Location Map

LIST OF APPENDICES
Appendix A – Logs of Exploratory Borings (This and Previous Explorations) Appendix B – Laboratory Test Results (This and Previous Explorations) Appendix C – ARS Curves and Percolation Testing Data Sheets Appendix D – General Earthwork and Grading Specifications Appendix E – GBA – Important Information about this Geotechnical Report

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

1 1.0 INTRODUCTION

1.1 Purpose and Scope of Work
The purpose of this report is to provide geotechnical recommendations for design and construction of the proposed improvements. Our scope of work included the following:
 A background review of readily available literature and relevant geotechnical reports pertinent to this area. Relevant documents reviewed are referenced at the end of this report.
 Obtaining an encroachment permit from City of Temecula to perform the field exploration/coring within the subject street right-of-way.  A site reconnaissance and excavation of 8 exploratory borings within the area of new roadway and three percolation/infiltration tests located along the alignment.

Approximate locations of these and previous borings are depicted on Figure 2. The logs of the borings are included in Appendix A.
 Geotechnical laboratory testing of selected soil samples collected during this exploration. The test results are presented in Appendix B.  Geotechnical engineering analysis performed or as directed by a California registered Geotechnical Engineer (GE).
 Preparation of this report, presenting our findings, conclusions and geotechnical recommendations for earthwork construction.

1.2 Site Description / Existing Improvements
Diaz Road is an active arterial highway in the City of Temecula with 2 lanes in each direction, except for the middle portion generally located between Via Montezuma and Winchester Road, where existing Diaz Road has only two lanes (one lane in each direction). The limits of the proposed work begin just north of Rancho Road Station 17+50 (near EMWD Pump Station) and continue north to the future extension with Cherry Street (See Figure 1). Diaz Road currently terminates approximately 800-feet north of the intersection with Dendy Parkway at the entrance gate to the Rancho California Water District’s (RCWD’s) storage ponds. Eastern Municipal Water District (EMWD) and RCWD have numerous underground utility lines located along the east shoulder of the existing roadway. The northbound (east) shoulder along Murrieta Creek is currently landscaped along most of the alignment with mulch and a meandering multi-use trail. Drainage pipes/culverts currently cross Diaz Road at various locations and discharge into Murrieta Creek. The westbound is generally fully developed with existing curbs and sidewalks along most of the alignment.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

2 1.3 Street Designation
For the purpose of pavement design and based on information provided, the traffic index for a 20-year design life for Diaz Road is 10 (TI=10).

1.4 Project Improvements
As depicted on the Preliminary Street Improvement Plans by David Evans and Associates (DEA, 2020), the proposed Diaz Road improvements within the project limits include the following:
 New Roadway: A new lane will be added to the northbound side of Diaz Road from approximate station 17+50 to approximate station 63+00. The new lane will tie-in with existing widened areas on the north and southern portions of the project.

An existing dirt portion of Diaz Road between Dendy Parkway and Cherry Street (future) will also be paved/improved.
 New Curbed Center Median: In addition to the added travel lanes, an elevated curbed concrete center median will be constructed throughout the project alignment. The median will create turn pockets and crossings at intersections.  Multi-use Trail Re-alignment: Portions of the new roadway will encroach into the existing multi-use trail. The trail will be re-aligned in these areas. Alternative trail alignments may be considered to reduce environmental impact, utility conflicts and Right-of-Way (ROW) encroachments.
 Drainage Culvert Extension: The new roadway will require the extension of multiple drainage culverts and the creation of new headwalls at Murrieta Creek.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001 3 2.0 F IELD EXPLORATION AND LABORATORY TESTING

2.1 Field Exploration
Our field exploration consisted of the excavation of eight (8) borings and three (3) percolation/infiltration tests excavated along the proposed alignment to provide basis for pavement design and earthwork construction. Prior to excavation, the boring locations were marked for coordination with Underground Service Alert (USA) and an encroachment permit was acquired from City of Temecula. During exploration, in-situ undisturbed (Cal Ring) and disturbed/bulk samples were collected from the borings for further laboratory testing and evaluation. Approximate locations of the exploratory borings from this and previous investigations are depicted on the Boring Location Map (Figure 4). Sampling was conducted by a staff geologist from our firm. After logging and sampling, the excavations were loosely backfilled with spoils generated during excavation. The exploration logs are included in Appendix A.

2.2 Laboratory Testing
Laboratory tests were performed on representative bulk and ring samples collected during our field exploration to determine the geotechnical engineering properties of subsurface materials. The following laboratory tests were performed:
Sieve Analysis,
Collapse Potential,
Expansion Index,
Maximum density and moisture content relationships,
Atterberg Limits,
Corrosivity,
Sand Equivalent; and
R-value.

The laboratory tests were performed in general conformance with ASTM or California Test Methods. The laboratory results are included in Appendix B.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001 4 3.0 SUMMARY OF GEOLOGIC FINDINGS

3.1 Regional Geologic Setting
The site is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. This province is characterized by steep, elongated ranges and valleys that generally trend northwestward. Tectonic activity along the numerous faults in the region has created the geomorphology present today.

Specifically, the site is located along the southern portion of a fault controlled down dropped graben, known as the Elsinore Trough. The Elsinore Trough is bounded on the northeast by the Wildomar Fault segment of the Elsinore Fault Zone and on the southwest by the Murrieta Creek and Willard faults (See Fig. 3)

3.2 Subsurface Conditions / Earth Materials
Based on our field exploration, the site is covered by artificial fill and underlain by alluvial soils. These units are discussed in the following sections in order of increasing age. A more detailed description of each unit is provided on the logs of borings in Appendix A. Artificial Fill: Artificial fill was encountered along the project alignment in all borings varying in depth from 2 to 7.5 feet below ground surface (BGS). As encountered in our borings,the fill is loose to medium dense and consists of silty sand (SM)near the surface and sandy lean clay (CL)at greater depth. The results of our laboratory testing on representative soil samples indicate that this fill possesses R-Values ranging from 4 to 18 and expansion index of less than 51. Alluvium: The alluvium was encountered below the artificial fill along the proposed alignment to the maximum depth explored of 21.5 feet BGS. The alluvium predominantly consists of medium stiff to stiff sandy lean clay (CL)and loose to medium dense, silty to clayey sand (SC-SM) and interbedded poorly-to well-graded sand (SP-SW)at depth.The results of our laboratory testing on representative soil samples indicate that this fill possesses R-Values ranging from 4 to 18 and expansion index of less than 51.

Based on our field exploration, the pavement thickness in existing Diaz Road varies from one location to another. The pavement thickness as encountered in our borings and previous borings are summarized below.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001 5 Table 1. Existing Pavement Thickness

3.3 Observed Pavement Condition
The existing pavement surface condition as well as pavement thickness appears to vary within this portion of Diaz Road. Our observations can be summarized as follows:
The AC thickness generally varies from 5.0 to 10.5 inches and aggregate base (AB) layer varies from 10 to 17 inches as summarized in Table 1 above. Existing pavement is characterized with fair to poor surface conditions manifested in thermal cracking. Patching and potholing is typically noted in localized areas south of Winchester Road.
Existing pavement within the unimproved portion of Diaz Road (~Via Montezuma to Avenida Alvarado) is also characterized by severe alligator cracking and poor ride quality. There is no pavement north of Dendy Parkway.

3.4 Surface and Groundwater
No surface water was observed at the time of our field exploration along the proposed alignment. Groundwater was encountered in 4 of our recent borings at varying depths.

However, groundwater conditions can fluctuate seasonally and also be directly-impacted by other factors not observed at the time of our field explorations.Depth to groundwater (where encountered) is summarized in the table below.

Table 2. Depths to Groundwater

Location
(see Figure 4)
Approx. AC Thickness
(Inch)
Approx. Aggregate
Base Thickness (Inch)
LB-3 7.0 12.0
LB-7 5.5 7.0 (Geogrid)
LB-8 5.0 6.0
BH-6 10.5 17
BH-7 5.5 -(AC Core only)
BH-8 6.5 15
Boring # Approximate Depth to
Groundwater (ft)
LB-1 18.70
LB-3 13.25
LB-4 11.83
LB-7 11.33

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

6 4.0 CONCLUSIONS AND RECOMMENDATIONS

4.1 General
The proposed roadway improvements are feasible from a geotechnical viewpoint provided that the following recommendations are incorporated into the design and construction phases of development.

4.2 General Earthwork Considerations
Earthwork associated with the proposed improvements should be performed in accordance with applicable City standards, “Standard Specifications for Public Works Construction” (Green Book, latest edition), and the recommendations included in the text of this report. The General Earthwork and Grading Specifications in Appendix D, are general grading specifications provided for typical grading projects and some of the recommendations may not be strictly applicable to this project. In case of conflict, the specific recommendations contained in the text of this report supersede those included in Appendix D.

4.3 Subgrade Preparation and Remedial Earthwork
Prior to earthwork, the areas to receive fill and new pavement should be cleared and stripped of debris, deleterious material, organics, and vegetation. Cleared and grubbed material that may be encountered or created should be removed and appropriately disposed of. Voids created by removal of buried/unsuitable materials should be backfilled with properly compacted soil in general accordance with the recommendations of this report. Specific remedial grading recommendations for the proposed improvements should be as follows:

 New Road Embankment / Pavement and Miscellaneous Retaining walls and/or Drainage Structures: The upper 3 feet of soils/alluvium below planned subgrade or footing elevation should be over-excavated (OX) and recompacted. The horizontal limits of OX below footings or fills should be equivalent to the vertical OX (projected down and away at a 1:1 slope from the outside edge of footings/fill).

Localized areas of deeper or shallower OX may be required, depending on the actual conditions encountered during construction.
 Street Sidewalks and Multi-Use Trail: In landscape or unpaved areas that are going to receive new Bike Trail pavement and/or fill, a minimum of 1.5-foot OX should be anticipated prior to placement of new fill or new pavement. The OX should extend horizontally a minimum distance of 2 feet from edges of new fills or improvement. The required OX depth should be further verified during construction.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

7 After remedial removal described above is completed, the exposed subgrade surface should be scarified, moisture conditioned and compacted to at least 90 percent relative compaction (per ASTM D1557). Further field evaluation by the geotechnical consultant during construction may require localized additional removal and compaction.

Excavations should be performed in accordance with the project plans, specifications, and all applicable OSHA requirements.

4.4 Fill Materials
Onsite soils should generally be suitable as fill materials for street subgrade provided they are free of rocks over 6 inches in diameter and organic matter. Fill should be compacted in uniform horizontal lifts by mechanical means to at least 90 percent relative compaction as determined per ASTM D 1557 (Modified Proctor) or as required per City standards.

Import soils and/or borrow sites, if needed, should be evaluated by the geotechnical consultant prior to import. Import soils should be uncontaminated, granular in nature, free of organic material (loss on ignition less-than 2 percent), have a low expansion potential (EI<51) and R-value greater than 12 if to be used in upper 12 inches of street subgrade.

4.5 Shrinkage
The volume change of excavated onsite materials upon compaction is expected to vary with depth of excavation, location, material type and compaction effort during grading. As such, the in-place and compacted densities of these materials vary and accurate determination of shrinkage for any specific area cannot be made, especially in the case of this project where soils vary considerably from one area to another.. For preliminary planning purposes and based on our field observations, we recommend that a shrinkage factor of 10 percent to 15 percent be applied for the proposed remedial grading.

4.6 Utility Trenches
Utility trenches should be backfilled with compacted fill in accordance with Sections 306-1 of the Standard Specifications for Public Works Construction (“Greenbook”), latest edition.

Fill material above the pipe zone should be placed in lifts not exceeding 8 inches in un- compacted thickness and should be compacted to at least 90 percent relative compaction (per ASTM D1557) by mechanical means only. Site soils may generally be suitable as trench backfill provided these soils are screened of rocks over 3 inches in diameter and organic matter.

Excavation of utility trenches should be performed in accordance with the project plans, specifications and the California Construction Safety Orders (latest Edition). The contractor

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

8 should be responsible for providing a “competent person” as defined in Article 6 of the California Construction Safety Orders. Contractors should be advised that sandy soils (such as fills generated from the onsite fill and alluvium) could make excavations particularly unsafe if all safety precautions are not properly implemented. In addition, excavations at or near the toe of slopes and/or parallel to slopes may be highly unstable due to the increased driving force and load on the trench wall. Spoil piles from the excavation(s) and construction equipment should be kept away from the sides of the trenches. Leighton does not consult in the area of safety engineering.

4.7 Preliminary Pavement Design
The preliminary pavement design provided below is based on the Caltrans Highway Design Manual (HDM) and applicable City street standards. Based on testing of our collected samples, R-values of the near-surface soils are expected to generally vary from 4 to 18. As such, an average R-value of 12 has been used for preliminary design purposes. City of Temecula minimum pavement section for a traffic index of 10 is 0.50’ AC over 1.17’ AB.

Table 3. Preliminary Pavement Design
Boring Design
R-value
Traffic
Index Pavement Structural Sections (ft)
LB-2 12 10 0.50 AC / 1.60 CAB
-AC is asphalt concrete conforming to applicable City Standards, Greenbook. and Caltrans Standard Specs -AB is aggregate base (CAB, Class 2 AB or CMB) conforming to applicable City Standard, Greenbook, and Caltrans Standard Specifications

Pavement design and construction should also conform to applicable City and industry standards. Final pavement section may differ from stated in table above depending on actual R-value of subgrade soils during construction. The Caltrans pavement section design calculations were based on a pavement life of approximately 20 years with a normal amount of flexible pavement maintenance.

Although not anticipated on this project, any imported materials placed within the upper

2.5 feet of finished grade should have a minimum R-value of 12 and should be non- corrosive and of low expansion. Other construction materials such as aggregates, asphalt, and Portland cement should be imported from local commercial sources. No potential sources for import materials have been pre-tested for this project. Therefore, prior to import, the materials should be tested and approved by the Geotechnical Engineer.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

9 4.8 Rehabilitation of Existing Pavement
Based on our review and alignment pavement borings (See Table 1), the current pavement section does not meet the City minimum (except BH-6) or minimum design thickness. However, there are several rehabilitation methods that can be implemented by the City to help preserve existing pavement, although not improve to current design requirements.. The pros and cons of each method can be evaluated based on cost analysis, desired life span, and construction sequence and its impact on existing traffic.

Based on our experience with similar projects and existing pavement conditions, the most viable options may include the following:
 Option 1: Application of slurry seal after properly cleaning existing cracks and filling with elastomeric crack sealant. This option is typically considered the least expensive option, provides no structural improvement and the shortest life span.  Option 2: Cold plane/milling minimum of 0.15-foot of existing HMA and placement of a minimum of 0.15-foot Rubberized Hot Mix Asphalt (RHMA) or HMA overlay.

This option typically provides a longer life span than Option 1, as well as better ride quality, but will not meet current design requirements.  Option 3: Complete removal of existing AC layer or AC/AB layer and placement of new HMA layer on top of properly prepared aggregate base and subgrade. This method is only applicable to limited areas where existing pavement distress appears to be associated with subgrade failure, but will not meet current design requirements.
 Option 4: In order to meet current pavement thickness minimum, a complete removal of AC and underlying AB layer and pavement re-construction will be required. Alternatives such as full depth reclamation or cold central plant recycling can also be considered.

4.9 Retaining Walls / Culverts
For design of culverts and/or retaining walls associated with this project, the calculated Peak Ground Acceleration (PGA) is approximately 0.54g for this site using Caltrans ARS online tool (V2.3.09) with a mean moment magnitude (Mw) of 6.87. Details of the ARS analysis and resulting ARS curve are presented in Appendix C.

Where applicable, Caltrans Standard Reinforced Concrete retaining walls up to 20 feet in height can be constructed on this project since the Coefficient of Horizontal Acceleration, kh does not exceed 0.2 (or <1/3 PGA=0.54g). Where conventional retaining walls are to be designed, the following preliminary design parameters may be considered:
 Average Moist Unit weight of soil = 120 pcf

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

10  Average Saturated Unit Weight of Soil = 140 pcf
 Service Permissible Net Contact Stress = 2.5 ksf (footing width >4 feet)  Strength Factored Gross Nominal Bearing Resistance = 5 ksf (footing width >4 ft)  Extreme Event Factored Gross Nominal Bearing Resistance = 6 ksf (footing >6 ft)  Friction coefficient = 0.35
 A minimum of 3-foot over-excavation (OX) will be required for footings founded at 3 feet below existing ground surface (BGS), or shallower. A 2-foot OX will be required if footings are founded at depths greater than 4 feet BGS or deeper.

For non-restrained walls, an incremental seismic earth pressures of 14H psf, where H is the retaining wall stem height in feet, should be applied for design in addition to static earth and surcharge pressures discussed below. For restrained walls, an equivalent pressure of 55 pcf should be applied. For 2:1 (horizontal:vertical) sloping backfill, we recommend an equivalent fluid pressure of 52 pounds per cubic foot (pcf) for the active condition, and 80 pcf for the at-rest condition. Hydrostatic pressure should also be incorporated into to the above equivalent fluid pressures, where applicable.

Surcharge loads such as adjacent structures, and/or traffic loading should be considered in design of retaining walls. Loads applied within a 1:1 (horizontal:vertical) projection down from the surcharging structure on the stem of the wall should also be considered in wall design. In general, 0.30 of uniform vertical surcharge-loads should be applied as a horizontal pressure on cantilever (active) retaining walls, while half of uniform vertical surcharge-loads should be applied as a horizontal pressure on braced (at-rest) retaining walls (assuming sand soils backfill).

