HomeMy WebLinkAbout2013-04-03; Planning Commission; Resolution 6950
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A RESOLUTION OF THE PLANNING COMMISSION OF THE
CITY OF CARLSBAD, CALIFORNIA, APPROVING AN
ADDENDUM TO ENVIRONMENTAL IMPACT REPORT 04-02
TO ALLOW DREDGING AND IMPROVEMENTS FOR
ENHANCED FLOOD CONTROL ON PROPERTY
GENERALLY LOCATED AT AND NEAR THE
INTERSECTION OF EL CAMINO REAL AND CANNON
ROAD AND IN A PORTION OF RANCHO CARLSBAD IN
LOCAL FACILITIES MANAGEMENT ZONES 8, 14, 15, AND
24.
CASE NAME: AGUA HEDIONDA & CALAVERA CREEKS
CASE NO: EIR 04-02(A)
WHEREAS, City of Carlsbad, “Developer,” has filed a verified application with
the City of Carlsbad regarding property owned by Carlsbad Canterbury Association, Evans
Point Homeowners Association, Calavera Hills II LLC, and the multiple owners of the
Rancho Carlsbad residential community, “Owners,” with easements granted or dedicated to
the City of Carlsbad for road, drainage, open space, sewer, and maintenance purposes and
described as
A portion of Lot 148 of City of Carlsbad Tract No 96-07, Kelly
Ranch Village E, in the City of Carlsbad, County of San Diego, State of California, according to map thereof No. 13715, as
filed in the Office of the County Recorder of San Diego County
on December 31, 1998; a portion of Lot 195 of City of Carlsbad
Tract No. 91-3, Evans Point, in the City of Carlsbad, County of
San Diego, State of California, according to map thereof No.
13189, as filed in the Office of the County Recorder of San
Diego County on February 10, 1995; a portion of Parcel 1 of City of Carlsbad Minor Subdivision 96-08 in the City of
Carlsbad County of San Diego, State of California, according
to Parcel Map 17985, as filed in the Office of the County
Recorder of San Diego County on February 4, 1998, and;
Parcel 2 and a portion of the remainder parcel of City of
Carlsbad Minor Subdivision 92-01, Robertson Ranch, in the City of Carlsbad, County of San Diego, State of California,
according to map thereof No. 19804, as filed in the Office of the
County Recorder of San Diego County on August 3, 2005
("the Property”); and
PLANNING COMMISSION RESOLUTION NO. 6950
PC RESO NO. 6950 -2-
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WHEREAS, on January 16, 2008, the Planning Commission of the City of
Carlsbad certified Environmental Impact Report (EIR) 04-02, adopted the Candidate Findings of
Fact, and the Mitigation Monitoring and Reporting Program for AGUA HEDIONDA &
CALAVERA CREEKS (“Project”); and
WHEREAS, modifications have been made to the project as a result of the city
conducting additional engineering analysis and the resource agencies requesting project changes;
and
WHEREAS, in compliance with the California Environmental Quality Act
(“CEQA”), an Addendum to EIR 04-02 – EIR 04-02(A) (“Addendum”) was prepared to
determine if the preparation of a subsequent or supplemental EIR was required for the Project
changes; and
WHEREAS, the Planning Commission did on April 3, 2013, hold a duly noticed
public hearing as prescribed by law to consider said request; and
WHEREAS, the Addendum was presented to the Planning Commission and the
Planning Commission reviewed and considered the information contained in EIR 04-02, as
modified, including the Findings of Fact, as modified, and Mitigation Monitoring and Reporting
Program prior to approving the Project; and
WHEREAS, at said public hearing, upon hearing and considering all testimony
and arguments, examining the Addendum, analyzing the information submitted by city staff, and
considering any written and oral comments received, the Planning Commission considered all
factors relating to the Addendum.
NOW, THEREFORE, BE IT HEREBY RESOLVED by the Planning
Commission of the City of Carlsbad as follows:
A) That the foregoing recitations are true and correct.
. . .
PC RESO NO. 6950 -3-
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B) That based on the evidence presented at the public hearing, the Commission
APPROVES the addendum to AGUA HEDIONDA & CALAVERA
CREEKS – EIR 04-02(A), based on the following findings that are supported by
evidence in the Record.
Findings:
1. The Planning Commission of the City of Carlsbad does hereby find that the Addendum
has been prepared in accordance with requirements of the California Environmental
Quality Act (CEQA), the CEQA Guidelines, and the Environmental Review Procedures
of the City of Carlsbad.
2. The Planning Commission of the City of Carlsbad has reviewed, analyzed, and
considered the Addendum along with EIR 04-02 prior to APPROVAL of the Project,
and it reflects the independent judgment of the City of Carlsbad Planning Commission.
3. The Planning Commission of the City of Carlsbad does hereby find that adopting of
an Addendum to EIR 04-02 is appropriate and in conformance with CEQA in this
case because some changes or additions to EIR 04-02 are necessary, but none of the
conditions described in Section 15162 and 15163 of the CEQA Guidelines calling
for preparation of a subsequent or supplemental EIR have occurred, in that:
a. There are no significant new environmental effects and no substantial
increase in the severity of a previously identified significant effect. The
analysis and mitigation contained in EIR 04-02 remain adequate to address
all modifications proposed.
b. There has been no substantial change with respect to the circumstances under which the Project is being undertaken which would require major
revisions to EIR 04-02.
c. There is no new information of substantial importance that was not known
and could not have been known with the exercise of reasonable diligence at
the time EIR 04-02 was certified.
d. The Project will not have any significant effects not discussed in EIR 04-02.
e. There are no new or additional mitigation measures that need to be added and there are no mitigation measures previously found not to be feasible
that are now found to be feasible that would substantially reduce one or
more significant effects of the Project.
4. The Addendum is incorporated by reference herein, and the findings and
substantial evidence presented in the Addendum are adopted as findings to these
proceedings.
. . .
. . .
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Section 1: Introduction
The City of Carlsbad (City) prepared the Final Environmental Impact Report for the City’s Drainage
Master Plan Update in 2007 and certified the Report in 2008 (SCH #20060041066, referred to herein as
the 2007 EIR). In addition to the programmatic environmental analysis of implementing the city-wide
Drainage Master Plan, the 2007 EIR also included project-level analysis of a project that would remove
sediment from and construct physical improvements in adjacent segments of Agua Hedionda Creek and
Calavera Creek in central Carlsbad, near the intersection of El Camino Real and Cannon Road (the
project). The City’s Utilities Engineering Division is preparing to implement the project, but the current
plan for the dredging and other improvements differs from the project plans that were analyzed in the
2007 EIR. Changes to the project include: 1) installation of additional riprap in Agua Hedionda Creek
channel in place of slope stabilization using V-max; 2) installation of riprap drop structures in place of
gabion drop structures in Agua Hedionda and Calavera creek channels; 3) installation of a riprap
structure in Agua Hedionda creek channel, beneath the Cannon Road bridge and in the Coastal Zone; 4)
installation of additional riprap along both banks of Agua Hedionda creek channel between the Cannon
Road and El Camino Real bridges and in the Coastal Zone; 5) removal of approximately 7,000 additional
cubic yards of sediment within the two channels to accommodate the riprap.
This addendum to the 2007 EIR has been prepared in accordance with State CEQA Guidelines Section
15164. The City’s Utilities Department and Planning Division have reviewed the project changes and
considered how those changes affect the analysis and conclusions presented in the 2007 EIR. Based on
this analysis, the City determined that an addendum is the appropriate method of achieving compliance
for this project. This addendum discusses the project changes, analyzes their environmental impacts,
and documents the reasoning for concluding that the changes would not result in new significant
environmental impacts that were not identified in the 2007 EIR or result in substantial increases in
significant impacts that were identified in the 2007 EIR.
Section 2: Project Description
2.1: Previously Approved Project
The project described in the 2007 EIR entailed dredging and infrastructure improvements along Agua
Hedionda Creek and Calavera Creek channels to increase flood protection, as described in Section 3.4 of
the 2007 EIR. Section 3.4 includes project background, an explanation of the project limits, and a
description of the proposed work in both creek channels, as analyzed at a project level in the 2007 EIR.
Agua Hedionda Creek improvements were referred to in the 2007 EIR as “Project B” and Calavera Creek
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improvements were referred to as “Project BN.” This section of the addendum summarizes the
information provided in Section 3.4 of the 2007 EIR.
