HomeMy WebLinkAboutBaker Industrial Project - DBESP AnalysisDetermination of
Biologically Equivalent or Superior Preservation (DBESP)
Analysis
For Impacts to MSHCP Riparian/Riverine Areas and Vernal
Pools, and Narrow Endemic/Criteria Area Plants
Baker Industrial Project
Permittee
City of Lake Elsinore
Applicant
Ecosystem Investment Partners
1505 Bridgeway, Suite 107
Sausalito, California 94965
Contact: Glen Williams
Phone: (415) 465-4423
Consultant
Glenn Lukos Associates, Inc.
1940 E. Deere Avenue, Suite 250
Santa Ana, California 92705
Contact: David Moskovitz
Phone: (949) 340-2562
February 28, 2024
Revised, February 5, 2025
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Contents
1.0 EXECUTIVE SUMMARY ......................................................................................... 3
2.0 INTRODUCTION ...................................................................................................... 3
2.1 Project Area ....................................................................................................... 3
2.2 Project Description ............................................................................................. 4
2.3 Existing Conditions ............................................................................................. 9
3.0 RIPARIAN/RIVERINE MITIGATION (SECTION 6.1.2) .......................................... 10
3.1 Methods ........................................................................................................... 10
3.2 Results/Impacts ................................................................................................ 15
3.3 Mitigation and Equivalency............................................................................... 22
4.0 NARROW ENDEMIC PLANT SPECIES MITIGATION (SECTION 6.1.3) .............. 31
4.1 Methods ........................................................................................................... 31
4.2 Results/Impacts ................................................................................................ 32
4.3 Mitigation and Equivalency............................................................................... 32
5.0 ADDITIONAL SURVEY NEEDS (SECTION 6.3.2) ................................................ 35
5.1 Criteria Area Species Survey Area - Plants ..................................................... 35
5.2 Burrowing Owl .................................................................................................. 38
5.3 Mammals.......................................................................................................... 41
5.4 Amphibians ...................................................................................................... 41
6.0 DELHI SANDS FLOWER-LOVING FLY ................................................................. 41
7.0 REFERENCES....................................................................................................... 41
TABLES
Table 2-1. Summary of Project Components ................................................................. 5
Table 2-2. Summary of Vegetation/Land Use Types for the Project Site ..................... 10
Table 3-1. Summary of Least Bell’s Vireo Surveys ...................................................... 14
Table 3-2. Summary of Southwestern Willow Flycatcher Surveys ............................... 15
Table 3-3. MSHCP Riparian/Riverine Areas at the Project site .................................... 15
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Table 3-4. Impacts to MSHCP Riverine Areas ............................................................. 19
Table 3-5. MSHCP Vernal Pools at the Project Site ..................................................... 20
Table 3-6. Comparison of Existing and Proposed Hydrologic Conditions .................... 29
Table 5-1. Summary of Burrowing Owl Surveys ........................................................... 39
EXHIBITS
Exhibit 1 Regional Map
Exhibit 2 Vicinity Map
Exhibit 3 Project Components Map
Exhibit 4A MSHCP Overlay Map
Exhibit 4B MSHCP Species Survey Area Map
Exhibit 5 Vegetation Map
Exhibit 6 Soils Map
Exhibit 7 MSHCP Riparian/Riverine Areas and Vernal Pools
Exhibit 8 Rare Plants Map
Exhibit 9 Plant Restoration Map
Exhibit 10 Burrowing Owl Survey Map
Exhibit 11 Site Photographs
Exhibit 12 LBV Habitat with LTCV
APPENDICES
Appendix A Conceptual Grading Plan – Baker Industrial Project
Appendix B Report of 2023 Dry Season Fairy Shrimp Surveys [Pending]
Appendix C Report of 2023/2024 Wet Season Fairy Shrimp Surveys [Pending]
Appendix D Report of 2020 Southwestern Willow Flycatcher and Least Bell’s
Vireo Surveys
Appendix E Baker Industrial Hydrology Memorandum
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1.0 EXECUTIVE SUMMARY
This document provides an analysis in support of a Determination of Biologically
Equivalent or Superior Preservation (DBESP) for the Baker Industrial Project (the
Project) located in the City of Lake Elsinore, Riverside County, California, in regard to
the Multiple Species Habitat Conservation Plan (MSHCP) requirements for Protection of
Species Associated with Riparian/Riverine Areas and Vernal Pools (MSHCP Volume I,
Section 6.1.2).
This document has been prepared following the MSHCP DBESP Report Template
created by the Regional Conservation Authority (RCA), to demonstrate that with the
appropriate mitigation, the Project will represent a “biologically equivalent or superior”
alternative to avoidance. This document summarizes the findings of general biological
surveys, habitat assessments, and vegetation mapping, as they relate to riparian and
vernal pool resources, and species with MSHCP survey requirements.
2.0 INTRODUCTION
2.1 Project Area
The Project site comprises approximately 124.60 acres in the City of Lake Elsinore,
Riverside California [Exhibit 1 – Regional Map] and is located within an un-sectioned
portion of Township 5 South, Range 5 West, of the U.S. Geological Survey (USGS) 7.5-
minute quadrangle map Lake Elsinore, California [Exhibit 2 – Vicinity Map]. The Project
site is located southwest of Interstate-15, the Lake Elsinore Outlet Center and Temescal
Creek/Collier Marsh. The Project site includes the following Assessor’s Parcel Numbers
(APNs):
Onsite
378-020-014
378-020-015
378-020-016
378-020-028
378-020-029
378-020-030
378-020-031
378-020-036
378-020-037
378-020-048
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Offsite
378-020-012
378-020-038
378-020-039
378-020-042
378-020-043
378-114-064
389-080-058
389-080-013
RCA Conserved Land
378-020-024
378-020-033
378-020-034
378-020-040
378-020-041
378-020-054
2.2 Project Description
2.2.1 General Description
The overall Project site totals 124.60 acres and is presented here in five distinct
components:
1. The Industrial Project development footprint (referred to as the “onsite” portion of
the Project)
2. Baker Street Improvements (offsite)
3. A proposed City Maintenance Area (offsite) – to be located along the edge of
Baker Street
4. Additional Street Improvements (offsite) – includes improvements to Pierce
Street and Nichols Road
5. RCA Conserved Lands – includes 33.66 acres of lands to be conserved by the
Project located northeast of the proposed City Maintenance Area and southeast
of Pierce Street/Nichols Road
All impacts will be permanent. There will be no temporary impacts. All construction
staging will occur within the development footprint and/or the offsite improvements
areas. The Project will not require additional impacts outside of the development
footprint for staging. All fuel modification/weed abatement zones will be contained
within the impact limits for both the onsite and offsite project components. The five
Project components are depicted on Exhibit 3 [Project Components Map]. Table 2-1
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summarizes the acreages of these five components, broken out for portions inside
versus outside of Criteria Cells.
Table 2-1. Summary of Project Components
Project Component Inside
Criteria Cells
(Acres)
Outside
Criteria Cells
(Acres)
Total
(Acres)
Industrial Project 34.25 31.56 65.81
Baker Street Improvements 4.45 1.66 6.11
City Maintenance Area 2.44 0.29 2.73
Additional Street
Improvements
5.83 10.46 16.29
RCA Conserved Lands 32.00 1.66 33.66
Total 78.97 45.63 124.60
2.2.2 Industrial Project (Onsite)
The Baker Industrial Project (Project) is proposing two industrial buildings for a total of
approximately 1,002,000 square feet of industrial space. The proposed site plan
provides adequate standard vehicle parking fields and an additional trailer parking field
along the southern end of the property.
The Project grading consists of a development pad graded to convey onsite and offsite
stormwater northerly while maintaining the hydrologic regime of the property and
surrounding tributaries. Larger slopes and associated retaining walls are located along
the southerly property line.
The Project will accept offsite flows from the southern tributaries (developed) through
two flow-by basins also located along the southerly property line. Storm flows are then
conveyed through the Project storm system and discharged in flow and quantity at their
historical locations along the northern side of Baker Street. Onsite flows are collected
through inlets/catch basins and conveyed through the proposed storm drain system to
one of three underground storm chambers. With limited opportunities to infiltrate onsite
storm flows, each chamber system will treat the pollutants of concern and discharge all
treated flows consistent with historical quantities and flow characteristics along the
northerly right-of-way of Baker Street.
The Project includes the preparation of a Preliminary Hydrology Study to analyze the
existing condition storm flows across the property as well as the proposed condition
conveyances to existing discharge locations. The hydrology study will confirm flow
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values based on standard storm intensities and discharge volumes, flow rates, and
velocities. The Project also includes a Preliminary Water Quality Management Plan
(WQMP) that identifies the Best Management Practices (BMPs) proposed to be
implemented to treat project related pollutants for onsite and offsite impervious
improvements. The WQMP will identify the post-construction treatment control and site
design BMPs to treat specific pollutants from onsite impervious areas as well as the
public right-of-way prior to discharge at historical locations on the northern side of the
proposed Baker Street corridor improvements. BMPs located within the public right-of-
way of Baker Street and Nichols Road will treat roadway specific pollutants within bio-
retention/modular wetland facilities upstream of the specified discharge locations. A
Storm Water Pollution Prevention Plan (SWPPP) will be prepared and implemented
prior to onsite and offsite project construction disturbance. The SWPPP will focus on the
design, installation, and treatment of construction related pollutants. The SWPPP
document will be approved through the State of California and the Project will be
registered as required by the Construction General Permit. The Project will be
monitored before, during and after rain events to ensure BMP implementation and
effectiveness in protecting downstream habitats and receiving water bodies.
The Project proposes to construct an 8-inch sewer pipeline within Baker Street to
convey wastewater flows north westerly to the existing Nichols Road Lift Station. The
pipeline is proposed at standard depth and will connect to the existing Elsinore Valley
Municipal Water District (EVMWD) 15-inch sewer line constructed within the Pierce and
Baker intersection. The Nichols Lift Station will require an upgrade to its ultimate build-
out capacity. The lift station upgrades will occur within the existing EVMWD parcel and
will also require an upsized force main between the lift station and the discharge
manhole within the Nichols and Collier intersection. EVMWD has master planned a new
force main from the permanent lift station to convey flow south in Baker Street to
Turnbull Avenue. From there a new gravity sewer line is identified in Turnbull Avenue
and south to the Regional Wastewater Treatment Plant. The gravity sewer alignment
would require construction of many sections of the gravity sewer line in private streets
and private property where easements would need to be acquired. The EVMWD
Master Plan exhibit in Attachment 2 provides the proposed alignment of the force main
and downstream gravity sewer.
An alternative sewer force main alignment was studied by KWC Engineers in 2015 that
would route the force main in Collier Avenue. The force main and downstream gravity
sewer improvements under the revised alignment would keep all improvements within
existing public right-of-way. The Collier Avenue alignment would also allow the
improvements to be phased by constructing a force main with the first phase of the
permanent lift station and then constructing a parallel or replacement force main when
the lift station is expanded to its ultimate capacity. The Collier Avenue alignment
alternative was reviewed with EVMWD staff recently and they take no objection to
proceeding with that alignment. EVMWD did, however, note that they will need to
evaluate the downstream impacts of flows routed down Collier Avenue and that
depending on the extent of required downstream improvements, not all the
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improvements may be eligible for fee credits. Once the capacity study currently being
reviewed by EVMWD is approved, KWC will initiate the PDR for the lift station and
coordinate with EVMWD on the downstream sewer system analysis.
For water service, an EVMWD 36-inch 1434 Zone CIP line is proposed to be installed in
Nichols Road from Terra Cotta Road to Baker Street and in Baker Street to the existing
20-inch line that supplies the Baker Reservoir. The Project proposes to receive water
service by making two connections to the proposed transmission line in Baker Street
and constructing a looped piping system onsite between the two connections. EVMWD
does not allow fire hydrants to be served off private systems so the onsite loop will need
to be public. The onsite line will be located in an easement and be located in
accordance with EVMWD requirements which includes not locating the line beneath
landscaped medians or parking stalls. The 1434 Zone has a large surplus of reservoir
storage capacity and additional storage is not required to provide service to the Project.