4.10 Corrosion Potential
Caltrans Corrosion Guidelines (Caltrans, 2018) state that a site is considered to be corrosive to foundation elements or underground structures if one or more of the following conditions exist for the soil and/or water samples taken at the site:
 Chloride concentration greater than or equal to 500 ppm  Sulfate concentration greater than or equal to 1,500 ppm  pH of 5.5 or less

Based on our laboratory testing on a representative soil sample, the onsite soils are considered to be non-corrosive to foundation elements or underground structures.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

11 4.11 Percolation/Infiltration Testing
Three (3) percolation tests were performed for preliminary screening along the proposed alignment (see, Figure 4) in general accordance with the procedures of the Riverside County Flood Control and Water Conservation District (RCFC&WCD) Design Handbook (RCFC, 2018). Percolation tests were performed at a depth of approximately 5 feet BGS.

Due to relatively high clay/silt content and dense artificial fill, the onsite soils/artificial fill possess very poor percolation characteristics (practically impermeable). The actual test results/data sheets are included in Appendix C.

4.12 Construction Observation
Observation and testing should be performed by Leighton’s representatives during excavation/construction. It should be anticipated that the substrata exposed during construction may vary from that encountered in the test borings. Reasonably continuous construction observation and review during the proposed improvements allows for evaluation of the actual soil conditions and the ability to provide appropriate revisions where required during construction.

Site preparation, removal of unsuitable soils, trench excavation, shoring, approval of imported earth materials, fill placement of bedding and backfill, and other site geotechnically-related operations should be observed and tested by Leighton.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

12 5.0 LIMITATIONS
This report was necessarily based in part upon data obtained from a limited number of observances, site visits, soil samples, tests, analyses, histories of occurrences, spaced subsurface explorations and limited information on historical events and observations.

Such information is necessarily incomplete. The nature of many sites is such that differing characteristics can be experienced within small distances and under various climatic conditions. Changes in subsurface conditions can and do occur over time. This evaluation was performed with the understanding that the proposed improvements are as described in Section 1.1 of this report.

The client is referred to Appendix E regarding important information provided by the Geoprofessional Business Association (GBA) on geotechnical engineering studies and reports and their applicability.

This report was prepared for our Client based on their needs, directions, and requirements at the time of our investigation. This report is not authorized for use by, and is not to be relied upon by any party except our Client, and its successors and assigns as owner of the property, with whom Leighton has contracted for the work. Use of or reliance on this report by any other party is at that party's risk. Unauthorized use of or reliance on this report constitutes an agreement to defend and indemnify Leighton from and against any liability which may arise as a result of such use or reliance, regardless of any fault, negligence, or strict liability of Leighton.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

13 REFERENCES

American Association of State Highway and Transportation Officials (AASHTO), 2012, LRFD Bridge Design Specifications, 6th Edition,
Bryant, W.A., and Hart, E.W., 2007, Fault-Rupture Hazard Zones in California, Alquist- Priolo Earthquake Fault Zoning Act with Index to Earthquake Zones Maps, Department of Conservation, California Geological Survey, Special Publication 42, 2007 Interim Revision.

California Building Code, 2019, California Code of Regulations Title 24, Part 2, Volume 2 of 2.

California Geological Survey, 2018, Earthquake Fault Zones, A Guide for Government Agencies, Property Owners/Developers, and Geoscience Practitioners for Assessing Fault Rupture Hazards in California, Special Publication 42.

California, Code of Regulations, 2018, Division of Industrial Safety, Title 8, Subchapter 4, Construction Safety Orders, https://www.dir.ca.gov/title8/sub4.html Caltrans, 2013b, Seismic Design Criteria, Version 1.7, April. http://www.dot.ca.gov/hq/esc/techpubs/manual/othermanual/other-engin- manual/seismic-design-criteria/sdc.html
Caltrans, June 2017, Foundation Reports for Earth Retaining Systems (ERS), http://www.dot.ca.gov/hq/esc/geotech/geo_manual/page/FR_ERS_June2017.pdf Caltrans, 2018a, Corrosion Guidelines, Version 3.0, March.

Caltrans, 2018b, Highway Design Manual (HDM), July.

Caltrans, 2018c, Standard Specifications.

David Evans and Associates, Inc., 2020, City of Temecula, Department of Public Works, Diaz Road Expansion, PW 17-25, Street Improvement Plan, Preliminary, dated March 6, 2020.

Geotracker, State Water Resources Control Board, Geotracker Online Database http://geotracker.waterboards.ca.gov/ , Accessed July 12, 2018.

Leighton Consulting, Inc., Geotechnical Exploration, Eastern Municipal Water District (EMWD), Temecula Valley Regional Water Reclamation Facility Recycled Water Pipeline Project, Temecula/Murrieta Area, Riverside County, California, Project No. 10807.001, dated March 7, 2016.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

14 Morton, D.M., Miller, F.K., 2006, Geologic Map of the San Bernardino and Santa Ana 30’ x 60’ Quadrangles, California: U.S. Geological Survey, Open-File Report OF-2006- 1217, scale 1:100,000.

Morton, D.M., 2004, Preliminary Digital Geologic Map of the Santa Ana 30’ X 60’ Quadrangle, Southern California, Ver. 2.0, USGS Open-File Rep. 99-172, scale 1:100,000.

OSHPD, 2020, Seismic Design Maps, an interactive computer program on OSHPD website to calculate Seismic Response and Design Parameters based on ASCE 7-10 seismic procedures, https://seismicmaps.org/
Riverside County, 2018, Map My County, Riverside County Integrated Project Website, https://gis.countyofriverside.us/Html5Viewer/?viewer=MMC_Public Sladden Engineering, 2011, Geotechnical Investigation, Proposed EMWD Warm Springs Recycled Water Pipeline Project, Northern Alignment – Phase 1, Temecula California, Project No. 644-11020, 11-11-203, dated November 7, 2011.

Temecula, City of, Improvement Standard Drawings, Website, https://temeculaca.gov/DocumentCenter/Index/217 , accessed December 2019.

University California at Berkeley, Pacific Earthquake Engineering Research Center, The 5 NGA-West2 horizontal ground motion prediction equations, Updated on April 14, 2015, https://peer.berkeley.edu/research/data-sciences/databases USGS, 2020, Web-Service Wrapper Around the nshmp-haz Probabilistic Seismic Hazard Analysis (PSHA) Platform, https://earthquake.usgs.gov/hazards/interactive/

³
0 2,000 4,000
Feet
Figure 1
Scale:

Leighton
Base Map: ESRI ArcGIS Online 2020
Thematic Information: Leighton
1 " = 2,000 '
Project: 12502.001 Eng/Geol: SIS/RFR
Map Saved as V:\Drafting\12502\001\Maps\12502-001_F01_SLM_2020-06-12.mxd on 5/18/2020 11:41:17 AM Author: Leighton Geomatics (btran)
Date: July 2020 SITE LOCATION MAP
Diaz Road Geotechnical Exploration PW 17-25
Temecula, California
Approximate
Project Alignment

Qss
Qya
gr
pKm
Qa
Tv
Qyf
Esri, HERE, Garmin, (c) OpenStreetMap contributors, Copyright:© 2013 National Geographic Society, i-cubed
³
0 2,000 4,000
Feet
Figure 2
Scale:

Leighton
Base Map: ESRI ArcGIS Online 2020
Thematic Information: Leighton, USGS
1 " = 2,000 '
Project: 12502.001 Eng/Geol: SIS/RFR
Map Saved as V:\Drafting\12502\001\Maps\12502-001_F02_RGM_2020-06-12.mxd on 5/18/2020 11:52:51 AM Author: Leighton Geomatics (btran)
Date: July 2020 REGIONAL GEOLOGY MAP
Diaz Road Geotechnical Exploration PW 17-25
Temecula, California
Approximate
Site Location
Legend
!
!
!!
!!
!!Qya, Young Alluvial Valley
Qyf, Young Alluvial Fan
Qa, Alluvial Valley
Qss, Coarse-grained formations of
Pleistocene age and younger;
primarily sandstone and
conglomerate
Tv, Tertiary age formations of
volcanic origin
gr, Granitic and other intrusive
crystalline rocks of all ages
pKm, Cretaceous and Pre-
Cretaceous metamorphic formations
of sedimentary and volcanic origin

Wildo
ma
r
f
a
u
l
t
WolfV
al
l
eyfau
l
t
M u r rietta HotSpringsfault
Elsinore fault
Wildo
m
arfa
ult
Glen Ivy N
ort
h
Will
ardfault
Willard fault
Esri, HERE, Garmin, (c) OpenStreetMap contributors, Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community
³
048
Miles
Figure 3
Scale:

Leighton
Base Map: ESRI ArcGIS Online 2020
Thematic Information: Leighton, Bryant, W. A. (compiler), 2005, Digital Database of Quaternary and Younger Faults from the Fault Activity Map of California, version 2.0: CGS 1 " = 4 miles
Project: 12502.001 Eng/Geol: SIS/RFR
Map Saved as V:\Drafting\12502\001\Maps\12502-001_F03_RFM_2020-06-12.mxd on 5/18/2020 11:46:19 AM Author: Leighton Geomatics (btran)
Date: July 2020 REGIONAL FAULT MAP
Diaz Road Geotechnical Exploration PW 17-25
Temecula, California
Approximate
Project Alignment
Legend
Historic ( 1.6M years)

Map Saved as V:\Drafting\12502\001\Maps\12502-001_F04_BLM_2020-06-12.mxd on 6/12/2020 10:09:28 AM

BORING LOCATION MAP
Diaz Road Geotechnical Exploration PW 17-25
Temecula, California
Figure 4
Leighton
Legend
& Approximate Location of Boring
(Leighton, 2016)
&>Approximate Location of Boring
(Sladden, 2001)
Approximate Project Alignment
³
0 800 1,600
Feet
Scale:

Base Map: ESRI ArcGIS Online 2020
Thematic Information: Leighton
1 " = 800 '
Project: 12502.001 Eng/Geol: SIS/RFR
Author: Leighton Geomatics (btran)
Date: July 2020

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

APPENDIX A

Logs of Exploratory Borings (This and Previous Explorations)

The attached subsurface exploration logs and related information depict subsurface conditions only at the locations indicated and at the particular date designated on the logs. Subsurface conditions at other locations may differ from conditions occurring at these logged locations. The passage of time may result in altered subsurface conditions due to environmental changes. In addition, any stratification lines on the logs represent the approximate boundary between sampling intervals and soil types; and the transition may be gradual.

11 17
19 8
12 15
5 9
11 6
10 10
3 6
12 4
5 5
109
115
SM
SP-SM
CL
SC
SC-SM
SW-SM
B-1
R-1
R-2
R-3
R-4
R-5
R-6
4 16
Artificial Fill (Af); SILTY SAND, gray, slightly moist, fine grained sand
SILTY SAND, medium dense, grayish brown, moist, fine to medium grained sand
Poorly graded SAND with SILT, medium dense, grayish brown, moist, fine to medium grained sand
Quaternary Alluvium (Qal); SANDY Lean CLAY, stiff, dark grayish brown, moist, fine to medium grained sand
CLAYEY SAND, medium dense, dark grayish brown, moist, fine to medium grained sand
SILTY, CLAYEY SAND, medium dense, dark grayish brown,
moist, fine to medium grained sand, roots, petrochemical odor
Well-graded SAND with SILT, loose, dark grayish brown, wet, fine to coarse grained sand
Drilled to 21.5' Sampled to 21.5' Groundwater at 18.7' Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-1 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 7
8 9
6 7
9 2
3 5
2 3
5 4
11 11
112
106
94 SM
CLR-1
R-2
B-1
R-3
R-4
R-5
16 21
29 Artificial Fill (Af); SILTY SAND with GRAVEL, grayish brown, slightly moist, fine to coarse grained sand
Quaternary Alluvium (Qal); SANDY Lean CLAY, stiff, dark grayish brown, moist, fine to medium grained sand
SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand, MD = 125.3 @ 11.0%, EI = 55, RV = 16
SANDY Lean CLAY, medium stiff, dark gray, moist, fine grained sand
SANDY Lean CLAY, medium stiff, dark gray, moist, fine grained sand
Lean CLAY, stiff, olive brown, moist, no recovery, resample W/SPT
Drilled to 16.5' Sampled to 16.5' Groundwater not
encountered Backfilled with cuttings

MD, EI,
RV, AL
CR
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-2 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 2
3 4
5 12
16 3
5 6
3 5
6 2
3 6
4 10
16 112
113
102

ASPHALT
CL
CL
B-1
R-1
R-2
R-3
R-4
R-5
R-6
15 16
22 7"AC/12"AB
Artificial Fill (Af); Lean CLAY with SAND, dark grayish brown, moist, fine to coarse grained sand
SANDY Lean CLAY with GRAVEL, medium stiff, dark grayish brown, moist, fine to coarse grained sand with fine gravel SANDY Lean CLAY, stiff, dark gray, moist, fine to medium grained sand
Quaternary Alluvium (Qal); Lean CLAY, medium stiff, dark brown, moist
SANDY Lean CLAY, stiff, dark grayish brown, moist, fine to medium grained sand
SANDY Lean CLAY, stiff, dark grayish brown, wet, fine to coarse grained sand
SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand Drilled to 21.5' Sampled to 21.5' Groundwater at 13.25' Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-3 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 10
13 9
10 19
28 8
9 12
7 13
33 6
8 11
127
120
112
SM
ML
SM
SC
SW
SC
R-1
R-2
B-1
R-3
R-4
R-5
10 13
13 Artificial Fill (Af); SILTY SAND with GRAVEL, grayish brown, moist, fine to coarse grained sand with fine gravel
SILTY SAND, medium dense, dark grayish brown, moist, fine to coarse grained sand
SANDY SILT, hard, dark grayish brown, moist, fine grained sand, MD = 129.5 @ 8.8%
Quaternary Alluvium (Qal); SILTY SAND, medium dense, dark gray, moist, fine to medium grained sand
CLAYEY SAND, medium dense, dark grayish brown, moist, fine to medium grained sand
Well-graded SAND, medium dense, gray, wet, fine to coarse grained sand
CLAYEY SAND, medium dense, dark grayish brown, moist, fine to medium grained sand
Drilled to 16.5' Sampled to 16.5' Groundwater at 11.83' Backfilled with cuttings

MD, SA,
CR
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-4 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 6
5 6
10 20
23 8
12 11
3 6
5 3
4 3
5 4
6 115
106
ML
SM
SM
SC
SW
B-1
R-1
R-2
R-3
R-4
R-5
R-6
13 21
Artificial Fill (Af); SANDY SILT, grayish brown, slitghtly moist, fine grained sand, RV = 18
SILTY SAND with GRAVEL, loose, dark grayish brown, moist, fine to coarse grained sand with fine gravel
SILTY SAND, medium dense, dark gray, moist, fine to coarse grained sand
Quaternary Alluvium (Qal); SILTY SAND, medium dense, dark grayish brown, moist, fine grained sand
CLAYEY SAND, medium dense, dark gray, wet, fine grained sand
Well-graded SAND, loose, dark gray, wet, fine to coarse grained sand
Well-graded SAND, loose, dark gray, wet, fine to coarse grained sand
Drilled to 21.5' Sampled to 21.5' Groundwater not
encountered Backfilled with cuttings
RV, SA
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-5 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 19
20 16
10 14
15 2
4 5
5 12
12 3
6 8
124
95 SC
SM
CL
SC-SM
CL
R-1
R-2
B-1
R-3
R-4
R-5
10 27
Artificial Fill (Af); CLAYEY SAND, dark gray, moist, fine grained sand
SILTY SAND with GRAVEL, medium dense, dark gray, moist, fine to coarse grained sand with fine gravel
SILTY SAND with GRAVEL, medium dense, dark gray, moist, fine to coarse grained sand with fine gravel
Quaternary Alluvium (Qal); SANDY Lean CLAY, medium stiff, dark gray, moist, fine grained sand
SILTY, CLAYEY SAND, medium dense, dark brown, moist, fine to medium grained sand
SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand Drilled to 16.5' Sampled to 16.5' Groundwater not
encountered Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-6 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 2
3 4
3 6
8 4
4 6
3 5
6 5
7 10
5 7
20 94
98 108

ASPHALT
CL-ML
CL
SW
B-1
R-1
R-2
R-3
R-4
R-5
R-6
25 24
19 5.5"AC/7"AB/Geogrid
Artificial Fill (Af); SILTY CLAY with SAND, dark gray, moist, fine grained sand, MD = 118.7 @ 11.5%, EI = 41, RV = 4
SILTY CLAY, medium stiff, dark gray, moist
Quaternary Alluvium (Qal); Lean CLAY, medium stiff, dark brown, moist
Lean CLAY, stiff, dark grayish brown, moist
SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand SANDY Lean CLAY, stiff, dark gray, moist, fine grained sand Well-graded SAND, medium dense, gray, wet, fine to medium grained sand
Drilled to 21.5' Sampled to 21.5' Groundwater at 11.33' Backfilled with cuttings

MD, EI,
RV, AL
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-7 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 5"AC/6"AB
Hole terminated at .92' due to underground utilities
Groundwater not encountered Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-8 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 3
3 4
CL
S-1
Artificial Fill (Af); Lean CLAY, dark gray, moist
SANDY Lean CLAY with GRAVEL, stiff, dark grayish brown, moist, fine to coarse grained sand with fine gravel
Drilled to 5' Sampled to 5' Groundwater not encountered Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG P-1 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 5
5 4
SM
SCS-1
Artificial FIll (Af); SILTY SAND, gray, moist, fine grained sand CLAYEY SAND, medium dense, dark gray, moist, fine to
medium grained sand
Drilled to 5' Sampled to 5' Groundwater not encountered Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG P-2 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 4
6 6
SM
SCS-1
Artificial Fill (Af); SILTY SAND with GRAVEL, light brownish gray, slightly moist, fine to coarse grained sand with fine gravel
SILTY SAND, dark gray, moist, fine to medium grained sand CLAYEY SAND, medium dense, dark gray, moist, fine to
medium grained sand
Drilled to 5' Sampled to 5' Groundwater not encountered Backfilled with cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.5-15-20

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Boring Location Map
Diaz Road Geotechnical Exploration
12502.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG P-3 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 CR, SE
CO
10 13
13 5
6 7
3 4
6 120
93 108
SM
SC
SM
ML
CL
R-1
B-1
R-2
R-3
13 26
19 Artificial Fill (Af); SILTY SAND with GRAVEL, dark grayish brown, moist, fine to coarse grained sand, gravel to 1" CLAYEY SAND, dark brown, moist, fine to medium grained
sand
SILTY SAND with GRAVEL, medium dense, dark grayish brown, moist, fine to coarse grained sand with fine gravel, SE = 9 Quaternary Allvium (Qal); SILT with SAND, moist, very dark grayish brown, very fine to fine grained sand
SILTY CLAY, stiff, dark grayish brown, moist, fine grained sand, CO = -0.6%
Lean CLAY, stiff, dark grayish brown, moist
Drilled to 16.5' Sampled to 16.5' Groundwater not
encountered Backfilled with Cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.9-18-14

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Figure 4
Temecula Valley Recycled Water Pipeline
10807.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-8 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 SA
EI
10 14
17 6
7 8
4 5
6 6
6 7
113
118
107
SM
ML
SM
R-1
R-2
B-1
R-3
R-4
17 17
19 Artificial Fill (Af); SILTY SAND with GRAVEL, light brownish gray, dry to moist, fine to coarse grained sand with gravel and cobble to 5"
SILTY SAND with GRAVEL, grayish brown, moist, fine to coarse grained sand with fine gravel
Quaternary Alluvium (Qal); SILT with SAND, stiff, dark grayish brown, moist, very fine to fine grained sand
SILT with SAND, stiff, dark brown, moist, very fine to fine grained sand, EI = 43
SANDY SILT, stiff, very dark brown, moist, fine to medium grained sand
SILTY SAND, loose, very dark brown, moist to wet, fine grained sand, no recovery, resample with spt
Drilled to 16.5' Sampled to 16.5' Groundwater not
encountered Backfilled with Cuttings
Hole Diameter
MoistureGround Elevation
DepthBlowsElevationPer 6 InchesPage 1 of 1
'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
JTD
Hollow Stem Auger - 140lb - Autohammer - 30" Drop
Soil Class.9-18-14

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Project No.