2.1.1: Project Location and Background Information
The boundaries of Projects B and BN, as analyzed in the 2007 EIR, include spans of Agua Hedionda and
Calavera creek channels within and adjacent to the Rancho Carlsbad residential community. Both creeks
flow within constructed earthen channels throughout the extent of the project, except under bridges
where riprap sides exist. Agua Hedionda Creek flows west through the southwestern portion of Rancho
Carlsbad, bends southwest at the confluence with the Calavera Creek tributary, and exits the Rancho
Carlsbad community under El Camino Real. West of El Camino Real, Agua Hedionda Creek bends west,
where it passes beneath Cannon Road and flows off site into a natural stream channel that drains into
Agua Hedionda Lagoon approximately 1.25 miles southwest of the project site. Two road crossings,
Cannon Road Bridge and El Camino Real Bridge, are located within the downstream portion of the
proposed work area. The length of work in Agua Hedionda Creek, within the project boundary, is
approximately 3,000 feet, extending from approximately 100 feet below the downstream edge of
Rancho Carlsbad Drive Bridge on the east to the downstream edge of Cannon Road Bridge on the west.
Calavera Creek originates at Lake Calavera, approximately 1 mile north of the project site, and meanders
in a southerly direction through open space, then flows south through an 11-foot by 7-foot reinforced
concrete box culvert under the intersection of College Boulevard and Cannon Road, and enters the
Rancho Carlsbad community at the point of confluence with a tributary known as Little Encina Creek.
Calavera Creek then flows southwest, along the northwest boundary of the Rancho Carlsbad
community, to a point of confluence with Agua Hedionda Creek, located approximately 300 feet east of
El Camino Real. The approximate length of Calavera Creek within the project boundary is 3,400 feet,
extending from the box culvert at the intersection of Cannon Road and College Boulevard to the
confluence with Agua Hedionda Creek.
The original segments of Agua Hedionda and Calavera creeks were reconstructed as man-made, earthen
trapezoidal channels in conjunction with the development of the Rancho Carlsbad community
development according to plans dated June 1969. Approximately 1.2 miles of the Agua Hedionda and
Calavera creeks were reconstructed as part of the overall development for the Rancho Carlsbad
community. In 1998, additional channel enhancement and repair work occurred west of El Camino Real
with the construction of Cannon Road Bridge over Agua Hedionda Creek. Agua Hedionda Creek has
experienced significant sediment accumulation since its reconstruction, which has reduced the channel
capacity and created a backwater effect within Calavera Creek, which in turn has reduced the capacity of
Calavera Creek. Localized scour along Calavera Creek banks has threatened to undermine residential
foundations during heavy storm events, and several residents have installed revetment walls and/or
rock slope protection to protect their homes from damage during heavy storm events.
The reduced channel capacity has also led to increases in flood inundation in Rancho Carlsbad. A 2004
study referenced in the 2007 EIR concluded that 278 of the 504 homes in this community were subject
to 100-year flood inundation. The proposed project is a part of a Program of three Flood Control
Projects. The City has already implemented two of the projects which included construction of two
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major flood retention facilities; the repair and rehabilitation of the outlet works to Lake Calavera Dam,
and the construction of an 84” storm drain pipe paralleling Calavera Creek. The dredging and
improvement of the Agua Hedionda and Calavera Creeks is the third and final project proposed for
implementation. Currently, 168 homes remain in the flood inundation area. With implementation of
this final flood control project, all but 22 homes would be removed from the floodplain.
Heavy storms in 2004 resulted in additional scouring of the banks within Calavera Creek and the
undercutting of several home foundations. In March 2006 the City conducted emergency channel
dredging in portions of Agua Hedionda and Calavera creeks to provide immediate flood protection for
the residential community of Rancho Carlsbad, removing approximately 16,000 cubic yards (cy) of
material. The 2006 emergency dredge activities improved conditions to address immediate flood
control and public safety needs, but the City concluded that additional dredging and improvements
were needed to restore the channels’ flood control capacity, and this dredging and improvement was
analyzed in the 2007 EIR as Projects B and BN.
2.1.2: Project Components
Project B proposed sediment removal and channel improvements along approximately 3,000 LF of the
channel bottom of Agua Hedionda Creek from near Rancho Carlsbad Drive to the downstream edge of
Cannon Road Bridge. The dredging was proposed to include a combination of widening and deepening
the channel, and was anticipated to generate approximately 27,400 cy of material for export. Channel
improvements in Agua Hedionda Creek under Project B included the following:
installation of a series of gabion drop structures at the eastern end of the project-related
segment to control flow velocity;
slope stabilization using slope treatment material such as Vmax in the vicinity of the gabion drop
structures to protect against erosion and scour;
removal and replacement of overside drains and culverts to accommodate the channel
expansion;
removal of a retaining wall on the south bank of the channel; and
construction of a desilting basin within the channel.
The project also proposed installation of an access road near the confluence of the creeks for equipment
access, with riprap proposed for slope protection in the vicinity of the road. An optional project
component was the installation of pier encasements beneath the two bridges to provide for smoother
flow of water and reduced scour under the bridges.
Project BN proposed sediment removal along approximately 300 LF of Calavera Creek and channel
improvements elsewhere in the creek. The dredging was anticipated to generate approximately 600 cy
of material for export. Channel improvements proposed in Calavera Creek under Project BN included the
following:
installation of gabion drop structures at the eastern and western ends of the project-related
segment to control flow velocity;
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slope stabilization using slope treatment material such as Vmax in the vicinity of the gabion drop
structures to protect against erosion and scour;
removal of existing concrete aprons in the channel bottom;
removal and replacement of existing overside drains to accommodate the widened channel; and
removal of an existing ornamental wall on the north side of the creek to enable dredging access,
and replacement after project completion.
Increasing the capacity of these two creek channels was anticipated to improve flood conditions in the
Rancho Carlsbad area such that only nine of the 504 residences would partially remain in the 100-year
floodplain after project implementation. All nine of these units were identified as standing on elevated
foundations that would raise their first-floor elevation above the 100-year floodplain level.
2.1.2: Project Construction
Construction was proposed during daytime hours, between 7:00 a.m. and sunset, Monday through
Friday, and 8:00 a.m. to sunset on Saturdays, in compliance with the City noise ordinance, and was
anticipated to occur over 100 working days (up to 4½ months). Typical construction equipment
anticipated to be used included excavators, loaders, scrapers, dozers, hand tools, and trucks. Excavation
activities was estimated to require up to eight construction members on a daily basis; repair work would
require a construction crew of three to six workers.
The 2007 EIR considered two potential options for dredged material disposal. One option was to use
most of the material as opportunistic beach fill, transporting it to and depositing it at the South Carlsbad
receiver site, located southwest of the site and south of the Palomar Airport Road/Carlsbad Boulevard
interchange. The other option was disposal at an approved off-site location, as would be determined by
the City and their contractor. The 2007 EIR estimated that material disposal would require
approximately 1,650 truck trips (assuming 20 cy truck capacity), with 55 working days dedicated to
material hauling, resulting in an average of 30 round-trip truck trips per day.
2.2: Proposed Changes in the Project
Additional engineering analysis of the proposed channel improvements and consultation with the
resource agencies during the permitting process led to several refinements in the project design
(referred to herein as the “revised project”). Changes to the project include: 1) installation of additional
riprap in Agua Hedionda Creek channel in place of slope stabilization using V-max; 2) installation of
riprap drop structures in place of gabion drop structures in Agua Hedionda and Calavera creek channels;
3) installation of a riprap structure in Agua Hedionda creek channel, beneath the Cannon Road bridge
and in the Coastal Zone; 4) installation of additional riprap along both banks of Agua Hedionda creek
channel between the Cannon Road and El Camino Real bridges and in the Coastal Zone; 5) removal of
approximately 7,000 additional cubic yards of sediment within the two channels to accommodate the
riprap. The proposed changes do not entail relocation or expansion of the project limits.
The decision to install additional riprap along the banks of Agua Hedionda Creek was the result of
refined engineering analysis that determined it was necessary to further protect the banks from
erosion. The change from gabion drop structures to riprap drop structures in both creeks was
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made at the request of the U.S. Army Corps of Engineers, who expressed concerns related to the
stability of the previously proposed gabions. The inclusion of the riprap structure beneath the
Cannon Road bridge was made at the request of the California Department of Fish and Wildlife,
who expressed concerns with potential sedimentation and/or erosion in the habitat preserve
immediately downstream of the bridge. This feature is proposed in place of the optional
improvement identified in the 2007 EIR, which indicated the potential to install pier encasements
beneath the two bridges. The revised project does not propose improvements beneath the El Camino
Real bridge.