The 1434 Zone has a large surplus of reservoir storage capacity and additional storage
is not required to provide service to the Project.
2.2.3 Baker Street (Offsite)
Existing Baker Street is an unimproved dirt road with a 60-foot-wide right-of-way. The
Project proposes to dedicate four feet on each side of Baker Street to the ultimate 68
feet right-of-way required by the City of Lake Elsinore’s (City) Collector roadway
designation and as listed within the City’s circulation element. The Project will also be
realigning Baker Street for a direct connection and new intersection with Nichols Road,
which is discussed below under “Additional Street Improvements”. The Baker Street
Collector section consists of a six-inch curb and gutter, a five-foot-wide sidewalk within
a 10-foot parkway and 22 feet of pavement from centerline to lip of gutter on each side
of the street. Baker Street is proposed to be elevated an average of five feet above its
existing elevations to support drainage conveyance and flood protection of the public
right-of-way. The northeast parkway of Baker Street will slope down from the proposed
five-foot sidewalk to daylight within the northerly properties.
The Project proposes to elevate the road surface of Baker Street to support drainage
protection and conveyance. Along the northern edge of Baker Street, a graded and
landscaped slope will daylight to existing ground within the parcels north of existing
Baker Street right-of-way. The proposed slope will provide areas to safely construct
storm drain outlets that will convey historical storm flows to existing flow lines and
environmentally sensitive areas identified within the Project studies of these properties.
The storm outlets will include energy dissipation improvements to control the storm
water outlet depth and velocity to mimic existing conditions.
2.2.4 City Maintenance Area (Offsite)
As noted above, the Project proposes to elevate the road surface of Baker Street to
support drainage protection and conveyance. Along the northern edge of Baker Street,
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a graded and landscaped slope will daylight to existing ground within the parcels north
of existing Baker Street right-of-way. The proposed slope will provide areas to safely
construct storm drain outlets that will convey historical storm flows to existing flow lines
and environmentally sensitive areas identified within the Project studies of these
properties. The storm outlets will include energy dissipation improvements to control the
storm water outlet depth and velocity to mimic existing conditions. Specifically, the
Project proposes to construct three water spreading structures that are designed to
mimic the existing sheet flow conditions into the adjacent open space [Sheets 1 and 2 of
Appendix E]. The spreading structures will be constructed on the northeastern side of
Baker Street adjacent to each of the three vernal pools described below. The pre- and
post-Project hydrology relative to the three vernal pools are summarized below in the
impact analysis as well as being presented in Appendix E.
A maintenance access road is proposed along the toe-of-slope for ongoing
maintenance of the slope, the associated landscaping, any required fencing, and the
outlet structures. Where sensitive environmental areas exist (vernal pools identified
within the Project environmental studies), the improvements are proposed to be scaled
back to minimize or eliminate impacts in and adjacent to the defined zones.
Construction buffers will be implemented to reduce accidental disturbance and the
areas will be clearly delineated and recognizable to construction crews/personnel.
2.2.5 Additional Street Improvements (Offsite)
In addition to the Baker Street improvements described above, the Project will also
improve Pierce Street and Nichols Road. The Project will realign Baker Street for a
direct connection and new intersection with Nichols Road. The intersection design will
likely consist of signal pole placement consistent with the ultimate build-out of Nichols
Road (Urban Arterial Highway – 120’ right-of-way). Nichols Road improvements will
likely consist of an interim intersect with appropriate pavement tapering to the east and
west leading away from the new intersection with Baker Street. Minor roadway
resurfacing may be required along the existing Nichols Road segment between the
Baker Street intersection and the Collier Avenue intersection. The Nichols and Collier
intersection may also include minor surface improvements, revised lane striping and
potential traffic control/signage improvements.
Existing Pierce Street varies in right-of-way width along the Project’s frontage. The
Project proposes to construct Pierce Street to its ultimate 60-foot width between Baker
Street and Hoff Avenue. The ultimate street section will include a six-inch curb, standard
gutter, five-foot-wide sidewalk within an overall 10-foot parkway and 18 feet of
pavement from centerline to lip-of-gutter on each side of the street. Other project related
street improvements beyond the Project frontage will be assessed with the traffic impact
analysis.
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2.2.6 RCA Conserved Land
The Project is conserving 33.66 acres of lands bordered by the Baker Street, Pierce
Street and Nichols Road improvements. As described below, the Project is proposing
several types of mitigation within with the Conserved Lands, including San Diego
ambrosia (Ambrosia pumila) translocation, vernal pool expansion/restoration, and
mitigation for other MSHCP plants, including Coulter’s goldfields (Lasthenia glabrata
ssp. coulteri). If the long-term management of these mitigation areas will exceed that
which the RCA receives funding for through the MSHCP, it is acknowledged that the
Project would provide an endowment to fund supplemental management.
2.3 Existing Conditions
The overall Project site varies in topography from slightly hilly to flat, sloping from
southwest to northeast. The onsite portion of the Project site (industrial component)
consist of several small hills and ridges sloping from the southwest down to the existing
dirt road of Baker Street, with the site being flatter on the northern end near the Baker
Street/Pierce Street intersection. Northeast of Baker Street, the landscape is flat with a
very gradual change in elevation to the northeast towards Alberhill Creek/Collier Marsh.
Elevations at the Project site range from approximately 1,400 feet above mean sea level
(AMSL) at the southwestern boundary of the development footprint to 1,250 feet AMSL
at the northeastern limits of the proposed RCA Conserved Lands.
Soils within the onsite portion of the Project site consist mainly Lodo Rocky Loam and
Willows Silty Clay (saline-alkali). The Willows soils occur in the lower portions of site,
with the rocky loam soil occurring in the higher elevation areas. The Willows soils
extend into the site from the adjacent Collier Marsh area. These alkaline soils are
strongly associated with the plant species that occur occurring in the vernal pools
immediately northeast of Baker Street. The offsite (undeveloped) portions of the Project
site predominantly consist of fine sandy loam soils. The proposed RCA Conserved
Lands consist of Willows silty clay soils as well as the fine sandy loam soils.
GLA mapped nine distinct vegetation/land use types for the Project site, including Akali
Grassland, Akali Playa, Disturbed/Developed, Open Water, Riversidean Sage Scrub,
Semi-Natural Herbaceous Grassland, Disturbed Semi-Natural Herbaceous Grassland,
Southern Willow Scrub and Vernal Pool. Table 2-2 provides a summary of the
vegetation types and their corresponding acreage. A Vegetation Map is attached as
Exhibit 6. Photographs depicting the Project site are shown in Exhibit 12.
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Table 2-2. Summary of Vegetation/Land Use Types for the Project Site
Vegetation/Land Use Type
Inside
Criteria Cells
(acres)
Outside
Criteria Cells
(acres)
Total
(acres)
Alkali Grassland 3.59 0 3.59
Alkali Playa 0.73 0 0.73
Disturbed/Developed 9.62 8.72 18.34
Open Water 0.09 0 0.09
Riversidean Sage Scrub 2.49 0.52 3.01
Semi-Natural Herbaceous Grassland 38.88 30.83 69.71
Disturbed Semi-Natural Herbaceous
Grassland 20.71 5.56 26.27
Southern Willow Riparian Scrub 1.14 0 1.14
Vernal Pool 1.72 0 1.72
Total 78.97 45.63 124.60
3.0 RIPARIAN/RIVERINE MITIGATION (SECTION 6.1.2)
3.1 Methods
3.1.1 Riparian/Riverine Areas
The MSHCP defines riparian areas as “lands which contain habitat dominated by trees,
shrubs, persistent emergent mosses and lichens, which occur close to, or which depend
upon soils moisture from a nearby fresh water source. In the absence of riparian habitat,
the MSHCP defines riverine areas as areas with fresh water flow during all or a portion
of the year.”
GLA surveyed the Project site for riparian/riverine areas. GLA biologists Jillian
Stephens and David Moskovitz initially evaluated the site in April 2020, with follow-up
visits conducted by GLA regulatory specialists Chris Waterston and Lesley Lokovic-
Gamber on February 9, 2021, and April 20 and July 29, 2022.
3.1.2 Vernal Pools
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 wetland indictors of
hydrology and/or vegetation during the drier portion of the growing season.”
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GLA surveyed the Project site for vernal pools as part of the jurisdictional delineation to
identify seasonal wetlands. GLA biologists evaluated the topography of the site,
including whether the site contained depressional features/topography with the potential
to become inundated; whether the site contained soils associated with vernal/seasonal
pools; and whether the site supported plants that suggested areas of localized ponding.
The site was evaluated on multiple occasions during the rainfall season, including in
2020, 2021, and 2022 and 2024. GLA biologists Jillian Stephens and David Moskovitz
initially evaluated the site in April 2020, with follow-up visits conducted on February 9,
2021, and April 20, 2022. The 2024 monitoring corresponded with the wet season fairy
shrimp surveys.
3.1.3 Fairy Shrimp
The Project site contains four seasonally ponding features with a potential to support
listed fairy shrimp, including one stock pond feature (Pool 4) within the Industrial portion
of the Project, and three vernal pools that either overlap with the offsite improvements
and maintenance area associated with Baker Street or are immediately adjacent in the
proposed RCA Conserved Lands. All four features require protocol surveys (dry season
and wet season) to determine the presence or absence of listed fairy shrimp. To
complete the survey protocol for all four features, dry season surveys were completed in
2023 [Appendix B – 2023 Dry Season Fairy Shrimp Report] and wet season surveys
were completed for the 2023-2024 rainfall season [Appendix C – 2023/2024 Wet
Season Fairy Shrimp Report].
Dry Season Surveys
Soil sample collection followed the USFWS Survey Guidelines for the Listed Large
Branchiopods (Survey Guidelines). 1 GLA biologist David Moskovitz (PER0010680-0)
supervised the collection of soil samples along with GLA biologists Stephanie Cashin
and Chris Waterston in October and November 2023. Soil samples were collected
when the pools were dry using a hand trowel to collect intact chunks of soil from the top
1–3 cm of pool sediment. The number of soil samples collected from each of features
was based on feature size according to the Survey Guidelines. Starting at the edge of
each depression, samples were taken from equidistant points along the longest transect
and widest transect of each depression. Additional samples were taken at the deepest
part of each feature.
Soil samples of approximately 100 milliliters (ml) each were removed at each sub-
sample location using a hand trowel and were combined into a labeled bag for each
feature with the collection date, location and feature ID, and name of collector for future
processing. Samples were stored in a dry location out of direct sunlight until delivery for
processing.
1 USFWS. Survey Guidelines for the Listed Large Branchiopods, Revised: November 13, 2017.
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The soil samples were processed by D. Christopher Rogers (TE796284-7). Soil
samples were labelled with the numbers on their respective bags and prepared for
examination by dissolving the clumps of soil in water and sieving the material through
300- and 150- µm pore size screens. The small size of these screens ensures that the
eggs from the shrimp species will be retained. The portion of each sample retained in
the screens was dissolved in a brine solution to separate the organic material from the
inorganic material. The organic fraction was then examined under a microscope. Counts
were made by estimating the number of eggs per 100ml of soil, because not all samples
had the same volume of soil collected originally.
Isolated eggs from each sample were cultured separately. Adult shrimp were reared
from the recovered eggs using methods following Martin, Rogers & Olesen (2016).
Hatched shrimp were fed a standard Daphnia food that includes; fish food, fish oil,
baker’s yeast, and the alga Selenastrum capricornutum. The shrimp were reared to
maturity. Adult Branchinecta reared from culture were killed in 90% ethyl alcohol and
examined under a stereo dissection microscope. Identifications were made based upon
comparisons with specimens in our collections, the original species descriptions, and
professional experience.