See Figure 4
Temecula Valley Recycled Water Pipeline
10807.001
Drilling Method
8"Sample No.FeetAttitudesSAMPLE TYPES:
2R Drilling
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * *Content, %GEOTECHNICAL BORING LOG LB-9 Logged By
Date Drilled
JTD
FeetS (U.S.C.S.)LogType of TestsGraphicpcfLocation
Dry DensityN
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE STRENGTH
0 5
10 15
20 25
30 DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

APPENDIX B

Laboratory Test Results(This and Previous Explorations)

Compaction; LB-2, B-1 (05-15-20)
Tested By:F. Mina Date:06/03/20
Input By: M. Vinet Date:06/10/20
LB-2 Depth (ft.):5.0 - 10.0
X Moist Mechanical Ram
Dry Manual Ram
Mold Volume (ft³)0.03340 Ram Weight = 10 lb.; Drop = 18 in. 1 2 3 4 5 6
5613 5679 5638
3565 3565 3565
2048 2114 2073
1776.3 1561.9 1335.3
1651.8 1434.2 1215.5
328.2 329.0 326.4

9.4 11.6 13.5
135.2 139.5 136.8
123.6 125.1 120.6
125.3 11.0

PROCEDURE USED
X Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 3/8 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 3/4 in. (19.0 mm) Sieve
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20% and +¾ in.
is <30%
Particle-Size Distribution:

GR:SA:FIAtterberg Limits:32:13:19LL,PL,PI
Optimum Moisture Content (%) Maximum Dry Density (pcf) Net Weight of Soil (g)
Wet Density (pcf)
Dry Density (pcf)
Moisture Content (%)
Wet Weight of Soil + Cont. (g)
Dry Weight of Soil + Cont. (g)
Weight of Container (g)
Weight of Mold (g)
Diaz Rd Expansion
Preparation Method:

Wt. Compacted Soil + Mold (g)
B-1
12502.001
TEST NO.

Soil Identification:

Project Name:

Sample No.:

Lean Clay with Sand (CL)s, Dark Yellowish Brown.

MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project No.:

Boring No.:
115.0
120.0
125.0
130.0
135.0

0.0 5.0 10.0 15.0 20.Dry Density (pcf)Moisture Content (%) SP. GR. = 2.65
SP. GR. = 2.70
SP. GR. = 2.75
XX

Compaction; LB-4, B-1 (05-15-20)
Tested By:F. Mina Date:06/03/20
Input By: M. Vinet Date:06/10/20
LB-4 Depth (ft.):5.0 - 10.0
X Moist Mechanical Ram
Dry Manual Ram
Mold Volume (ft³)0.03340 Ram Weight = 10 lb.; Drop = 18 in. 1 2 3 4 5 6
5600 5680 5711 5654
3565 3565 3565 3565
2035 2115 2146 2089
1322.2 1566.0 1156.4 1005.5
1262.1 1470.4 1073.6 922.8
277.4 278.4 278.8 279.2

6.1 8.0 10.4 12.8
134.3 139.6 141.6 137.9
126.6 129.2 128.3 122.2
129.5 8.8

PROCEDURE USED
X Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 3/8 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 3/4 in. (19.0 mm) Sieve
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20% and +¾ in.
is <30%
Particle-Size Distribution:
0:47:53GR:SA:FIAtterberg Limits:

LL,PL,PI
Optimum Moisture Content (%) Maximum Dry Density (pcf) Net Weight of Soil (g)
Wet Density (pcf)
Dry Density (pcf)
Moisture Content (%)
Wet Weight of Soil + Cont. (g)
Dry Weight of Soil + Cont. (g)
Weight of Container (g)
Weight of Mold (g)
Diaz Rd Expansion
Preparation Method:

Wt. Compacted Soil + Mold (g)
B-1
12502.001
TEST NO.

Soil Identification:

Project Name:

Sample No.:

Sandy Silt s(ML), Black.

MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project No.:

Boring No.:
115.0
120.0
125.0
130.0
135.0

0.0 5.0 10.0 15.0 20.Dry Density (pcf)Moisture Content (%) SP. GR. = 2.65
SP. GR. = 2.70
SP. GR. = 2.75
XX

Compaction; LB-7, B-1 (05-15-20)
Tested By:F. Mina Date:06/03/20
Input By: M. Vinet Date:06/10/20
LB-7 Depth (ft.):0 - 5.0
X Moist Mechanical Ram
Dry Manual Ram
Mold Volume (ft³)0.03340 Ram Weight = 10 lb.; Drop = 18 in. 1 2 3 4 5 6
5507 5580 5576 5542
3565 3565 3565 3565
1942 2015 2011 1977
1574.7 1668.6 1606.8 1191.0
1474.3 1521.8 1454.9 1067.6
420.8 329.2 415.0 332.7

9.5 12.3 14.6 16.8
128.2 133.0 132.7 130.5
117.0 118.4 115.8 111.7
118.7 11.5

PROCEDURE USED
X Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
Procedure B
Soil Passing 3/8 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 3/4 in. (19.0 mm) Sieve
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20% and +¾ in.
is <30%
Particle-Size Distribution:

GR:SA:FIAtterberg Limits:33:18:15LL,PL,PI
Optimum Moisture Content (%) Maximum Dry Density (pcf) Net Weight of Soil (g)
Wet Density (pcf)
Dry Density (pcf)
Moisture Content (%)
Wet Weight of Soil + Cont. (g)
Dry Weight of Soil + Cont. (g)
Weight of Container (g)
Weight of Mold (g)
Diaz Rd Expansion
Preparation Method:

Wt. Compacted Soil + Mold (g)
B-1
12502.001
TEST NO.

Soil Identification:

Project Name:

Sample No.:

Lean Clay (CL), Black.

MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project No.:

Boring No.:
105.0
110.0
115.0
120.0
125.0

5.0 10.0 15.0 20.0 25.Dry Density (pcf)Moisture Content (%) SP. GR. = 2.65
SP. GR. = 2.70
SP. GR. = 2.75
XX

Project Name:Tested By:F. Mina Date:6/3/20
Project No. :Checked By:M. Vinet Date:6/10/20
Boring No.:Depth:5.0 - 10.0
Sample No. :Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)
100.3

0.5000
10 0.5000
6/4/20 8:00

1.0 1.0
15:40 1.06/3/20
Wt. of Mold (gm.)
6/3/20
105.8
Moisture Content (%)
Date
15:30
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
117.7
632.2
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
7 0.682
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
EXPANSION INDEX of SOILS

98.4 4.01

2.70 3703.5

0.0 590.5
3703.5

60.1 1.0551
N/A
Diaz Rd Expansion
12502.001
LB-2
B-1
ASTM D 4829
Lean Clay with Sand (CL)s, Dark Yellowish Brown.

MOLDED SPECIMEN

4.01 1.0000
7Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
200.2

2.70 350.7
200.2

23.2 0.405

88.5 200.2
632.2
123.5
Elapsed Time
(min.)
Dial Readings
(in.)

91.951.4
Pressure
(psi)

0.373Total Porosity

SPECIMEN INUNDATION

77.1 Time
Dry Wt. of Soil + Cont. (gm.)

11.3 350.0
319.5

0.594

50.0 Project Name:Tested By:F. Mina Date:6/3/20
Project No. :Checked By:M. Vinet Date:6/10/20
Boring No.:Depth:0 - 5.0
Sample No. :Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)

96.1 0.5000
10 0.5000
6/4/20 8:00

1.0 1.0
17:10 1.06/3/20
Wt. of Mold (gm.)
6/3/20
100.0
Moisture Content (%)
Date
17:00
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
112.5
606.0
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
8 0.754
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
EXPANSION INDEX of SOILS

98.3 4.01

2.70 2870.2

0.0 573.2
2870.2

49.9 1.0405
N/A
Diaz Rd Expansion
12502.001
LB-7
B-1
ASTM D 4829
Lean Clay (CL), Black.

MOLDED SPECIMEN

4.01 1.0000
8Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
200.2

2.70 331.6
200.2

22.4 0.430

92.6 200.2
606.0
117.6
Elapsed Time
(min.)
Dial Readings
(in.)

80.249.2
Pressure
(psi)

0.407Total Porosity

SPECIMEN INUNDATION

84.2 Time
Dry Wt. of Soil + Cont. (gm.)

12.5 333.7
300.4

0.686

33.7 Project Name:Date:6/4/20
Project Number:12502.001 Technician:F. Mina
Boring Number:LB-2 Depth (ft.):5.0 - 10.0
Sample Number:B-1 Sample Location:

Sample Description:Lean Clay with Sand (CL)s, Dark Yellowish Brown.

TEST SPECIMEN A B C
MOISTURE AT COMPACTION %12.7 14.8 15.9
HEIGHT OF SAMPLE, Inches 2.45 2.57 2.59
DRY DENSITY, pcf 111.0 108.2 104.3
COMPACTOR AIR PRESSURE, psi 150 100 75
EXUDATION PRESSURE, psi 683 309 169
EXPANSION, Inches x 10exp-4 72 37 20
STABILITY Ph 2,000 lbs (160 psi)68 119 134
TURNS DISPLACEMENT 4.50 4.60 4.96
R-VALUE UNCORRECTED 43 16 9
R-VALUE CORRECTED 43 17 10
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1.0 1.0 1.0
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft.0.91 1.33 1.44
EXPANSION PRESSURE THICKNESS, ft.2.72 1.40 0.75

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART R-VALUE BY EXPANSION:16
R-VALUE BY EXUDATION:17
EQUILIBRIUM R-VALUE:16

R-VALUE TEST RESULTS
ASTM D 2844
Diaz Rd Expansion
N/A

0.00 0.50

1.00 1.50

2.00 2.50

3.00 3.50

4.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00COVER THICKNESS BY EXPANSION in feetCOVER THICKNESS BY STABILOMETER in feet
0 10
20 30
40 50
60 70
80 90
0100200300400500600700800R-VALUEEXUDATION PRESSURE (psi)

Project Name:Date:6/4/20
Project Number:12502.001 Technician:F. Mina
Boring Number:LB-5 Depth (ft.):0 - 5.0
Sample Number:B-1 Sample Location:

Sample Description:Sandy Silt s(ML), Dark Yellowish Brown.

TEST SPECIMEN A B C
MOISTURE AT COMPACTION %12.4 13.5 15.8
HEIGHT OF SAMPLE, Inches 2.53 2.52 2.55
DRY DENSITY, pcf 113.2 111.6 107.1
COMPACTOR AIR PRESSURE, psi 150 125 75
EXUDATION PRESSURE, psi 408 309 126
EXPANSION, Inches x 10exp-4 32 18 8
STABILITY Ph 2,000 lbs (160 psi)95 115 134
TURNS DISPLACEMENT 4.20 4.48 4.56
R-VALUE UNCORRECTED 29 18 10
R-VALUE CORRECTED 29 18 10
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1.0 1.0 1.0
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft.1.14 1.31 1.44
EXPANSION PRESSURE THICKNESS, ft.1.21 0.68 0.30

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART R-VALUE BY EXPANSION:26
R-VALUE BY EXUDATION:18
EQUILIBRIUM R-VALUE:18

R-VALUE TEST RESULTS
ASTM D 2844
Diaz Rd Expansion
N/A

0.00 0.50

1.00 1.50

2.00 2.50

3.00 3.50

4.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00COVER THICKNESS BY EXPANSION in feetCOVER THICKNESS BY STABILOMETER in feet
0 10
20 30
40 50
60 70
80 90
0100200300400500600700800R-VALUEEXUDATION PRESSURE (psi)

Project Name:Date:6/4/20
Project Number:12502.001 Technician:F. Mina
Boring Number:LB-7 Depth (ft.):0 - 5.0
Sample Number:B-1 Sample Location:

Sample Description:Lean Clay (CL), Black.

TEST SPECIMEN A B C
MOISTURE AT COMPACTION %16.6 17.2 18.5
HEIGHT OF SAMPLE, Inches 2.55 2.48 2.55
DRY DENSITY, pcf 100.2 104.3 101.5
COMPACTOR AIR PRESSURE, psi 165 150 125
EXUDATION PRESSURE, psi 623 416 250
EXPANSION, Inches x 10exp-4 39 17 10
STABILITY Ph 2,000 lbs (160 psi)130 141 150
TURNS DISPLACEMENT 4.31 4.61 4.87
R-VALUE UNCORRECTED 12 7 3
R-VALUE CORRECTED 12 7 3
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1.0 1.0 1.0
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft.1.41 1.49 1.55
EXPANSION PRESSURE THICKNESS, ft.1.47 0.64 0.38

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART R-VALUE BY EXPANSION:13
R-VALUE BY EXUDATION:4
EQUILIBRIUM R-VALUE:4

R-VALUE TEST RESULTS
ASTM D 2844
Diaz Rd Expansion
N/A

0.00 0.50

1.00 1.50

2.00 2.50

3.00 3.50

4.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00COVER THICKNESS BY EXPANSION in feetCOVER THICKNESS BY STABILOMETER in feet
0 10
20 30
40 50
60 70
80 90
0100200300400500600700800R-VALUEEXUDATION PRESSURE (psi)

Project Name:Tested By:FLM Date:06/01/20
Project No.:12502.001 Checked By:MRV Date:06/10/20
Boring No.:LB-4 Depth (feet):5.0 - 10.0
Sample No.:B-1
Soil Identification:Sandy Silt s(ML), Black
S 800.7
800.7 757.2
421.0 421.0
336.2 12.9
S
581.7
421.0
160.7
(in.)(mm.)
3"75.000
1"25.000
3/4"19.000
1/2"12.500
3/8"9.500
#4 4.750
#8 2.360
#16 1.180
#30 0.600
#50 0.300
#100 0.150
#200 0.075
GRAVEL:0 %
SAND:47 %
FINES:53 %
GROUP SYMBOL:s(ML)N/A
N/A
Remarks:
100.0

99.9 158.3

80.9 52.9
112.0 66.7
After Wet Sieve Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)
Wt. of Dry Soil + Cont. (g)

96.2 98.83.9
100.0

12.7 Dry Wt. of Soil (g)
Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

0.0 0.4
PAN

64.3 Moisture Content of Total Air - Dry Soil

91.3 Wt. of Container No._____ (g)
Container No.

Percent Passing (%)
Wt. of Air-Dry Soil + Cont. (g)

29.1 100.0
100.0
Wt. of Air-Dried Soil + Cont.(g)
Moisture Content (%)
100.0
Wt. of Container (g)
U. S. Sieve Size Cumulative Weight
Dry Soil Retained (g)

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Diaz Rd Expansion
of SOILS USING SIEVE ANALYSIS

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
12502.001
SAND

SILT FINE

HYDROMETER
Diaz Rd Expansion
Project No.:LB-4 Sample No.:

Soil Type :

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification:Sandy Silt s(ML), Black
s(ML)
GR:SA:FI : (%)
Boring No.:

Depth (feet):5.0 - 10.0
Project Name:B-1
Jun-200:47 :53
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000PERCENT FINER BY WEIGHTPARTICLE -SIZE (mm) "
Sieve; LB-4, B-1 (05-15-20)

Project Name:Tested By:FLM Date:06/01/20
Project No.:12502.001 Checked By:MRV Date:06/10/20
Boring No.:LB-5 Depth (feet):0 - 5.0
Sample No.:B-1
Soil Identification:Sandy Silt s(ML), Dark Yellowish Brown.

