HomeMy WebLinkAboutThirtieth Street Architects, Inc. (PA2005-158) 2961 Cliff DriveCITY OF NEWPORT BEACH
PLANNING COMMISSION STAFF REPORT
Agenda Item No. 3
March 23, 2006
TO: PLANNING COMMISSION
FROM: Planning Department
Jaime Murillo, Associate Planner
j murillo(cbcity. newport- beach. ca. us
(949) 644 -3209
SUBJECT: 2961 Cliff Drive
General Plan Amendment No. 2005 -003 and
Parcel Map No. 2005 -035
(PA 2005 -158)
APPLICANT: Thirtieth Street Architects, Inc.
ISSUE
Should the City approve a General Plan Amendment and Parcel Map to allow the
subdivision of an existing single- family lot into two single - family parcels? The applicant
requests the approval of an amendment to the Land Use'Element of the General Plan to
allow the subdivision of a property located within Statistical Area H -2, where subdivisions
are currently prohibited.
RECOMMENDATION
Staff recommends that the Planning Commission recommend approval of General Plan
Amendment No. 2005 -003 and Tentative Parcel Map No. 2005 -035 to the City Council
by adopting the attached draft resolution.
PROJECT DESCRIPTION
Site Description
The lot is currently developed with a single- family dwelling, approximately 2,123 square
feet in size, which was constructed in 1947. To the north, across Cliff Drive, are single -
family dwellings. To the southeast is a single - family dwelling, developed in a similar
manner as the existing subject property. To the south, across the partially unimproved
Avon Street, are retail/commercial office uses and an automobile dealership. To the
northwest, across Santa Ana. Avenue, are additional single - family dwellings.
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The subject lot is 33,193 square feet in size. The northeasterly 1/3 portion of the lot is
relatively flat and developed with the existing dwelling. The southwesterly 2/3 portion of
the lot consists of sloping undeveloped terrain, primarily consisting of dirt, weeds, shrubs
and grass. A significant depression in the slope occurs immediately south of the existing
dwelling structure, in which the slope exceeds a 2:1 ratio, however, a majority of the site
(91 %) maintains a slope of less that 2:1 (Exhibit 2 - Slope Analysis).
Project Description
The applicant is proposing to demolish the existing single - family residence and subdivide
the existing lot into two parcels for the development of two separate single - family
residences. The applicant has designed the parcels to comply with all applicable
requirements of the Zoning Code and applicable provisions of the Subdivision Map Act
and the City's Subdivision Code (Title 19). (Exhibit 3 - Tentative Parcel Map)
Parcel 1
Parcel 1 is the northeasterly of the two parcels and is proposed to be 14,767 square feet
in area. The parcel will have Cliff Drive as its primary street frontage and it will take
vehicular access from Cliff Drive. The parcel will maintain the minimum required 20 -foot
front yard setback from Cliff Drive, 4 -foot side yard setbacks, and 10 -foot rear yard
setback. The resulting buildable area of the parcel is 11,204 square feet allowing for a
potential structure with 22,408 square feet of gross floor area.
Parcel 2
Parcel 2 is the southwesterly of the two parcels and is proposed to be 18,426 square feet
in area. The parcel will have Santa Ana Avenue as its primary street frontage and it will
take vehicular access from Santa Ana Avenue. This parcel will maintain the minimum
required 20 -foot front yard setback from Santa Ana Avenue, 4 -foot side yard setbacks,
and 10 -foot rear yard setback. The resulting buildable area of Parcel 2 is 12,777 square
feet allowing for a potential structure with 25,554 square feet of gross floor area. No
vehicular access to Avon Street is proposed and is prohibited by the Land Use Element.
Architectural Plans
Generally, the approval of the General Plan Amendment and Parcel Map would review
the suitability and design of the proposed parcels; however, specific structures are
typically not required or reviewed. However, the applicant has designed two custom
residences, which the property owner is committed to constructing and intends to submit
plans for building permits upon receiving approval of the subdivision. Detailed
architectural plans, a conceptual grading plan, and landscape plans have been prepared
and attached as Exhibit 4 and serve the purpose of illustrating that the site is physically
suitable for the type and density of the proposed development. In addition to those plans,
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the applicant has prepared preliminary geotechnical investigations and preliminary
hydrology /hydraulic report for the site, to demonstrate that the property is safe and
suitable for the development of two separate dwelling units (Exhibits 5 and 6).
The residences. have been designed with the hope of being compatible with the
surrounding neighborhood and to minimize view impacts to the maximum extent possible,
and therefore a condition of approval has be incorporated requiring the final design of the
dwellings to be within substantial compliance with the architectural plans stamped with the
date of approval. The residence on the upper lot. is proposed to be approximately 9,500
square feet and the residence on the lower parcel is proposed to be approximately 8,800
square feet. The lower residence in particular, has been designed into the hillside using
the natural topography of the parcel, with a majority of the building mass below the curb
line of Santa Ana Avenue. In addition, the lower residence is proposed to include
elements of a sod roof to visually minimize and soften the mass and aesthetics of the
proposed residence as viewed form the neighboring homes. The two residences have
been carefully designed to follow the natural contours of the sloping lot, and therefore
should easily comply with the 24 -foot height limit as measured from natural grade.
Grade
As mentioned, a detailed conceptual grading plan has been prepared for the project and
incorporated into the tentative parcel map. Section 20.65.030(B)(1) of the Zoning Code
states that for the propose of measuring height, the grade shall be the unaltered natural
vertical location of the ground surface unless , `At the time of subdivision, the City has
approved a grading plan or map, under which circumstances grade shafl be finished
grade as shown on the plan or map so approved ". However, the applicant prepared the
grading plan to illustrate that the site is physically suitable for the proposed development
using the natural slope of the property, and not for the purposes of establishing a new
grade. Therefore, to ensure that future dwelling units are constructed utilizing the existing
topography of the property for the purposes of measuring height,. a condition as been
included requiring the height to be measured from the natural grade as depicted on the
topographic survey prepared by Myers & Associates on August 31, 2005 (Exhibit 7).
