HomeMy WebLinkAboutCDP 15-17; 6125 PASEO DEL NORTE; PRELIMINARY BIOLOGICAL RESOURCES EVALUATION; 2015-04-30HELIX Environmental Planning, Inc.
7578 El Cajon Boulevard
Suite 200
La Mesa, CA 91942
619.462.1515 tel
619.462.0552 fax
www.helixepi.com
April 30, 2015
Mr. Jeff Blair
BSD Builders, Inc.
8825 Rehco Road, Suite A
San Diego, CA 92121
HELIX
Environmental Planning .
BBI-01
Subject: Preliminary Biological Resources Evaluation for the Paseo Del Norte Open Space
Parcel
Dear Mr. Blair:
This letter briefly summarizes the results of a preliminary biological resources evaluation
performed by HELIX Environmental Planning, Inc. (HELIX) for an existing open space lot,
herein referred to as the "Paseo Del Norte Open Space Parcel" or "property", situated
immediately south of 6125 Paseo Del Norte in the City of Carlsbad, San Diego County,
California. This letter report is intended to facilitate ongoing review of a proposal put forth by
Surgery One to develop a parking lot extension within disturbed portions of the property.
METHODS
HELIX Principal Biologist, Karl Osmundson, performed an initial reconnaissance of the
property on April 25, 2015 and a general biological survey on April 29, 2015. The purpose of the
survey was to obtain a preliminary inventory of existing biological resources at the property,·
including vegetation communities/habitat types, dominant plant species, non-native and invasive
plant species, general wildlife use, and potential boundaries of jurisdictional waters and wetlands.
Particular attention was directed toward delineating the boundaries of sensitive upland and
wetland habitat types, in addition to identifying candidate areas for restoration and enhancement.
The potential boundaries of jurisdictional waters and wetlands were determined based only on
vegetation and hydrology indicators readily visible during the time of the general survey. The
scope of the survey was limited to a preliminary evaluation and did not include a complete
botanical inventory, rare plant survey, focused surveys for animal species, formal jurisdictional
delineation or establishment of wetland sampling points. Mapping performed for this evaluation
is preliminary and will require additional study.
Letter to Jeff Blair
April 30, 2015
EXISTING CONDITIONS SUMMARY
Page 2 of7
The enclosed Figure 1 depicts the proposed parking lot extension (proposed site plan) in relation
to the existing Carlsbad Habitat Management Plan hardline preserve areas (HMP hardline) and
the approximate boundaries of vegetation communities/habitat types, including boundaries of
potential coastal wetlands and· setback distances from those wetlands. Candidate areas for
restoration and enhancement are also depicted on Figure 1.
The general biological survey identified five habitat types within the survey area: southern
willow scrub-disturbed, coyote brush scrub-disturbed (Diegan coastal sage scrub: Baccharis-
dominated), non-native vegetation, eucalyptus woodland, and disturbed habitat. Of these habitat
types, s u he wiIL scru._.-_._co¥ot b e consider.e ens1t1 de
amework 0£ the adop_ted CarlshacLHM_ an certified ocal Coastal Pro
communities are afforded the qualifier of "disturbed" in this evaluation based primarily on
prevalence of non-native plant species and other anthropogenic-related disturbances, such as
trash. These communities are depicted in the mid-ground of Photo 1 below.
Photo 1: East-facing overview of southern willow scrub and coyote brush scrub in north-central
portion of the property.