Whole Sample Sample Passing
#4 Whole Sample Sample
passing #4
P P Wt. of Air-Dry Soil + Cont.(g)2345.5 1037.5
2345.5 1037.5 Wt. of Dry Soil + Cont. (g)2123.0 1037.5 716.2 716.2 Wt. of Container No._____(g) 716.2 716.2
1407.0 321.3 Moisture Content (%)15.8 0.0
P
875.8
716.2
159.6
(mm.)
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#8
#16
#30
#50
#100
#200
GRAVEL:3 %
SAND:48 %
FINES:49 %
GROUP SYMBOL:SM N/A
N/A
Remarks:
158.3

20.8 35.6

59.7 103.7

0.075
PAN

16.4 18.7

48.54.750

2.360

1.180

0.600

0.300

0.150
Passing #4 Material After Wet Sieve

37.500
U. S. Sieve Size

25.000

19.000

12.500

9.500
Whole Sample

98.7 100.0

96.6 93.7

49.0 100.0

78.7 65.4
Wt. Air-Dried Soil + Cont.(g)

98.8 Cumulative Weight of Dry Soil Retained (g)
Sample Passing #4

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Diaz Rd Expansion
Moisture ContentsCalculation of Dry Weights
of SOILS USING SIEVE ANALYSIS
Dry Wt. of Soil (g)

0.0 Wt. of Container (g)
Container No.
100.0

90.3 85.9
Percent Passing
(%)
Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)

9.5 Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =

3 :48 :49
B-1
Jun-20
Boring No.:

Depth (feet):0 - 5.0 Soil Type :

Project Name:

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification:Sandy Silt s(ML), Dark Yellowish Brown.

SM
GR:SA:FI : (%)
Diaz Rd Expansion
Project No.:LB-5 Sample No.:12502.001
SAND

SILT FINE

HYDROMETER

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000PERCENT FINER BY WEIGHTPARTICLE -SIZE (mm) "
Sieve; LB-5, B-1 (05-15-20)

ASTM D 4318
Project Name:Tested By:F. Mina Date:6/4/20
Project No. :Input By:M. Vinet Date:6/10/20
Boring No.:Checked By:M. Vinet Date:6/10/20
Sample No.:Depth (ft.)5.0 - 10.0
PLASTIC LIMIT **IN-SITU
1 2 1 2 3 MOISTURE
15 25 35

21.61 21.76 20.19 20.45 20.75

20.70 20.82 18.58 18.82 19.08

13.63 13.79 13.75 13.66 13.67

12.9 13.4 33.3 31.6 30.9
Liquid Limit 32
Plastic Limit 13
Plasticity Index 19
Classification CL
PI at "A" - Line = 0.73(LL-20) = 8.76
One - Point Liquid Limit Calculation
LL =Wn(N/25)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
Multipoint - Dry
X Procedure A
Multipoint Test
Procedure B
One-point Test
Rev. 08-04
20 25 30 40 50 60 70 80 90 Moisture Content (%) [Wn]
TEST NO.

Number of Blows [N]
Wet Wt. of Soil + Cont. (gm)
Dry Wt. of Soil + Cont. (gm)

ATTERBERG LIMITS
Wt. of Container (gm)
LB-2
B-1
Diaz Rd Expansion
12502.001
Sample Description:Lean Clay with Sand (CL)s, Dark Yellowish Brown.

LIQUID LIMIT
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90 100Plasticity Index (PI)Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of
coarse-grained soils

28.0 29.0

30.0 31.0

32.0 33.0

34.0 35.0
10 100Moisture Content (%)Number of Blows
20 25 30 50 9070604080
"A" Line
7 4
CH or OH
CL-ML

ASTM D 4318
Project Name:Tested By:F. Mina Date:6/4/20
Project No. :Input By:M. Vinet Date:6/10/20
Boring No.:Checked By:M. Vinet Date:6/10/20
Sample No.:Depth (ft.)0 - 5.0
PLASTIC LIMIT **IN-SITU
1 2 1 2 3 MOISTURE
15 25 35

23.85 23.41 20.95 22.50 21.12

22.33 21.94 19.17 20.33 19.36

13.78 13.71 13.95 13.77 13.85

17.8 17.9 34.1 33.1 31.9
Liquid Limit 33
Plastic Limit 18
Plasticity Index 15
Classification CL
PI at "A" - Line = 0.73(LL-20) = 9.49
One - Point Liquid Limit Calculation
LL =Wn(N/25)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
Multipoint - Dry
X Procedure A
Multipoint Test
Procedure B
One-point Test
Rev. 08-04

ATTERBERG LIMITS
Wt. of Container (gm)
LB-7
B-1
Diaz Rd Expansion
12502.001
Sample Description:Lean Clay (CL), Black.

LIQUID LIMIT
20 25 30 40 50 60 70 80 90 Moisture Content (%) [Wn]
TEST NO.

Number of Blows [N]
Wet Wt. of Soil + Cont. (gm)
Dry Wt. of Soil + Cont. (gm)
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90 100Plasticity Index (PI)Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of
coarse-grained soils

29.0 30.0

31.0 32.0

33.0 34.0

35.0 36.0
10 100Moisture Content (%)Number of Blows
20 25 30 50 9070604080
"A" Line
7 4
CH or OH
CL-ML

Project Name:Diaz Rd Expansion Tested By :F. Mina Date:06/04/20 Project No. :12502.001 Data Input By:M. Vinet Date:06/10/20 Boring No.LB-7
Sample No.B-1
Sample Depth (ft)0 - 5.0
100.00
100.00

0.00 0.00
100.00
4 4
850
Timer
45 24.8569

24.8502

0.0067
275.70
276
ml of Extract For Titration (B)30
ml of AgNO3 Soln. Used in Titration (C)2.2
PPM of Chloride (C -0.2) * 100 * 30 / B 200
PPM of Chloride, Dry Wt. Basis 200

8.50 21.0
PPM of Sulfate (A) x 41150
Wet Weight of Soil + Container (g)
Wt. of Residue (g) (A)
Beaker No.

Crucible No.

Furnace Temperature (°C)
PPM of Sulfate, Dry Weight Basis
Wt. of Crucible (g)
CL
Wt. of Crucible + Residue (g)
CHLORIDE CONTENT, DOT California Test 422
Time In / Time Out
Weight of Soaked Soil (g)
Dry Weight of Soil + Container (g)
Weight of Container (g)
Duration of Combustion (min)
Temperature °C
pH Value
pH TEST, DOT California Test 643
TESTS for SULFATE CONTENT
CHLORIDE CONTENT and pH of SOILS
SULFATE CONTENT, DOT California Test 417, Part II
Soil Identification:

Moisture Content (%)

Project Name:Diaz Rd Expansion Tested By :F. Mina Date:06/04/20 Project No. :12502.001 Data Input By:M. Vinet Date:06/10/20 Boring No.LB-2 LB-4
Sample No.B-1 B-1
Sample Depth (ft)5.0 - 10.0 0 - 5.0
100.00 100.00
100.00 100.00

0.00 0.00

0.00 0.00
100.00 100.00
1 2
1 2
850 850
Timer Timer
45 45

26.1035 24.4732

26.0942 24.4667

0.0093 0.0065
382.69 267.47
383 267
TESTS for SULFATE CONTENT
SULFATE CONTENT, DOT California Test 417, Part II
Soil Identification:

Moisture Content (%)
s(ML)
Time In / Time Out
Weight of Soaked Soil (g)
PPM of Sulfate, Dry Weight Basis
Wt. of Crucible (g)
(CL)s
Wt. of Crucible + Residue (g)
Wet Weight of Soil + Container (g)
Dry Weight of Soil + Container (g)
Weight of Container (g)
Duration of Combustion (min)
Wt. of Residue (g) (A)
Beaker No.

Crucible No.

Furnace Temperature (°C)
PPM of Sulfate (A) x 41150

R-1
Feb-160:26 :74
Project Name:

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification:Silt with Sand (ML)s, brown.
(ML)s
GR:SA:FI : (%)
Exploration No.:

Depth (feet):5.0
SAND

SILT FINE

HYDROMETER
KJ/EMWD TVRW Pipeline
Project No.:LB-9 Sample No.:

Soil Type :10807.002

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000PERCENT FINER BY WEIGHT PARTICLE - SIZE (mm) "

Sieve; LB-9, R1 (10-2-14)

Project Name:Tested By: MRV Date: 10/7/14
Project No. :Checked By: JHW Date: 10/9/14
Boring No.:Depth (ft.) 7.5
Sample No. :Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)
107.1

0.5000
10 0.4996
10/8/14 6:30

1.0 1.0
14:50 1.010/7/14
10/7/14
107.3
Moisture Content (%)
Date
14:40
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
119.1
Time
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
5 0.639
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
Wt. of Mold (gm.)

99.7 4.01

2.70 980.6

0.0 595.4
980.6

2.5 1.0430
634.6
EXPANSION INDEX of SOILS
ASTM D 4829
**
KJ/EMWD TVRW Pipeline Geo Exploration
10807.001
LB-9
R-2/B-1
Silt with Trace Gravel (ML), dark brown.

MOLDED SPECIMEN

4.01 1.0000
5Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
200.6

2.70 355.7
200.6

22.0 0.390

84.2 200.6
634.6
130.7
Elapsed Time
(min.)
Dial Readings
(in.)

93.152.0
Pressure
(psi)

0.364Total Porosity

SPECIMEN INUNDATION

75.3 Dry Wt. of Soil + Cont. (gm.)

11.0 339.3
309.6

0.571

39.3 Project Name:FLMDate:Project No. :FLMDate:Client:JHWDate:7490#DIV/0!85011:5012:00 12:02 12:2213.6 1.0811:52 12:02 12:04 12:2413.4 1.29#REF! #REF! #REF! #REF!T1 = Starting Time T3 = Settlement Starting Time Sand Equivalent = R2 / R1 * 100T2 = ( T1 + 10 min) Begin Agitation T4 = ( T3 + 20 min) Take Clay Reading (R1) Record SE as Next Higher Integer R29 SAND EQUIVALENT TEST ASTM D 2419 / DOT CA Test 2179/25/14T1 T2 T3 T4Boring No.9/25/1410/9/14Tested By: Computed By:Checked By:Depth (ft.)Average SESoil DescriptionSER1LB-8 B-1 5.0 - 10.0 SC10807.001KJ/EMWD TVRW Pipeline Geo ExplorationKennedy/Jenks Consultants, Inc.Sample No.Sand Equivalent; LB-8, B-1 (9-18-14)

One-Dimensional Swell or Settlement
Potential of Cohesive Soils
(ASTM D 4546) -- Method 'B'

Project Name:Tested By:MRV Date:10/6/14
Project No.:Checked By:JHW Date:10/9/14
Boring No.:LB-8 Sample Type: IN SITU
Sample No.:R-2 Depth (ft.)10.0
Sample Description:

Source and Type of Water Used for Inundation: Arrowhead ( Distilled ) ** Note: Loading After Wetting (Inundation) not Performed Using this Test Method.

Initial Dry Density (pcf): 99.3 Final Dry Density (pcf): 104.4 Initial Moisture (%): 25.5 Final Moisture (%) : 23.8
Initial Height (in.): 0.9970 Initial Void ratio: 0.6968 Initial Dial Reading (in): 0.0500 Specific Gravity (assumed): 2.70 Inside Diameter of Ring (in): 2.416 Initial Degree of Saturation (%): 98.7

1.050 0.9747 0.00 -2.24 -2.24

2.013 0.9600 0.00 -3.71 -3.71
H2O 0.9542 0.00 -4.29 -4.29
-0.60

Rev. 01-10
KJ/EMWD TVRW Pipeline Geo Exploration

0.6240

0.0753

0.0900

0.0958
Silty Clay (CL-ML), dark brown.
10807.001
Swell (+)
Settlement (-)
% of Sample
Thickness
Load
Compliance
(%)
Apparent
Thickness
(in)
Percent Swell / Settlement After Inundation =
Corrected
Deformation
(%)
Pressure (p)
(ksf)

0.6589

0.6339
Final Reading
(in)Void Ratio
-5.00
-4.00
-3.00
-2.00
-1.00

0.00 1.00

2.00 3.00

4.00 5.00

0.010 0.100 1.000 10.000Deformation %Log Pressure (ksf) Deformation % - Log Pressure Curve
Inundate With
Distilled Water

Project Name:Tested By : G. Berdy Date:

Project No. :Data Input By: J. Ward Date:

Boring No.:Depth (ft.) :

Sample No. :

Soil Identification:*
*California Test 643 requires soil specimens to consist only of portions of samples passing through the No. 8 US Standard Sieve before resistivity testing. Therefore, this test method may not be representative for coarser materials.

Wt. of Container (g)31.31 800

6.69 225.45
Moisture Content (%) (MCi)
Wet Wt. of Soil + Cont. (g)
Dry Wt. of Soil + Cont. (g)
5 Min. Resistivity Moisture Content Sulfate Content
Specimen
No.
1 2
Water
Added (ml)
(Wa)
30 800
720
Resistance
Reading
(ohm)

39.51 55.93
DOT CA Test 532 / 643DOT CA Test 417 Part II DOT CA Test 422 710
DOT CA Test 532 / 643

1.000
Chloride Content
(ohm-cm)
130.003690
7104
40 50
60 47.72
690 48.1 529 182 8.00 22.2

SOIL RESISTIVITY TEST
DOT CA TEST 532 / 643
Temp. (°C)pH
Soil pH
720
690
214.65

53.14 MC =(((1+Mci/100)x(Wa/Wt+1))-1)x100
KJ/EMWD TVRW Pipeline Geo Exploration 10/06/14
10/07/14
5-10
10807.001
LB-8
(%) (ppm) (ppm)
B-1
Container No.

Initial Soil Wt. (g) (Wt)
Box Constant
SC, dark brown
Adjusted
Moisture
Content
(MC)
Soil
Resistivity
(ohm-cm)
600
650
700
750
800
850

25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0Soil Resistivity (ohm-cm)Moisture Content (%)

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

APPENDIX C

ARS Curves and Percolation Testing Data Sheets

exceedance in 50 years).

T (sec)
Base
Spectrum
S(a)
Basin
Factor
Near
Fault
Factor
Final Adj.

Spectrum
S(a)Period (sec)
INPUT
USGS Deagg.

Spec Accel
ARS Online
Base Sa(g)
% Difference
(bet. USGS &
ARS Online)

0.01 0.54 1 1 0.54 0 0.53 0.54 1.9%

0.1 0.92 1 1 0.92 0.3 1.34 1.35 0.7%

0.2 1.24 1 1 1.24 1 0.81 0.80 1.3%

0.3 1.35 1 1 1.35 3 0.28 0.27 3.7%

0.5 1.24 1 1 1.24

0.75 0.99 1 1.1 1.09
1 0.8 1 1.2 0.96 Max % Difference =
2 0.41 1 1.2 0.49 3.7%
3 0.27 1 1.2 0.32
4 0.19 1 1.2 0.23
5 0.14 1 1.2 0.17
Project Data:

Lattitude: 33.5139
Longitude: -117.1658
Shear Wave Velocity Vs = 270 m/s
Peak Ground Accelaration = 0.54 g
References
Caltrans SDC V2.0 (April 2019)
ARS Online Probabilistic Data V3.0.1 per Caltrans SDC
V2.0.