Similar to the Project B and BN addressed in the 2007 EIR, the revised project proposes the
following channel improvements:
removal and replacement of overside drains and culverts in both channels to accommodate the
channel expansions;
removal of a retaining wall on the south bank of the channel Agua Hedionda Creek channel;
removal of existing concrete aprons in the Calavera Creek channel bottom;
removal and replacement of an existing ornamental wall on the north side of Calavera Creek;
and
construction of an access road near the confluence of the creeks.
The revised project does not include construction of a desilting basin in the Agua Hedionda Creek
channel. Appendix A, of this Addendum, provides a graphical comparison of the revised project and the
project included in the 2007 EIR, based on the relevant pages of the updated project plans and the
relevant pages of the plans included in Appendix B of the 2007 EIR.
The project changes would result in some changes in the construction process due to the additional
dredging and riprap installation, both of which would increase on- and off-hauling of material, which
would increase the amount of temporary truck trips. There would be no change in the equipment or
workforce. Timing of construction would not be affected, and the revised project would still occur in
accordance with the City noise ordinance. Increased dredging and riprap installation is not anticipated to
increase the project’s duration of 100 working days; however, this work is expected to result in an
increase in the number of days in which haul trips occur beyond that stated in the 2007 EIR.
With respect to off-hauling of dredged material, the City has opted to not use material from the revised
project for beach replenishment, though dredged materials generated by future maintenance work may
be used for such purposes. The revised project would entail disposal at an approved and licensed off-
site location, as selected by the City and the construction contractor at a later date.
Section 3: Environmental Assessment
This section presents a discussion of whether/how the proposed project changes affect the analysis and
conclusions of the respective environmental issue sections in the 2007 EIR.
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3.1: Land Use
Land use impacts of the previously proposed project are discussed in Section 4.1 of the 2007 EIR. The
2007 EIR concluded that the project’s land use impacts would be less than significant because the
project does not entail changes in land use or zone designations, and the project would be consistent
with the City of Carlsbad General Plan (General Plan), the McClellan-Palomar Airport Land Use
Compatibility Plan, and the City’s Habitat Management Plan (HMP). The project site is not within the
HMP’s Hardline Preserve Area. The proposed changes in the project do not alter the project location or
substantially expand the project boundaries. The additional excavation and inclusion of riprap proposed
in the revised project would have no bearing on the 2007 EIR’s land use conclusions. Therefore, there
are no substantial changes in land use impacts as analyzed in the 2007 EIR.
3.2: Agricultural Resources
Agricultural resources impacts of the previously proposed project are discussed in Section 4.2 of the
2007 EIR. The 2007 EIR concluded that the project’s agricultural resources impacts would be less than
significant because there is no designated farmland or Williamson Act contract in the project area, and
the project would not affect agricultural uses. The proposed changes do not alter the project location or
expand the project boundaries, and additional excavation and inclusion of riprap would have no bearing
on the 2007 EIR’s agricultural resources conclusions. Therefore, there are no substantial changes in
agricultural resources impacts as analyzed in the 2007 EIR.
3.3: Visual Resources
Visual resources impacts of the previously proposed project are discussed in Section 4.3 of the 2007 EIR,
which concluded that the project would have a less-than-significant impact on visual resources. With
respect to construction impacts, Section 4.3 states that although construction activities would be visible
from the adjacent El Camino Real and Cannon Road, which intersect near the project site and are
designated as a Community Theme Corridor and a Community Scenic Corridor in the Carlsbad General
Plan, respectively, this would not be considered significant because the visibility would be only a
temporary disturbance to the area’s visual character. Furthermore, the staging activity was determined
not to be visible to motorists and Rancho Carlsbad residents due to intervening walls.
With respect to the project’s permanent impacts, the lowered and widened channel bottoms are
identified in the EIR as minimally visible to motorists traveling on El Camino Real and Cannon Road so as
not to have a significant effect on the scenic quality as perceived from these roads. Project-related
vegetation removal was determined to reduce some existing screening along the roadways, but the EIR
concluded that retention of mature trees along the banks in this area would maintain adequate
screening. Accordingly, the project was determined to not conflict with the City’s Scenic Corridor
Guidelines, which require “visually pleasing intersections at points where scenic corridors cross,”
especially because certain cleared areas would be re-landscaped to maintain the area’s overall visual
quality. The ultimate conclusion of the 2007 EIR is that the project would result in an overall visual
enhancement of the creeks by removing eroded slopes and concrete and replacement with vegetated
and Vmax-stabilized slopes.
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The revised project’s construction activity would not result in a considerable change in the temporary
impact identified in the 2007 EIR. Due to the installation of riprap and additional excavation from the
creeks, the project would entail a more intensive construction process than initially anticipated in the
2007 EIR. The less-than-significant visual impact identified for construction activities in the 2007 EIR
would remain and would be slightly greater than stated in the 2007 EIR, but this short-term impact
would not be considered significant.
Permanently visible changes in the revised project compared to the previously proposed project include
installation of additional riprap for bank stabilization and channel protection. Riprap installed in the
banks of the creeks would be visible to residents of Rancho Carlsbad—a gated community—and to
motorists, bicyclists, and pedestrians traveling on El Camino Real and Cannon Road, which are
designated as scenic features in the General Plan. Current views of this area are of earth-bottom creeks
with patchy vegetation and some degraded concrete lining in certain places, which would be replaced by
slopes and channel bottoms lined with riprap, typically composed of grey-brown rocks of various sizes.
Figure 1 shows visual simulations of the project upstream and downstream from the El Camino Real
bridge compared to existing conditions, and Figure 2 shows a simulation from the Don Juan Drive bridge
over the project within the Rancho Carlsbad community. Don Juan Drive is a private road located within
the gated community. The greatest degree of visibility of the project would be to the residential viewers
of Rancho Carlsbad. The elevation of the public roads above the creek would limit direct views from the
roadway, which would be further obscured in certain areas due to the intervening railing on the bridge
and surrounding vegetation. Project changes would be visible from certain residences and from private
roads and adjacent common areas within the development, but would have limited visibility to public
viewers.
The 2007 EIR did not include visual simulations of the project, so a side-by-side comparison of the two
versions of the project is not possible. Some viewers may respond negatively to the appearance of the
riprap, which could be interpreted as adding an industrial appearance to an area that once had a more
natural setting. This would constitute a greater impact than indicated in the 2007 EIR for the area
upstream of El Camino Real. The project-related span downstream of El Camino Real currently features
riprap underneath the sediment and vegetation. Uncovering the riprap in this downstream location, as
shown in Key View 1 (Figure 1), does not substantially differ from the plan considered in the 2007 EIR,
and there is no change in the aesthetic impacts due to the project changes.
Many views of the portion of the project upstream of El Camino Real, including those from the
neighboring Rancho Carlsbad residences, are screened by intervening vegetation outside the project
limits that would not be disturbed as part of the project (see Figure 1, Key View 2 and Key View 3).
Furthermore, project-related vegetation planting would generally improve visual conditions in the area
once project construction is complete. Existing trees that would remain pursuant to the project tree
plan include a variety of cottonwood, sycamore, citrus, cyprus, eucalyptus, oak, oleander, palm, pine,
and yucca. Additional trees that will be planted include western sycamore, Fremont cottonwood, and
California live oak. With a combination of the project maintaining existing vegetation and planting
additional vegetation, there would not be a significant change to the overall scenic quality of the project
area. Therefore, though the impacts on scenic quality associated with the revised project would be
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greater than the less-than-significant impact stated in the 2007 EIR, the increase would not be
substantial enough to be considered a significant impact.
Similar to the project’s original proposal, the project would remove some vegetation from within and
along the edge of the creeks, though the revised project would entail a slight increase in vegetation
removal, compared to that analyzed in the 2007 EIR. As with the originally proposed project, some of
this removal would be visible from El Camino Real and Cannon Road, which are designated as scenic
corridors in the General Plan. A slight increase in the amount of vegetation removed from this area
would not affect the 2007 EIR conclusion with respect to compatibility with the City’s Scenic Corridor
Guidelines, which require “visually pleasing intersections at points where scenic corridors cross.”
Landscaping in this area as part of the project would ensure the area remains visually pleasing when
viewed from this intersection. Therefore, this would not be considered a significant impact that was not
identified in the 2007 EIR.