Southern willow sc • pacian abita trp th • • ~_,.,===_;.;.,~,_rainage fea
an often supports ndition_ ithin the The southern willow scrub on the
property is associated with a lower reach of Encinas Creek. The boundaries of potential wetlands
were preliminarily delineated based on the presence of hydrophytic vegetation, which was
HELIX Environmental Planning
Letter to Jeff Blair
April 30, 2015
Page 3 of 7
generally taken to the riparian dripline. This is consistent with the one parameter definition used
for wetlands in the coastal zone. A ferma1 j1:1r-isdieti0nal oelineatio :was o ondcu',!~ct~e~:!!,!..JI-'-.............. _,
the general sur.vey and i-s require to moFe definitive.Jy establish coastal wetlan b1umd •
Under the framework of the Carlsbad HMP and LCP, wetlands require a protective buffer of 100
feet and riparian habitat requires a buffer of 50 feet. As depicted on Figure 1, the portion of the
proposed parking lot that abuts the HMP hardline is setback in excess of 50 feet from the riparian
dripline and potential coastal wetland boundary. At its shortest lenght, the setback is measured at
68 feet. At its longest length, the setback exceeds 130 feet. The average setback of the proposed
parking lot from the riparian dripline and potential coastal wetland boundary is about 90 feet.
Portions of the property are characterized by a relatively high percentage of non-native plant
species. As depicted on Figure 1, these portions of the property represent both upland ( coastal
sage scrub) and riparian/wetland (southern willow scrub) restoration and enhancement candidate
areas. Notable non-native and invasive plant species observed include Mexican fan palm
(Wahingtonia robusta), Canary Island date palm (Phoenix canariensis), tamarisk (Tamarix sp .),
castor bean (Ricinus communis), pampas grass (Cortaderia selloana), hottentot-fig (Carpobrotus
edulis), ice plant (Mesembryanthemum nodiforum), among others. Non-native invasive plant
species are prevalent throughout the property, as depicted in Photo 2 below.
Photo 2: South-facing overview of property depicting non-native invasive plant species that are
prevalent throughout the site.
HELIX
Environmental Planning
Letter to Jeff Blair
April 30, 2015
Page 4 of 7
Enhancement measures should target the removal of palms and tamarisk from the riparian scrub,
in addition to the removal of castor bean, pampas grass, and other non-native ornamentals
intermixed with natives in the upland scrub. Restoration measures should target conversion of
the larger patches and stands of pampas grass and ice plant into functioning upland and riparian
scrub. Photo 3 depicts the disturbed habitat targeted for parking lot extension and buffer
restoration.
Photo 3: Proposed parking lot and upland scrub buffer restoration opportunity on the slope.
Several southwestern spiny rush individuals were observed scattered throughout the property,
including highly disturbed areas characterized by disturbed habitat and targeted for parking lot
development. Southwestern spiny rush is not federally or state listed as endangered or threatened,
but is designated by the California Native Plant Society (CNPS) as a California Rare Plant Rank
(CRPR) 4.2 species. Although sensitive, this species is relatively widespread throughout the
reg10n.
HELIX Environmental Planning
Letter to Jeff Blair
April 30, 2015
Page 5 of 7
A typical specimen observed in the disturbed habitat is depicted below within Photo 4.
Photo 4: View of typical spiny rush observed in the disturbed habitat.
Portions of the property characterized by southern willow scrub and coyote brush scrub have a
low potential to support other rare plants known to the local area, although none were observed
during the general survey. In addition, several sensitive animal species have a low potential to
occur, including species such as least Bell's vireo (Vireo bellii pusillus) and yellow warbler
(Setophaga petechia) in the southern willow scrub, and Coronado Island skink (Eumeces
skiltonianus interparietalis) and silvery legless lizard (Anniella pulchra pulchra) in the coyote
brush scrub. No sensitive animal species were observed or otherwise detected during the general
survey. Existing disturbances, proximity to developments, and overall poor quality habitat
strongly reduce the potential for sensitive animals to occur.