Comparison of the 2014 USGS Probabilistic Seismic
Hazard Data and ARS Online Probabilistic Data
ARS Curve per Caltrans Seismic Design Criteria (SDC) V2.0 https://arsonline.dot.ca.gov/
975-year return period (5% probability of exceedance in 50 years)

0.0 0.2

0.4 0.6

0.8 1.0

1.2 1.4

1.6 00.511.522.533.544.55Spectral Acceleration, Sa (g)Period (sec) Caltrans Deisgn Spectrum (5% Damping)
Final Adjusted ARS Curve
Scale: NTS
Proj: 12324.001
Date: 05/2020
Prepared by: BSS
Checked By: SIS Design Accelaration Response Spectrum
Diaz Road Expansion Project (PW17-25
Temecula, California
Figure C-1

60 °
8 4
7:33:00
8:03:00
8:03:00
8:33:00
8:33:00
9:03:00
9:03:00
9:33:00
9:33:00
10:03:00
10:03:00
10:33:00
10:33:00
11:03:00
11:03:00
11:33:00
11:33:00
12:03:00
12:03:00
12:33:00
Tested by:JTD Date Tested 5/19/2020
Soil Unit:Artificial Fill Depth of Test Hole (in.)75
Test Hole Number:P-1 Project Diaz Road
Date Excavated:5/15/2020 Project Number 12502.001
USCS Soil Type:Sandy Lean CLAY Diameter (in.)Effective Radius (in) Time Δt
(min)
Total
Time
(min)
Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration
Rate*
(inches/hour)
Peroclation
Rate
(minute/inch)
30 30 35.50 36.50 1.00 0.15 30.0

30.0 30 90 34.50 35.00 0.50 0.07 60.0
30 60 36.50 37.50 1.00 0.16

60.0 30 150 35.50 36.00 0.50 0.08 60.0
30 120 35.00 35.50 0.50 0.07

60.0 30 210 34.00 34.50 0.50 0.07 60.0
30 180 36.00 36.50 0.50 0.08

60.0 30 270 35.00 35.50 0.50 0.07 60.0
30 240 34.50 35.00 0.50 0.07

60.03030035.00 35.50 0.50 0.07
Date:May-20
* Based on Porchet Method
Percolation Project Number:12502.001
Leighton
Test Data
Project Name:Diaz Road
P-1

0.00 0.02

0.04 0.06

0.08 0.10

0.12 0.14

0.16 0.18
0 50 100 150 200 250 300 350
Infiltration Rate
(in./hr)
Time (min)

60 °
8 4
7:36:00
8:06:00
8:06:00
8:36:00
8:36:00
9:06:00
9:06:00
9:36:00
9:36:00
10:06:00
Tested by:JTD Date Tested 5/19/2020
Soil Unit:Artificial Fill Depth of Test Hole (in.)75
Test Hole Number:P-2 Project Diaz Road
Date Excavated:5/15/2020 Project Number 12502.001
USCS Soil Type:Clayey SAND Diameter (in.)Effective Radius (in) Time Δt
(min)
Total
Time
(min)
Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration
Rate*
(inches/hour)
Peroclation
Rate
(minute/inch)
30 30 28.00 28.00 0.00 0.00 N/A
N/A
30 90 28.00 28.00 0.00 0.00 N/A
30 60 28.00 28.00 0.00 0.00
N/A
30 150 28.00 28.00 0.00 0.00 N/A
30 120 28.00 28.00 0.00 0.00
End Of Test
Date:May-20
* Based on Porchet Method
Percolation Project Number:12502.001
Leighton
Test Data
Project Name:Diaz Road
P-2

0.00 0.20

0.40 0.60

0.80 1.00
0 20 40 60 80 100 120 140 160
Infiltration Rate
(in./hr)
Time (min)

60 °
8 4
7:41:00
8:11:00
8:11:00
8:41:00
8:41:00
9:11:00
9:11:00
9:41:00
9:41:00
10:11:00
10:11:00
10:41:00
10:41:00
11:11:00
11:11:00
11:41:00
11:41:00
12:11:00
Tested by:JTD Date Tested 5/19/2020
Soil Unit:Artificial Fill Depth of Test Hole (in.)75
Test Hole Number:P-3 Project Diaz Road
Date Excavated:5/15/2020 Project Number 12502.001
USCS Soil Type:Clayey SAND Diameter (in.)Effective Radius (in) Time Δt
(min)
Total
Time
(min)
Initial Water Depth
(inches)
Final Water Depth
(inches)
Change In Water Level
(inches)
Infiltration
Rate*
(inches/hour)
Peroclation
Rate
(minute/inch)
30 30 30.50 31.00 0.50 0.06 60.0
N/A
30 90 31.00 31.50 0.50 0.07 60.0
30 60 31.00 31.00 0.00 0.00

60.0 30 150 32.00 32.00 0.00 0.00 N/A
30 120 31.50 32.00 0.50 0.07
N/A
30 210 32.00 32.00 0.00 0.00 N/A
30 180 32.00 32.00 0.00 0.00
N/A
30 270 32.00 32.00 0.00 0.00 N/A
30 240 32.00 32.00 0.00 0.00
End Of Test
Date:May-20
* Based on Porchet Method
Percolation Project Number:12502.001
Leighton
Test Data
Project Name:Diaz Road
P-3

0.00 0.01

0.02 0.03

0.04 0.05

0.06 0.07
0 50 100 150 200 250 300
Infiltration Rate
(in./hr)
Time (min)

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

APPENDIX D

General Earthwork and Grading Specifications

APPENDIX D

LEIGHTON CONSULTING, INC.

EARTHWORK AND GRADING GUIDE SPECIFICATIONS

TABLE OF CONTENTS

Section Appendix D Page
D-1.0 GENERAL ........................................................................................................... 1 D-1.1 Intent ............................................................................................................. 1 D-1.2 Role of Leighton Consulting, Inc. ................................................................... 1 D-1.3 The Earthwork Contractor ............................................................................. 1 D-2.0 PREPARATION OF AREAS TO BE FILLED ..................................................... 2 D-2.1 Clearing and Grubbing .................................................................................. 2 D-2.2 Processing ..................................................................................................... 3 D-2.3 Overexcavation ............................................................................................. 3 D-2.4 Benching ....................................................................................................... 3 D-2.5 Evaluation/Acceptance of Fill Areas .............................................................. 3 D-3.0 FILL MATERIAL ................................................................................................. 4 D-3.1 Fill Quality ...................................................................................................... 4 D-3.2 Oversize ........................................................................................................ 4 D-3.3 Import ............................................................................................................ 4 D-4.0 FILL PLACEMENT AND COMPACTION ........................................................... 4 D-4.1 Fill Layers ...................................................................................................... 4 D-4.2 Fill Moisture Conditioning .............................................................................. 5 D-4.3 Compaction of Fill .......................................................................................... 5 D-4.4 Compaction of Fill Slopes .............................................................................. 5 D-4.5 Compaction Testing ...................................................................................... 5 D-4.6 Compaction Test Locations ........................................................................... 5 D-5.0 EXCAVATION ..................................................................................................... 6 D-6.0 TRENCH BACKFILLS ........................................................................................ 6 D-6.1 Safety ............................................................................................................ 6 D-6.2 Bedding and Backfill ...................................................................................... 6 D-6.3 Lift Thickness ................................................................................................ 7

D-1
D-1.0 GENERAL
D-1.1 Intent
These Earthwork and Grading Guide Specifications are for grading and earthwork shown on the current, approved grading plan(s) and/or indicated in the Leighton Consulting, Inc. geotechnical report(s). These Guide Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the project-specific recommendations in the geotechnical report shall supersede these Guide Specifications. Leighton Consulting, Inc. shall provide geotechnical observation and testing during earthwork and grading. Based on these observations and tests, Leighton Consulting, Inc. may provide new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s).

D-1.2 Role of Leighton Consulting, Inc.

Prior to commencement of earthwork and grading, Leighton Consulting, Inc. shall meet with the earthwork contractor to review the earthwork contractor’s work plan, to schedule sufficient personnel to perform the appropriate level of observation, mapping and compaction testing. During earthwork and grading, Leighton Consulting, Inc. shall observe, map, and document subsurface exposures to verify geotechnical design assumptions. If observed conditions are found to be significantly different than the interpreted assumptions during the design phase, Leighton Consulting, Inc. shall inform the owner, recommend appropriate changes in design to accommodate these observed conditions, and notify the review agency where required. Subsurface areas to be geotechnically observed, mapped, elevations recorded, and/or tested include (1) natural ground after clearing to receiving fill but before fill is placed, (2) bottoms of all "remedial removal" areas, (3) all key bottoms, and (4) benches made on sloping ground to receive fill.

Leighton Consulting, Inc. shall observe moisture-conditioning and processing of the subgrade and fill materials, and perform relative compaction testing of fill to determine the attained relative compaction. Leighton Consulting, Inc. shall provide Daily Field Reports to the owner and the Contractor on a routine and frequent basis.

D-1.3 The Earthwork Contractor
The earthwork contractor (Contractor) shall be qualified, experienced and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moisture-conditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Guide

Leighton Consulting, Inc. Earthwork and Grading Guide Specifications

D-2
Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing grading and backfilling in accordance with the current, approved plans and specifications.

The Contractor shall inform the owner and Leighton Consulting, Inc. of changes in work schedules at least one working day in advance of such changes so that appropriate observations and tests can be planned and accomplished. The Contractor shall not assume that Leighton Consulting, Inc. is aware of all grading operations.

The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish earthwork and grading in accordance with the applicable grading codes and agency ordinances, these Guide Specifications, and recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of Leighton Consulting, Inc., unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than required in these specifications, Leighton Consulting, Inc. shall reject the work and may recommend to the owner that earthwork and grading be stopped until unsatisfactory condition(s) are rectified.

D-2.0 PREPARATION OF AREAS TO BE FILLED
D-2.1 Clearing and Grubbing
Vegetation, such as brush, grass, roots and other deleterious material shall be sufficiently removed and properly disposed of in a method acceptable to the owner, governing agencies and Leighton Consulting, Inc.. Care should be taken not to encroach upon or otherwise damage native and/or historic trees designated by the Owner or appropriate agencies to remain. Pavements, flatwork or other construction should not extend under the “drip line” of designated trees to remain.

Leighton Consulting, Inc. shall evaluate the extent of these removals depending on specific site conditions. Earth fill material shall not contain more than 3 percent of organic materials (by dry weight: ASTM D 2974). Nesting of the organic materials shall not be allowed.

If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be informed immediately for proper evaluation and handling of these materials prior to continuing to work in that area. As presently defined by the State of California, most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that

Leighton Consulting, Inc. Earthwork and Grading Guide Specifications

D-3
are considered to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall not be allowed.

D-2.2 Processing
Existing ground that has been declared satisfactory for support of fill, by Leighton Consulting, Inc., shall be scarified to a minimum depth of 6 inches (15 cm). Existing ground that is not satisfactory shall be over-excavated as specified in the following Section D-2.3. Scarification shall continue until soils are broken down and free of large clay lumps or clods and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction.

D-2.3 Overexcavation
In addition to removals and over-excavations recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic- rich, highly fractured or otherwise unsuitable ground shall be over-excavated to competent ground as evaluated by Leighton Consulting, Inc. during grading. All undocumented fill soils under proposed structure footprints should be excavated D-2.4 Benching
Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), (>20 percent grade) the ground shall be stepped or benched. The lowest bench or key shall be a minimum of 15 feet (4.5 m) wide and at least 2 feet (0.6 m) deep, into competent material as evaluated by Leighton Consulting, Inc.. Other benches shall be excavated a minimum height of 4 feet (1.2 m) into competent material or as otherwise recommended by Leighton Consulting, Inc.. Fill placed on ground sloping flatter than 5:1 (horizontal to vertical units), (<20 percent grade) shall also be benched or otherwise over-excavated to provide a flat subgrade for the fill.

D-2.5 Evaluation/Acceptance of Fill Areas
All areas to receive fill, including removal and processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded, and/or tested prior to being accepted by Leighton Consulting, Inc. as suitable to receive fill. The Contractor shall obtain a written acceptance (Daily Field Report) from Leighton Consulting, Inc. prior to fill placement. A licensed surveyor shall provide the survey control for determining elevations of processed areas, keys and benches.

Leighton Consulting, Inc. Earthwork and Grading Guide Specifications

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D-3.0 FILL MATERIAL
D-3.1 Fill Quality
Material to be used as fill shall be essentially free of organic matter and other deleterious substances evaluated and accepted by Leighton Consulting, Inc. prior to placement. Soils of poor quality, such as those with unacceptable gradation, high expansion potential, or low strength shall be placed in areas acceptable to Leighton Consulting, Inc. or mixed with other soils to achieve satisfactory fill material.

D-3.2 Oversize
Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 6 inches (15 cm), shall not be buried or placed in fill unless location, materials and placement methods are specifically accepted by Leighton Consulting, Inc.. Placement operations shall be such that nesting of oversized material does not occur and such that oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 feet (3 m) measured vertically from finish grade, or within 2 feet (0.61 m) of future utilities or underground construction.

D-3.3 Import
If importing of fill material is required for grading, proposed import material shall meet the requirements of Section D-3.1, and be free of hazardous materials (“contaminants”) and rock larger than 3-inches (8 cm) in largest dimension. All import soils shall have an Expansion Index (EI) of 20 or less and a sulfate content no greater than () 500 parts- per-million (ppm). A representative sample of a potential import source shall be given to Leighton Consulting, Inc. at least four full working days before importing begins, so that suitability of this import material can be determined and appropriate tests performed.

D-4.0 FILL PLACEMENT AND COMPACTION
D-4.1 Fill Layers
Approved fill material shall be placed in areas prepared to receive fill, as described in Section D-2.0, above, in near-horizontal layers not exceeding 8 inches (20 cm) in loose thickness. Leighton Consulting, Inc. may accept thicker layers if testing indicates the grading procedures can adequately compact the thicker layers, and only if the building officials with the appropriate jurisdiction approve. Each layer shall be spread evenly and mixed thoroughly to attain relative uniformity of material and moisture throughout.

Leighton Consulting, Inc. Earthwork and Grading Guide Specifications

D-5
D-4.2 Fill Moisture Conditioning
Fill soils shall be watered, dried back, blended and/or mixed, as necessary to attain a relatively uniform moisture content at or slightly over optimum. Maximum density and optimum soil moisture content tests shall be performed in accordance with the American Society of Testing and Materials (ASTM) Test Method D 1557.

D-4.3 Compaction of Fill
After each layer has been moisture-conditioned, mixed, and evenly spread, each layer shall be uniformly compacted to not-less-than (≥) 90 percent of the maximum dry density as determined by ASTM Test Method D 1557. In some cases, structural fill may be specified (see project-specific geotechnical report) to be uniformly compacted to at- least (≥) 95 percent of the ASTM D 1557 modified Proctor laboratory maximum dry density. For fills thicker than (>) 15 feet (4.5 m), the portion of fill deeper than 15 feet below proposed finish grade shall be compacted to 95 percent of the ASTM D 1557 laboratory maximum density. Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity.

D-4.4 Compaction of Fill Slopes
In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by back rolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet (1 to 1.2 m) in fill elevation, or by other methods producing satisfactory results acceptable to Leighton Consulting, Inc.. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of the ASTM D 1557 laboratory maximum density.

D-4.5 Compaction Testing
Field-tests for moisture content and relative compaction of the fill soils shall be performed by Leighton Consulting, Inc.. Location and frequency of tests shall be at our field representative(s) discretion based on field conditions encountered. Compaction test locations will not necessarily be selected on a random basis. Test locations shall be selected to verify adequacy of compaction levels in areas that are judged to be prone to inadequate compaction (such as close to slope faces and at the fill/bedrock benches).

D-4.6 Compaction Test Locations
Leighton Consulting, Inc. shall document the approximate elevation and horizontal coordinates of each density test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that Leighton

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D-6
Consulting, Inc. can determine the test locations with sufficient accuracy. Adequate grade stakes shall be provided.

D-5.0 EXCAVATION
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by Leighton Consulting, Inc. during grading. Remedial removal depths shown on geotechnical plans are estimates only. The actual extent of removal shall be determined by Leighton Consulting, Inc. based on the field evaluation of exposed conditions during grading. Where fill-over-cut slopes are to be graded, the cut portion of the slope shall be made, then observed and reviewed by Leighton Consulting, Inc. prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by Leighton Consulting, Inc..

D-6.0 TRENCH BACKFILLS
D-6.1 Safety
The Contractor shall follow all OSHA and Cal/OSHA requirements for safety of trench excavations. Work should be performed in accordance with Article 6 of the California Construction Safety Orders, 2009 Edition or more current (see also:
http://www.dir.ca.gov/title8/sb4a6.html ).

D-6.2 Bedding and Backfill
All utility trench bedding and backfill shall be performed in accordance with applicable provisions of the 2015 Edition of the Standard Specifications for Public Works Construction (Green Book). Bedding material shall have a Sand Equivalent greater than 30 (SE>30). Bedding shall be placed to 1-foot (0.3 m) over the top of the conduit, and densified by jetting in areas of granular soils, if allowed by the permitting agency.

Otherwise, the pipe-bedding zone should be backfilled with Controlled Low Strength Material (CLSM) consisting of at least one sack of Portland cement per cubic-yard of sand, and conforming to Section 201-6 of the 2015 Edition of the Standard Specifications for Public Works Construction (Green Book). Backfill over the bedding zone shall be placed and densified mechanically to a minimum of 90 percent of relative compaction (ASTM D 1557) from 1 foot (0.3 m) above the top of the conduit to the surface. Backfill above the pipe zone shall not be jetted. Jetting of the bedding around the conduits shall be observed by Leighton Consulting, Inc. and backfill above the pipe zone (bedding) shall be observed and tested by Leighton Consulting, Inc..

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D-7
D-6.3 Lift Thickness
Lift thickness of trench backfill shall not exceed those allowed in the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to Leighton Consulting, Inc. that the fill lift can be compacted to the minimum relative compaction by his alternative equipment and method, and only if the building officials with the appropriate jurisdiction approve.

DRAFT-1Geotechnical Design Report July 6, 2020
Proposed Diaz Road Expansion Project (PW17-25) Project No. 12502.001

APPENDIX E

GBA-Important Information about This
Geotechnical Report

Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.

While you cannot eliminate all such risks, you can manage them. The following information is provided to help.

The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.

Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation
techniques that can be of genuine benefit for
everyone involved with a construction project.

Understand the Geotechnical-Engineering Services
Provided for this Report
Geotechnical-engineering services typically include the planning, collection, interpretation, and analysis of exploratory data from widely spaced borings and/or test pits. Field data are combined with results from laboratory tests of soil and rock samples obtained from field exploration (if applicable), observations made during site reconnaissance, and historical information to form one or more models of the expected subsurface conditions beneath the site. Local geology and alterations of the site surface and subsurface by previous and proposed construction are also important considerations. Geotechnical engineers apply their engineering training, experience, and judgment to adapt the requirements of the prospective project to the subsurface model(s). Estimates are made of the subsurface conditions that will likely be exposed during construction as well as the expected performance of foundations and other structures being planned and/or affected by construction activities.

The culmination of these geotechnical-engineering services is typically a geotechnical-engineering report providing the data obtained, a discussion of the subsurface model(s), the engineering and geologic engineering assessments and analyses made, and the recommendations developed to satisfy the given requirements of the project. These reports may be titled investigations, explorations, studies, assessments, or evaluations.

Regardless of the title used, the geotechnical-engineering report is an engineering interpretation of the subsurface conditions within the context of the project and does not represent a close examination, systematic inquiry, or thorough investigation of all site and subsurface conditions.

Geotechnical-Engineering Services are Performed
for Specific Purposes, Persons, and Projects,
and At Specific Times
Geotechnical engineers structure their services to meet the specific needs, goals, and risk management preferences of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client.

Likewise, geotechnical-engineering services are performed for a specific project and purpose. For example, it is unlikely that a geotechnical- engineering study for a refrigerated warehouse will be the same as one prepared for a parking garage; and a few borings drilled during a preliminary study to evaluate site feasibility will not be adequate to develop geotechnical design recommendations for the project.

Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project or purpose;
• for a different site (that may or may not include all or a portion of the original site); or
• before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations.