3.4: Transportation/Circulation
Transportation/circulation impacts of the previously proposed project are discussed in Section 4.6 of the
2007 EIR, which concludes that the project would result in less-than-significant impacts on a temporary
and ongoing basis. Section 4.4 concluded that the project’s construction-related trip generation would
be most intense during off-hauling of the dredged channel spoils. Hauling was estimated at 1,650 haul
loads over 55 working days, or an average of 30 loads per day when spread throughout the span of the
project, which equate to an average-daily-trips (ADT) count of 60. Because segments and intersection
counts at Cannon Road and El Camino Real, the two public roadways nearest to the project site, showed
the facilities operating at either level of service (LOS) A or LOS B under existing conditions, the addition
of this small amount of truck traffic was determined to not result in a substantial increase in local traffic
or substantial degradation of segment or intersection service.
The 2007 EIR also concluded that project construction would not result in a significant traffic hazard or
safety issue because the project would include preparation and implementation of a traffic control plan,
which would include measures such as notices to local neighbors, signage, flaggers, and other warning
devices to control heavy equipment traffic and direct pedestrians to safe crossings. This plan would also
identify emergency access routes, leading to the conclusion that project construction would not impair
emergency access to and from the Rancho Carlsbad community.
With respect to operational impacts, Section 4.4 of the 2007 EIR indicated that a minimal amount of
maintenance traffic would occur in relation to ongoing sediment- and waste-hauling in the project area.
The referenced discussion did not quantify maintenance trips, although it did characterize maintenance
trips as much less than the 60 ADT estimated for off-hauling of dredged channel spoils and, therefore,
less than significant.
The project changes have no bearing on emergency access or safety hazards impacts during
construction; therefore, no revision of this analysis is necessary. The project changes would not result in
additional maintenance trips to and from the project area, as the same level of effort and frequency of
maintenance would be required for the revised project as for the project analyzed in the 2007 EIR.
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Therefore, there is no change to the maintenance-related operational traffic impact analysis or
conclusions stated in Section 4.4 of the 2007 EIR. However, there are two factors that require
reexamination of the project’s construction-related traffic analysis provided in the 2007 EIR. First, the
existing conditions information that served as the basis for the 2007 EIR traffic analysis is several years
old, with the traffic counts occurring in 2005 and 2006. Establishing an appropriate baseline for the
construction-period traffic impact analysis requires updated traffic data. Second, the proposed changes
in the project compared to that which was analyzed in the 2007 EIR entail an increase in construction-
period traffic due to haul trips for riprap and an increased amount of excavated material off-hauling.
Updated ADT counts for the segments of El Camino Real and Cannon Road adjacent to the project site
were obtained from the Carlsbad Transportation Department. The updated counts were recorded in
2009 through 2011, allowing a more current approximation of current traffic conditions.1 Table 1 shows
the updated counts compared to the prior counts.
Table 1
ADT Comparison
2007 EIR
Counts
Updated
Counts
Cannon Road
Frost Ave. to El Camino Real 9,300 11,775
El Camino Real to Hilltop Street 14,700 17,710
El Camino Real
Crestview Drive to Cannon Road 27,700 25,748
Cannon Road to Rancho Carlsbad Drive 32,500 32,597
*Source: City of Carlsbad Transportation Department
As the table shows, traffic appears to have generally increased in the project area since the counts were
taken in 2005 and 2006. All of these segments were identified as operating at LOS A and LOS B under
existing conditions in the 2007 EIR. The increase in traffic since those counts is not substantial enough
to result in a major downgrade in LOS for these segments, and the segments continue to operate at
acceptable levels. Updated intersection LOS information for the El Camino Real/Cannon Road
intersection shows that the intersection is operating at LOS B and LOS C in the morning and evening
peak hour. This is an acceptable level of operation, though a downgrade in service since the 2007 EIR,
which listed the intersection as operating at LOS A in the morning peak time and LOS B in the evening
1 The segments included in the updated data are not identical to those that appeared in the 2007 EIR data, and the
segments appearing in the 2007 EIR are slightly longer than those that appear in the updated counts; however, the
segments do overlap and all segments from the updated data are contained within the prior segments, giving an
adequate basis for comparison.
10
peak. Though there is a slight increase in the amount of traffic using the roads in the vicinity of the
project site since publication of the 2007 EIR, segments and intersections that would carry project-
related construction and maintenance traffic are operating at acceptable levels and, therefore, there has
not been a significant change in existing conditions compared to the existing conditions stated in the
2007 EIR.
As with the prior version of the project, the most notable traffic issue will be construction hauling. The
project will result in a greater amount of haul trips than was analyzed in the 2007 EIR due to an increase
in spoils off-hauling and the addition of on-haul trips for riprap, which were not anticipated in the 2007
EIR. The EIR estimated the ADT for spoils hauling at 60 ADT, based on 1,650 haul loads spread out over
55 working days. The revised project is estimated to require 1,750 truck loads for the spoils hauling
(35,000 cubic yards in 20-cubic-yard truck loads), plus 1,250 truck loads for the riprap hauling (25,000
cubic yards in similar trucks). Dredging is anticipated for a duration of 55 working days, while bank
stabilization is anticipated for a duration of 45 working days, both of which are consistent with the
construction schedule stated in EIR Table 3-5. On average, this would mean 32 haul loads per day during
the dredging phase of the revised project, or an ADT of 64, and 28 haul loads a day during the riprap
installation phase, or an ADT of 56.
The dredging-phase ADT of the revised project is slightly higher than anticipated in the 2007 EIR for
spoils off-hauling, while the riprap-phase ADT of the revised project is slightly lower than that estimated
for spoils off-hauling. This slight increase in ADT during the dredging phase and additional trips resulting
from the riprap installation phase do not represent significant impacts. The local roadway system
continues to operate under acceptable conditions, and the project’s addition of traffic would not
constitute a significant traffic impact to daily conditions. The increased duration of the haul trips would
extend the occurrence of this less-than-significant impact for a longer duration, but this impact would
remain less than significant. Therefore, the revised project would not result in a new significant impact
that was not identified in the 2007 EIR.
3.5: Air Quality
Air quality impacts of the previously proposed project are discussed in Section 4.5 of the 2007 EIR, which
concluded that the project would result in less-than-significant construction and operational impacts.
Section 4.5 presents quantitative estimates of construction-related emissions associated with the
project, including spoils hauling, equipment delivery and operation, and worker trips. Since the San
Diego Air Pollution Control District (APCD) does not have quantitative emissions criteria for CEQA
evaluations, the analysis used conformity thresholds developed for assessment of federal projects.
These conformity thresholds (or “de minimis” thresholds) are annual figures stated in tons per year that
are based on the federal non-attainment status of the relevant air basin. Threshold values are 100 tons
per year for reactive organic gases (ROG), oxides of nitrogen (NOx), and carbon monoxide (CO); and 70
tons per year for fine particulate matter (PM10). The estimated project emissions stated in the 2007 EIR
are considerably less than these thresholds and the project’s construction-related impacts were
determined to be less than significant.
11
With respect to operational impacts, Section 4.5 identifies maintenance-related emissions from
equipment, stating that the intensity and duration would be less than that for the project’s construction
effort, which would be less than significant.
The analysis in Section 4.3 of the 2007 EIR also indicated that there would be a potential for odor
emissions from dredging and removal of wet sediments from the creek channels, but that odors would
dissipate relatively rapidly and would not be noticeable for more than one week. Potential air quality
impacts associated with stockpiles of dredge material were identified as being minimized with
implementation of project design features/measures and construction practices. Therefore, project-
related odor impacts were determined to be less than significant.
Changes in the revised project and in the regulatory environment make it necessary to revisit the air
quality analysis presented in the 2007 EIR. The additional dredging and riprap installation in the revised
project would not result in an extension of the construction schedule identified in the 2007 EIR, but
would result in additional haul truck trips that were not included in the 2007 EIR analyses. The analysis
in the 2007 EIR also relied on the 2002 version of the commonly used URBEMIS emissions modeling
software, which was the most current version at the time of the analysis. Newer software has been
developed since that time. Changes to the emission factors and methodology pursuant to the updated
modeling software would result in different emission estimates.
Furthermore, the air quality analysis presented in the 2007 EIR relied on federal conformity thresholds.