BACKGROUND
The existing lot was approved for subdivision (Resubdivision No. 707) into four parcels
by the Planning Commission in 1982, prior to the current prohibition of subdivisions.
The Planning Commission's decision was subsequently overruled by the City Council
with the project being denied.
The project proposed under Resubdivision No. 707 would have created four parcels
ranging in size from 6,577 square feet to 8,077 square feet, with three parcels taking
vehicular access off Santa Ana Avenue and one parcel taking access.off Avon Street.
Additionally, land dedication and substantial improvements were required, connecting
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Avon Street to Santa Ana Avenue. Several residents of the community expressed
opposition to the project; comments raised specifically related to the higher density
resulting on the site, opposition to the extension of Avon Street due to increased traffic,
potential traffic impacts resulting from the proposed driveway access onto the narrow
Santa Ana Avenue, obstruction of views, hydrology, and soil stability. It appears that for
these reasons, the City Council denied the project.
ANALYSIS
General Plan- Land Use Element
The Land Use Element of the General Plan sets forth objectives, policies and limitations
for development in the City and designates the general distribution and location of land
uses and residential and commercial densities. The Land Use Element designates the
site as Single - Family Detached. The proposed subdivision is consistent with this
designation; however, the project site is located in Sub -Area 1 of Statistical Area H2
(Newport Heights), which states that, "No subdivision which will result in additional
dwelling units is permitted... ".Therefore, this subject General Plan Amendment is required
to permit the proposed subdivision and increase the development allocation for the area
by one additional unit. The revised language, should this amendment be approved, is
proposed to read as follows:
Newport Heights Area (Statistical Area H2)
1. Newport Heights. This area is located northerly of the Mariner's Mile Specific Plan area
between Santa Ana Avenue and Irvine Avenue. The area is designated predominantly for
Single Family Detached development, with the area near 16th Street and Tustin Avenue
shown for Two - Family Residential and Multi- Family Residential land use. No subdivision
which will result in additional dwelling units is permitted, except for the site at 'n tz„
2961 Cliff Drive, which may be subdivided to create one additional parcel with a
minimum lot area of 14,500 square feet. A minimum of 2, 000 sq. ft. of buildable lot area is
required for duplex development in the Two Family area, and one unit is allowed for.each
2,178 sq. ft. of buildable lot area in the Multi- Family Residential area. The area is
allocated a maximum of X90 791 dwelling units. Residential access from Avon Street is
prohibited, except for lots where no access is available from either Cliff Drive or Santa Ana
Avenue.
'Note: The previous exception granted for the subdivision of 2919 Cliff Drive is proposed to be
removed since the property was subdivided into four separate single- family homes (2907, 2911,
2915, and 2919 Cliff Drive).
Staff believes the neighborhood controversy surrounding the requested four parcel
subdivision of this subject property in 1982, as well as other similar requests on adjacent
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lots, may have contributed to the prohibition of subdivisions in this particular Statistical
Sub -Area, which was included as part of the 1988 update to the Land Use Element.
The proposed subdivision to create two separate single - family lots is compatible with the
neighborhood because the resulting density of the project (2.6 d.u. /acre) is substantially
less than the surrounding lots in the community and will not cause the area to increase in
average density. Additionally, the existing topography of the lot naturally divides the
property into two building pad levels and is conducive to the construction of two
structures, unlike previous attempts to subdivide this property which attempted to divide
the property into four separate parcels.
The Land Use Element has 12 general policies to guide consideration of the potential
amendments. During its review, staff found that Policy D should be considered. Land
Use Element Policy D states:
D. The siting of new buildings and structures shall be controlled and regulated to
ensure, to the extent practical, the preservation of public views, the preservation
of unique natural resources, and to minimize the alteration of natural landforms
along bluffs and cliffs.
Unique natural resources do not exist on the site and the sloping property is not a
natural landform requiring protection as identified in the Implementation Measures of
Policy D. Implementation Measure D-1 identifies natural coastal bluffs as a significant
scenic and environmental resource, and as defined in Policy D, a "coastal bluff' is any
natural landform having an average slope of 26.6 degrees (50 %) or greater, with a
vertical rise of 25 feet or greater. A slope analysis has been performed on the site and
concludes that the site does not meet the definition of a coastal bluff as defined per this
policy because only 9% of the property consists of a slope 2:1 or greater. Additionally, as
discussed later in detail in the Coastal Resource Protection section of this report, the site
does not meet the Coastal Land Use. Plan definition of a bluff, or coastal bluff, because
the topography of the slope does not consist of a headland, nor does it consist of a
precipitous or steep cliff face, and it is not subject to marine erosion. Therefore the
specific development requirements of Implementation Measure D-2, related to grading
and blufftop setbacks for structures located on coastal bluffs, do not apply. And as stated
previously, the existing lot can be completely developed with one large single - family home
with no restrictions beyond the minimum development standards.
The subject site is not identified in the City's Coastal Land Use Program as a public
view point or to provide public coastal views through the site, nor is Cliff Drive and
Santa Ana Avenue identified as a coastal view road requiring public view protection.
Private views from adjacent residences may be affected, and Santa Ana Avenue does
currently afford a coastal view, however the City does not have any private view
protection ordinances or policies. As mentioned, the lower residence has been
designed into the hillside using the natural topography of the parcel, maintaining a
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majority of the building mass below the Santa Ana Avenue curb line and preserving the
views from Santa Ana Avenue. Additionally, the applicant held a community workshop
on September 22, 2005 to discuss the proposed development with neighbors, in which
several neighbors discussed concerns related to view impacts. The applicant then
substantially modified the design of the upper house by reducing the overall height and
mass of the proposed residence by reducing the second floor and shifting the second
floor back closer to Cliff Drive, preserving the existing views to the maximum extent
possible. Therefore, the project as designed does not impact any public views and
minimizes potential private view impacts to the greatest extent possible.