Note, too, the reliability of a geotechnical-engineering report can be affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying the recommendations in it. A minor amount of additional testing or analysis after the passage of time – if any is required at all – could prevent major problems.

Read this Report in Full
Costly problems have occurred because those relying on a geotechnical- engineering report did not read the report in its entirety. Do not rely on an executive summary. Do not read selective elements only. Read and refer to the report in full.

You Need to Inform Your Geotechnical Engineer
About Change
Your geotechnical engineer considered unique, project-specific factors when developing the scope of study behind this report and developing the confirmation-dependent recommendations the report conveys.

Typical changes that could erode the reliability of this report include those that affect:
• the site’s size or shape;
• the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
• the composition of the design team; or
• project ownership.

As a general rule, always inform your geotechnical engineer of project or site changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept

responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered.

Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s subsurface using various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing is performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgement to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team through project completion to obtain informed guidance quickly, whenever needed.

This Report’s Recommendations Are
Confirmation-Dependent
The recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgement and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions exposed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation.

This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical- engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a continuing member of the design team, to:
• confer with other design-team members;
• help develop specifications;
• review pertinent elements of other design professionals’ plans and specifications; and
• be available whenever geotechnical-engineering guidance is needed.

You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction- phase observations.

Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for information purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect.

Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. This happens in part because soil and rock on project sites are typically heterogeneous and not manufactured materials with well-defined engineering properties like steel and concrete. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes.

To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations,” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions.

Your geotechnical engineer should respond fully and frankly.

Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical-engineering report does not usually provide environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not obtained your own environmental information about the project site, ask your geotechnical consultant for a recommendation on how to find environmental risk-management guidance.

Obtain Professional Assistance to Deal with
Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, the engineer’s services were not designed, conducted, or intended to prevent migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies.

Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team.

Geotechnical engineers are not building-envelope or mold specialists.

Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.

Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.

Telephone: 301/565-2733
e-mail: [email protected] www.geoprofessional.org

911 S. Primrose Ave., Unit N, Monrovia, CA 91016
(562) 818-7713
[email protected] • www.paleosolutions.com

OFFICES
Denver, CO; Redlands, CA; Oceanside, CA; Bend, OR

CERTIFICATIONS
DBE • SBE • WBE • SDB • WOSB • EDWOSB

PALEONTOLOGICAL TECHNICAL STUDY

DIAZ ROAD EXPANSION PROJECT

Prepared for: HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
La Mesa, CA 91942

Prepared by: Paleo Solutions, Inc.
911 S. Primrose Ave., Unit N
Monrovia, CA 91016

Courtney Richards, M.S. – Principal Investigator
Betsy Kruk, M.S. – Report Author

PSI Report: CA20RiversideHEL03R

June 5, 2020

City of Temecula

HELIX ENVIRONMENTAL PLANNING, INC.

DIAZ ROAD EXPANSION PROJECT
PSI REPORT NO.: CA20RIVERSIDEHEL03R

2 This page intentionally left blank.

HELIX ENVIRONMENTAL PLANNING, INC.

DIAZ ROAD EXPANSION PROJECT
PSI REPORT NO.: CA20RIVERSIDEHEL03R

3 TABLE OF CONTENTS

1.0 Executive Summary................................................................................................................... 5

2.0 Introduction............................................................................................................................... 6

2.1 Project Description and Location ................................................................................................................ 6

3.0 Definition and Significance of Paleontological Resources ......................................................12

4.0 Laws, Ordinances, Regulations, and Standards ......................................................................13

4.1 State Regulatory Setting ............................................................................................................................... 13

4.1.1 California Environmental Quality Act (CEQA) .................................................................................. 13

4.1.2 State of California Public Resources Code ........................................................................................... 13

4.2 Local Regulatory Setting .............................................................................................................................. 13

4.2.1 Riverside County....................................................................................................................................... 13

4.2.2 City of Temecula ....................................................................................................................................... 14

5.0 Methods ....................................................................................................................................14

5.1 Analysis of Existing Data ............................................................................................................................ 15

5.2 Field Survey.................................................................................................................................................... 15

5.3 Criteria For Evaluating Paleontological Potential.................................................................................... 15

6.0 Analysis of Existing Data .........................................................................................................16

6.1 Literature Search ........................................................................................................................................... 17

6.1.1 Artificial Fill (Unmapped) ....................................................................................................................... 17

6.1.2 Younger Sedimentary Deposits (Qa, Qyaa, Qyfa, Qyva, Qyag) ....................................................... 17

6.1.3 Older Alluvial Flood Plain Deposits (Qoa) .......................................................................................... 18

6.1.4 Pauba Formation, Sandstone and Fanglomerate Members (Qp/Qpfs, Qpf/Qpff) ..................... 18

6.1.5 Igneous and Metamorphic Rocks (Kt, KJm) ....................................................................................... 19

6.2 Paleontological Record Search Results ...................................................................................................... 19

7.0 Field Survey ............................................................................................................................. 22

8.0 Conclusions and Recommendations ....................................................................................... 26

9.0 References ............................................................................................................................... 27 Appendix A. Museum Records Search Results ................................................................................... 29

TABLES
Table 1. Diaz Road Expansion Project Summary ....................................................................................................... 10 Table 2. Potential Fossil Yield Classification (BLM, 2016) ........................................................................................ 15

FIGURES
Figure 1. Project location map. ........................................................................................................................................ 7 Figure 2a. Project overview map 1 of 2. ........................................................................................................................ 8 Figure 2b. Project overview map 2 of 2. ........................................................................................................................ 9 Figure 3a. Project overview map 1 of 2. ...................................................................................................................... 20 Figure 3b. Project geologic map 2 of 2. ....................................................................................................................... 21 Figure 4. Overview of the survey area along the northeastern end of Diaz Road, showing access road and current ground disturbances. View facing to the southeast. ............................................................................. 23

HELIX ENVIRONMENTAL PLANNING, INC.

DIAZ ROAD EXPANSION PROJECT
PSI REPORT NO.: CA20RIVERSIDEHEL03R

4 Figure 5. Overview of the survey area overlooking the river channel along the riverbank opposite of Avenida Alvarado. View facing to the southwest. .............................................................................................................. 23 Figure 6. Overview of the survey area along the southwestern side of Diaz Road, showing low relief on the paved road. View facing to the northwest............................................................................................................ 24 Figure 7. Overview of the survey area along the northeastern side of Diaz Road, exposing a fill slope with vegetation. View facing to the southwest. ............................................................................................................ 24 Figure 8. Earthen channel bank slope exposing pockets of Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva), consisting primarily of sands. View facing to the north. .......................................... 25 Figure 9. Weathered Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva) as seen at and near the surface along the southwestern end Diaz Road, along the river channel bank. View facing down. ...................................................................................................................................................................................... 25

HELIX ENVIRONMENTAL PLANNING, INC.

DIAZ ROAD EXPANSION PROJECT
PSI REPORT NO.: CA20RIVERSIDEHEL03R

5 1.0 EXECUTIVE SUMMARY
This report presents the results of the paleontological technical study conducted by Paleo Solutions, Inc. (Paleo Solutions), under contract to HELIX Environmental Planning, Inc. (HELIX), in support of the Diaz Road Expansion Project (Project) in the City of Temecula, Riverside County, California. This work was required by the City of Temecula to fulfill their responsibilities as the lead agency under the California Environmental Quality Act (CEQA).

The paleontological potential of the Project area was evaluated based on an analysis of existin g paleontological data and a field survey. The three components of the analysis of existing data included a geologic map review, a literature search, and a museum records search at the Western Science Center (WSC) in Hemet, California. The analysis of existing data was supplemented with a pedestrian field survey.

Geologic mapping by Kennedy et al. (2003) and Tan et al. (2000) indicates that the Project area is underlain by Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) and Pleistocene-age older alluvial flood plain deposits (Qoa). Geologic units present within a half mile buffer of the Project area may also be impacted at depth by ground-disturbing activities. These units are therefore included in this analysis and consist of Holocene-age active alluvial flood plain deposits (Qa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), Holocene- and late Pleistocene-age young alluvial fan deposits (Qyfa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyag), Pleistocene-age Pauba Formation, Sandstone Member (Qp, Qpfs), Pleistocene-age Pauba Formation, Fanglomerate Member (Qpf, Qpff), Cretaceous-age tonalite undivided (Kt), and Cretaceous- and Jurassic-age metavolcanics and metasedimentary rocks (KJm). Although not mapped by Tan et al. (2000) and Kennedy et al (2003), recent artificial fill may be present within the bounds of the Project area. Thus, this unit is also included in the analysis of existing data for this Project.

The field survey was only able to confirm the presence of sediments interpreted as Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) due to vegetation and previous ground disturbances, such as the paved road and earthen drainage channel. However, the geologic units mapped by Kennedy et al. (2003) and Tan et al. (2000) are likely present at shallow depth within the bounds of the Project area. There are no documented paleontological localities with in the boundaries of the Project area; however, fossils have been recovered from older sedimentary deposits in the vicinity of the Project area (Radford, 2020; Appendix A).

Prior to construction, a paleontological resource impact mitigation program (PRIMP) should be prepared. It should provide detailed recommended monitoring locations; a description of a paleontological resources worker environmental awareness program to inform construction personnel of the potential for fossil discoveries and of the types of fossils that may be encountered; detailed procedures for monitoring, fossil recovery, laboratory analysis, and museum curation; and notification procedures in the event of a fossil discovery by a paleontological monitor or other project personnel. In the event that paleontological resources are discovered during the construction phase of the Project, a curation agreement from the WSC, or another accredited repository, will be obtained.

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6 2.0 INTRODUCTION
This report presents the results of the paleontological technical study conducted by Paleo Solutions , under contract to HELIX, in support of the Diaz Road Expansion Project in the City of Temecula, Riverside County, California. (Figure 1). All paleontological work was completed in compliance with CEQA, local regulations, and best practices in mitigation paleontology (Murphey et al., 2019).

2.1 PROJECT DESCRIPTION AND LOCATION
The Project area is situated along Diaz Road in the City of Temecula between its intersection with Cherry Street in the northwest and its intersection with Rancho California Road in the south. It encompasses approximately 2.2 miles and is located in an unsectioned area of Townships 8 and 7 South and Range 3 West and is mapped on the United States Geologic Survey (USGS) Temecula (1975) and Murrieta (1976) 7.5’ topographic quadrangles (Figure 2, Table 1).

The Project consists of widening the existing Diaz Road segment and extending the northwestern end of Cherry Street to meet the standard of a 76 feet wide roadway with a 14-foot raised median, and 12-foot parkways on each side of the road. This Project would complete the City’s only north-south corridor west of Murrieta Creek.

Geologic mapping by Kennedy et al. (2003) and Tan et al. (2000) indicates that the Project area is underlain by Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) and Pleistocene-age older alluvial flood plain deposits (Qoa). Geologic units present within a half mile buffer of the Project area may also be impacted at depth by ground-disturbing activities. These units are therefore included in this analysis and consist of late Holocene-age active alluvial flood plain deposits (Qa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), Holocene- and late Pleistocene-age young alluvial fan deposits (Qyfa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyag), Pleistocene-age Pauba Formation, Sandstone Member (Qp, Qpfs), Pleistocene-age Pauba Formation, Fanglomerate Member (Qpf, Qpff), Cretaceous-age tonalite undivided (Kt), and Cretaceous- and Jurassic-age metavolcanics and metasedimentary rocks (KJm). Although not mapped by Kennedy et al. (2003) and Tan et al. (2000), recent artificial fill may be present within the bounds of the Project area and is also included in this assessment.

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7 Figure 1. Project location map.

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8 Figure 2a. Project overview map 1 of 2.

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9 Figure 3b. Project overview map 2 of 2.

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Table 1. Diaz Road Expansion Project Summary
Project Name Diaz Road Expansion Project
Project Description
The Project consists of widening the existing Diaz Road segment and extending the northwestern end of Cherry Street to meet the standard of a 76 feet wide roadway with a 14- foot raised median, and 12-foot parkways on each side of the road. This Project would complete the City’s only north-south corridor west of Murrieta Creek.

Project Area
The Project area is situated along Diaz Road in the City of Temecula between its intersection with Cherry Street in the northwest and its intersection with Rancho California Road in the south.

Total Miles 2.2
Location (PLSS)
Quarter-Quarter Section Township Range
N/A - Unsectioned N/A 7S 3W 8S
Land Owner Undetermined
Topographic Map(s) Temecula (1975) and Murrieta (1976) 7.5’ Topographic Quadrangles Geologic Map(s)
Kennedy, M.P., Morton, D.M., Alvarez, R.M., and Morton, G., 2003, Preliminary Geologic Map of the Murrieta 7.5’ Quadrangle, Riverside County, California: U.S. Geological Survey; Open-File Report OF-2003-189, scale 1:24,000.

Tan, S.S., Kennedy, M.P., Nelson, B., and Patt, G., 2000, Geologic Map of the Temecula 7.5’ Quadrangle, San Diego and Riverside Counties, California: A Digital Database: California Geological Survey, Preliminary Geologic Maps; scale 1:24,000.

Mapped Geologic
Unit(s) and age(s)
Geologic Unit Map Symbol Age Paleontological
Potential (PFYC)
Artificial fill N/A – Not Mapped Recent 2 (Low)
Active alluvial flood
plain deposits Qa late Holocene 2 (Low)
Young alluvial channel
deposits Qyaa Holocene to late
Pleistocene 2 (Low)
Young alluvial fan
deposits Qyfa Holocene to late
Pleistocene 2 (Low)
Young alluvial valley
deposits Qyva Holocene to late
Pleistocene 2 (Low)
Young alluvial channel
deposits Qyag Holocene to late
Pleistocene 2 (Low)
Older alluvial flood
plain deposits Qoa Pleistocene 3 (Moderate)
Pauba Formation,
Sandstone Member Qp/Qpfs Pleistocene 4 (High)
Pauba Formation,
Fanglomerate Member Qpf/Qpff Pleistocene 4 (High)
Tonalite undivided Kt Cretaceous 1 (Very Low)
Metavolcanic and
metasedimentary rocks KJm Cretaceous and Jurassic 1 (Very Low) Surveyor(s) Daniel Nolan, B.S.

Date(s) Surveyed May 15, 2020
Geologic Units
Surveyed
Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) and areas mapped as Pleistocene-age older alluvial flood plain deposits (Qoa) Previously
Documented Fossil
According to the WSC, there are no previously recorded fossil localities within the Project area. However, numerous fossil localities have been recorded from within one mile of the Project area from older sedimentary deposits and include specimens of fossil mammoth

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11 Localities within the
Project area
(Mammuthus columbi), ground sloth (Paramylodon sp.), bison (Bison sp.), and horse (Equus sp.) (Radford, 2020).

Paleontological
Results
No paleontological resources were discovered during the survey. Therefore, no fossils were collected.

Disposition of
Fossils Not applicable; no fossils observed or collected during survey.

Recommendation(s)
Prior to construction, a PRIMP should be prepared. It should provide detailed recommended monitoring locations; a description of a paleontological resources worker environmental awareness program to inform construction personnel of the potential for fossil discoveries and of the types of fossils that may be encountered; detailed procedures for monitoring, fossil recovery, laboratory analysis, and museum curation; and notification procedures in the event of a fossil discovery by a paleontological monitor or other project personnel. In the event that paleontological resources are discovered during the construction phase of the Project, a curation agreement from the WSC, or another accredited repository, will be obtained.

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12 3.0 DEFINITION AND SIGNIFICANCE OF

PALEONTOLOGICAL RESOURCES
As defined by Murphey and Daitch (2007): “Paleontology is a multidisciplinary science that combines elements of geology, biology, chemistry, and physics in an effort to understand the history of life on earth. Paleontological resources, or fossils, are the remains, imprints, or traces of once-living organisms preserved in rocks and sediments. These include mineralized, partially mineralized, or unmineralized bones and teeth, soft tissues, shells, wood, leaf impressions, footprints, burrows, and microscopic remains. Paleontological resources include not only fossils themselves, but also the associated rocks or organic matter and the physical characteristics of the fossils’ associated sedimentary matrix.

The fossil record is the only evidence that life on earth has existed for more than 3.6 billion years.

Fossils are considered non-renewable resources because the organisms they represent no longer exist.

Thus, once destroyed, a fossil can never be replaced. Fossils are important scientific and educational resources because they are used to:

• Study the phylogenetic relationships amongst extinct organisms, as well as their relationships to modern groups;

• Elucidate the taphonomic, behavioral, temporal, and diagenetic pathways responsible for fossil preservation, including the biases inherent in the fossil record;

• Reconstruct ancient environments, climate change, and paleoecological relationships;

• Provide a measure of relative geologic dating that forms the basis for biochronology and biostratigraphy, and which is an independent and corroborating line of evidence for isotopic dating;

• Study the geographic distribution of organisms and tectonic movements of land masses and ocean basins through time;

• Study patterns and processes of evolution, extinction, and speciation; and

• Identify past and potential future human-caused effects to global environments and climates.”

Fossil resources vary widely in their relative abundance and distribution and not all are regarded as significant. According to Bureau of Land Management (BLM) Instructional Memorandum (IM) 2009-011, a “Significant Paleontological Resource” is defined as:

“Any paleontological resource that is considered to be of scientific interest, including most vertebrate fossil remains and traces, and certain rare or unusual in vertebrate and plant fossils.

A significant paleontological resource is considered to be of scientific interest if it is a rare or previously unknown species, it is of high quality and well -preserved, it preserves a previously unknown anatomical or other characteristic, provides new information about the history of life on earth, or has an identified educational or recreational value. Paleontological resources that may be considered not to have scientific significance include those that lack provenience or context, lack physical integrity due to decay or natural erosion, or that are overly redundant or are otherwise not useful for research. Vertebrate fossil remains and traces

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13 include bone, scales, scutes, skin impressions, burrows, tracks, tail drag marks , vertebrate coprolites (feces), gastroliths (stomach stones), or other physical evidence of past vertebrate life or activities” (BLM, 2008).