Wet Season Surveys
Wet season fairy shrimp surveys were performed for the four seasonal pond features for
the 2023-2024 rainfall season, as a follow up to the pending dry season surveys. The
surveys were performed by GLA biologists Stephanie Cashin (TE-20280D-0) and Chris
Waterston (ESPER-2380694). In accordance with the USFWS Survey Guidelines for
the Listed Large Branchiopods (Survey Guidelines) dated November 13, 2017, site
visits were conducted following measurable rainfall events to determine whether any of
the features contained a minimum of three centimeters (cm) of ponding after 24 hours
from the rainfall event. Storms in late December 2023 and early January 2024 initiated
hydrologic monitoring of the pools. Pool 3 began to sustain ponding after storms
between January 19 - 23, 2024, with sampling in Pool 3 initiated beginning January 26,
2024. Pools 1 and 4 began to sustain ponding beginning February 2, 2024. After a
multiple day storm in early February 2024, all pools reached the maximum extent of
ponding. Pool 1 remained ponded until May 9, 2024. Pool 3 remained ponded until May
14, 2024. Pool 2 and 4 remained ponded until May 22, 2024.
Sampling for the presence of fairy shrimp was performed using a dip net within
representative portions of the depression bottom, edges, and vertical water column
when there was adequate ponding. Specimens were placed into vials, with unique
depression information, containing 95% ethanol solution. Specimens were identified
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through microscopy and using the “Key to California Fairy Shrimps” found in Eriksen
and Belk (1999, Revised 2016).
3.1.4 Riparian Birds
The MSHCP requires habitat assessments and focused surveys (if suitable habitat) for
least Bell’s vireo (Vireo bellii pusillus), southwestern willow flycatcher (Empidonax traillii
extimus), and western yellow-billed cuckoo (Coccyzus americanus occidentalis). The
proposed development areas of the Project do not contain suitable habitat for these
species; however, Alberhill Creek contains suitable habitat for the vireo and flycatcher,
and because the proposed improvements to Nichols Road are adjacent to the creek,
focused surveys were conducted for both species. GLA performed protocol surveys for
least Bell’s vireo and southwestern willow flycatcher in 2020. The survey methods and
results are summarized here. A separate survey report is included as Appendix D.
Least Bell’s Vireo
GLA biologists Stephanie Cashin, Jeff Ahrens and April Nakagawa conducted focused
surveys for the least Bell’s vireo (LBV) within the portions of Alberhill Creek in proximity
to the Project site. Surveys were conducted in accordance with the 2001 USFWS
survey guidelines, which stipulate that eight surveys should be conducted between April
10 and July 31, with a minimum of ten days separating each survey visit. The survey
guidelines state that surveyors should not survey more than three linear kilometers or
more than 50 hectares (about 120 acres) of habitat on any given survey day. There is
no suitable habitat for LBV within the onsite portion of the Project. The only suitable
habitat relative to the Project is the portion of Alberhill Creek that is adjacent to a portion
of Nichols to be improved and coincides with the northern portion of the proposed
conservation lands. As such, GLA’s survey area for LBV comprised less then 1,000
linear feet and less than five acres, representing a small fraction of the maximum area
allowed for a single survey visit.
Focused surveys were conducted on April 13, May 5, 18 and 28, June 8 and 19, and
July 15 and 28, 2020. As is described below, a single LBV was first detected during the
May 5 survey by Jeff Ahrens and confirmed again during subsequent visits. Mr. Ahrens
performed the first survey for the southwestern willow flycatcher on May 18, 2020, with
the first half of the morning dedicated to the flycatcher, walking upstream through
Alberhill Creek, and then surveying for LBV walking downstream through the creek.
Furthermore, because LBV had already been confirmed present on May 5, the May 18
visit re-confirmed LBV presence.
Pursuant to the survey guidelines, the surveys were conducted between sunrise and
11:00 a.m. Weather conditions during the surveys were conducive to a high level of
bird activity. Table 3-1 summarizes the vireo survey visits.
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Table 3-1. Summary of Least Bell’s Vireo Surveys
Survey Date Biologist(s) Start/End
Time
Start/End
Temperature
(°F)
Start/End
Wind
Speed
(mph)
Cloud
Cover
4/13/20 SC 0620/1000 60/68 0-1/0-1 100/100
5/5/20 JA 0550/0920 56/75 1-2/0-2 0/0
5/18/20 JA 0550/1100 57/69 1-2/1-2 80/50
5/28/20 AN 0600/1100 62/84 0-1/0-1 0/0
6/8/20 AN 0645/1100 58/75 8-10/8-10 0/0
6/19/20 SC 0615/1015 59/67 0-2/0-1 100/50
7/15/20 AN 0645/1100 62/77 0-1/0-1 100/0
7/28/20 AN 0700/1100 62/88 0-1/4-5 0/0
SC = Stephanie Cashin; JA = Jeff Ahrens; AN = April Nakagawa
Southwestern Willow Flycatcher
GLA biologist Jeff Ahrens conducted focused surveys for the southwestern willow
flycatcher for all suitable habitat areas within the Project site. Surveys were conducted
in accordance with the 2010 USFWS survey guidelines, which stipulate five survey
visits between May 15 and July 17, divided into three survey periods. The southwestern
willow flycatcher is one of three subspecies of willow flycatcher that occur within
southern California but is the only subspecies that breeds in southern California. The
other subspecies may occur in southern California as they migrate through the area
onwards to northern breeding areas but will not breed in southern California. If present,
these subspecies may be detected during the first and/or second survey periods. The
presence of the southwestern willow flycatcher is determined by willow flycatchers that
remain in southern California during the third survey period.
Focused surveys were conducted on May 18, June 9 and 23, and July 1 and 16, 2020.
As noted above, Mr. Ahrens’ visit on May 18 was also counted as a LBV survey visit,
but the survey efforts were divided, first surveying for the flycatcher while walking
upstream through Alberhill Creek and then surveying for LBV while walking downstream
through the creek. Pursuant to the survey guidelines, the surveys were conducted
between one hour prior to sunrise and 10:00 a.m. Weather conditions during the
surveys were conducive to a high level of bird activity. Table 3-2 summarizes the
flycatcher survey visits.
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Table 3-2. Summary of Southwestern Willow Flycatcher Surveys
Survey Date Biologist(s) Start/End
Time
Start/End
Temperature
(°F)
Start/End
Wind
Speed
(mph)
Cloud Cover
5/18/20 JA 0550/1100 57/69 1-2/1-2 80/50
6/9/20 JA 0600/0940 53/73 1-2/1-2 0/0
6/23/20 JA 0555/1000 58/68 0-1/0-1 100/0
7/1/20 JA 0555/0930 60/66 1-2/1-2 100/100
7/16/20 JA 0550/0930 59/72 1-2/0-1 30/0
JA = Jeff Ahrens
3.2 Results/Impacts
3.2.1 Riparian/Riverine Areas
The Project site contains approximately 3.03 acres of MSHCP riparian/riverine areas,
including 2.36 acres of riparian habitats associated with Alberhill Creek, and 0.67 acre
associated with six drainage features (Drainage A through F) [Exhibit 8 – MSHCP
Riparian/Riverine Areas and Vernal Pools]. Approximately 2.58 acres of
riparian/riverine areas are inside Criteria Cells and 0.45 acre of riverine areas are
outside Criteria Cells. The 2.36 acres associated with Alberhill Creek includes 1.14
acres of Southern Willow Riparian Scrub, 0.73 acre of Alkali Playa, 0.09 acre of Open
Water, and 0.40 acre of Semi-Natural Herbaceous Grassland. Table 3-3 below
summarizes the riparian/riverine areas at the Project site.
Table 3-3. MSHCP Riparian/Riverine Areas at the Project site
Inside Criteria Cells Outside Criteria Cells
Drainage Riverine
(acres)
Riparian
(acres)
Riverine
(acres)
Riparian
(acres)
Total
(acres)
Alberhill Creek 0 2.36 0 0 2.36
Drainage A 0.15 0 0.03 0 0.18
Drainage B 0 0 0.13 0 0.13
Drainage C 0.03 0 0 0 0.03
Drainage D 0 0 0.09 0 0.09
Drainage E 0.04 0 0 0 0.04
Drainage F 0 0 0.20 0 0.20
Total 0.22 2.36 0.45 0 3.03
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Alberhill Creek
Alberhill Creek enters the Project’s RCA Conserved Land from the southeast and
extends in a northwesterly direction before exiting the conserved parcels just before the
Nichols Road crossing.
Alberhill Creek is dominated by southern willow scrub riparian habitat with an alkali
playa component occurring in the abutting floodplain. A majority of the alkali playa
component in the northeastern portion of the site exhibits at least some degree of soil
disturbance and alterations to the hydrologic regime as evidenced by the presence of
tire tracks, road ruts, and unauthorized dumping.
Most of the riparian habitat (1.08 acres) associated with Alberhill Creek identified for the
Project site is within the proposed open space. Approximately 0.06 acre of riparian
habitat is mapped within the footprint for Nichols Road, consisting of willow limbs
overhanging the roadway. As is described below, improvements to Nichols Road
consisting of re-surfacing the existing roadway will not require the trimming of the
overhanging willow limbs.
Dominant riparian/wetland vegetation associated with Alberhill Creek includes salt cedar
(Tamarix ramosissima), black willow (Salix gooddingii), arroyo willow (Salix lasiolepis),
and mulefat (Baccharis salicifolia), with alkali bulrush (Bolboschoenus maritimus),
common toad rush (Juncus bufonius), and cattail (Typha spp.). Other common plants
include common nettle (Urtica dioica), shortpod mustard (Hirschfeldia incana),
silverscale saltbush (Atriplex argentea), San Jacinto Valley crownscale (Atriplex
coronata var. notatior), western ragweed (Ambrosia psilostachya), saltgrass (Distichlis
spicata), and annual rabbitsfoot grass (Polypogon monspeliensis).
Drainage A
Drainage A originates offsite to the southwest, extending through the onsite portion of
the Project to Baker Street where it crosses under Baker Street through a pipe culvert
continuing in a northeasterly direction before its confluence with Alberhill Creek. The
lower portion of Drainage A in the parcel boundary drains into one of three seasonal
ponds (described separately below) before continuing its course towards Alberhill
Creek. Drainage A ranges from two to six feet in width as evidenced by water marks,
changes in soil characteristics, and bent vegetation.
Vegetation associated with Drainage A includes foxtail barley (Hordeum murinum), soft
chess (Bromus hordeaceus), ripgut brome (Bromus diandrus), red brome (Bromus
madritensis ssp. rubens), rattail fescue (Festuca myuros), common Mediterranean
grass (Schismus barbatus), cheeseweed (Marva parviflora), wild oats (Avena fatua),
common fiddleneck (Amsinckia intermedia), stinknet (Oncosiphon piluliferum), annual
mustard (Brassica ssp.), shortpod mustard, goldenbush (Isocoma menziesii), London
rocket (Sisybrium irio), alkali heliotrope (Heliotropium curassavicum), and a single
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tamarisk. Additional species observed in the downstream reach include salt grass,
alkali weed, ragweed, and a single tamarisk. This feature flows only in direct response
to precipitation and was completely dry during the field investigations.
Drainage B
Drainage B is an earthen ephemeral drainage that enters the Baker parcel from the
west along the edge of a former residential property and extends in a northeasterly
direction towards Baker Street. Drainage B conveys storm water flows and receives
irrigation runoff from the adjacent rural residence. The drainage extends up to ten feet in
width as evidenced by changes in soil characteristics and bent vegetation.