Since publication of the 2007 EIR, APCD has identified daily trigger levels that are more relevant to
California’s air emissions policies and to this project’s local environment. Though these trigger levels do
not specifically apply to construction projects, they are instructive for comparative and analytical
purposes, and are useful for analysis of short-term construction projects because they measure daily
emissions rather than annual emissions.2 Therefore, it is appropriate for informational purposes to
analyze construction impacts of the revised project pursuant to these thresholds.3
The analysis of the revised project assumed that work would consist of three non-overlapping phases
that last for a total of 100 construction days (approximately 5 months), with the first two phases being
dredging and sediment removal along different parts of the project alignment (including sediment off-
hauling), and the third phase being riprap delivery and installation. Construction equipment is
anticipated to include 1 dozer, 2 loaders, and 2 heavy trucks operating for the full duration of
construction period. Additional equipment would include 1 crane and 1 scraper operating for 75% of
the construction period. It was also assumed that 35,000 cubic yards of dredged and excavated
materials would be hauled off-site. Assuming a truck capacity of 20 cubic yards, off-site hauling would
result in 32 round trips per day to a disposal site located approximately 20 miles from the project site.
2 The County of San Diego has established these levels as screening-level thresholds that may be used to evaluate
construction projects.
3 Construction emissions associated with the project were quantified using the California Emission Estimator
Model (CalEEMod) Version 2011.1.1. For construction projects, CalEEMod allows the user to enter project-specific
information such as types of equipment, vehicle trip generation rates, and construction phasing and schedule.
12
The project would also involve the delivery of 25,000 cubic yards of riprap, or 28 round trips per day, to
the project site. The nearest supplier is approximately 20 miles from the project site. Estimated
construction emissions are shown in Table 2. The particulate-matter emissions shown in this table
reflect dust-control benefits from watering the site 2 times per day, which is mandatory for standard
construction practices in San Diego County, pursuant to APCD requirements.
Table 2
Summary of Modeled Construction Emissions
Emissions (lbs/day)
ROG NOX CO SOX PM10 PM2.5
Phase 1 13 115 57 0.1 45 7
Phase 2 13 115 57 0.1 12 7
Phase 3 12 112 56 0.1 37 7
Maximum Daily Emissions 13 115 57 0.1 45 7
Significance Threshold 75 250 550 250 100 55
Exceeds Threshold? No No No No No No
*Source: AECOM 2012
As shown in Table 2, construction-related emissions of ROG, NOX, CO, SOX, PM10, and PM2.5 would not
exceed the screening-level thresholds and would not violate any air quality standard or contribute
substantially to an existing or projected air quality violation. The less-than-significant impact identified
in the 2007 EIR would be slightly greater due to the extended construction period, but would remain
less than significant. Therefore, the revised project would not result in a new significant impact that was
not identified in the 2007 EIR.
The project changes would not result in additional maintenance, as the same level of effort and
frequency of maintenance would be required for the revised project as for the project analyzed in the
2007 EIR. Therefore, there is no change to the maintenance-related operational air quality impact
analysis or conclusions stated in Section 4.5 of the 2007 EIR.
3.6: Noise
Noise impacts of the previously proposed project are discussed in Section 4.6 of the 2007 EIR. The 2007
EIR concluded that noise impacts would be less than significant. Project construction and maintenance
were identified as generating noise adjacent to residences, which would be limited to daylight hours, as
permitted by the City’s noise ordinance. The EIR stated that when equipment is within 50 feet of a
residence, short-term noise levels would exceed 75 dBA, and 1-hour average noise levels would likely
13
exceed 75 dBA, but the duration of the noise impact at any residence was anticipated to be 1-3 days, as
the dredging would proceed along each creek at approximately 50-100 feet per day. Because
construction activity would not result in excessive noise levels for a period of greater than 3 days,
impacts were concluded to be less than significant.
Proposed changes do not entail activities that would increase noise levels or new work locations that
would subject additional receptors to construction-related noise that was not anticipated in the 2007
EIR. The riprap component of the project generally would be a larger effort than that anticipated in the
2007 EIR, but the total duration of the project’s noise generation would not increase. Similar to the
previously proposed project, the revised project includes two three-day construction phases, though in
the revised project the second of these phases includes a greater amount of riprap installation in place
of the previously anticipated bank stabilization. The increased riprap installation would generate similar
noise levels anticipated in the slope stabilization efforts considered in the 2007 EIR. With the project
changes, project construction would not cause any residences to receive noise for longer than three
consecutive days, as the installation phase would follow the dredging phase. Therefore, there are no
substantial changes in noise impacts as analyzed in the 2007 EIR.
3.7: Recreation
Recreation impacts of the previously proposed project are discussed in Section 4.7 of the 2007 EIR,
which concluded that impacts would be less than significant because the project site does not contain
any public recreational facilities and the project would not affect any recreational facilities. The EIR
identified the Rancho Carlsbad community pool located approximately 300 feet from the site, but
concluded this facility would be unaffected by project activity. The proposed changes in the project do
not alter the project location or expand the project boundaries. Additional excavation and inclusion of
riprap in the revised project would have no bearing on the 2007 EIR’s recreational conclusions.
Therefore, there are no substantial changes in recreation impacts as analyzed in the 2007 EIR.
3.8: Geology/Soils
Geology/soils impacts of the previously proposed project are discussed in Section 4.8 of the 2007 EIR,
which concluded that the impacts would be less than significant. The 2007 EIR stated that project
activities would conform to City’s erosion control requirements to minimize potential erosion, and the
California Building Code to minimize the threat of damage associated with seismic activity. The project
area was stated to be flat and not subject to hazardous landslides, and void of any mineral resource
recovery areas. The project area was identified as having the potential to feature expansive soils, but
those would be addressed through proper design and incorporation of BMPs.
Proposed changes in the project do not alter the project location or substantially expand the project
boundaries, and would have no bearing on the 2007 EIR’s geology and soils conclusions. The revised
project would entail additional excavation beyond that considered in the 2007 EIR, but this would not
change the geologic conditions of the site, expose different soil conditions, or subject the project to
additional or greater hazards beyond those identified in the 2007 EIR. One of the purposes of the
additional riprap in the revised project is to protect the channel banks from erosion, resulting in a
beneficial geology/soils impact in the project area and downstream. Installation of riprap would require
14
different design considerations than the prior plans to limit potential hazards from expansive soils and
seismic events, but this would not expose the project to additional or greater hazards beyond those
identified in the 2007 EIR. Therefore, there are no substantial changes in recreation impacts as analyzed
in the 2007 EIR.
3.9: Hydrology/Water Quality
Section 4.9 of the 2007 EIR presents an analysis of the project’s hydrology and water quality impacts.
The analysis determined that dredging and construction activities had the potential to degrade water
quality in Agua Hedionda and Calavera creeks, but because the project would be required to incorporate
design features and construction BMPs as part of the project-specific Storm Water Pollution Prevention
Plan (SWPPP) in compliance with all relevant permit requirements, these impacts would be less than
significant. The 2007 EIR stated the project would implement in-stream water quality controls, as well
as upland construction site BMPs to minimize water quality impacts. Ultimately, the 2007 EIR concluded
the project would improve flood control within the creeks and reduce the 100-year floodplain within the
project area. Potential short-term impacts to hydrology/water quality during construction were
determined to be less than significant, and long-term impacts were determined to be beneficial.
The revised project entails an increase in the amount of dredged material and riprap installation in both
creeks, compared to the previously proposed project. These changes could potentially increase
construction-related impacts to water quality and require a reexamination of the 2007 EIR’s conclusions.
In addition to these project changes, a number of the compliance documents referenced in the 2007 EIR
have been updated since the EIR was published, as summarized below:
The NPDES General Permit for Storm Water Discharges Associated with Construction and Land
Disturbance Activities (Construction General Permit) has been updated since publication of the
2007 EIR, which references Order No. 99-08-DWQ. The project would now be required to
adhere to Order No. 2009-0009-DWQ (as amended by 2010-0014-DWQ), which was prepared in
2009. The updated permit includes updated compliance measures that would be required to be
implemented by the project.
The San Diego Municipal Storm Water Permit Tentative Order No. R9-2006-0011 referenced in
the 2007 EIR has been revised since publication of the EIR. The project would be required to
comply with the current Municipal Permit, Order No. R9-2007-0001, which was prepared in
2007.
The 303(d) list referenced in the 2007 EIR has been updated since the 2007 EIR was published.