Vertebrate fossils, whether preserved remains or track ways, are classified as significant by most state and federal agencies and professional groups (and are specifically protected under the California Public Resources Code). In some cases, fossils of plants or invertebrate animals are also considered significant and can provide important information about anci ent local environments.

The full significance of fossil specimens or fossil assemblages cannot be accurately predicted before they are collected, and in many cases, before they are prepared in the laboratory and compared with previously collected fossils. Pre-construction assessment of significance associated with an area or formation must be made based on previous finds, characteristics of the sediments, and other methods that can be used to determine paleoenvironmental and taphonomic conditions.

4.0 LAWS, ORDINANCES, REGULATIONS, AND

STANDARDS
This section of the report presents the regulatory requirements pertaining to paleontological resources that apply to this Project.

4.1 STATE REGULATORY SETTING

4.1.1 California Environmental Quality Act (CEQA)
The procedures, types of activities, persons, and public agencies required to comply with the CEQA are defined in the Guidelines for Implementation of CEQA (State CEQA Guidelines), as amended on March 18, 2010 (Title 14, Section 15000 et seq. of the California Code of Regulations) and further amended January 4, 2013 and December 28, 2018. One of the questions listed in the CEQA Environmental Checklist is: “Would the project directly or indirectly destroy a unique paleontological resource or site or unique geologic feature?” (State CEQA Guidelines Appendix G, Section VII, Part F).

4.1.2 State of California Public Resources Code
The State of California Public Resources Code (Chapter 1.7), Sections 5097 and 30244, includes additional state level requirements for the assessment and management of paleontological resources.

These statutes require reasonable mitigation of adverse impacts to paleontological resources resulting from development on state lands, and define the excavation, destructio n, or removal of paleontological “sites” or “features” from public lands without the express permission of the jurisdictional agency as a misdemeanor. As used in Section 5097, “state lands” refers to lands owned by, or under the jurisdiction of, the state or any state agency. “Public lands” is defined as lands owned by, or under the jurisdiction of, the state, or any city, county, district, authority, or public corporation, or any agency thereof.

4.2 LOCAL REGULATORY SETTING

4.2.1 Riverside County
The Riverside County General Plan requires consideration of paleontological resources under the Multipurpose Open Space Element of the general plan (County of Riverside, 2015). The Riverside

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14 County General Plan recommendations are based on the Society of Verteb rate Paleontology (SVP) Guidelines (SVP, 2010) for the mitigation of paleontological resources. The Multipurpose Open Space Element of the general plan (County of Riverside, 2015) provides the following requirements for paleontological sensitive areas within the county:

• OS 19.6 Whenever existing information indicates that a site proposed for development has high paleontological sensitivity as shown on Figure OS-8 [of the County of Riverside General Plan Multipurpose Open Space Element, 2015] , a paleontological resource impact mitigation program (PRIMP) shall be filed with the County Geologist prior to site grading.

The PRIMP shall specify the steps to be taken to mitigate impacts to paleontological resources.

• OS 19.7 Whenever existing information indicates that a site proposed for development has low paleontological sensitivity as shown on Figure OS-8, no direct mitigation is required unless a fossil is encountered during site development. Should a fossil be encountered, the County Geologist shall be notified and a paleontologist shall be retained by the project proponent. The paleontologist shall document the extent and potential significance of the paleontological resources on the site and establish appropriate mitigation measures for further site development.

• OS 19.8 Whenever existing information indicates that a site proposed for development has undetermined paleontological sensitivity as shown on Figure OS-8, a report shall be filed with the County Geologist documenting the extent and potenti al significance of the paleontological resources on site and identifying mitigation measures for the fossil and for impacts to significant paleontological resources prior to approval of that department.

• OS 19.9 Whenever paleontological resources are found, the County Geologist shall direct them to a facility within Riverside County for their curation, including the Western Science Center in the City of Hemet.

4.2.2 City of Temecula
The Open Space/Conservation Element of the City of Temecula General Plan (City of Temecula, 2005) contains one goal and two policies regarding paleontological resources. Goal 6 states that significant historical and cultural resources shall be preserved as a record of Temecula’s heritage.

Policies 6.1 and 6.5 require that the City:

• Maintain an inventory of areas with archaeological/pal eontological sensitivity, and historic sites.

• Work to preserve or salvage potential archaeological and paleontological resources.

5.0 METHODS
This paleontological analysis of existing data included a geologic map review, a literature search, and museum records search. The analysis of existing data was supplemented with a pedestrian field survey. The goal of this report is to evaluate the paleontological potential of the Project area and make recommendations for the mitigation of adverse impacts on paleon tological resources that may occur as a result of the proposed Project. Betsy Kruk, M.S., performed the background research and authored this report. Daniel Nolan, B.S., conducted the field survey. Elisa Barrios, B.S., created the GIS figures. Courtney Richards, M.S., oversaw all aspects of the Project as the Paleontological Principal Investigator.

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15 Paleo Solutions will retain an archival copy of all Project information including field notes , maps, and other data.

5.1 ANALYSIS OF EXISTING DATA
Paleo Solutions reviewed geologic mapping of the Project area by Kennedy et al. (2003) and Tan et al. (2000). The literature reviewed included published and unpublished scientific papers.

Paleontological museum records search results from the WSC were analyzed and incorporated into this paleontological investigation.

5.2 FIELD SURVEY
The field survey was conducted by Paleo Solutions’ paleontologist Daniel Nolan, B.S. The paleontological survey was conducted to check for any exposures of native, previously undisturbed rock or sediments of the underlying geologic units, and if present, assess the potential for fossils.

The Project area and surrounding areas were documented and photographed, with photographed areas spatially referenced with a GPS unit.

5.3 CRITERIA FOR EVALUATING PALEONTOLOGICAL POTENTIAL
The Potential Fossil Yield Classificatio n (PFYC) system was developed by the BLM (BLM, 2016).

Because of its demonstrated usefulness as a resource management tool, the PFYC has been utilized for many years for projects across the country, regardless of land ownership. It is a predictive resource management tool that classifies geologic units on their likelihood to contain paleontological resources on a scale of 1 (very low potential) to 5 (very high potential). This system is intended to aid in predicting, assessing, and mitigating paleontological resources. The PFYC ranking system is summarized in Table 2.

Table 2. Potential Fossil Yield Classification (BLM, 2016)

BLM PFYC
Designation
Assignment Criteria Guidelines and Management Summary (PFYC System)
1 = Very Low
Potential
Geologic units are not likely to contain recognizable paleontological resources.

Units are igneous or metamorphic, excluding air-fall and reworked volcanic ash units.

Units are Precambrian in age.

Management concern is usually negligible, and impact mitigation is unnecessary except in rare or isolated circumstances.
2 = Low Potential
Geologic units are not likely to contain paleontological resources.

Field surveys have verified that significant paleontological resources are not present or are very rare.

Units are generally younger than 10,000 years before present.

Recent eolian deposits.

Sediments exhibit significant physical and chemical changes (i.e., diagenetic alteration) that make fossil preservation unlikely.

Management concern is generally low, and impact mitigation is usually unnecessary except in occasional or isolated circumstances. 3 = Moderate
Potential
Sedimentary geologic units where fossil content varies in significance, abundance, and predictable occurrence.

Marine in origin with sporadic known occurrences of paleontological resources.

Paleontological resources may occur intermittently, but these occurrences are widely scattered.

The potential for authorized land use to impact a significant paleontological resource is known to be low-to-moderate.

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16 BLM PFYC
Designation
Assignment Criteria Guidelines and Management Summary (PFYC System)
Management concerns are moderate. Management options could include record searches, pre-disturbance surveys, monitoring, mitigation, or avoidance.

Opportunities may exist for hobby collecting. Surface-disturbing activities may require sufficient assessment to determine whether significant paleontological resources occur in the area of a proposed action and whether the action could affect the paleontological resources.
4 = High Potential
Geologic units that are known to contain a high occurrence of paleontological resources.

Significant paleontological resources have been documented but may vary in occurrence and predictability.

Surface-disturbing activities may adversely affect paleontological resources.

Rare or uncommon fossils, including nonvertebrate (such as soft body preservation) or unusual plant fossils, may be present.

Illegal collecting activities may impact some areas.

Management concern is moderate to high depending on the proposed action. A field survey by a qualified paleontologist is often needed to assess local conditions. On-site monitoring or spot-checking may be necessary during land disturbing activities. Avoidance of known paleontological resources may be necessary.
5 = Very High
Potential
Highly fossiliferous geologic units that consistently and predictably produce significant paleontological resources.

Significant paleontological resources have been documented and occur consistently.

Paleontological resources are highly susceptible to adverse impacts from surface disturbing activities.

Unit is frequently the focus of illegal collecting activities.

Management concern is high to very high. A field survey by a qualified paleontologist is almost always needed and on-site monitoring may be necessary during land use activities. Avoidance or resource preservation through controlled access, designation of areas of avoidance, or special management designations should be considered.

U = Unknown
Potential
Geologic units that cannot receive an informed PFYC assignment Geological units may exhibit features or preservational conditions that suggest significant paleontological resources could be present, but little information about the actual paleontological resources of the unit or area is unknown.

Geologic units represented on a map are based on lithologic character or basis of origin, but have not been studied in detail.

Scientific literature does not exist or does not reveal the nature of paleontological resources.

Reports of paleontological resources are anecdotal or have not been verified.

Area or geologic unit is poorly or under-studied.

BLM staff has not yet been able to assess the nature of the geologic unit.

Until a provisional assignment is made, geologic units with unknown potential have medium to high management concerns. Field surveys are normally necessary, especially prior to authorizing a ground-disturbing activity.

6.0 ANALYSIS OF EXISTING DATA
The Project area is located within the northwestern portion of the Peninsular Ranges Geomorphic Province, a region characterized by northwest-trending fault-bounded mountain ranges, broad intervening valleys, and low-lying coastal plains (Yerkes et al., 1965). The Peninsular Ranges extend approximately 920 miles from the Los Angeles Basin to the southern tip of Baja California and vary

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17 in width from approximately 30 to 100 miles. Bedrock units within the Peninsular Ranges include pre-Cretaceous- and Cretaceous-age igneous rocks of the Southern California Batholith, Late Cretaceous-age sedimentary rocks, and post-Cretaceous-age sedimentary rocks or sediment (Yerkes et al., 1965; Norris and Webb, 1976). All post-Cretaceous-age rocks lie unconformably on either the Cretaceous-age sedimentary rocks or on basement rocks (Norris and Webb, 1976). Pliocene-age nonmarine rocks and sediments and thick and widespread throughout the northern Peninsular Ranges, and Quaternary deposits include fluvial and lacustrine sediments within the inland interior of the province (Norris and Webb, 1976).

6.1 LITERATURE SEARCH
Geologic mapping by Kennedy et al. (2003) and Tan et al. (2000) indicates that the Project area is underlain by Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) and Pleistocene-age older alluvial flood plain deposits (Qoa). Within a half mile of the Project area, Holocene-age active alluvial flood plain deposi ts (Qa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), Holocene- and late Pleistocene-age young alluvial fan deposits (Qyfa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyag), Pleistocene-age Pauba Formation, Sandstone Member (Qp, Qpfs), Pleistocene-age Pauba Formation, Fanglomerate Member (Qpf, Qpff), Cretaceous-age tonalite undivided (Kt), and Cretaceous- and Jurassic-age metavolcanics and metasedimentary rocks (KJm) are also present and may underlie the geologic units mapped at the surface within the Project area at shallow depth (Figure 3). Although not mapped by Kennedy et al. (2003) and Tan et al. (2000), recent artificial fill may be present within the bounds of the Project area. Thus, these units are also included in the analysis of existing data for this Project.

6.1.1 Artificial Fill (Unmapped)
Although Kennedy et al. (2003) and Tan et al. (2000) do not map fill within the Project area or its immediately vicinity, recent artificial fill may be present within the bounds of the Project area, particularly underlying built structures or areas, such as underlying the asphalt and gravel in the Right-Of-Way (ROW). These sediments consist of previously disturbed, reworked sediments and any fossils recovered from artificial fill have lost their stratigraphic and scientific significance.

Therefore, artificial fill has a low paleontological potential (PFYC 2).

6.1.2 Younger Sedimentary Deposits (Qa, Qyaa, Qyfa, Qyva, Qyag) Late Holocene-age active alluvial flood plain deposits (Qa); and Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), young alluvial fan deposits (Qyfa), young alluvial valley deposits (Qyva), and yo ung alluvial channel deposits (Qyag) were formed during the Holocene (approximately 11,700 years ago to present) and late Pleistocene (11,700 years ago to 129,000 years ago). Younger deposits are undissected, unconsolidated, and composed of clay, silt, sa nd, and gravel (Kennedy et al., 2003; Tan et al., 2000). Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) directly underlies the majority of the Project area, while late Holocene-age active alluvial flood plain deposits (Qa); and Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), young alluvial fan deposits (Qyfa), and young alluvial channel deposits (Qyag) are mapped at the margins of the Project area

Holocene-age (less than 11,700 years old) sediments are typically too young to contain fossilized material (SVP, 2010), but they transition to, and may overlie sensitive older (e.g., Pleistocene- and Pliocene-age) deposits at variable depth. These deposits (Qa, Qyaa, Qyfa, Qyva, Qyag) are assigned low paleontological potential (PFYC 2) at the surface using BLM (2016) guidelines. However, they have an unknown paleontological potential in the subsurface since there is potential for these deposits to be conformably underlain by older, paleontologically sensitive geologic un its.

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18 It should be noted that while Kennedy et al. (2003) map the sediment underlying the Project area as Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) (PFYC 2), Tan et al. (2000) map the same sediments as Pleistocene-age older alluvial flood plain deposits (Qoa) (PFYC 3).

6.1.3 Older Alluvial Flood Plain Deposits (Qoa)
Pleistocene-age older alluvial flood plain deposits (Qoa) are mapped at the southern portion of the Project area (Tan et al., 2000; Figure 3). These deposits consist of moderately well consolidated, poorly sorted sand derived from flood plain deposits (Tan et al., 2000).

Taxonomically diverse and locally abundant Pleistocene-age fossil animals and plants have been collected from older alluvial deposits throughout southern California and include mammoth (Mammuthus), mastodon (Mammut), camel (Camelidae), horse (Equidae), bison (Bison), giant ground sloth (Megatherium), peccary (Tayassuidae), cheetah (Acinonyx), lion (Panthera), saber tooth cat (Smilodon), capybara (Hydrochoerus), dire wolf (Canis dirus), and numerous taxa of smaller mammals (e.g., Rodentia) (Blake, 1991; Jahns, 1954; Jefferson, 1991). According to the Paleobiology Database (PBDB), numerous Pleistocene-age fossil localities have been recorded within Riverside County, including those from the Diamond Valley Lake east and west dams, which yielded a new specie s of mastodon (Mammut pacificus), Columbian mammoth (Mammuthus columbi), fox (Urocyon sp.), rabbit (Sylvilagus sp.), mole (Scapanus sp.), rodent (Dipodomys sp., Thomomys sp., Neotoma sp., Microtus sp.), quail (Callipepla sp.), and snake (Colubridae) (Dooley et al., 2019; PBDB, 2020). The University of California Museum of Paleontology (UCMP) online fossil locality da tabase also contains numerous records of Pleistocene-age fossils in Riverside County, including horse (Equus sp., Equus bautistensis, Hipparionini), tapir (Tapirus merriami), pronghorn (Capromeryx sp., Antilocapra sp.), deer (Odocoileus), giant ground sloth (Megalonyx), mammoth (Mammuthus sp.), rabbit (Lepus sp.), rodent (Microtus sp., Microtus californicus, Neotoma sp.), and tortoise (Gopherus sp., Gopherus agassizii), as well as invertebrates and plants (UCMP, 2020). Therefore, Pleistocene-age older alluvial flood plain deposits (Qoa) are assigned a moderate paleontological potential (PFYC 3).

It should be noted that while Tan et al. (2000) map the sediments within the Project area as Pleistocene-age older alluvial flood plain deposits (Qoa) (PFYC 3), Kennedy et al. (2003) map the same sediments as Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) (PFYC 2).

6.1.4 Pauba Formation, Sandstone and Fanglomerate Members (Qp/Qpfs, Qpf/Qpff)
Pleistocene-age Pauba Formation is divided into two informal members: a sandstone member (Qp/Qpfs) and a fanglomerate member (Qpf/Qpff) (Kennedy et al., 2003; Tan et al., 2000; Figure 3). Pl eistocene-age Pauba Formation, Sandstone Member (Qp/Qpfs) and Fanglomerate Member (Qpf/Qpff) are mapped along the margins of the Project area and are likely present at unknown depth below younger sedimentary deposits. The Sandstone Member (Qp/Qpfs) is composed of light brown, moderately-well indurated and cross-bedded sandstone containing sparse cobble to boulder conglomerate beds (Kennedy et al., 2003; Tan et al., 2000). The Fanglomerate Member (Qpf/Qpff) is composed of grayish-brown, well indurated, poorly sorted fanglomerate, breccia, and mudstone (Kennedy et al., 2003; Tan et al., 2000).