Vegetation associated with Drainage B consists primarily of semi-natural herbaceous
grassland that includes foxtail barley, soft chess, ripgut brome, red brome, rattail fescue,
common Mediterranean grass, cheeseweed, wild oats, common fiddleneck, stinknet,
annual mustard, summer mustard, goldenbush, heliotrope, and London rocket.
Drainage C
Drainage C is an erosional ephemeral drainage that originates offsite from the adjacent
hillsides and extends in a northerly direction towards Baker Street. Drainage C
averages two feet in width as evidenced by changes in soil characteristics and eroded
channel banks in the upstream reach. The drainage bottom contains cobbles and was
completely dry during the field investigations.
Vegetation associated with Drainage C consists primarily of semi-natural herbaceous
grassland that includes foxtail barley, soft chess, ripgut brome, red brome, rattail fescue,
common Mediterranean grass, cheeseweed, wild oats, common fiddleneck, stinknet,
annual mustard, summer mustard, goldenbush, heliotrope, and London rocket. Areas
adjacent to the drainage contain patches of California buckwheat (Eriogonum
fasciculatum), bush sunflower (Encelia californica), and California sagebrush (Artemisia
californica).
Drainage D
Drainage D is an erosional drainage that occurs in the southwestern portion of the
Baker parcel. The drainage originates offsite from the southwest and meanders in a
northeasterly direction before exiting the parcel boundary at an existing rural residence.
Drainage D ranges between two and six feet in width and contains eroded banks and
cobbles. This feature conveys flow only in direct response to precipitation and was
completely dry during the field investigation.
Vegetation associated with Drainage D consists primarily of semi-natural herbaceous
grassland that includes foxtail barley, soft chess, ripgut brome, red brome, rattail fescue,
common Mediterranean grass, cheeseweed, wild oats, common fiddleneck, stinknet,
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annual mustard, summer mustard, goldenbush, heliotrope, and London rocket. Areas
adjacent to the drainage contain patches of California buckwheat, bush sunflower, and
California sagebrush.
Drainage E
Drainage E is an earthen ephemeral drainage that originates as run-off from Nichols
Road. This feature extends in an easterly direction before dissipating as sheet flow. The
drainage averages three feet in width, and depending on rainfall amounts, conveys a
surficial connection to Alberhill Creek. Vegetation associated with the drainage is limited
to non-native upland grasses and weeds including foxtail barley, soft chess, ripgut
brome, red brome, rattail fescue, common Mediterranean grass, cheeseweed, wild oats,
common fiddleneck, stinknet, annual mustard, summer mustard, heliotrope, and London
rocket. This drainage lacks hydrophytic vegetation and was completely dry during the
field investigations.
Vegetation associated with Drainage E consists primarily of semi-natural herbaceous
grassland that includes foxtail barley, soft chess, ripgut brome, red brome, rattail fescue,
common Mediterranean grass, cheeseweed, wild oats, common fiddleneck, stinknet,
annual mustard, summer mustard, goldenbush, heliotrope, and London rocket.
Drainage F
Drainage F consists of a roadside drainage channel along the northern edge of Nichols
Road. This feature extends in an easterly direction. The drainage averages six feet in
width and is generally unvegetated.
The proposed Project will permanently (directly) impact approximately 0.50 acre of
MSHCP riverine areas but will not impact any riparian habitat. Impacts will occur to five
drainage features (A, B, C, D and F). Table 3-4 summarizes impacts to riverine
features.
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Table 3-4. Impacts to MSHCP Riverine Areas
Drainage Inside
Criteria Cells
(acres)
Outside
Criteria Cells
(acres)
Total Impacts
(acres)
Drainage A 0.02 0.03 0.05
Drainage B 0 0.13 0.13
Drainage C 0.03 0 0.03
Drainage D 0 0.09 0.09
Drainage F 0 0.20 0.20
Total 0.05 0.45 0.50
The drainage features to be impacted by the Project are vegetated with semi-natural
herbaceous grassland, which is dominated by a mix of non-native grasses and native
and non-native forbs. As such, the drainages to not support biological functions for the
MSHCP Section 6.1.2 species. The functions of the drainage features are limited to
hydrologic functions, specifically conveyance downstream towards the Alberhill Creek
floodplain. The drainage features collect runoff from the southwest and generally
convey flows to the northeast. As documented in the Project’s Vernal Pool Hydrology
Memorandum (Appendix E), the Project is designed to collect the runoff and mimic the
existing hydrologic conditions to the three vernal pools and the downstream Alberhill
Creek resources to the maximum extent feasible, such that the Project is not expected
to adversely affect the hydrologic functions of the vernal pool and riparian/riverine
resources.
The Project will not impact riparian habitat associated with Alberhill Creek. Most of the
riparian habitat is within the proposed open space. Approximately 0.06 acre of riparian
habitat is mapped within the footprint for Nichols Road, consisting of willow limbs
overhanging the roadway. Improvements to Nichols Road consisting of re-surfacing the
existing roadway will not require the trimming of the overhanging willow limbs.
3.2.2 Vernal Pools
The Project site contains three areas on the northeastern side of Baker Street that pond
seasonally and exhibit the three wetland parameters to meet the definition of MSHCP
Vernal Pools. These areas are referenced herein as Vernal Pools 1, 2, and 3, all of
which are inside Criteria Cells. Vernal Pools 1 and 2 are in proximity to, but do not
directly abut, Alberhill Creek. Vernal Pool 3 is connected to Drainage A, which connects
with Alberhill Creek. All three vernal pools are in areas mapped as containing Willows
Silty Clay soils [Exhibit 7 – Soils Map]. Each of the vernal pools, as described below,
are unique in terms of their hydrology, soils appearance, relationship to the ecosystem
and vegetation assemblage. Table 3-5 summarizes vernal pools at the Project site and
impacts to those pools.
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Table 3-5. MSHCP Vernal Pools at the Project Site
Vernal Pool Total Pool
Area
(acres)
Impacts to
Vernal Pools
(acres)
Vernal Pool 1 0.45 0
Vernal Pool 2 0.41 0.01
Vernal Pool 3 0.86 0.16
Total 1.72 0.17
Vernal Pool 1
Vernal Pool 1 is approximately 0.45 acre. The vernal pool is in an area mapped as
containing Willow Silty Clay soils (saline-alkali) and the strong alkaline component is
evident in the white color of the spoils. The main ponding area does not become
heavily vegetated due to the alkalinity; however, the areas surrounding the ponding
basin supports species such as salt grass, Coulter’s goldfields, vernal barley, and San
Jacinto Valley crownscale. Adjacent to the area of Vernal Pool 3, the floodplain of the
Alberhill Creek/Collier Marsh bows out and is proximal to the vernal pool, such that it
appears that this vernal pool is more directly influenced hydrologically and historically in
its formation by the creek.
Vernal Pool 2
Vernal Pool 2 is approximately 0.41 acre. As with Vernal Pool 1, this vernal pool is in
an area mapped as containing Willow Silty Clay soils (saline-alkali). However, Vernal
Pool 2 has a different appearance than Vernal Pool 1 in the soils and the resulting
vegetative makeup. All three vernal pools at the Project site have been disturbed in the
past and it is possible that soils underlying Vernal Pool 2 have been modified, possibly
with in-fill soils. Regardless, the vernal pool contains a strong alkaline component. A
few individuals of Coulter’s goldfields were observed on the edge of the pool; however,
the other species associated with Vernal Pools 1 and 3 were not detected in Vernal
Pool 2.
Vernal Pool 3
Vernal Pool 3 is approximately 0.86 acre. As with Vernal Pools 1 and 2, this vernal pool
is in an area mapped as containing Willow Silty Clay soils (saline-alkali). However, the
appearance (color) of the soils associated with Vernal Pool 3 suggests a lesser alkaline
component than with Vernal Pool 1, which is also reflected in the denser vegetation
within Vernal Pool 3, including a sizeable population of Coulter’s goldfields. Additional
vernal pool plant species noted in Vernal Pool 3 includes vernal barley and woolly
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marbles (Psilocarphus brevissimus var. brevissimus) and alkali popcorn flower
(Plagiobothrys leptocladus).
Hydrologically, Vernal Pool 3 is different than the other two vernal pools. Drainage A is
connected to the downslope end of the pool and runoff from Drainage A helps to feed
the pool along with runoff from Baker Street, and vertical rainfall falling on the pool and
from the immediate watershed.
The Project will permanently impact up to 0.17 acre of vernal pools including 0.01 acre
of Vernal Pool 2 and 0.16 acre of Vernal Pool 3 along the southern edge because of
constructing the storm drain outlets along the edge of the Baker Street improvements.
As described below, the southern edge of Vernal Pool 3 will be recontoured following
the completion of construction of the Baker Street improvements and the storm drain
outlets/spreading structures, and the vernal pool will be part of the Project’s proposed
RCA Conserved Land. The potential impact to Vernal Pool is limited to 0.01 acre at the
southern edge. Vernal Pools 1 will be avoided by the Project, and both Vernal Pools 1
and 2 will also be part of the RCA Conserved Land.
Regarding indirect effects, Vernal Pool 3 is hydrologically unique compared with the
other two vernal pools, in that Vernal Pool 3 is partially fed by Drainage A, which flows
through the topographically lower end of the vernal pool. The vernal pool also receives
hydrologic input from another culvert location at the edge of Baker Street. As noted
above in the project description, the Project will construct a spreading structure along
the edge of Vernal Pool 3 to mimic the existing sheet flow conditions to the vernal pool,
while also accounting for the direct streamflow that currently enters the pool. The
Project’s Hydrology Memorandum is included as Appendix E.
3.2.3 Fairy Shrimp
Dry Season Surveys
Cysts belonging to the genus Branchinecta were isolated from soil samples in Pools 1,
2 and 3, but not from Pool 4. Adult B. lindahli were reared from cultures in Pools 1, 2
and 3. No suspected hybrids between B. lindahli and the federally listed B.
sandiegonensis were identified.
Wet Season Surveys
The versatile fairy shrimp (B. lindahli) was detected in Pools 1, 2 and 3, but not in Pool
4. These results are consistent with the findings of the preceding dry season surveys.
No listed fairy shrimp species were detected. The western spadefoot (Spea hammondii)
was detected in Pools 1, 2 and 3.
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3.2.4 Riparian Birds
GLA biologists did not detect the southwestern willow flycatcher during the focused
surveys. A male LBV (presumed nesting based on behavior) was detected within
Alberhill Creek during multiple visits within close proximity to Nichols Road and the
Project’s proposed conservation, with the LBV first detected during the May 5, 2020,
survey visit. All subsequent visits were used to confirm the extent of use of the
presumed nesting pair. Based on the detections, the habitat with Alberhill Creek
between Nichols Road and the proposed conservation would be considered occupied
and have long-term conservation value for least Bell’s vireo, with approximately 1.08
acres of the habitat occurring within the proposed conservation area, and approximately
0.06 acre of habitat consisting of willow canopy overhanging Nichols Road.
The Project is not expected to directly impact riparian birds, including least Bell’s vireo.
The Project will not remove any riparian habitat, including habitat with LTVC for the
vireo. Riparian habitat is located adjacent to Nichols Road with approximately 0.06 acre
of canopy overhanging into the roadway; however, proposed improvements adjacent to
Alberhill Creek will be limited to road re-surfacing and re-striping, with no additional
widening. Furthermore, the road improvements will not require the removal of the
overhanging willow limbs. The riparian habitat within the Project site is included in the
proposed RCA Conserved Land. The Industrial (onsite) component of the Project is not
expected to indirectly impact riparian birds. The onsite portion of the Project is nearly
one-quarter mile from Alberhill Creek and therefore construction and operation of the
industrial facility will not have edge effects on habitat within the Creek, including from
noise and lighting.