Agua Hedionda Creek was listed for trace metals (manganese and selenium), sulfates, and total
dissolved solids (TDS) on the 303(d) list at the time the EIR was published, but is now also listed
as impaired for coliform bacteria, nutrients (phosphorus and nitrogen), and toxicity on the most
recent 303(d) list, which was prepared in 2010.
The 2004 California Stormwater Quality Association Construction BMP Handbook referenced in
the 2007 EIR was updated in 2009.
15
The 2007 EIR also identifies the need for the project to obtain a Conditional Letter of Map Revision
(CLOMR) and Letter of Map Revision (LOMR) from the Federal Emergency Management Agency to
address the change in Flood Insurance Rate Maps (FIRM) for the area. FEMA issued the CLOMR in
October 2011, and the LOMR is still outstanding. This issuance does not change the analysis or
conclusions in the 2007 EIR.
The revised project entails an increase in dredging and the introduction of riprap, which would slightly
increase the intensity of construction and result in a slight increase in the temporary impacts on water
quality that were identified in the 2007 EIR. Additionally, Agua Hedionda Creek, to which the project
would discharge, is now listed as an impaired water body on the 303(d) list for additional pollutants than
it was listed for at the time the 2007 EIR was published. However, being principally a temporary
construction-related impact that provides long-term beneficial impacts to streambed and bank stability,
the revised project would not contribute the pollutants of concern as a result of implementation, no
additional impacts would be expected.
Similar to the conclusions stated in the 2007 EIR, the project would be required to comply with all
relevant permits, standards and regulations, including both the Municipal Permit and Construction
General Permit. As stated in the 2007 EIR, erosion and sediment controls would be used and a project-
specific SWPPP would be in place during construction activities to reduce the amount of sediments
disturbed and to prevent disturbed sediments from entering runoff to receiving waters. Updates to the
Construction General Permit (2010-0014-DWQ) since publication of the 2007 EIR include:
Monitoring and reporting of and numeric effluent limitations for pH and turbidity in storm water
discharges;
A Rain Event Action Plan for higher-risk sites;
Annual reporting on monitoring activities; and
Specific training or certifications of key personnel (e.g., SWPPP preparers, inspectors) to ensure
their level of knowledge and skills are adequate to ensure their ability to design and evaluate
project specifications that will comply with General Permit requirements.
Construction-related impacts on water quality from the additional dredging and riprap placement would
be temporary and, by successfully complying with relevant permit requirements and required
construction measures, impacts would be less than significant. The increased amount of riprap
proposed for the project would be beneficial to post-construction water quality, as it would provide
additional bank stabilization and erosion control over the original design initially evaluated in 2007.
Ultimately, the proposed project would improve flood control within Agua Hedionda and Calavera creek
channels and reduce the 100-year floodplain within the project area, thereby alleviating the majority of
residences from inundation during a 100-year flood event. The revised project does not remove as
many homes from the 100-year floodplain as was anticipated for the previously approved project due to
the increase in riprap, which results in a slight decrease in the planned capacity of the channel. The
most recent analysis of post-project conditions shows 22 structures remaining in the floodplain, versus 9
structures with the previously approved project. However, this change is necessary to provide
16
adequate bank stabilization. Despite this change, the long-term impacts of the proposed project would
be beneficial to water quality, hydrology, drainage capacity, and creek bed and bank stability. No new
significant impacts are anticipated with the revised proposed project.
3.10: Biological Resources
Biological resources impacts of the previously proposed project are discussed in Section 4.10 of the 2007
EIR. This section stated different impact conclusions for wildlife, habitat/jurisdictional areas, wildlife
movement, and plan consistency, and included several mitigation measures that would ensure that all
impacts would be reduced to less-than-significant levels. These topics are discussed in separate
subsections below.
3.10.1: Wildlife
Section 4.10 of the 2007 EIR concluded the previously proposed project’s wildlife impacts would be less
than significant with incorporation of several mitigation measures. Surveys of the project area for the
2007 EIR did not identify any listed species, and the EIR concluded that no listed species were
anticipated to occur in the project area. However, listed species were observed within 500 feet of the
site, in the habitat conservation area downstream of the Cannon Road Bridge. Section 4.10 of the 2007
EIR concluded that project construction has the potential to result in significant indirect impacts on least
Bell’s vireo, southwestern willow flycatcher, and light-footed clapper rail due to noise and increased
human activity in the area during construction. The following measures were listed as mitigation for
these species to ensure these temporary impacts would be less than significant:
Bio-7a If dredging and improvement activities cannot be conducted outside the breeding season for
sensitive wildlife species, then prior to commencement of construction activities, a
preconstruction survey shall be conducted by a qualified biologist to determine
presence/absence of nesting birds. If nesting birds are detected on-site, vegetation removal
shall be delayed until the chicks have fledged or the nest has failed.
Bio-7b To address potential impacts to the light-footed clapper rail, a qualified biologist shall survey
the area and surrounding 500-foot buffer area for light-footed clapper rails prior to
implementation of dredging activities. There is no need to survey the area upstream of El
Camino Real since this area is void of suitable clapper rail habitat (freshwater marsh). If
clapper rails are detected in the project area, they should be flushed, prior to the onset of any
vegetation removal.
Bio-7c For potential indirect impacts to least Bell’s vireo, mitigation measures Bio 1-h through Bio 1-j
shall be implemented, as applicable. (These cross-referenced measures are listed below.)
Bio-1h: Prior to the first preconstruction meeting for each project component, the City shall
verify that the following statement is included in the construction specifications: No clearing,
grubbing, grading, or other construction activities within or adjacent to potential least Bell’s
vireo habitat shall occur between March 15 and September 15 (least Bell’s vireo breeding
season) until the following requirements (Bio-1i and Bio-1j) have been met to the satisfaction
of the City.
17
Bio-1i: A qualified Biologist shall survey those wetland areas that would be subject to
construction noise levels exceeding 60 dBA Leq for the presence of least Bell’s vireo. Least
Bell’s vireo surveys shall be conducted a minimum of 8 weeks (within the breeding season)
prior to commencement of construction. If least Bell’s vireos are present, then the following
conditions must be met:
Between March 15 and September 15, no construction activities shall occur within any
portion of the site where such activities would result in noise levels exceeding 60 dBA Leq
at the edge of occupied least Bell’s vireo habitat. An analysis showing that construction-
generated noise would not exceed 60 dBA Leq at the edge of occupied habitat must be
completed by a qualified Acoustician (possessing current noise engineer license or
registration), with experience monitoring noise levels for listed wildlife species) and
approved by the City at least 2 weeks prior to commencement of construction activities;
OR
At least 2 weeks prior to commencement of construction activities, and under the
direction of a qualified Acoustician, noise attenuation measures (e.g., berms, walls) shall
be implemented to ensure that construction generated noise would not exceed 60 dBA
Leq at the edge of occupied least Bell’s vireo habitat. Concurrent with commencement of
construction activities and with implementation of necessary noise attenuation measures,
noise monitoring shall be conducted at the edge of occupied habitat to ensure that
construction-generated noise does not exceed 60 dBA Leq. If the noise attenuation
measures implemented are determined to be inadequate by the qualified Acoustician or
Biologist, then the associated construction activities shall cease until such time that
adequate noise attenuation is achieved or until the end of the breeding season
(September 16).
Bio-1j: If least Bell’s vireos are not detected during the preconstruction survey within areas of
potential habitat that would be subject to construction noise levels exceeding 60 dBA Leq, the
qualified Biologist shall provide evidence to the City and applicable regulatory agencies
demonstrating whether noise attenuation measures (e.g., berms, walls) are necessary
between March 15 and September 15 as follows:
If this evidence indicates the potential is high for least Bell’s vireo to be present based on
historical records or site conditions, then condition 1i shall be adhered to as specified
above.
If this evidence concludes that no impacts to this species are anticipated, no mitigation
measures would be necessary.
Bio-7d For potential indirect impacts to southwestern willow flycatcher, implementation mitigation
measures Bio 1-k through Bio 1-m shall be implemented, as applicable. (These cross-
referenced measures are listed below.)
18
Bio-1k: Prior to the first preconstruction meeting for each phase of the project component,
the City shall verify that the following statement is included in the construction specifications:
No clearing, grubbing, grading, or other construction activities within or adjacent to potential
southwestern willow flycatcher habitat shall occur between May 1 and September 1
(southwestern willow flycatcher breeding season) until the requirements in Bio-1l and Bio-1m
have been met to the satisfaction of the City.