Implementation Measure D -3 states that no structures shall be permitted in areas of
geologic hazard where natural geologic processes can pose a threat to the public health,
safety, and welfare. These areas of hazard contain earthquake faults, existing or potential
landslides, areas with expansive or collapsible soils, excessive settlement and
subsidence, and areas subject to potential erosion and siltation. Preliminary Geotechnical
Investigations have been prepared. for both of the proposed residences and concluded
that the proposed residential developments are feasible and safe from a geotechnical
viewpoint, provided it is constructed with the conclusions and recommendations provided
within the reports (Exhibit 5). No active faults were observed or previously mapped
through the site, and fault rupture across the property is not anticipated. No slumps or
landslips that may impact the site were noted in the study area or on any reviewed
referenced publications. And the lack of groundwater in the upper 50 feet of the subject
site results in the potential for liquefaction to be considered remote. Additionally, it was
concluded that the development of the site will not geotechnically adversely impact
adjoining properties provided the recommendations of the report are implemented in,
design, construction, and maintenance. Therefore, for the reasons discussed above, this
project is consistent with this Policy D and its implementation measures.
Local Coastal Program
The Coastal Land Use Plan of the Local Coastal Program (LCP) sets forth goals,
objectives, and policies that govern the use of land and water in the coastal zone within
the City and addresses land use and development, public access and recreation, and
coastal resource protection. Currently, the project site is. designated for Very Low
Density Residential (RVL 2.6 - 4.5 DU /AC). The proposed subdivision is consistent with
this designation as the proposed project density is 2.6 d.u. /acre. During its review, staff
found that several of the policies contained within the LCP should be considered and
are discussed below:
Location of New Development
2.2.1 -1 Continue to allow redevelopment and infill development within and adjacent
to the existing developed areas in the coastal zone subject to the density
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and intensity limits and resource protection policies of the Coastal Land Use
Plan.
2.2.1 -2 Require new development be located in areas with adequate public
services or in areas that are capable of having public services extended or
expanded without significant adverse effects on coastal resources.
The subject property is located within an existing developed area of the Coastal Zone and
its current density is well below the maximum density limit established for the RVL
designation of the Coastal Land Use Plan. Redevelopment of the site into two separate
parcels will continue to remain below the density limit. Public services and infrastructure
are available to serve the proposed development, and all applicable improvements
required by Section 19.28 (Subdivision Improvements) of the Subdivision Code are to be
satisfied by the applicant.
Residential Development
2.7 -1. Continue to maintain appropriate setbacks and density, floor area, and
height limits for residential development to protect the character of
established neighborhoods and to protect coastal access and coastal
resources.
The residential structures proposed to be constructed within the subject parcels must
comply with all applicable R -1 development regulations of the City's Zoning Code,
specifically pertaining to setbacks, floor area, and height limitations, to insure design
compatibility with the surrounding neighborhood.
Hazards and Protective Devices
2.8.1 -1. Review all applications for new development to determine potential
threats from coastal and other hazards.
2.8.1 -2. Design and site new developmenf to avoid hazardous areas and minimize
risks to life and property from coastal and other hazards.
2.8.1 -3. Design land divisions, including lot line adjustments, to avoid hazardous
areas and minimize risks to life and property from coastal and other
hazards.
2.8.1 -4. Require new development to assure stability and structural integrity, and
neither create nor contribute significantly to erosion, geologic instability, or
destruction of the site or surrounding area or in any way require the
construction of protective devices that would substantially alter natural
landforms along bluffs and cliffs.
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2.8.7 -1. Require new development to provide adequate drainage and erosion
control facilities that convey site drainage in a non - erosive manner in
order to minimize hazards resulting from increased runoff, erosion and
other hydrologic impacts to streams.
2.8.7 -2. Require applications for new development, where applicable [i.e., in areas
of known or potential geologic or seismic hazards], to include a
geologic/soilslgeotechnical study that identifies any geologic hazards
affecting the proposed project site, any necessary mitigation measures,
and contains a statement that the project site is suitable for the proposed
development and that the development will be safe from geologic hazard.
Require such reports to be signed by a licensed Certified Engineering
Geologist or Geotechnical Engineer and subject to review and approval by
the City.
As previously discussed in the Land Use Element analysis, Preliminary Geotechnical
Investigations have been prepared for both of the proposed residences and concluded
that the proposed residential developments are feasible and safe from a geotechnical
viewpoint. Additionally, the study noted that geologic hazards were not observed or
anticipated on the site.
A Preliminary Hydrology /Hydraulic Report was prepared for the proposed project by
Gilbert Engineering & Associates, Inc., to determine the storm water discharges
generated within the local drainage areas and to demonstrate that the storm water and
flood protection goals are met. The report concludes that the drainage patterns or
direction of flow did not change from the existing conditions to the proposed development.
However, the discharge will improve from uncontrolled sheet flow down the slope to a
controlled concentrated flow through the V- ditches, ultimately improving the drainage.
Additionally, the proposed drainage system (designed to a 10 -year frequency storm) is
adequate to transport the drainage off site and that in the event of a 100 year frequency
storm, there should be no significant damage to the proposed structures.
Upon submitting final design drawings for the construction of the proposed residences,
new geotechnical and hydrological reports will be required to be reviewed and approved
by the City, additionally a Water Quality Management Plan will be required to ensure that
the project complies with the City's water quality and on -site storm runoff retention
requirements. Therefore, it is staffs belief that the project is consistent with these policies.
Coastal Resource Protection
Policies 4.4.1 -1 through 4.4.1 -10 pertain to the design of structures to protect public
coastal views. The subject site is not identified by the LCP as a public view point or to
provide any public coastal views through the site, nor is Cliff Drive and Santa Ana
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Avenue identified as a coastal view road requiring public view protection. However, as
previously discussed in the Land Use Element section of this report, the applicant has
significantly mitigated potential private view impacts through careful design of the
proposed residences.