3.3 Mitigation and Equivalency
3.3.1 Direct Effects
Riparian/Riverine Areas
The Project will mitigate impacts to 0.50 acre of riverine areas offsite through the
purchase of mitigation credits from the Riverpark Mitigation Bank. The mitigation credits
will include a minimum 1:1 of re-establishment and 2:1 of re-establishment and/or re-
habilitation. Since the Riverpark Mitigation Bank involves the restoration of areas
adjacent to the San Jacinto River, the mitigation bank lands provide hydrologic functions
to the San Jacinto River floodplain similar to the functions provided by drainage features
to be impacted at the Project site that are tributary to the Alberhill Creek floodplain. As
a matter of habitat replacement, the purchase of 1.50 acres of mitigation credits (1:1 of
re-establishment and 2:1 of re-establishment and/or re-habilitation) will be biologically
superior compared with the impacts.
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Vernal Pools
As noted above, up to 0.17 acre of the vernal pools (0.01 acre of Vernal Pool 2 and 0.16
acre of Vernal Pool 3) will be directly impacted to construct the Baker Street
improvements and spreading structures/storm drain outlets. Following the completion
of construction, the southern edge of Vernal Pool 3 will be re-contoured and any portion
of the 0.16-acre impacts that are temporary will be restored, including a revegetation
coinciding with the Coulter’s goldfields mitigation (discussed below). Permanent
impacts to the vernal pools will be mitigated by expanding Vernal Pool 3 on the opposite
side from the impacts through recontouring and revegetating. In addition, Vernal Pool 2
might also be expanded and enhanced. The vernal pools will be expanded by at least a
3:1 ratio versus the permanent impacts. Assuming up to 0.17-acre of permanent
impacts, the vernal pool(s) will be expanded by at least 0.51 acre. The HMMP will, at a
minimum, include details about the type of mitigation, acreages, when the mitigation
would be implemented, plant palettes, site preparation, weeding plan, success criteria,
monitoring plan (e.g., years/duration, frequency, etc.), reporting, the proposed
management entity, and contingency measures in the event the mitigation is not
successful. The monitoring will include hydrologic monitoring to confirm that the
recontoured areas inundate sufficiently to support seasonal ponding/wetland conditions.
The type of contingency measures would depend on which success criteria have not
been met. If the vernal pools are not meeting plant coverage and/or non-native criteria,
then additional plant remediation/maintenance efforts would be implemented, and the
monitoring period would be extended. If the expanded vernal pools are not meeting
inundation criteria, then possibly the pools would be regraded, or the soils remediated to
address hydrology. Additional details will be provided in the HMMP. The HMMP will be
provided to the RCA and Wildlife Agencies for review and approval. The proposed
mitigation will be subject to approval through the DBESP process, in addition to JPR.
Fairy Shrimp
The Project will not impact listed fairy shrimp, although it will impact populations of the
non-listed versatile fairy shrimp. Mitigation is not required for impacts to the non-listed
versatile fairy shrimp.
Riparian Birds
The Project will not impact habitat for riparian birds, including habitat with LTCV for least
Bell’s vireo. Therefore, mitigation for habitat loss will not be required for riparian birds.
Because a portion of Nichols Road to be improved is adjacent to riparian habitat that
had been previously determined to be occupied by LBV, there is a potential for indirect
effects due to construction noise, if LBV were to be present during construction
activities. If feasible, construction activities will avoid the LBV breeding season (March
15 to September 30). However, if the Nichols Road improvements adjacent to Alberhill
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Creek cannot avoid the LBV breeding season, then the following measures are
proposed to address noise effects:
· Avoidance Buffer – If Nichols Road improvements adjacent to the Alberhill
Creek riparian habitat will occur during the LBV breeding season (March 15 to
September 30), then applicable measures will be implemented for any work
within 300 feet of the habitat to avoid indirect impacts to LBV. The measures
may include the installation of sound barriers, pre-construction surveys and/or
clearance surveys. The Project proponent will implement an Environmental
Awareness Training program prior to the start of construction to advise workers
of sensitive biological areas within Alberhill Creek adjacent to the Nichols Road.
· Sound Barriers – The Project proponent may install sound barriers along
Nichols Road adjacent Alberhill Creek to prevent any adverse noise effects to
LBV during construction. If utilized, the sound barriers will be installed prior to
any work conducted after March 15 and will remain in place until August 31,
unless it is first determined through surveys that LBV are not occupying habitat in
the adjacent creek. To confirm the effectiveness of the sound barriers, a
qualified biological monitor will measure noise levels within the creek on the
opposite side of the sound barriers from the Nichols Road. The monitor will
determine the existing ambient noise level, and then whether noise levels exceed
60 dB (or the ambient noise levels) due to construction activities. For areas
where pre-construction ambient noise levels exceed 60 dB, pre-construction,
ambient noise measurements can be taken by a qualified entity during the full
daylight period (sunrise to sunset), and subsequently, the median average
ambient noise level can be used as the baseline in lieu of 60 dB. For any
nighttime construction activities, the same would be done as above but with
measurements taken during the full nighttime period (sunset to sunrise). If
construction noise levels exceed 60 dB or the ambient noise level, whichever is
greater, then the sound barrier will be adjusted, and measurements will be re-
taken. If construction noise levels are determined to be under 60 dB or the
ambient noise level, whichever is greater, then construction activities will
continue without any additional noise monitoring.
· Pre-Construction and Clearance Surveys – At least three pre-construction
surveys and/or clearance surveys will be conducted for LBV in riparian habitat
within Alberhill Creek that is within 300 feet of construction activities. The
number of surveys will depend on when the surveys commence and whether
LBV individuals are detected during the surveys. The survey visits will be
conducted by a qualified biologist familiar with songs, whisper songs, calls,
scolds, and plumage characteristics of adult and juvenile vireos. Surveys will be
conducted between sunrise and 11:00 am. Surveys will not be conducted during
periods of excessive or abnormal cold, heat, wind, rain, or other inclement
weather that individually or collectively may reduce the likelihood of detection.
Any detections of LBV are to be mapped with behavior tracked across
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detections/sightings. The qualified biologist must have experience with nesting
ecology and behavior of LBV to determine pre-nesting/nesting behavior.
o If construction activities within the 300-foot buffer begin prior to March 15,
then weekly surveys will be conducted by a qualified biologist starting on
March 15 (or on the following Monday, if the 15th occurs during a
weekend) and will continue until one or more individuals are detected, or
until May 1 if no LBV are detected.
o If construction activities within the 300-foot buffer begin after March 15 but
before May 1, then at least three weekly surveys will be conducted starting
one week prior to the initiation of activities and will continue until May 1, or
later to complete the minimum three surveys, unless one or more LBV
individuals are detected.
o If sound barriers are installed prior to the initiation of construction
activities, and one or more LBV individuals are detected within the 300-
foot buffer, then noise monitoring will be conducted as described in the
Sound Barrier measure. If the sound barriers are demonstrated to be
effective at reducing noise below the stated thresholds, then additional
noise monitoring will not be required. However, the monitoring biologist
will inspect the sound barriers weekly to ensure the barriers are intact and
will advise the Project proponent if repairs are needed to the sound
barriers.
· Noise Monitoring – If sound barriers are not installed prior to the start of
construction activities, then daily noise monitoring will be conducted between
March 15 and September 30 if LBV are detected at any point during the pre-
construction/clearance surveys. A qualified biological monitor will measure noise
levels at the edge of the occupied habitat and work shall cease if, at any time,
noise levels exceed 60 dB due to construction activities, or the existing ambient
level if that is over 60 dB. Work will re-start if sound barriers are installed and are
demonstrated to effectively reduce monitoring. If it is determined that the sound
barriers are not sufficiently reducing noise levels, then the work will remain
halted, and the Project proponent will contact CDFW and USFWS to discuss if
other methods are available to reduce noise levels below the stated threshold.
· Lighting – Any night lighting needed during construction within 300 feet of
occupied vireo habitat will be down shielded or directed away from the vireo
habitat to prevent the illumination of the adjacent habitat.
· Dust Emissions – The Project, as a part of standard best management
practices (BMPs) pursuant to South Coast Air Quality Management District Rule
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403, will introduce dust control measures for the duration of construction
activities to minimize any dust-related effect on adjacent vireos.
3.3.2 Indirect Effects
The Project is designed to avoid or otherwise minimize indirect effects to sensitive
MSHCP resources. The focus of the analysis is on hydrologic effects to the vernal
pools located in the adjacent proposed RCA Conserved Land, and downstream aquatic
resources in Alberhill Creek/Temescal Wash, as well as the effects of noise and lighting
on adjacent RCA Conserved Land.
Hydrology Effects
The Project is designed to avoid or otherwise minimize indirect effects to sensitive
MSHCP resources. The focus of the analysis is on hydrologic effects to the three vernal
pools located in the adjacent proposed RCA Conserved Land, and downstream aquatic
resources in the Alberhill Creek/Temescal Wash, as well as the effects of noise and
lighting on adjacent RCA Conserved Land. The Project is part of the overall watershed
for Alberhill Creek/Temescal Wash. The Project’s Hydrology Memorandum [Appendix E]
describes the Project site as being part of four smaller drainage areas (Watersheds A,
B, C and D) that each drain a specific area. Three of these watersheds each contain
one of the three vernal pools that are described above. Each of these smaller
watersheds are described below in detail, including the acreage of each watershed in
the existing condition, the flows associated with each watershed for the 2-, 5-, and 10-
year rainfall events, and the resources that each watershed drains to. The Hydrology
Memorandum includes an exhibit (Appendix B) depicting each watershed in the existing
condition. The Hydrology Memorandum evaluates the potential hydrologic effects of the
Project on the vernal pools and associated plant resources, and Alberhill Creek by
modelling the flow rates for the same rainfall events after Project implementation. The
goal of the Project is to ensure that the same or similar amounts of water reach the
adjacent Conserved Lands to mimic the existing condition. However, through the
modification of the site drainage, the four watersheds vary from the existing condition in
where the water is drawn from that feeds the different open space areas adjacent to the
Project. For example, the sheet flows from Watershed C in the existing condition that
originate from direct rainfall onto the site and flow towards Vernal Pool 1 will, in the
post-Project condition, drain towards Vernal Pool 3. To mimic the existing hydrologic
condition for Vernal Pool 1, the water draining into the modified Vernal Pool 1
watershed will come entirely from the improved sections of Pierce Street and Baker
Street to re-create what came from the original Watershed C. The proposed condition
is provided in Appendix C of the Hydrology Memorandum.
Watershed A – Watershed A is located on the southeastern side of the Project and has
an existing-condition tributary of approximately 165.20 acres, corresponding with
Drainage D (described above). The tributary watershed originates offsite to the south
and west, extending northeast to Baker Street and eventually to Alberhill Creek/
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Temescal Wash. Watershed A does not contribute to either of the three vernal pools,
but instead sheet flows directly to the offsite creek floodplain. Table 5-5 below
summarizes the flow rates for the 2-, 5- and 10-year rainfall events. In the proposed
condition, the Project will decrease the total watershed acreage slightly to 163.30 acres.
The flows that originate offsite will be directed towards a proposed flow-by basin along
the edge of the Project site. Flows will then bypass the Project through a public storm
drain that discharges on the northern side of Baker Street and continue down to
Alberhill Creek/Temescal Wash as they have done historically. In the proposed
condition, the flow rates will increase slightly for each of the three rainfall events
modelled, including from 84.20 cfs to 88.07 cfs in the 2-year event (4.6 percent), 132.10
cfs to 136.99 cfs in the 5-year event (3.7 percent), and from 197.60 cfs to 202.45 cfs in
the 10-year event (2.5 percent). These increases are negligible from an engineering
standpoint and are not expected to adversely affect downstream resources in Alberhill
Creek/Temescal Wash.
Watershed B – Watershed B is located north of Watershed A and has an existing-
condition tributary of approximately 27.79 acres. Watershed B originates offsite to the
southwest although the majority of watershed onsite. Sheet flows from the watershed
cross Baker Street and contribute to the hydrology of Vernal Pool 2. In the proposed
condition, the Project will increase the total watershed acreage slightly to 28.54 acres.