Bio-1l: A qualified Biologist shall survey those wetland areas that would be subject to
construction noise levels exceeding 60 dBA Leq for the presence of southwestern willow
flycatcher. Southwestern willow flycatcher surveys shall be conducted pursuant to USFWS
protocol survey guidelines a minimum of 6 weeks (within the breeding season) prior to
commencement of construction. If southwestern willow flycatchers are present, then the
following conditions must be met:
Between May 1 and September 1, no construction activities shall occur within any portion
of the site where such activities would result in noise levels exceeding 60 dBA Leq at the
edge of occupied southwestern willow flycatcher habitat. An analysis showing that
construction-generated noise would not exceed 60 dBA Leq at the edge of occupied
habitat must be completed by a qualified Acoustician (possessing current noise engineer
license or registration, with experience monitoring noise levels for listed wildlife species)
and approved by the City at least 2 weeks prior to commencement of construction
activities; OR
At least 2 weeks prior to commencement of construction activities, and under the
direction of a qualified Acoustician, noise attenuation measures (e.g., berms, walls) shall
be implemented to ensure that construction generated noise would not exceed 60 dBA
Leq at the edge of occupied southwestern willow flycatcher habitat. Concurrent with
commencement of construction activities and with implementation of necessary noise
attenuation measures, noise monitoring1 shall be conducted at the edge of occupied
habitat to ensure that construction-generated noise does not exceed 60 dBA Leq. If the
noise attenuation measures implemented are determined to be inadequate by the
qualified Acoustician or Biologist, then the associated construction activities shall cease
until such time that adequate noise attenuation is achieved or until the end of the
breeding season (September 2).
Bio-1m: If southwestern willow flycatchers are not detected during the preconstruction survey
within areas of potential habitat that would be subject to construction noise levels exceeding
60 dBA Leq, the qualified Biologist shall submit substantial evidence to the City and applicable
regulatory agencies demonstrating whether noise attenuation measures (e.g., berms, walls)
are necessary between May 1 and September 1 as follows:
If this evidence indicates the potential is high for southwestern willow flycatcher to be
present based on historical records or site conditions, then measure Bio-1l shall be
adhered to as specified above.
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If this evidence concludes that no impacts to this species are anticipated, no mitigation
measures would be necessary.
Bio-7e To discourage sensitive bird species from entering active construction areas between El
Camino Real and Cannon Road bridges, a physical barrier (construction fence) shall be
installed on the downstream side of Cannon Road before dredging or vegetation removal
commences. The barrier would be removed once the construction activity has ceased on the
south side of El Camino Real.
The revised project would result in similar temporary construction impacts as identified in Section 4.10
of the 2007 EIR, and the revised project must implement the same mitigation measures listed above,
which will ensure that all impacts on listed species would be reduced to a less-than-significant level.
Increased dredging and addition of riprap installation would not extend the construction duration and,
therefore, would not substantially increase indirect impacts on listed bird species beyond that identified
in the EIR. The proposed changes in the project do not alter the project location or substantially expand
the project boundaries, so no additional listed species are anticipated to occur in the off-site area
beyond those identified in the 2007 EIR. Therefore, the project changes would not result in impacts on
additional species not identified in the 2007 EIR.
3.10.2: Habitat/Jurisdictional Areas
The 2007 EIR concluded that the project would result in a less than significant impact with incorporation
of mitigation. Section 4.10 states that the project would result in temporary and permanent impacts on
unvegetated channel, willow riparian forest, southern willow scrub, and non-native/ornamental
vegetation, as noted in Table 4.10-10 in the 2007 EIR. Impacts to willow riparian forest (0 acres of
temporary impacts and 0.53 acre of permanent impacts) and southern willow scrub (0 acres of
temporary impacts and 0.03 acre of permanent impacts) were considered significant and would require
implementation of the following measures:
Bio-5 Mitigation measures listed for Bio-1a and Bio-2a and 2b shall be implemented as applicable to
address project-specific vegetation impacts within Agua Hedionda and Calavera creeks.
(These cross-referenced measures are listed below.)
Bio-1a: For impacts to Type A habitats (coastal salt marsh, alkali marsh, freshwater marsh,
estuarine, salt pan/mudflats, riparian forest, riparian woodland, riparian scrub, disturbed
wetlands, flood channel, fresh water, Engelmann oak woodland, coast live oak woodland) a
goal of no net loss of habitat value or function shall be met. Habitat replacement ratios and
the specific location of mitigation lands shall be determined in consultation with the USFWS,
USACE, and CDFW as appropriate in accordance with the requirements of the federal CWA,
federal wetland policies, and the California Fish and Game Code. All mitigation lands for
impacts to riparian and wetland habitats shall be in the City or MHCP plan area, at a ratio to
be determined by the applicable resource agencies at the time of project permitting.
Bio-2b: Mitigation ratios shall be consistent with the provisions of the HMP and LCP. For all
projects affecting riparian and wetland habitat, habitat replacement ratios and the specific
20
location of mitigation lands shall be determined in consultation with the USFWS, USACE, and
CDFW as appropriate in accordance with the requirements of the federal CWA, federal
wetland policies, and the California Fish and Game Code. All mitigation lands for impacts to
riparian and wetland habitats shall be in the City or MHCP plan area.
Bio-6 The project shall mitigate impacts to wetland and riparian habitat through on-site restoration
and/or off-site wetland and riparian habitat creation/restoration/enhancement at a ratio to
be determined in coordination with the applicable resources agencies at the time of
permitting, consistent with LCP and HMP policies and provisions, as applicable. If adequate
acreage to satisfy mitigation is not available on-site and/or at the Lake Calavera Mitigation
Bank, then alternative mitigation credits may be purchased from the North County Mitigation
Bank, or other alternative sites deemed acceptable by the resource agencies.
The revised project would result in similar impacts on vegetation types and wetland features as stated in
the 2007 EIR, including unvegetated channel, willow riparian forest, southern willow scrub, and non-
native/ornamental vegetation. Table 3 shows a comparison of the revised project’s jurisdictional
habitats impacts to those identified in the 2007 EIR.
Table 3
Jurisdictional Habitats Impact Comparison
2007 EIR
Acreages
Revised
Project
Acreages
Nonnative Vegetation/
Ornamental (CDFW jurisdiction only) 1.56 1.76
Unvegetated Channel 3.35 3.08
Willow Riparian Forest 0.53 0.55
Southern Willow Scrub 0.03 0.03
Total Acres 5.49 5.42
As shown in the table, the revised project would result in a very slight reduction in overall impact on
jurisdictional habitat compared to the previously proposed project. The project will be required to
implement the same mitigation measures listed above for habitat impacts, including revegetation of
wetland and sensitive communities. The City is currently finalizing the revegetation mitigation plan and
seeking approval from the resource agencies. The mitigation plan will identify the final acreages of
impacts and revegetation required for the revised project. Implementation of the revegetation plan will
ensure that the project would result in a less-than-significant impact on habitat and jurisdictional areas.
Therefore, this does not constitute a substantial increase in the significant impact identified in the 2007
EIR.
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3.10.3: Wildlife Movement
Section 4.10 of the 2007 EIR concluded that the project’s wildlife movement impact would be less than
significant. The EIR stated the project area serves as a moderate wildlife corridor for various species,
linking up stream open space areas to Agua Hedionda Lagoon. Construction and ongoing maintenance
activities would result in temporary obstruction to this movement, but the project would not result in
long-term loss of this function. The proposed addition of riprap in the channel bottom as part of the
revised project would add a partial obstacle to wildlife movement through the project area. This
movement would not be completely restricted under the revised project because of existing vegetated
areas that would remain adjacent to the creek, and would be enhanced with additional native plantings
as part of the revegetation plan. By maintaining this functionality in the moderate wildlife corridor in
the project site, this impact would be less than significant, and this does not constitute an additional
significant impact that was not identified in the 2007 EIR.
3.10.4: Plan Consistency
Section 4.10 of the 2007 EIR concluded that the project’s impact with respect to consistency with
biological resources plans would be less than significant with incorporation of mitigation. The EIR stated
the project area is not within the HMP Hardline Preserve. The Agua Hedionda channel improvement is
anticipated in the HMP, and is listed in Appendix B-3 of the HMP in a list of future drainage projects that
are needed to complete the Master Drainage Plan and Storm Water Quality Management Plan, so the
project was identified as consistent with this aspect of the HMP. The HMP establishes a no-net-loss
conservation goal for wetlands, and Section 4.10 identified impacts on wetland communities. These
impacts would be reduced to less-than-significant levels by mitigation measures Bio-1a and Bio-2b, as
discussed above. The EIR also indicated the project is consistent with Local Coastal Plan (LCP) Policy 3-
1.7(a)(5), which permits impacts on wetlands for maintenance dredging required for public service
purposes.