Policies 4.4.3 -1 through 4.4.3 -18 pertain to the protection of coastal bluffs as a
significant scenic and environmental resource. Specific development restrictions,
including bluff top setbacks, construction techniques, and site designs standards are
addressed to protect and minimize alteration to natural coastal bluffs. For the purposes
of implementing the Coastal Land Use Plan, a coastal bluff is defined as, "A bluff
overlooking a beach or shoreline or that is subject to marine erosion ". Additionally, a
bluff is defined as, A high bank or bold headland with a broad, precipitous, sometimes
rounded cliff face overlooking a plain or body of water". However, the subject site does
not meet the definition of a bluff, nor a coastal bluff, as the topography of the slope
does not consist of a headland, nor does it consist of a precipitous or steep cliff face,
and it is not subject to marine erosion. And although the site does afford views of the
harbor, the site does not immediately overlook a beach or a shoreline. Therefore the
referenced policies do not apply to this subject development.
Policies 4.5.1 -1 through 4.5.1 -5 pertain to. the protection of paleontological and
archaeological resources. Specific requirements of the policies relate to monitoring,
preservation of resources, and notification of cultural organizations. Six Native American
Tribes, as identified by the Native American Heritage Commission, that may have
traditional lands or cultural places located within the boundaries of the General Plan
Amendment, were notified of the project and invited to consult in the planning process of
this application. Only one tribe, The Gabrieleno Band of Mission Indians, responded to
the notice and requested monitoring of the site and that if any artifacts are removed, that
they be returned to the proper tribe. Condition Nos. 41, 42, and 43 are consistent with this
request, as well as the policies of the Coastal Land Use Plan, and will insure that should
any paleontological/archaeological resources be uncovered,: development activity will be
suspended to avoid destruction of such resources until a determination can be made as
to their significance.
Zoning Code (Title 20)
The subject property is located within the R -1 (Single - Family Residential) District and the
proposed subdivision will remain consistent with this designation. The proposed design of
the two parcels meets the minimum lot development standards as illustrated below:
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Subdivision Compliance (Title 19 of the Municipal Code)
In accordance with Title 19 (Subdivision Code), approval of a Parcel Map is required for
the subdivision of land creating 4 or fewer parcels. The Planning Commission must
make the following findings in approving the tentative parcel map:
1. That the proposed map and the design or improvements of the subdivision are
consistent with the General Plan and any applicable specific plan, and with
applicable provisions of the Subdivision Map Act and this Subdivision Code.
As noted in the previous sections, staff believes that the proposed subdivision can be
found consistent with the Single Family Detached General Plan designation of the site.
Should the proposed amendment not be approved, this finding cannot be made given
the proposed uses, design and improvements proposed by the applicant. The Public
Works Department has reviewed the proposed tentative map and believes it is
consistent with the Newport Beach Subdivision Code (Title 19) and applicable
requirements of the Subdivision Map Act. The project has been conditioned to provide a
number of public improvements, including the construction of full length sidewalks along
both the Cliff Drive and Santa Ana Avenue frontages. However, due to topographical
constraints that exist between Santa Ana Avenue and Avon Street, the development will
not be required to connect Avon Street to Santa Ana Avenue. Additional conditions of
approval have been included to ensure compliance with Title 19.
2. That the site is physically suitable for the type and density of development.
The two parcels are proposed for residential development and are of sufficient size for
the intensity and density of the proposed residential development. The proposed
density of the two parcels is substantially less than the surrounding lots in the
community. Vehicular access to the upper parcel will be from Cliff Drive and access to
the lower parcel will be from Santa Ana Avenue, consistent with the Land Use Element
prohibition of taking access from Avon Street. Condition No. 13 as been incorporated to
insure access is designed to this effect and prohibited from Avon Street. The
Preliminary Geotechnical Investigations that have been prepared for both of the proposed
residences concluded the residential developments as feasible and safe from a
geotechnical viewpoint.
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3. That the design of the subdivision or the proposed improvements are not likely to
cause substantial environmental damage nor substantially and avoidably injure
fish or wildlife or their habitat. However, notwithstanding the foregoing, the
decision - making body may nevertheless approve such a subdivision if an
environmental impact report was prepared for the project and a finding was
made pursuant to Section 21081 of the California Environmental Quality Act that
specific economic, social, or other considerations make infeasible the mitigation
measures or project alternatives identified in the environmental impact report.
The site currently exists as a single - family lot with a two -story residence developed on
the upper portion of the property. The lower portion of the site is isolated from other
natural areas and dominated by non - native vegetation, and given its location within a
developed urban setting, the likelihood that the proposed project would cause
substantial environmental damage or adversely affect wildlife or their habitat is
improbable. Additionally, the project qualifies for Class 3 Categorical Exemption (New
Construction or Conversion of Small Structures) under the California. Environmental
Quality Act as the project will result in the construction of one additional single - family
residence and is located on a developed site with no environmentally significant
resources present.
4. That the design of the subdivision or the type of improvements is not likely to
cause serious public health problems.
The development of two parcels for residential use is not expected to cause serious
public health problems given the use of typical construction materials and practices. No
evidence is known to exist that would indicate that the proposed subdivision will
generate any serious public health problems. The parcels have been designed in
compliance with all applicable subdivision standards of Title 19 and the proposed
residences are conditioned to comply with R -1 development standards of the Zoning
Code, insuring the protection of adequate light; air, privacy, and open space for each
dwelling unit, and insuring design compatibility with the surrounding neighborhood.
5. That the design of the subdivision or the type of improvements will not conflict
with easements, acquired by the public at large, for access through or use of
property within the proposed subdivision. in this connection, the decision - making
body may approve a map if it finds that alternate easements, for access or for
use, will be provided and that these easements will be substantially equivalent to
ones previously acquired by the public. This finding shall apply, only to
easements of record or to easements established by judgment of a court of
competent jurisdiction and no authority is hereby granted to the City Council to
determine that the public at large has acquired easements for access through or
use of property within a subdivision.