Once the sheet flows from Watershed B (and C) will be collected and treated via BMPs,
they are discharged into a proposed trough system. As concentrated flows leave each
pipe from the BMP structures, the flows will hit the splash wall of the trough and spread
out across the entire length of the trough system. The northern side of the trough
system will have six-inch openings every five feet that will help create a sheet flow
condition towards Vernal Pool 2 (and towards Vernal Pool 1) that mimics existing
condition. In the proposed condition, the flow rates will increase for each of the three
rainfall events modelled, including from 25.16 cfs to 27.27 cfs in the 2-year event (8.4
percent), 36.51 cfs to 38.77 cfs in the 5-year event (6.2 percent), and from 45.19 cfs to
47.41 cfs in the 10-year event (4.9 percent). These increases are negligible from an
engineering standpoint and are not expected to adversely affect Vernal Pool 2.
Furthermore, as noted above, Vernal Pool 2 will be enhanced (including a slight
increase in size) with the increase in hydrology expecting to benefit the proposed
enhancement of the vernal pool. As also noted above, Vernal Pool 2 will be monitored
for at least five years as part of the enhancement effort to document ponding metrics of
the pool (total basin area, depth and ponding duration).
Watershed C – Watershed C is located north of Watershed B and south of Watershed
D. Watershed C comprises 6.40 acres, nearly all of which is contained within the
Project site. Vernal Pool 1 is within Watershed C. The watershed begins at the top of a
hill and then flattens out as it approaches Baker Street. Sheet flows from the watershed
slow down as the flows reach the flatter area, with some proportion of the flows
reaching and crossing over Baker Street, some flows percolating into the ground and
continuing subsurface under Baker Street towards the vernal pool, and some of the
water not reaching vernal pool. The amount and proportion of water reaching the vernal
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pool varies depending on the level of storm event. The vernal pool is also heavily
dependent on direct vertical rainfall for the pool to inundate, requiring multiple rainfall
events for the soil particles to charge and the substrate to seal up allowing the pool to
hold water for a longer term. As part of GLA’s wet season fairy shrimp surveys
conducted in 2024, GLA began monitoring Vernal Pool 1 after initial measurable rainfall
in the middle of January 2024; however, the vernal pool did not exhibit prolonged
inundation to initiate fairy shrimp sampling for another two weeks. On February 2,
2024, the vernal pool was measured as 8 m by 6 m with a depth of 10 cm. By the
following week, the pool was measured as 50 m by 27 m with a depth of 30 cm, and
then because of off-and-on rain events, the vernal pool generally maintained those
dimensions until the middle of April. GLA biologists did not observe clear evidence of
sheet flows over the top of Baker Street and there are no road culverts at that location.
As such, it is GLA’s opinion that a higher proportion of the vernal pool hydrology is due
to direct vertical rainfall, while additionally supported (at least based on the rainfall
events observed in 2024) by a proportion of sheet flows that mostly (if not entirely)
reach the immediate vernal pool watershed via subsurface flow.
In the proposed condition, the portion of Watershed C that is southwest of Baker Street
will be become part of the new Watershed D that feeds Vernal Pool 3. In its place, a
new Watershed C will be created, drawing from the newly developed portions of Pierce
Street and Baker Street. The total acreage of the new Watershed C will be 6.20 acres.
This represents a slight decrease compared with the existing Watershed C, but the
acreage is less relevant when compared with the new source of water that will feed into
the remaining portions of the Vernal Pool 1 watershed northeast of Baker Street. The
water collected from the road rights-of-way will be collected and treated via BMPs, and
then discharged into the proposed trough system located adjacent to the immediate
Vernal Pool 1 watershed. As concentrated flows leave each pipe from the BMP
structures, the flows will hit the splash wall of the trough and spread out across the
entire length of the trough system. The northern side of the trough system will have six-
inch openings every five feet that will create a sheet flow condition towards Vernal Pool
1, mimicking the existing condition. However, the trough system will be constructed on
the side of Baker Street facing the vernal pool, providing a more direct sheet flow
release towards the immediate vernal pool watershed. Whereas in the existing
condition, most of the sheet flows do not reach the vernal pool side of Baker Street as
surface flows. In the proposed condition, the flow rates will slightly decrease for each of
the three rainfall events modelled, including from 5.46 cfs to 5.06 cfs in the 2-year event
(7.3 percent), 7.84 cfs to 7.30 cfs in the 5-year event (6.9 percent), and from 9.64 cfs to
9.01 cfs in the 10-year event (6.5 percent). However, when considering the nature of
the existing condition, by constructing the trough system in closer proximity to the
immediate vernal pool watershed, the relative amount of surface and subsurface flows
reaching the pool basin might increase by a small margin, or at least will represent less
of a decrease than has been modelled. As part of the Project’s mitigation activities, the
hydrology of Vernal Pool 1 will be monitored post-project for at least five years to
document the ponding metrics of the vernal pool compared with what was observed in
2024.
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Watershed D – Watershed D is located on the northwestern part of the Project and has
an existing-condition tributary of approximately 217.79 acres, corresponding with
Drainages A, B and C described above. The portion of the watershed feeding Drainage
A originates offsite from a basin at the Terracina development tract into Drainage A,
conveying flows towards and through the Project site before entering Vernal Pool 3 on
the northern side of Baker Street. Flows feeding Drainage B onsite become sheet flows
that cross Baker Street in the proposed open space located west of Vernal Pool 3.
Flows feeding Drainage C also enter Vernal Pool 3 after crossing Baker through a
separate culvert pipe. In the proposed condition, the Project will increase the total
watershed acreage slightly to 220.06 acres. Flows originating offsite from the Terracina
tract will enter a proposed debris basin at western edge of the Project site and then flow
through the Project site through a public storm that discharges into a separate trough
system that is like what is described above for Watersheds B and C (Vernal Pools 2 and
1). The trough system will also accept onsite runoff generated within the watershed.
This separate trough system will mimic the existing condition flows to Vernal Pool 3 by
providing both a point source and supportive sheet flow. The trough system is designed
to let larger flows during high storm events continue down the existing flowline that
leads to Alberhill Creek/Temescal Wash, while still operating returning concentrated
flows to sheet flow during smaller storm events. In the proposed condition, the flow
rates will increase for each of the three rainfall events modelled, including from 154.14
cfs to 178.18 cfs in the 2-year event (15.6 percent), 230.40 cfs to 244.60 cfs in the 5-
year event (6.2 percent), and from 284.45 cfs to 290.89 cfs in the 10-year event (2.3
percent). These increases are not expected to adversely affect Vernal Pool 3, nor
downstream resources associated with Alberhill Creek/Temescal Was. Furthermore, as
noted above, Vernal Pool 3 will be enhanced (expanded in size) with the increase in
hydrology benefitting the proposed enhancement of the vernal pool. As also noted
above, Vernal Pool 3 will be monitored for at least five years as part of the
enhancement effort to document ponding metrics of the pool.
Table 3-6. Comparison of Existing and Proposed Hydrologic Conditions
Watershed A
Condition Acreage Q2 (cfs) Q5 (cfs) Q10 (cfs)
Existing 165.20 84.20 197.59 332.50
Proposed 163.30 88.07 178.35 299.61
Change +4.6 % +3.7 % +2.5 %
Watershed B (Vernal Pool 2)
Condition Acreage Q2 (cfs) Q5 (cfs) Q10 (cfs)
Existing 27.79 25.16 36.51 45.19
Proposed 28.54 27.27 38.77 47.41
Change +8.4 % +6.2 5 +4.9 %
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Watershed C (Vernal Pool 1)
Condition Acreage Q2 (cfs) Q5 (cfs) Q10 (cfs)
Existing 6.40 5.46 7.84 9.64
Proposed 6.20 5.06 7.30 9.01
Change -7.3 % -6.9% -6.5%
Watershed D (Vernal Pool 3)
Condition Acreage Q2 (cfs) Q5 (cfs) Q10 (cfs)
Existing 217.79 154.14 230.40 284.45
Proposed 220.06 178.18 244.60 290.89
Change +15.6 % +6.2 % + 2.3 %
Lighting
Night lighting shall be directed away from the MSHCP Conservation Area to protect
species within the MSHCP Conservation Area from direct night lighting. If night lighting
is required during construction, shielding shall be incorporated to ensure ambient
lighting in the MSHCP Conservation Area is not increased.
The Project will incorporate an onsite lighting design that provides the required lighting
levels for normal operation onsite. Exterior lighting can be designed as downward
facing to prevent unnecessary foot candles outside of the Project boundary. The City of
Lake Elsinore requires public streetlights every 200 feet on both sides of newly
constructed public roadways per Lake Elsinore standards 503 and 508. The Project will
work with the City to design a public roadway lighting design that is sensitive to
neighboring sensitive receptors.
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.
The Project is not expected to adversely affect wildlife in the adjacent/proximal
Conservation Area due to noise. The onsite portion of the Project is buffered from the
proposed RCA Conserved Lands by the Baker Street improvements. Additionally, the
proposed Conserved Lands adjacent to the development footprint does not contain
habitat that would support wildlife sensitive to noise effects. The portion of existing
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Nichols Road that crosses Alberhill Creek is adjacent to habitat occupied by least Bell’s
vireo and other riparian birds. The proposed re-surfacing will either be performed
outside of the vireo season, or if work is performed during the vireo season, then noise
attenuation measures will be implemented, if needed.
4.0 NARROW ENDEMIC PLANT SPECIES MITIGATION (SECTION 6.1.3)
4.1 Methods
Volume I, Section 6.1.3 of the MSHCP requires that within identified Narrow Endemic
Plant Species Survey Areas (NEPSSA), site-specific focused surveys for Narrow
Endemic Plants Species will be required for all public and private projects where
appropriate soils and habitat are present. The Project site occurs within the NEPSSA for
the following target species:
· Munz’s onion (Allium munzii)
· San Diego ambrosia (Ambrosia pumila)
· Slender-horned spineflower (Dodecahema leptoceras)
· Many-stemmed dudleya (Dudleya multicaulis)
· Spreading navarretia (Navarretia fossalis)
· California Orcutt grass (Orcuttia californica)
· San Miguel savory (Clinopodium chandleri)
· Hammitt’s clay-cress (Sibaropsis hammittii)
· Wright’s trichocoronis (Trichocoronis wrightii var. wrightii).
GLA biologists performed general and focused plant surveys for the Project site in both
2020 and 2022. GLA biologists Jillian Stephens and David Moskovitz performed plant
surveys for most of the onsite part of the Project on April 13, and 23, and May 5 and 20,
2020, as well as for the proposed RCA Conserved Land. In 2022, GLA biologists Jillian
Stephens and Wanisa Jaikwang repeated surveys for the onsite portion, including
expanded areas that were not surveyed in 2020, as well as the offsite components. The
2022 surveys were conducted on March 14, April 4 and 6, and May 3, 2022. Surveys
were conducted in accordance with accepted botanical survey guidelines (CDFW 2018,
CNPS 2001, Nelson 1984, USFWS 2000). As applicable, surveys were conducted at
appropriate times based on precipitation and flowering periods. An aerial photograph, a
soil map, and/or a topographic map were used to determine the community types and
other physical features that may support sensitive and uncommon taxa or communities
within the Project site. Surveys were conducted by following meandering transects
within target areas of suitable habitat. All plant species encountered during the field
surveys were identified and recorded following the above-referenced guidelines.
Scientific nomenclature and common names used in this report follow Baldwin et al.
(2012), and Munz (1974).