CONCLUSIONS AND RECOMMENDATIONS
Based on the current parking lot design and the preliminary evaluation, adequate setbacks are in
place and no significant or unmitigable impacts on sensitive biological resources would be
expected to occur as a result of the parking lot extension. Potential coastal wetland boundaries
are conservatively delineated on Figure 1 to follow the dominance of hydrophytic vegetation or
riparian dripline (extent of southern willow scrub) in accordance with wetland definitions in the
coastal zone. The proposed parking lot setbacks, as currently designed, are measured at an
average distance of 90 feet (68 feet to 132 feet) away from the potential coastal wetland
boundaries. Portions of the setback buffer are characterized by marginal quality coyote brush -------
HELIX Environmental Planning
Letter to Jeff Blair
April 30, 2015
Page 6 of 7
scrub. The remaining portions of the buffer areas are mostly bare or heavily infested by non-
native and invasive plants, which present opportunities for substantial restoration and
enhancement of buffer and transition habitat. Other opportunities for enhancement exist within
the southern willow scrub. Non-native and invasive palm, tamarisk, castor bean, pampas grass,
and many others are prevalent throughout the property and could be treated for enhancement.
The overall quality of the existing habitat is considered low based on existing disturbance,
proximity to developments, and prevalence of non-native species. A single CNPS CRPR List 4.2
plant was incidentally observed throughout the property. Several other sensitive plant and animal
species have a low potential to occur, although the project would not be expected to have a
significant impact on any of them.
A wetland buffer reduction should be pursued in combination with project design features that
ensure avoidance and minimization of potential indirect impacts from project operation and
mitigation measures that ensure restoration, enhancement, and long-term preservation of habitat
to be avoided on the property.
The following project design features and measures are recommended:
• Dedicate open space and conservation easement or restrictive covenant over the open
space lot to prohibit encroachment, development, grading, or alterations within the lot.
• Prepare and implement a restoration and enhancement plan to target southern willow
scrub, coyote brush scrub, and transition and buffer areas.
• Select a conservation entity to manage the open space lot and easement areas for
conservation purposes. The San Diego Habitat Conservancy currently manages the open
space upstream to the north in the North County Habitat Bank.
• Prepare a Property Analysis Record or other acceptable method for estimating the cost of
management and monitoring the open space in perpetuity in accordance with the
requirements of the North County Multiple Habitat Conservation Plan (MHCP) and the
City's Open Space Management Plan.
• Provide a non-wasting endowment or other financial mechanism in an amount sufficient
for management and monitoring of the open space lot in perpetuity.
• Prepare a Preserve Management Plan to ensure adequate management of the open space
in perpetuity.
• Restrict all fire management activities completely within the development boundaries and
not within any of the HMP open space conservation areas or open space easement. Only
include low-fuel native species in landscaping to comply with HMP requirements.
• Prepare and implement an erosion control plan to protect areas susceptible to erosion on
the property and immediately adjacent to the HMP open space conservation and open
space easement areas.
• Use only native plant species in landscape palettes consistent with the adjacent native
vegetation communities. Prohibit the use of ornamental invasive species and limite the
use of fertilizers to prevent excess runoff from entering the HMP open space
conservation areas. Control irrigation of landscaping adjacent to the HMP conservation
HELIX Environmental Plannlng
Letter to Jeff Blair
April 30, 2015
Page 7 of 7
areas to prevent runoff from spreading into the preserve. Prohibit the use of cultivars of
native species to avoid genetic contamination of native species in the preserve areas.
• Install appropriate permanent fencing, such as five-foot-tall black vinyl-coated chain link
fence along the boundary of the open space to discourage human access.
• Install signage on the fence to educate and infom1 the public about the open space and to
prohibit access.
• Ensure lighting in the parking lot adjacent to the HMP preserve is of a minimum
necessary for safety and security, and that it is shielded and directed to shine downward
and not into the preserve area.
Successful implementation of these measures will ensure that sens1t1ve biological resources
within the property are avoided and setback from development, protected from indirect effects of
project operation, restored and enhanced to superior conditions, and preserved and properly
managed in perpetuity.
I appreciate the opportunity to provide you with this letter report. Please do not hesitate to
contact me at (619) 462-1515 or KarlO@helixepi.com if you have any questions or require
further assistance.
Sincerely,
Karl Osmundson
Biology Group Manager
Enclosures:
Figure 1: Biological Resources Map -Open Space Parcel
HELIX
Environmental Planning