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No public easements for access through or use of the property have been retained for
the use by the public at large.
6. That, subject to the detailed provisions of Section 66474.4 of the Subdivision
Map Act, if the land is subject to a contract entered into pursuant to the California
Land Conservation Act of 1965 (Williamson Act), the resulting parcels following a
subdivision of the land would not be too small to sustain their agricultural use or
the subdivision will result in residential development incidental to the commercial
agricultural use of the land.
The site is not subject to a Williamson Act contract; therefore, this finding does not
apply.
7. That, in the case of a "land project" as defined in Section 11000.5 of the
California Business and Professions Code: (a) there is an adopted specific plan
for the area to be included within the land project, and (b) the decision- making
body finds that the proposed land project is consistent with the specific plan for
the area.
The subject property is not located within the boundaries of a specific plan; therefore,
this finding does not apply.
8. That solar access and passive heating and cooling design requirements have
been satisfied in accordance with Sections 66473.1 and 66475.3 of the
Subdivision Map Act.
Title 24 of the Uniform Building Code requires new construction to meet minimum
heating and cooling efficiency standards depending on location and climate. The
Newport Beach Building Department will enforce Title 24 compliance through the plan
check and field inspection processes for the construction of the proposed residences.
Additionally, since the lower dwelling unit will be built into the slope and benefits from
southern exposure of the sun, the project will take maximum advantage of solar and
passive heating.
9. That the subdivision is consistent with Section 66412.3 of the Subdivision Map
Act and Section 65584 of the California Government Code regarding the City's
share of the regional housing need and that it balances the housing needs of the
region against the public service needs of the City's residents and available fiscal
and environmental resources.
The proposed subdivision facilitates the creation of one new residential unit that will be
added to:the City's housing stock and furthers the City's,goal of meeting its housing
needs as identified in the Regional Housing Needs Assessment. The addition of one
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unit will not cause an undue strain on City resources and public services are available
to serve the proposed development of the site.
10. That the discharge of waste from the proposed subdivision into the existing
sewer system will not result in a violation of existing requirements prescribed by
the Regional Water Quality Control Board.
Waste discharge into the existing sewer system will be consistent with the existing
residential use of the property and does not violate Regional Water Quality Control
Board (RWQCB) requirements. Additionally, sewer connections have been conditioned
to be installed per City Standards, the applicable provisions of Chapter 14.24 (Sewer
Connection, Permits), and the latest revision of the Uniform Plumbing Code.
11. For subdivisions lying partly or wholly within the Coastal Zone, that the
subdivision conforms with the certified Local Coastal Program and, where
applicable, with public access and recreation policies of Chapter Three of the
Coastal Act.
The project is consistent with the City's new Local Coastal Program Land Use Plan as
discussed previously in this report. The subject site to be subdivided does not abut the
ocean or bay, and does not provide public access to coastal resources; therefore, no
impacts to coastal access are anticipated.
Charter Section 423 (Measure S)
Council Policy A -18 requires that proposed General Plan amendments be reviewed to
determine if a vote would be required. If a project generates more than 100 peak hour
trips, 40,000 square feet of non - residential floor area or exceeds 100 dwelling units, a
vote of the citizens would be required if the Council approves the suggested
Amendment. The proposed amendment requests approval of only 1 additional dwelling
unit, does not include any commercial floor area, and results in an increase of 0.75 AM
peak hour trips and 1.01 PM peak hour trips. Therefore, none of the three thresholds to
require a vote pursuant to Measure S (Greenlight) are exceeded. No other amendment
has been approved .for this statistical area, and therefore no vote would be required
based on a cumulative analysis. This amendment will be tracked for ten years in
accordance with Section 423.
Environmental Review
The project qualifies for a Categorical Exemption pursuant to Section 15303 (New
Construction or Conversion of Small Structures) of the Implementing Guidelines of the
California Environmental Quality Act as the project will result in the construction of one
additional single - family residence, below the maximum threshold permitted under this
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exemption, and is located on a developed site with no environmentally significant
resources present.
Public Notice
Notice of this hearing was published in the Daily Pilot, mailed to property owners within
300 feet of the property and posted at the site a minimum of 10 days in advance of this
hearing consistent with the Municipal Code. Additionally, the item appeared upon the
agenda for this meeting, which was posted at City Hall and on the city website.
Summary
Staff believes that findings necessary for project approval can be made. It is staffs
opinion that the two parcel subdivision would not prove detrimental to the area and is
compatible with the surrounding area of Newport Heights.
Should the Planning Commission conclude that the project as proposed would not be
compatible with the surrounding uses and that the project would not be appropriate for
the site; the project should be denied or modified to address issues of design if a
redesigned project is advisable.
Prepared by:
Ime Murillo, Associate Planner
Submitted by:
45�41A�-K
atrick Aif&cT, Actifig Planning Director
Exhibits
1. Draft Resolution No. 2005 findings and conditions of approval
2. Slope Analysis
3. Tentative Parcel Map
4. Architectural Plans
S. Preliminary Geotechnical Investigation Reports
6. Hydrology /Hydraulic Study
7. Topographic Survey
EXHIBIT 1
Draft Resolution No. 2005
6
RESOLUTION NO.
A RESOLUTION OF THE PLANNING COMMISSION OF THE CITY OF
NEWPORT BEACH RECOMMENDING THAT THE CITY COUNCIL
APPROVE GENERAL PLAN AMENDMENT NO. 2005 -003, AND,
TENTATIVE PARCEL MAP NO. 2005 -035 FOR PROPERTY LOCATED
AT 2961 CLIFF DRIVE (PA 2005 -158).