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4.2 Results/Impacts
One Narrow Endemic Plant species (San Diego ambrosia) was detected at the Project
site. The majority of plants within the Project site were at two locations in the southern
end of the site. Additional locations with fewer numbers of plants included one location
in the central portion of the site, three locations adjacent to Pierce Street, and one
location adjacent to Nichols Road [Exhibit 7 – Rare Plants Map]. GLA biologists
estimated 9,000 plants over 0.44 acre of habitat with long-term conservation value for
the species. These locations of San Diego ambrosia within the Project site have been
previously documented in the public record by other botanists, including by Steve Boyd
(1997), Mitch Provance (2005), and A.C. Sanders (2014 and 2015). Three other prior
records of San Diego ambrosia are within the proposed RCA Conserved Land, including
by F.M. Roberts (1997), D.E. Bramlet (1997), and Mitch Provance (2005). GLA
surveyed the areas of these prior records but did not detect San Diego ambrosia at
those locations. However, as these other locations are within the Project’s proposed
Conserved Lands, these locations will be protected by the Project. Additional San
Diego ambrosia known from the vicinity of the Project include one location northwest of
the Project site on the northern side of Nichols Road (2011 A.C Sanders) and two
locations to the southeast (2015) A.C. Sanders). Neither of these locales will be
affected by the Project.
Besides the San Diego ambrosia, one other Narrow Endemic Plant species (Munz’s
onion) is known from the vicinity of the Project site based on prior records. Both
locations are southeast of the Project site, including one record by Scott D. White
(2000) and another by S. Mashayehki (2010). Neither of these locales will be affected
by the Project.
The Project will directly impact San Diego ambrosia that, as noted above in Section 6.2,
was detected in several locations at the Project site, including in the southern portion of
the Industrial footprint (onsite) and within the proposed offsite road improvements along
Pierce Street and Nichols Road. Because the Project site is within the NEPSSA for San
Diego ambrosia and the species was detected, the Project is required by the MSHCP to
identify habitat with long-term conservation value for the species and to avoid at least
90 percent of the habitat. GLA has identified 0.44 acre of habitat with long-term
conservation value for the ambrosia within the Project footprint, all of which will be
impacted by the Project. As such, a DBESP must be approved to authorize impacts to
San Diego ambrosia.
4.3 Mitigation and Equivalency
4.3.1 Direct Effects
All impacts to San Diego ambrosia habitat with long-term conservation value will be
mitigated within the proposed RCA Conserved Lands. To mitigate the loss of 0.44 acre
of habitat with long-term conservation value for San Diego ambrosia, the Project will
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develop and implement a San Diego Ambrosia Translocation Plan (Ambrosia Plan).
The Ambrosia Plan will identify proposed receiver sites within the Project’s Conserved
Lands were ambrosia stems and soils will be translocated to. The receiver sites will be
located within a minimum of 1.32 acres of contiguous degraded habitat in the Alberhill
Creek floodplain to be restored by the Project [Exhibit 10 – Plant Restoration Map]. The
proposed restoration area consists of an area dominated by non-native grasses and
forbs where San Diego ambrosia was detected in the past (per public records), but due
to overgrowth by invasive vegetation, San Diego ambrosia was not detected during
plant surveys for the Project.
The general components of the Ambrosia Plan will include the salvage and collection of
individual ambrosia stems from the donor sites. Approximately 10-percent of the stems
would be salvaged and stored at a nursery facility for propagation, to be held as a
contingency source. Another 20-percent of the stems would be translocated directly to
the receiver sites, where the stems will be transplanted into study plots. The remaining
stems will be collected along with the soils, which will be bulk transferred to the receiver
sites. The expectation is that through rhizome spread, both within the plots and between
the plots, the number of stems will increase. The Ambrosia Plan will identify proposed
salvage and translocation methods from the donor sites, site preparation methods of the
receiver sites, plant palettes, success criteria, maintenance/long-term monitoring
procedures, and contingency measures. The Ambrosia Plan will be submitted to the
RCA and Wildlife Agencies for review and approval prior to implementation.
GLA met with the RCA and Wildlife Agencies on September 26, 2024, to discuss the
ambrosia mitigation concept. The RCA and Wildlife Agencies addressed an expectation
of restoring habitat with long-term conservation value at a minimum 3:1 ratio (1.32
acres) versus the impacts (0.44 acres) and that stem counts after a minimum of five
years would be three times the number of stems salvaged and translocated to the
receiver site. GLA proposes to translocate the 20-percent of stems to study plots that
would be distributed throughout out the receiver habitat, with soil from the remaining
impacted habitat to be spread in the areas surrounding the plots. The stems (and
rhizomes) salvaged as part of the 20-percent collection would be planted in the study
plots with some minimum spacing (to be determined) that would allow the rhizomes to
spread in multiple directions from each source “stem”, theoretically allowing the
rhizomes to fill in the spaces between the translocated stems over time, which in turn
would produce a proportional number of new stems. Although this would theoretically
provide the space to produce at least three times the number of stems compared with
what is translocated, GLA is concerned how long it would take to achieve this
performance standard, and whether it is reasonable to expect that the restoration site
will produce at least three times the number of translocated stems. Provided that the
receiver site soils are compatible, the site is prepared properly, the plots are established
as approved, the stem counts are deemed accurate prior to salvage and the salvage is
performed properly, and site maintenance is deemed successful, then everything will
have been done to support the translocation efforts. Furthermore, as propagation
through seed is not an option, then the efforts will be limited to the stems that can be
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translocated. The MSHCP requirement in mitigating the impacts to habitat and species
is to result in preservation that is at least biologically equivalent, if not superior, to the
existing condition. The proposed restoration area of 1.32 acres would replace the
impacted 0.44 acre of existing habitat at a minimum 3:1 ratio. Furthermore, the
proposed 1.32 acres of habitat would consist of one larger and contiguous block of
habitat, compared with 0.44 acre of existing habitat consisting of six smaller patches of
habitat scattered throughout the Project site. The restoration site will be managed to
minimize invasive plant species at maximum levels of percent cover to be described in
the Ambrosia Plan.
As noted above, the conditions will have been created with the restored receive habitat
to theoretically achieve stem numbers at a ratio of 3:1 (or greater). However, if in a
minimum timeframe of five years the stem numbers reach at least a 2:1 ratio versus the
existing condition, then combined with a 3:1 increase in habitat with long-term
conservation value, attaining stem numbers at least two times greater should be
considered at least biologically equivalent (if not superior). As such, this is the minimum
standard that GLA proposes. If the mitigation achieves a minimum 2:1 ratio of stems in
at least five years following translocation, then GLA proposes that the 10-percent stem
collection that will have been propagated in a nursery, will be translocated to the
mitigation site, which would further increase the population within the mitigation site.
GLA recently collected soil samples from the donor and proposed receiver sites, and the
soil samples were analyzed for compatibility to support the proposed translocation efforts.
The locations of the soil samples are included on Exhibit 10. The Project proponent will
provide the results of the soils analysis to the RCA and Wildlife Agencies as part of the
review process for the Translocation Plan.
4.3.2 Indirect Effects
The Project will not indirectly affect Narrow Endemic Plants. Besides the San Diego
ambrosia that will be directly impacted by the Project, there is no adjacent ambrosia or
other NEPSSA species that would be impacted. As noted above, the Project proposes
to mitigate the direct impacts to ambrosia in the Alberhill Creek floodplain. The
proposed mitigation area is far enough removed from the development footprint that
indirect impacts are not expected. As discussed above in Section 3.3.2, the Project is
designed such that the proposed hydrologic condition will mimic the existing condition
such that indirect effects are not anticipated.
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5.0 ADDITIONAL SURVEY NEEDS (SECTION 6.3.2)
5.1 Criteria Area Species Survey Area - Plants
Note that there are no survey areas for these designated plant species outside of the
MSHCP Criteria Area.
5.1.1 Methods
The Project site occurs within the CAPSSA for the following target species:
· Thread-leaved brodiaea (Brodiaea filifolia)
· Davidson’s saltscale (Atriplex serenana var. davidsonii)
· Parish’s brittlescale (Atriplex parishii)
· Smooth tarplant (Centromadia pungens spp. laevis)
· Round-leaved filaree (California macrophylla)
· Coulter’s goldfields (Lasthenia glabrata ssp. coulteri)
· Little mousetail (Myosurus minimus ssp. apus)
GLA biologists performed general and focused plant surveys for the Project site in both
2020 and 2022. GLA biologists Jillian Stephens and David Moskovitz performed plant
surveys for most of the onsite part of the Project on April 13, and 23, and May 5 and 20,
2020, as well as for the proposed RCA Conserved Land. In 2022, GLA biologists Jillian
Stephens and Wanisa Jaikwang repeated surveys for the onsite portion, including
expanded areas that were not surveyed in 2020, as well as the offsite components. The
2022 surveys were conducted on March 14, April 4 and 6, and May 3, 2022. Surveys
were conducted in accordance with accepted botanical survey guidelines (CDFW 2018,
CNPS 2001, Nelson 1984, USFWS 2000). As applicable, surveys were conducted at
appropriate times based on precipitation and flowering periods. An aerial photograph, a
soil map, and/or a topographic map were used to determine the community types and
other physical features that may support sensitive and uncommon taxa or communities
within the Project site. Surveys were conducted by following meandering transects
within target areas of suitable habitat. All plant species encountered during the field
surveys were identified and recorded following the above-referenced guidelines.
Scientific nomenclature and common names used in this report follow Baldwin et al.
(2012), and Munz (1974).
In addition to performing focused plant surveys within the Project site, GLA reviewed
species databases, including the California Natural Diversity Database (CNDDB) and
the Consortium of California Herbaria, to identify prior records of Narrow Endemic
Plants know from within and/or adjacent to the Project site.
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5.1.2 Results/Impacts
GLA biologists detected one Criteria Area Plant species (Coulter’s goldfields) that is
described for the CAPSSA associated with the Project site. GLA also detected the San
Jacinto Valley crownscale, which is a Criteria Area Plant species, but not one that is
described for the applicable CAPSSA. However, the crownscale is associated with
Vernal Pool 1, and so the crownscale is relevant to the Project pursuant to the MSHCP
Riparian/Riverine and Vernal Pool Policies (Section 6.1.2).
Coulter’s goldfields was detected in several locations within the Project site, including
the three vernal pools as well as locations within the proposed RCA Conserved Lands
nearer to Alberhill Creek. The majority of Coulter’s goldfields are associated with Vernal
Pool 1 and 3 [Exhibit 9 – Rare Plants Map]. GLA biologists mapped approximately
9,000 plants and based on those detections identified approximately 2.70 acres of total
habitat with long-term conservation value, the majority of which will not be directly
impacted by the Project. The locations of Coulter’s goldfields within the Project site have
been previously documented in the public record by other botanists, including by A.C.
Sanders (2008), D.E. Bramlet, R.L. Allen and F.M. Roberts (2011), and Mitch Provance
(2005 and 2017)2.
As noted above, the San Jacinto Valley crownscale is associated with Vernal Pool 1.
Crownscale individuals were most abundant in and around the vernal pool basin within
the proposed Conservation Land, but a smaller number of individuals (approximately
10) were mapped outwards from the pool basin closer to Baker Street. These
individuals occur in similar alkaline soils associated with the broader watershed of the
vernal pool.
GLA did not detect any other Criteria Area Plants besides Coulter’s goldfields and the
San Jacinto Valley crownscale. However, the Consortium of California Herbaria has
one University of California, Riverside (UCR) Herbarium record for little mousetail,
which was documented by Mitch Provance in 2017. The UCR record describes
mousetail occurring with other vernal pool indicator plants in a pool adjacent to Baker
Street. Based on the associated species noted by the record, it was presumably
associated with Vernal Pool 3, but again the presence of little mousetail was not
confirmed during GLA’s plant surveys.
The only other Criteria Area Plant species known from the vicinity of the Project site is
round-leaved filaree. There are two records of the species located southeast of the
Project site, although neither of these records are within the CAPSSA. One record is
within about 150 feet of the Project site (A.C. Sanders 2011), while the second record
(Mitch Provance 2017) is about 450 feet from the Project site.