None of the project changes would represent a considerable change in the project’s relationship to the
HMP or LCP. The revised project results in an increase in impacts compared to those identified in the
2007 EIR, due to the addition of riprap, but the overall acreage impacted is slightly less, and
implementation of measures Bio-1a and Bio-2b would ensure that this impact is properly addressed and
reduced to a less-than-significant level. Therefore, this does not constitute a considerable increase in the
severity of this significant impact identified in the 2007 EIR.
3.11: Cultural Resources
Cultural resources impacts of the previously proposed project are discussed in Section 4.11 of the 2007
EIR. The EIR concluded the project would result in a less-than-significant impact on cultural resources.
No resources were identified during the records search and field survey conducted of the project area
and none were expected to be encountered during project earthwork due to the general level of
disturbance in the project area due to prior construction of the creek channels and the surrounding
residential development. The 2007 EIR concluded that no mitigation would be required for cultural
resources. The proposed changes in the project do not alter the project location or substantially expand
the project boundaries. Project-related dredging would involve deeper excavation than previously
considered, but this does not change the conclusion that resources are not expected to be encountered
22
due to the previous level of disturbance in the area. Therefore, there are no changes to the conclusions
of the 2007 EIR with respect to cultural resources.
3.12: Paleontological Resources
Cultural resources impacts of the previously proposed project are discussed in Section 4.12 of the 2007
EIR, which concluded the project would result in a less-than-significant impact on paleontological
resources. The EIR identified the project area as located on Quaternary Alluvium, which has been
assigned a paleontological resources sensitivity rating of “low.” The proposed changes in the project do
not alter the project location or substantially expand the project boundaries, and would not move the
project area into another geological unit that would have a different sensitivity rating. Therefore, the
proposed changes have no bearing on the 2007 EIR’s paleontological resources conclusions.
3.13: Greenhouse Gas Emissions
The 2007 EIR did not include a greenhouse gas (GHG) emissions analysis because this was not a required
component of CEQA at the time the EIR was published. Revisions to the State CEQA Guidelines made in
2011 include a requirement to consider analysis of GHG emission impacts. Therefore, this analysis is
included in this addendum. As discussed below, impacts of the revised project with respect to GHG
emissions would be less than significant, and inclusion of this section does not constitute significant new
information that would necessitate preparation of a supplement to the 2007 EIR.
3.13.1 Environmental and Regulatory Setting
Emissions of GHGs have the potential to adversely affect the environment because such emissions
contribute, on a cumulative basis, to global climate change. Although it is unlikely that a single project
would contribute significantly to climate change, cumulative emissions from many projects could impact
global GHG concentrations and the climate system. GHGs are present in the atmosphere naturally, are
released by natural sources, or are formed from secondary reactions taking place in the atmosphere.
The following are the gases that are widely seen as the principal contributors to human-induced global
climate change:
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Hydrofluorocarbons (HFCs)
Perfluorocarbons (PFCs)
Sulfur Hexafluoride (SF6)
Senate Bill (SB) 97, signed August 2007, acknowledged that climate change is a prominent
environmental issue that requires analysis under CEQA. This bill directed the California Office of
Planning and Research (OPR) to prepare, develop, and transmit to the California Natural Resources
Agency guidelines for the feasible mitigation of GHG emissions or the effects of GHG emissions, as
required by CEQA by July 1, 2009. The California Natural Resources Agency adopted those guidelines on
December 30, 2009, and the guidelines became effective March 18, 2010.
23
3.13.2 Methodology
Global warming potential (GWP) is a concept developed to compare the ability of each GHG to trap heat
in the atmosphere relative to another gas; GWP is based on several factors, including the relative
effectiveness of a gas to absorb infrared radiation and length of time that the gas remains in the
atmosphere (“atmospheric lifetime”). The GWP of each gas is measured relative to CO2, the most
abundant GHG. GHGs with lower emissions rates than CO2 may still contribute to climate change
because they are more effective at absorbing outgoing infrared radiation than CO2. The concept of CO2-
equivalents (CO2e) is used to account for the different GWP potentials of GHGs to absorb infrared
radiation over a 100-year timeframe. The reference gas for GWP is CO2; therefore, CO2 has a GWP of 1.
The other main GHGs that have been attributed to human activity include CH4, which has a GWP of 21,
and N2O, which has a GWP of 310. For example, 1 ton of CH4 has the same contribution to the
greenhouse effect as approximately 21 tons of CO2.
3.13.3 Thresholds of Significance
As stated in Appendix G of the State CEQA Guidelines, the significance criteria established by the
applicable air quality management district may be relied on to make determinations about the CEQA
significance of a project’s GHG impacts. However, at the time of this writing, neither the California Air
Resources Board (ARB) nor APCD has identified a CEQA significance threshold for GHG emissions.
In light of the lack of established GHG emissions thresholds that would apply to the project, CEQA allows
projects to use thresholds of significance applicable to a proposed project that are supported by
substantial evidence. Therefore, to establish additional context in which to consider the order of
magnitude of the project’s operational GHG emissions, this analysis takes into account the following
considerations by other government agencies and associations about what levels of GHG emissions
constitute a cumulatively considerable incremental contribution to climate change:
The County of San Diego has established a threshold of 2,500 MT CO2e per year as a project-
level “bright line” GHG significance threshold that would apply to operational and construction
emissions from land use development projects.
South Coast Air Quality Management District (SCAQMD) is considering a threshold of 3,000 MT
CO2e per year as a project-level “bright line” GHG significance threshold that would apply to
operational emissions from land use development projects.
Facilities that generate greater than 25,000 MT CO2e per year are mandated to report their GHG
emissions to ARB pursuant to AB 32.
At the time of this writing, no federal, state, regional, or local air quality regulatory agency has adopted
a quantitative threshold of significance for construction-related GHG emissions. This information is
presented to put project-generated GHG emissions into the appropriate statewide context to evaluate
whether the GHG emissions contribution from the project would result in a significant cumulative
impact pursuant to CEQA.
3.13.4 Project Impacts
Heavy-duty off-road equipment, materials transport, and worker commutes during construction of the
project would result in exhaust emissions of GHGs. GHG emissions generated by construction would be
primarily in the form of CO,. Construction activities are the same as those discussed earlier under
"Revised Analysis of Project Impacts" related to Air Quality, and construction-related GHG emissions
were also quantified using CaiEEMod. Construction-related GHG emissions that would occur as a result
of implementation of the project would total 655 metric tons of co,e. The total construction-related
C02e emissions associated with the project would be less than any of the adopted or proposed GHG
levels or thresholds discussed earlier in this section. Standard mitigation measures for construction
exhaust, including minimizing idling time, would also reduce GHG emissions. Therefore, the project
would not generate GHG emissions, either directly or indirectly, that may have a significant impact on
the environment. This impact would be less than significant.
Section 4: Environmental Determination
This document has identified all project changes, changed circumstances, and new information related
to the project and its environmental analysis, and memorializes in detail the City's reasoned conclusion
that the revised project, as described in Section 2, does not create the conditions requiring the
preparation of a subsequent or supplemental EIR pursuant to State CEQA Guidelines sections 15162 and
15163.
Pursuant to Section 15164 of the State CEQA Guidelines and based upon the above discussion, I hereby
find that approval and implementation of the proposed project requires only minor technical changes
and additions to the 2007 EIR, as identified in this document, and that a subsequent EIR or supplemental
EIR is not necessary.
3-A:J-/,J
OON NEU, City Planner Date
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Key View 1
Key View 2
Source: AECOM 2012
Agua Hedionda and Calavera Creek Improvements -CEQA Assessment Memorandum
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Existing Conditions
Existing Conditions
Location Map
Location Map
Proposed Conditions (Simulation)
Proposed Conditions (Simulation)
Fi~ur~ 1
Existing and Proposed Conditions
Key View 3
Source: AECOM 2012
Agua Hedionda and Calavera Creek ImproYements -CEQA Assessment Memorandum
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Existing Conditions Location Map Proposed Conditions (Simulation)
Fi~ur~ 1
Existing and Proposed Conditions