WHEREAS, an application was filed by Thirtieth Street Architects, Inc., with respect
to property located at 2961 Cliff Drive, and legally described as Lot Park '2" of the First
Addition to Newport Heights in the City of Newport Beach, State of California, as per map
filed in Book 4, page 94, of miscellaneous maps, in the office of the County Recorder to
subdivide an existing single - family lot into two separate single- family parcels. The
application requests an amendment to the Land Use Element of the General Plan to allow
the subdivision of a property located within Statistical Area H -2, where subdivisions are
currently prohibited; and
WHEREAS, a public hearing was held by the Newport Beach Planning
Commission on March 23, 2006 in the City Hall Council Chambers, 3300 Newport
Boulevard, Newport Beach, California. A notice of time, place, and purpose of the meeting
was given in accordance with the Municipal Code and State Law. Evidence, both written
and oral, was presented to and considered by the Planning Commission at this meeting;
and
WHEREAS, the property is located in the Sub -Area 1 of Statistical Area H2
(Newport Heights) of the Land Use Element of the General Plan and has a land use
designation of Single Family Detached (SFD) and the property is zoned Single Family
Residential (R1); and
WHEREAS, a General Plan Amendment is required to allow the subdivision of
the subject single- family lot into two single - family parcels because Sub -Area 1 of
Statistical Area H2 currently prohibits subdivisions that would result in additional
dwelling units being permitted; and
WHEREAS, the proposed subdivision is consistent with the existing Single
Family Detached General Plan designation and will remain compatible with the
surrounding neighborhood as the density of the project is 2.6 d.u. /acre, which is
substantially less than the surrounding lots in the community and will not cause the area to
increase in average density; and
WHEREAS, the existing topography of the lot naturally divides the property into
two building pad levels and is conducive to the construction of two structures that will
remain compatible with the existing residential developments adjacent to the site; and
WHEREAS, the property is consistent with Policy D of the Land Use Element of
the General Plan which states, "The siting of new buildings and structures shall be
controlled and regulated to ensure, to the extent practical, the preservation of public
City of Newport Beach
Planning Commission Resolution No. _
Page 2 of 15
views, the preservation of unique natural resources, and to minimize the alteration of
natural landforms along bluffs and cliffs, "for the following reasons:
Unique natural resources do not exist on the site and the sloping property is not a
natural landform requiring protection as identified in the Implementation
Measures of Policy D because:
a. A slope analysis has been performed on the site and concludes that the site
does not meet the definition of a coastal bluff as defined per this policy
because only 9% of the property consists of a slope 2:1 or greater.
b. The site does not meet the Coastal Land Use Plan definition of a bluff or
coastal bluff because the topography of the slope does not consist of a
headland, nor does it consist of a precipitous or steep cliff face, and, it is
not subject to marine erosion.
c. The existing lot can be completely developed with one large single- family
home with no restrictions beyond the minimum development standards.
2. The proposed development does not impact any public views and minimizes
potential private view impacts to the greatest extent possible because:
a. The site is not identified in City's Coastal Land Use Program as a public
view point or to provide public coastal views through the site, nor is Cliff
Drive and Santa Ana Avenue identified as a coastal view road requiring
public view protection.
b. Private views from adjacent residences may be affected, and Santa Ana
Avenue does currently afford a coastal view, however the City does not
have any private view protection ordinances or policies.
c. The lower residence has been designed into the hillside using the natural
topography of the ' -parcel, maintaining a majority of the building mass
below the Santa Ana Avenue curb line and preserving views off Santa Ana
Avenue.
d. The applicant substantially modified the design of the upper house by
reducing the overall height and mass of the proposed residence by
reducing the second floor and shifting the second floor back closer to Cliff
Drive, preserving the existing views to the maximum extent possible.
3. The project is consistent with Implementation Measure D -3 which states that no
structures shall be permitted in areas of geologic hazard where natural geologic
processes can pose a threat to the public health, safety, and welfare, because:
t�
City of Newport Beach
Planning Commission Resolution No. _
Page 3 of 15
a. Preliminary Geotechnical Investigations have been prepared for both of the
proposed residences and concluded that the proposed residential
developments are feasible and safe from a geotechnical viewpoint and that
the project will not adversely impact adjoining properties, provided the
recommendations of the report are implemented in design, construction, and
maintenance.
b. No active faults were observed or previously mapped through the site, and
fault rupture across the property is not anticipated.
c. No slumps or landslips that may impact the site were noted in the study area
or on any reviewed referenced publications.
d. And the lack of groundwater in the upper 50 feet of the subject site results
in the potential for liquefaction to be considered remote.
WHEREAS, the Coastal Land Use Plan sets forth goals, objectives, and policies
that govern the use of land and water in the coastal zone and addresses land use and
development, public access and recreation, and coastal resources protection. The
proposed subdivision is consistent with the LCP for the following reasons:
The project site is designated for Very Low Density Residential (RVL 2.6 - 4.5
DU /AC) by the LCP.
2. The subject property is located within an existing developed area of the Coastal
Zone and its current density is well below the maximum density limit established for
the RVL designation of the LCP. Subdividing the site into two parcels will not cause
the site to exceed the density limit established under the RVL designation.
3. Public services and infrastructure are available to serve the proposed development,
and all applicable improvements required by Section 19.28 (Subdivision
Improvements) of the Subdivision Code are to be satisfied by the applicant.
4. The residential structures proposed to be constructed within the subject parcels are
proposed and conditioned to comply with all applicable R -1 development
regulations of the City's Zoning Code, specifically pertaining to setbacks, floor area,
and height limitations, to insure design compatibility with the surrounding
neighborhood.
5. Preliminary Geotechnical Investigations have been prepared for both of the
proposed residences and concluded that the proposed residential developments
are feasible and safe from a geotechnical viewpoint. Additionally, the study noted
that geologic hazards were not observed or anticipated on the site.
p
City of Newport Beach
Planning Commission Resolution No.
Page 4 of 15
6. The subject site is not identified by the LCP as a public view point or to provide
any public coastal views through the site, nor is Cliff Drive and Santa Ana
Avenue identified as a coastal view road requiring public view protection.
However, the applicant has significantly mitigated potential private view impacts
through careful design of the proposed residences.