2 CCH2 Portal. 2023. https://cch2.org/portal/index.php. Accessed on 12/11/23. University of California,
Riverside Herbarium Record.
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The Project will impact Coulter’s goldfields associated with Vernal Pool 3 due to the
construction and maintenance of the adjacent spreading structure. Because the Project
site is within the CAPSSA for Coulter’s goldfields, the Project is required by the MSHCP
to identify habitat with long-term conservation value for the species and to avoid at least
90-percent of the habitat. GLA has identified 2.70 acres of habitat with long-term
conservation value for Coulter’s goldfields, including 2.61 acres associated with the
three vernal pools. The proposed Project will directly impact 0.50 acre of the habitat (20
percent) of the habitat at the edge of Vernal Pool 3. As such, a DBESP must be
approved to authorize impacts to Coulter’s goldfields.
The Project will directly impact approximately 10 individuals (based on GLA’s plant
surveys) of San Jacinto Valley crownscale outside of the Vernal Pool 1 ponding basin,
but within the broader watershed of the pool. As noted above in Section 5.2.3,
hydrologic modelling indicates an approximately 7 percent decrease in flows from the
Vernal Pool 1 watershed over the 2-, 5, and 10-year rainfall events. However, when
considering the nature of the existing condition, by constructing the trough system in
closer proximity to the immediate vernal pool watershed, the relative amount of surface
and subsurface flows reaching the pool basin is likely to increase. Therefore, what is
modelled as a hydrologic decrease at Baker Street is likely to be closer to, if not slightly
exceeding, the existing hydrologic condition that supports the vernal pool.
As part of the Project’s mitigation activities, the hydrology of Vernal Pool 1 will be
monitored post-project for at least five years to document the ponding metrics of the
vernal pool compared with what was observed in 2024.
Although little mousetail was not detected within any of the vernal pools during GLA’s
plant surveys, based on the 2017 record of little mousetail at the property it is possible
that the record is associated with Vernal Pool 3 and that the partial impacts to Vernal
Pool 3 might impact little mousetail. If present, impacts would be up to 0.16 acre of
habitat with long-term conservation value, as that is the acreage of the vernal pool that
would be impacted by the Project.
5.1.3 Mitigation and Equivalency
To mitigate the loss of 0.50 acre of habitat with long-term conservation value for
Coulter’s goldfields, the Project will restore/expand Coulter’s goldfields habitat in two
areas. The first area consists of the expansion of Vernal Pool 3 by approximately 0.75
acre [Exhibit 10 – Plant Restoration Map]. The second area consists of the expansion
of another 0.75-acre area in the Alberhill Creek floodplain adjacent to an existing
population of Coulter’s goldfields and vernal barley. If little mousetail presently occurs in
Vernal Pool 3, then the expansion of the vernal pool would mitigate those impacts, as it
would address all vernal pool flora associated with Vernal Pool. However, because
there was no confirmation of little mousetail during GLA’s surveys, there will not be any
performance standards specific to little mousetail, as there is no guarantee of little
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mousetail propagules being present in the edge portion of the vernal pool to be
impacted where soil inoculum would be collected prior to impact.
The Project will develop a HMMP to address the mitigation efforts. The HMMP will, at a
minimum, include details about the type of mitigation, acreages, when the mitigation
would be implemented, plant palettes, site preparation, weeding plan, success
criteria/performance standards, monitoring plan (e.g., years/duration, frequency, etc.),
reporting, the proposed management entity, and contingency measures in the event the
mitigation is not successful. The type of contingency measures would depend on which
success criteria/performance standards have not been met. If the mitigation areas are
not meeting plant coverage and/or non-native criteria, then additional plant
remediation/maintenance efforts would be implemented, and the monitoring period
would be extended. The HMMP will be submitted to the RCA and Wildlife Agencies for
review and approval.
Although the Project is not subject to the Criteria Area Plant policies relative to the San
Jacinto Valley crownscale, because the Project site is not in the CAPSSA for the
crownscale the Project is subject to the Section 6.1.2 policies pertaining to vernal pools.
Because the crownscale occurs within Vernal Pool 1 and its immediate watershed,
impacts to the crownscale within the watershed will require mitigation. Specifically, seed
will be collected from crownscale individuals prior to any disturbance of the site, and
that seed will be transferred directly to Vernal Pool 1 to supplement the existing flora of
the pool. This seed collection/transfer will also be addressed in the HMMP.
5.2 Burrowing Owl
5.2.1 Methods
The Project site is within the survey area for the burrowing owl (Athene cunicularia).
As such, the MSHCP requires that the Project evaluate impacts to the burrowing owl
through habitat assessments/focused surveys.
Focused surveys are required to be conducted pursuant to the 2006 MSHCP Burrowing
Owl Survey Instructions. The Burrowing Owl Survey Instructions are divided into three
components, including Step I (habitat assessment), Step II-A (focused burrow survey),
and Step II-B (focused burrowing owl survey). The guidelines stipulate four focused
survey visits (Step II-B) be conducted on separate dates between March 1 and August
31.
GLA initially evaluated most of the proposed development footprint for burrowing owls in
2020, including the Step I habitat assessment and preliminary burrow mapping (Step II-
A). GLA biologist David Smith performed visits on April 16 and 28, 2020. The entire
Project site was evaluated for burrowing owls in 2022, including approximately 75 acres
of potentially suitable habitat that was subject to focused burrowing owl surveys (Step II-
B). As described above in Section 2.1, the total area of proposed development is 90.94
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acres, including 65.81 acres associated with the Industrial Facility (onsite), 6.11 acres of
Baker Street improvements, 2.73 acres identified as the City Maintenance Area
northeast of Baker Street, and Additional Street Improvements (16.29 acres). Initial
transects were walked within the onsite portion of the Project and along the various
offsite alignments to identify all suitable burrows. Burrows were limited to the onsite
portion of the Project and within the City Maintenance Area; however, burrows were not
detected within the alignments of the Additional Street Improvements, nor within the
Baker Street alignment. As such, focused burrowing owl surveys were concentrated in
the onsite portion of the Project, the City Maintenance Area, and immediately adjacent
portions of the proposed RCA Conserved Lands where burrows were also mapped.
These collective areas account for the approximately 75 acres of lands surveyed for
burrowing owls. Step II-B of the Survey Instructions requires a minimum of four survey
visits, indicating that a single biologist should not survey more than 100 acres per day.
As the survey area for the Project consisted of 75 acres, the area could be covered by a
single biologist in one day. GLA biologist Stephanie Cashin performed the focused owl
surveys on March 9, April 4, May 2, and June 3, 2022.
The burrowing owl survey visits are to be conducted during a period from one hour prior
to sunrise to two hours after sunrise or two hours before sunset to one hour after
sunset. All survey visits were conducted in the morning within the allotted timeframe.
The surveys were conducted during weather that was conducive to observing owls
outside their burrows and detecting burrowing owl sign, and not during rain, high winds
(> 20 mph), dense fog, or temperatures over 90 °F. Table 5-1 summarizes the focused
burrowing owl surveys conducted for the Project.
Table 5-1. Summary of Burrowing Owl Surveys
Survey Date Biologist(s) Survey
Period
Time
Start/End
Temperature
(°F)
Start/End
Wind Speed
(mph)
Cloud
Cover
(%)
3/9/2022 SC 0600/0815 40/54 0-2 0
4/4/2022 SC 0600/0805 51/58 0-3 0
5/2/2022 SC 0600/0830 57/63 0-1 0
6/3/2022 SC 0600/0810 55/60 0-1 50
SC = Stephanie Cashin
Surveys were conducted by walking meandering transects throughout areas of suitable
habitat. Exhibit 11 identifies the burrowing owl survey areas at the Project site,
including a 500-foot visual survey area around the Project site. Transects were spaced
at a maximum of 30 meters (100 feet) apart from each other, adjusting for vegetation
height and density, to provide adequate visual coverage of the survey areas. At the
start of each transect, and at least every 100 meters along the transects, the survey
area was scanned for burrowing owls using binoculars. All suitable burrows were
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inspected for diagnostic owl sign (e.g., pellets, prey remains, whitewash, feathers,
bones, and/or decoration) to identify potentially occupied burrows. The 500-foot visual
survey area was at least inspected with binoculars but was also accessed on foot where
feasible. The results of the burrowing owl surveys are documented in Section 4.0 of this
report.
5.2.2 Results/Impacts
No burrowing owls were detected within the Project site during focused surveys. Exhibit
11 provides the locations of areas surveyed, including approximate transect locations as
well as the locations of suitable burrows that were mapped. Burrows were scattered
throughout the onsite portion of the Project, with many concentrated along a fence line
within the proposed RCA Conserved Land. No burrowing owl sign was observed at any
of the burrows within the disturbance limits, but a single owl pellet was observed at a
burrow within the RCA Conserved Land along the fence line. It was not clear how old
the pellet was but given the lack of other sign and that no owls were observed during
the surveys, the pellet likely indicates a transient owl that was not occupying the site
during the focused surveys.
Based on the absence of burrowing owls within the disturbance limits, the Project will
not impact habitat with long-term conservation value.
5.2.3 Mitigation and Equivalency
Although burrowing owls were not detected during focused surveys, because the site
has the potential to support burrowing owls, pre-construction surveys will be required to
prevent harm to burrowing owls, should individuals occupy the site in the future. The
following burrowing owl measure will apply to the Project:
· Pre-construction burrowing owl surveys will be conducted in areas of suitable
habitat not more than 30 days prior to the initiation of ground disturbance (e.g.,
vegetation clearing, clearing and grubbing, tree removal, site watering, equipment
staging, grading, etc.) to ensure that no owls have colonized the site in the days or
weeks preceding the ground-disturbing activities. If burrowing owls have colonized
the project site prior to the initiation of ground-disturbing activities, the project
proponent will immediately inform the Regional Conservation Authority (RCA) and
the Wildlife Agencies and will need to coordinate further with RCA and the Wildlife
Agencies, including the possibility of preparing a Burrowing Owl Protection and
Relocation Plan, prior to initiating ground disturbance. If ground-disturbing
activities occur, but the site is left undisturbed for more than 30 days, a pre-
construction survey will again be necessary to ensure burrowing owl has not
colonized the site since it was last disturbed. If burrowing owl is found, the same
coordination described above will be necessary.
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5.3 Mammals
The Project site is not located within a mammal survey area. As such, focused surveys
are not required for designated mammal species and there are no other requirements
applicable to the Project for mammals.
5.4 Amphibians
The Project site is not located within an amphibian survey area. As such, focused
surveys are not required for designated amphibian species and there are no other
requirements applicable to the Project for amphibians.
6.0 DELHI SANDS FLOWER-LOVING FLY
The Project site is not located within Delhi soils mapped within the MSHCP baseline
data, and therefore habitat assessments/focused surveys are not required for the Delhi
Sands flower-loving fly (Rhaphiomidas terminatus abdominalis).
7.0 REFERENCES
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, 39p.
https://www.fws.gov/ventura/endangered/species/surveys-protocol.html
USFWS. 2001. Least Bell’s Vireo Survey Guidelines. January 19, 2001. Sacramento,
California: USFWS.
https://www.fws.gov/cno/es/Recovery_Permitting/birds/least_bells_vireo/
LeastBellsVireo_SurveyGuidelines_20010119.pdf
USFWS. 2016. A Natural History Summary and Survey Protocol for the Western
Distinct Population Segment of the Yellow-Billed Cuckoo. Prepared by M.
Halterman, M.J. Johnson, J.A. Holmes, and S.A. Laymon. Sacramento,
California: USFWS. May 2016.
https://www.fws.gov/southwest/es/arizona/Documents/SpeciesDocs/YellowBilled
Cuckoo/YBCU%20Survey%20Protocol_%20DRAFT_2016.pdf