Pleistocene-age Pauba Formation contains an extensive variety of late Irvingtonian and early Rancholabrean fossils that are primarily mammals (Kennedy et al., 2003; Morton and Miller, 2006; Pajak et al., 1996). The UCMP (2020) online database does not contain records for the Pauba Formation; however, the PBDB (2020) does contain numerous records of fossil localities from the

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19 Pauba Formation of Riverside County. These fossil localities have yielded pronghorn (Antilocapridae, Capromeryx sp.), deer (Odocoileus sp.), sheep (Ovis canadensis), camel (Camelops sp., Camelops hesternus, Hemiauchenia sp., Hemiauchenia macrocephala), tapir (Tapirus californicus), horse (Equus sp., Equus scotti), mammoth (Mammuthus sp., Mammuthus columbi), mastodon (Mammut americanum), ground sloth (Paramylodon sp., Paramylodon harlani), saber tooth cat (Smilodon fatalis), coyote (Canis latrans), bat (Chiroptera), rabbit (Leporidae, Lepus sp., Sylvilagus sp.), mustelid (Mustela sp.), shrew (Sorex sp.), rodent (Cricetidae, Dipodomys sp., Microtus sp., Microtus californicus, Neotoma sp., Perognathinae, Peromyscus sp., Sciuridae, Thomomys sp., Thomomys bottae), and mole (Scapanus sp.) (PBDB, 2020). Therefore, Pleistocene-age Pauba Formation, Sandstone Member (Qp/Qpfs) and Fanglomerate Member (Qpf/Qpff) have a high paleontological potential (PFYC 4).

6.1.5 Igneous and Metamorphic Rocks (Kt, KJm)
On the southern end of the Project area, Cretaceous-age tonalite, undivided (Kt) and Cretaceous- and Jurassic-age metavolcanic and metasedimentary rocks (KJm) are mapped by Tan et al. (2000).

Cretaceous-age tonalite, undivided (Kt) consists of light gray, coarse-grained hornblende-biotite tonalite, which is a plutonic igneous rock. Cretaceous- and Jurassic-age metavolcanic and metasedimentary rocks (KJm) consist of low grade, greenschist facies and are metamorphic rocks.

Igneous rocks are crystalline or non-crystalline rocks that form through the cooling and subsequent solidification of magma or lava, while metamorphic rocks are preexisting rocks that transform from to intense heat or pressure. Both intrusive (plutonic) igneous rocks and metamorphic rocks fo rm below the earth’s surface due to increases in temperature, changes in pressure, or changes in geochemical composition. Extreme temperatures and pressures in the environments in which igneous and metamorphic rocks form generally prevent the preservation of fossils. Therefore, Cretaceous-age tonalite, undivided (Kt) and Cretaceous- and Jurassic-age metavolcanic and metasedimentary rocks (KJm) have a very low potential to produce scientifically important paleontological resources (PFYC 1).

6.2 PALEONTOLOGICAL RECORD SEARCH RESULTS
According to the WSC, there are no previously recorded fossil localities within the Project area.

However, numerous fossil localities have been recorded from within one mile of the Project area from older sedimentary deposits. These fossil localities are associated with the Principe Salvage Collection, the Harveston I and II Projects, the Gafcon Project, and the Rancho California Water District Project. These localities produced fossil mammoth (Mammuthus columbi), ground sloth (Paramylodon sp.), bison (Bison sp.), and horse (Equus sp.) (Radford, 2020).

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20 Figure 3a. Project overview map 1 of 2.

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21 Figure 3b. Project geologic map 2 of 2.

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22 7.0 FIELD SURVEY
Paleo Solutions’ paleontologist, Daniel Nolan, B.S., surveyed the Project area on Friday, May 15, 2020. The survey consisted of a pedestrian reconnaissance of the Project area, safely inspecting the roadside and overall ROW for exposures of the geologic u nits mapped by Kennedy et al. (2003) and Tan et al. (2000). The Project area is situated along Diaz Road in the City of Temecula between its intersection with Cherry Street in the northwest and its intersection with Rancho California Road in the south. The Project area consists of paved and unpaved roads, which have low to flat topographic relief (Figures 4 and 6). A drainage channel runs parallel to Diaz Road with slopes on either side dipping moderately toward the channel b ase (Figures 5 and 8). Previous disturbances within the Project area include grading and associated spoils piles, paved asphalt, cement curbs, and an earthen drainage channel (Figures 4 and 7).

Sediments observed included previously disturbed sediments and sediments mapped as Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva). Previously disturbed sediments were observed along the northeastern section of the Project area; however, the majority of the Project area is paved asphalt. Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva), when not obscured by vegetation, was observed in the sidewalls and bases of the earthen drainage channel.

Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva) consist of pale yellowish- brown to buff yellowish-brown, moderately sorted, poorly to moderately compacted, medium- to coarse-grained sand (Figure 9).

No paleontological resources were observed or collected during the paleontological survey.

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23 Figure 4. Overview of the survey area along the northeastern end of Diaz Road, showing access road and current ground disturbances. View facing to the southeast.

Figure 5. Overview of the survey area overlooking the river channel along the riverbank opposite of Avenida Alvarado. View facing to the southwest.

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24 Figure 6. Overview of the survey area along the southwestern side of Diaz Road, showing low relief on the paved road. View facing to the northwest.

Figure 7. Overview of the survey area along the northeastern side of Diaz Road, exposing a fill slope with vegetation. View facing to the southwest.

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25 Figure 8. Earthen channel bank slope exposing pockets of Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva), consisting primarily of sands. View facing to the north.

Figure 9. Weathered Holocene- to late Pleistocene-age young alluvial valley deposits (Qyva) as seen at and near the surface along the southwestern end Diaz Road, along the river channel bank. View facing down.

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26 8.0 CONCLUSIONS AND RECOMMENDATIONS
Due to conflicting information regarding the age of the sediments within the Project area and the limited exposures of native sediment observed during the survey, it is recommended that construction excavations in areas mapped as Holocene- and late Pleistocene-age young alluvial valley deposits (Qyva) and Pleistocene-age older alluvial flood plain deposits (Qoa) be initially spot-checked to better assess the age of the sediments and the subsurface conditions. If the sediments are determined to be entirely Holocene in age, spot-checking should be reduced in consultation with the City of Temecula. If sediments are determined to be Pleistocene in age, full-time monitoring should be implemented. If encountered in the subsurface, Pleistocene-age Pauba Formation, Sandstone Member (Qp/Qpfs) and Fanglomerate Member (Qpf/Qpff) should be monitored on a full-time basis by a professional paleontologist in order to reduce potential adverse impacts to scientifically important paleontological resources to a less than significant level. Additionally, if artificial fill, Holocene-age active alluvial flood plain deposits (Qa), Holocene- and late Pleistocene-age young alluvial channel deposits (Qyaa), Holocene- and late Pleistocene-age young alluvial fan deposits (Qyfa), or Holocene- and late Pleistocene-age young alluvial channel deposits (Qyag) are encountered, they should be initially spot-checked to determine if older, more paleontologically sensitive deposits are disturbed at depth . Lastly, Cretaceous-age tonalite, undivided (Kt) and Cretaceous- and Jurassic-age metavolcanic and metasedimentary rocks (KJm) have very low potential for paleontological resources, and thus, do not require paleontological monitoring if encountered in the subsurface of the Project area.

Prior to construction, a PRIMP should be prepared. It should provide detailed recommended monitoring locations; a description of a paleontological resources worker environmental awareness program to inform construction personnel of the potential for fossil discoveries and of the typ es of fossils that may be encountered; detailed procedures for monitoring, fossil recovery, laboratory analysis, and museum curation; and notification procedures in the event of a fossil discovery by a paleontological monitor or other project personnel. In the event that paleontological resources are discovered during the construction phase of the Project, a curation agreement from the WSC, or another accredited repository, will be obtained.

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27 9.0 REFERENCES
Blake, G.H., 1991, Review of the Neogene Biostratigraphy and Stratigraphy of the Los Angeles Basin and Implications for Basin Evolution in Biddle, K.T., ed., Active Margin Basins: American Association of Petroleum Geologists, Memoir 52, Chapter 4, p. 135 -184.

Bureau of Land Management (BLM), 2008, Assessment and Mitigation of Potential Impacts to Paleontological Resources: BLM Instruction Memora ndum, no. 2009-011.

Bureau of Land Management (BLM), 2016, Potential Fossil Yield Classification system: BLM Instruction Memorandum, no. 2016-124 (PFYC revised from USFS, 2008).

City of Temecula, 2005, City of Temecula General Plan: Open Space/Conservation Element.

Available online: https://temeculaca.gov/345/General-Plan

County of Riverside, 2015, Riverside County General Plan: Multipurpose Open Space Element.

Available online: http://planning.rctlma.org/ZoningInformation/GeneralPlan.aspx

Dooley, A.C., Scott, E., Green, J., Springer, K.B., Dooley, B.S., Smith, G.J., 2019, Mammut pacificus sp. nov., a newly recognized species of mastodon from the Pleistocene of western North America. PeerJ 7:e6614 https://doi.org/10.7717/peerj.6614

Jahns, R.H., 1954, Geology of Southern California. State of California, Department of Natural Resources, Bulletin 170, Volume 1.

Jefferson, G.T., 1991, A catalogue of late Quaternary vertebrates from California: Part Two, Mammals: Natural History Museum of Los Angeles County Technical Reports, No. 7.

Kennedy, M.P., Morton, D.M., Alvarez, R.M., and Morton, G., 2003, Preliminary Geologic Map of the Murrieta 7.5’ Quadrangle, Riverside County, California: U.S. Geological Survey; Open - File Report OF-2003-189, scale 1:24,000.

Murphey, P.C., and Daitch, D., 2007, Paleontological overview of oil shale and tar sands areas in Colorado, Utah and Wyoming: U.S. Department of Energy, Argonne National Laboratory Report, Prepared for the U.S. Department of Interior Bureau of Land Management, scale 1:500,000, 468 p. and 6 maps.

Murphey, P.C., Knauss, G.E., Fisk, L.H., Deméré, T.A., Reynolds, R.E., 2019, Best Practices in Mitigation Paleontology: Proceedings of the San Diego Society of Natural History, No. 47.

Norris, R.M., and Webb, R.W., 1976, Geology of California, John Wiley & Sons, N.Y.

Pajak, A.F., III, Scott, E., and Bell, C.J., 1996, A review of the biostratigraphy of Pliocene and Pleistocene sediments in the Elsinore Fault Zone, Riverside County, California: PaleoBios, v. 17, no. 2-4, p. 28-49.

Paleobiology Database (PBDB), 2020, Available online: https://paleobiodb.org/

Radford, D., 2020, Western Science Center Museum Records Search for the Diaz Road Expansion Project, dated May 13, 2020.

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28 Society of Vertebrate Paleontologists (SVP), 2010, Standard Procedures for the Assessment and Mitigation of Adverse Impacts to Paleontological Resources, 11 p.

Online: http://vertpaleo.org/PDFS/68/68c554bb-86f1-442f-a0dc-25299762d36c.pdf

Tan, S.S., Kennedy, M.P., Nelson, B., and Patt, G., 2000, Geologic Map of the Temecula 7.5’ Quadrangle, San Diego and Riverside Counties, California: A Digital Database: California Geological Survey, Preliminary Geologic Maps; scale 1:24,000.

University of California Museum of Paleontology (UCMP), 2020, Available online:
https://ucmpdb.berkeley.edu/loc.html

Yerkes, R.F., McCulloh, T.H., Schoellhamer, J.E., and Vedder, J.G., 1965, Geology of the Los Angeles Basin, California: An Introduction: Professional Paper.

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29 APPENDIX A. MUSEUM RECORDS SEARCH

RESULTS

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30 PHASE I ENVIRONMENTAL SITE ASSESSMENT
DIAZ ROAD EXPANSION PROJECT (PW17-25)

BETWEEN RANCHO CALIFORNIA ROAD AND CHERRY STREET
TEMECULA, CALIFORNIA 92590

Prepared For:

DAVID EVANS & ASSOCIATES, INC.
41951 REMINGTON AVENUE, SUITE 220
TEMECULA, CALIFORNIA 92590

Project No. 12502.002

February 11, 2020

February 11, 2020

Project No. 12502.002

David Evans & Associates, Inc.
41951 Remington Avenue, Suite 220
Temecula, California 92590

Attention: Mr. Gavin Powell

Subject: Phase I Environmental Site Assessment
Diaz Road Expansion Project (PW17-25)
Between Rancho California Road and Cherry Street
Temecula, California 92590

Leighton Consulting, Inc. (Leighton) is pleased to present this draft copy of the Phase I Environmental Site Assessment for the Project Site in Temecula, California. Leighton declares that, to the best of our professional knowledge and belief, we meet the definition of Environmental Professional as defined in §312.10 of 40 Code of Federal Regulations (CFR) 312, and the ASTM International E1527-13.

Leighton has the specific qualifications based on education, training, and experience to assess a property of the nature, history, and setting of the subject site. Leighton has developed and performed the all appropriate inquiries in conformance with the standards and practices set forth in 40 CFR Part 312.

If you have questions regarding this report, please contact us. We appreciate the opportunity to be of service to David Evans & Associates, Inc.

Respectfully submitted,
LEIGHTON CONSULTING, INC.

Robert B. Hansen
Associate Env. Geologist

Distribution: Addressee

Phase I Environmental Site Assessment 12502.002
Diaz Road Expansion Project (PW17-25) (Between Rancho California Rd. & Cherry St.) Temecula, CA 92590
February 11, 2020
i

TABLE OF CONTENTS
Section Page

1.0 INTRODUCTION ............................................................................................................ 1

1.1 Authorization .......................................................................................................... 1

1.2 Purpose .................................................................................................................. 1

1.3 Scope of Work ........................................................................................................ 1

1.4 Significant Assumptions ......................................................................................... 2

1.5 Limitations and Exceptions ..................................................................................... 2

1.6 Special Terms and Conditions ................................................................................ 3

1.7 User Reliance......................................................................................................... 3

2.0 PROJECT SITE & ADJOINING PROPERTIES DESCRIPTION ..................................... 4

2.1 Project Site Description .......................................................................................... 4

2.2 Property and Vicinity General Characteristics......................................................... 5

2.3 Current Use of the Project Site ............................................................................... 5

2.4 Descriptions of Structures, Roads and Other Improvements on the Property ......... 5

2.5 Current Uses of Adjoining Properties ..................................................................... 6

3.0 USER PROVIDED INFORMATION ................................................................................ 7

3.1 Environmental Liens or Activity and Use Limitations............................................... 7

3.2 Specialized Knowledge .......................................................................................... 7

3.3 Commonly Known or Reasonably Ascertainable Information ................................. 7

3.4 Valuation Reduction for Environmental Issues ....................................................... 7

3.5 Owner, Property Manager, and Occupant Information ............................................ 7

3.6 Reason for Performing Phase I ESA ...................................................................... 8

3.7 Other ...................................................................................................................... 8

4.0 RECORDS REVIEW ...................................................................................................... 9

4.1 Physical Setting Source(s) ..................................................................................... 9

4.1.1 Topography ............................................................................................... 9

4.1.2 Surface Water ............................................................................................ 9

4.1.3 Geology and Soils ...................................................................................... 9

4.1.4 Hydrogeology .......................................................................................... 10

4.2 Standard Environmental Record Sources ............................................................. 11

4.2.1 Subject Property ...................................................................................... 11

4.2.2 Offsite ...................................................................................................... 11

4.2.3 Local and Regional Regulatory Agency Contacts .................................... 16

4.2.4 Radon ...................................................................................................... 18

4.2.5 Other Reports .......................................................................................... 19

4.2.6 Vapor Encroachment ............................................................................... 19

4.3 Historical Use Information on the Property ............................................................. 20

5.0 SITE RECONNAISSANCE ............................................................................................22

5.1 Methodology and Limiting Conditions ................................................................... 22

5.2 General Property Setting ...................................................................................... 22

Phase I Environmental Site Assessment 12502.002
Diaz Road Expansion Project (PW17-25) (Between Rancho California Rd. & Cherry St.) Temecula, CA 92590
February 11, 2020

ii

5.3 Exterior and Interior Observations ........................................................................ 22

5.3.1 Hazardous Substances, Drums, and Other Chemical Containers ............ 22

5.3.2 Storage Tanks ......................................................................................... 22

5.3.3 Polychlorinated Biphenyls (PCBs)............................................................ 23

5.3.4 Waste Disposal ........................................................................................ 23

5.3.5 Dumping .................................................................................................. 23

5.3.6 Pits, Ponds, Lagoons, Septic Systems, Wastewater, Drains, Cisterns, and Sumps ..................................................................................................... 23

5.3.7 Pesticide Use ........................................................................................... 23

5.3.8 Staining, Discolored Soils, Corrosion ....................................................... 23

5.3.9 Stressed Vegetation ................................................................................ 23

5.3.10 Unusual Odors ......................................................................................... 23

5.3.11 Onsite Wells ............................................................................................ 24

5.3.12 Other ....................................................................................................... 24

5.4 Adjoining Site Reconnaissance .......................................................................... 24

6.0 INTERVIEWS ................................................................................................................25

6.1 Interview with Owner ............................................................................................ 25

6.2 Interview with Property Manager .......................................................................... 25

6.3 Interviews with Occupants .................................................................................... 25

6.4 Interviews with Local Government Officials .......................................................... 25

6.5 Interviews with Others .......................................................................................... 25

7.0 SUMMARY OF FINDINGS ............................................................................................26

7.1 Onsite .................................................................................................................. 26

7.2 Offsite .................................................................................................................. 27

7.3 Data Gaps ............................................................................................................ 29

8.0 OPINION & CONCLUSIONS .........................................................................................30

8.1 Onsite .................................................................................................................. 30

8.2 Offsite .................................................................................................................. 30

9.0 DEVIATIONS .................................................................................................................32

10.0 QUALIFICATIONS OF ENVIRONMENTAL PROFESSIONALS.....................................32

10.1 Corporate ............................................................................................................. 32

10.2 Individual .............................................................................................................. 32

10.3 Environmental Professional Statement ................................................................. 32

Phase I Environmental Site Assessment 12502.002
Diaz Road Expansion Project (PW17-25) (Between Rancho California Rd. & Cherry St.) Temecula, CA 92590
February 11, 2020