7. The project has been conditioned to insure that should any
paleontological /archaeological resources be uncovered, development activity will
be suspended to avoid destruction of resources until a determination can be made
as to the significance of the resources.
8. No impacts to coastal access are anticipated given the project location, as the
site does not abut the ocean or bay and does not currently provide public access
to coastal resources.
WHEREAS, Charter Section 423 requires that proposed General Plan
amendments be reviewed to determine if a vote would be required. If a project
generates more than 100 peak hour trips, 40,000 square feet of non - residential floor
area or exceeds 100 dwelling units, a vote of the citizens would be required if the
Council approves the suggested Amendment. The proposed amendment requests
approval of only 1 additional dwelling unit, does not include any commercial floor area,
and results in an increase of 0.75 AM peak hour trips and 1.01 PM peak hour trips.
Therefore, none of the three thresholds to require a vote pursuant to Measure S
(Greenlight) are exceeded. Additionally, no other amendment has been approved for
this statistical area, and therefore no vote would be required based on a cumulative
analysis. This amendment will be tracked for ten years in accordance with Section 423;
and
WHEREAS, the project is located within Newport Heights where public services
and infrastructure are available to serve the additional dwelling unit to be created by this
proposed subdivsion. Additionally, all applicable improvements required by Section 19.28
(Subdivision Improvements) of the Subdivision Code are to be satisfied by the applicant;
and
WHEREAS, Pursuant to Section 19.12.070 of the City Subdivision Code, the
following standard findings must be made to approve the Tentative Parcel Map:
1. The proposed map and the design or improvements of the subdivision are
consistent with General Plan and any applicable specific plan, and with the
applicable provisions of the Subdivision Map Act and Title 19 because:
a. The proposed parcels are consistent with Single Family Detached General
Plan designation of the site.
p
City of Newport Beach
Planning Commission Resolution No. _
Page 5 of 15
b. The Public Works Department has reviewed the proposed Tentative
Parcel Map and found it consistent is consistent with the Title 19 and
applicable requirements of the Subdivision Map Act, an no exceptions
have been requested from the design standards.
c. Due to topographical constraints that exist between Santa Ana Avenue
and Avon Street, the development will not be required to connect Avon
Street to Santa Ana Avenue.
d. Conditions of approval have been included to ensure compliance with Title
19 and the Subdivision Map Act.
2. The site is physically suitable for the type and density of development because:
a. The two parcels are proposed for residential development and are of
sufficient size for the intensity and density of the proposed residential
development.
b. The proposed density of the two parcels is substantially less than the
surrounding lots in the community.
c. Vehicular access to the upper parcel will be from Cliff Drive and access to
the lower parcel will be from Santa Ana Avenue, consistent with the Land
Use Element prohibition of taking access from Avon Street.
d. The site is physically suitable for the development and geologic hazards
were not observed or anticipated on the site by the Preliminary
Geotechnical Investigations that have been prepared for both of the
proposed residences, which also concluded the residential developments as
feasible and safe from a geotechnical viewpoint.
1 The design of the subdivision or the proposed improvements are not likely to
cause substantial environmental damage nor substantially and avoidably injure
fish or wildlife or their habitat because:
a. The site currently exists as a single - family lot with a two -story residence
developed on the upper portion of the property and the property can
currently be completely built on with no development restrictions beyond
the minimum R-1 development standards of the Zoning Code.
b. The proposed subdivision will not change the possible level of
development that can occur on the site, but only increases the density by
permitting one additional unit.
P'}
City of Newport Beach
Planning Commission Resolution No. _
Page 6 of 15
c. The site is dominated by non - native vegetation, and given its location
within a developed urban setting, the likelihood that the proposed project
would cause substantial environmental damage or adversely affect wildlife
or their habitat is improbable.
4. The design of the subdivision or the type of improvements is not likely to cause
serious public health problems because:
a. The development of the two parcels is for residential use and is not
expected to cause serious public health problems given the use of typical
construction materials and practices.
b. No evidence is known to exist that would indicate that the proposed
subdivision will generate any serious public health problems.
c. The parcels have been designed in compliance with all applicable
subdivision standards of Title 19 and the proposed residences are
conditioned to comply with R -1 development standards of the Zoning
Code, insuring the protection of adequate light, air, privacy, and open
space for each dwelling unit, and insuring design compatibility with the
surrounding neighborhood.
5. The design of the subdivision or type of improvements will not conflict with
easements, acquired by the public at large, for access through, or use of,
property within the proposed subdivision because no public easements for
access through, or use of, the property have been retained for the use by the
public at large.
6. Solar access and passive heating and cooling design requirements have been
satisfied in accordance with Sections 66473.1 and 66475.3 of the Subdivision
Map Act because:
a. Title 24 of the Uniform Building Code requires new construction to meet
minimum heating and cooling efficiency standards depending on location
and climate.
b. The Newport Beach Building Department enforces Title 24 compliance
through the plan check and field inspection processes.
c. Since the lower dwelling unit will be built into the slope and benefits from
southern exposure of the sun, the project will take maximum advantage of
solar and passive heating.
9�°J
City of Newport Beach
Planning Commission Resolution No.
Page 7 of 15
7. The subdivision is consistent with Section 66412.3 of the Subdivision Map Act
and Section 65584 of the California Government Code regarding the City's share
of the regional housing need and that it balances the housing needs of the region
against the public service needs of the City's residents and available fiscal and
environmental resources because:
a. The proposed subdivision facilitates the creation of one new residential
unit that will be added to the City's housing stock and. further the City's
goal of meeting its housing needs as identified in the Regional Housing
Needs Assessment.
b. The addition of one unit will not cause an undue burden on City resources
and public services are available to serve the proposed development of
the site
8. The discharge of waste from the proposed subdivision into the existing sewer
system will not result in a violation of existing requirements prescribed by the
Regional Water Quality Control Board because:
a. Waste discharge into the existing sewer system will be consistent with the
existing residential use of the property and does not violate Regional
Water Quality Control Board (RWQCB) requirements.
b. Sewer connections have been conditioned to be installed per City
Standards, the applicable provisions of Chapter 14.24 (Sewer Connection,
Permits), and the latest revision of the Uniform Plumbing Code.
9. The subdivision conforms to the certified Coastal Land Use Plan and, where
applicable, with public access .and recreation policies of Chapter Three of the
Coastal Act because:
a. • The project has been designed and conditioned for consistency with the
City's new Local Coastal Program Land Use Plan.
b. The subject site to be subdivided does not abut the ocean or bay, and
does not provide public access to coastal resources; therefore, no impacts
to coastal access are anticipated.
WHEREAS, the project qualifies for a Categorical Exemption pursuant to Section
15303 (New Construction or Conversion of Small Structures) of the Implementing
Guidelines of the California Environmental Quality Act as the project will result in the
construction of one additional single - family residence, below the maximum threshold
permitted under this exemption, and is located on a developed site with no
environmentally significant resources present, and
�1
City of Newport Beach
Planning Commission Resolution No. _
Page 8 of 15
WHEREAS, the Planning Commission finds that judicial challenges to the City's
CEQA determinations and approvals of land use projects are costly and time
consuming. In addition, project opponents often seek an award of attorneys' fees in
such challenges. As project applicants are the primary beneficiaries of such approvals,
it is appropriate that such applicants should bear the expense of defending against any
such judicial challenge, and bear the responsibility for any costs, attorneys' fees, and
damages which may be awarded to a successful challenger; and
NOW, THEREFORE, BE IT RESOLVED:
Section 1. The Planning Commission hereby recommends that the City Council
of the City of Newport Beach adopt General Plan Amendment No. 2005 -003 to allow the
subdivision of 2961 Cliff Drive into two separate single - family parcels and revise
language contained within the Land Use Element pertaining to the change in
subdivision, as shown in Exhibit "A ".
Section 2. The Planning Commission hereby further recommends that the City
Council of the City of Newport Beach adopt Tentative Parcel Map No. 2005 -035, subject
to Conditions of Approval in Exhibit "B" attached hereto and made part hereof.
PASSED, APPROVED AND ADOPTED THIS 23`d DAY OF MARCH 2006.
M
mm
Michael Toerge, Chairman
Barry Eaton, Secretary
AYES:
NOES:
ABSENT:
-5
City of Newport Beach
Planning Commission Resolution No. _
Page 9 of 15
Exhibit "A"
THE FOLLOWING CHANGES WILL BE MADE TO THE LAND USE ELEMENT AND
OTHER PROVISIONS OF THE LAND USE ELEMENT SHALL REMAIN UNCHANGED:
Newport Heights Area (Statistical Area H2)
1. Newport Heights. This area is located northerly of the Manner's Mile Specific Plan area
between Santa Ana Avenue and Irvine Avenue. The area is designated predominantly for
Single Family Detached development, with the area near 16th Street and Tustin Avenue
shown for Two - Family Residential and Multi - Family Residential land use. No subdivision
which will result in additional dwelling units is permitted, except for the site at 2919 Cli
Drive, ...tde ..o,,.. ; «e.. ,. ,,..; «:..,,,..., ..c 7r 000 sq a ,. fb Hdable let r r each new «....,,et
2961 Cliff Drive, which may be subdivided to create one additional parcel with a
minimum lot area of 14,500 square feet. A minimum of 2,000 sq. ft. of buildable lot area
is required for duplex development in the Two Family area, and one unit is allowed for
each 2,178 sq. ft. of buildable lot area in the Multi - Family Residential area. The area is
allocated a maximum of 790 791 dwelling units. Residential access from Avon Street is
prohibited, except for lots where no access is available from either Cliff Drive or Santa Ana
Avenue.
A 1
ESTIMATED GROWTH FOR STATISTICAL AREA H2
Residential (in du's)
Commercial (in sq. ft.)
Existing
Gen. Plan
Projected
Existing
Gen. Plan
Projected
1/1/87
Projection
Growth
1/1/87
Projection
Growth
1. Newport Heights
773
784791
89
-0-
-0-
-0-
2. Cliff Drive Park
-0-
-0-
-0-
900
1,000
100
3. Ensign View Park
-0-
-0-
-0-
3,000
5,000
2,000
4. Newport Hgts. Elem.
-0-
-0-
-0-
35,248
39,683
3,435'
TOTAL
773
781791
89
39,148
45,683
5,535
Population
1,531
1,546
16
A 1
City of Newport Beach
Planning Commission Resolution No.
Page 10 of 15
Exhibit "B"
CONDITIONS OF APPROVAL
Tentative Parcel Map No. 2005 -035 (PA 2005 -158)
1. The proposed residential development shall comply with the R -1 development
standards of the Zoning Code and shall remain in substantial conformance with
the architectural plans stamped with the date of this meeting, except as noted in
the following conditions.
2. The Map shall be in substantial conformance with the Tentative Parcel Map
dated February 15, 2006, except as noted in the following conditions.
3. The project is subject to all applicable City ordinances, policies, and standards,
unless specifically waived or modified by the conditions. of approval.
4. The Tentative Parcel Map shall expire within 24 months from the date of approval
unless extensions are granted prior to expiration in accordance with the
Subdivision Ordinance and Subdivision Map Act.
5. The applicant shall obtain a Coastal Development Permit from the California
Coastal Commission prior to the recordation of the parcel map and prior to the
issuance of any building or grading permit for the project.
6. Height of proposed future residences shall be measured from natural grade as
depicted on the topographic survey prepared by Myers & Associates on August 31,
2005 for the subject site.
7. The applicant is required to obtain all applicable permits from the City Building and
Fire Departments. The construction plans must comply with the most recent, City-
adopted. version of the California Building Code.
8. All buildings shall be provided with fire sprinklers, as required by the Fire
Department.
9. Prior to the recordation of the parcel map, the applicant shall provide an additional
fire hydrant in a location approved by the Fire Department.
10. Prior to the recordation of the parcel map, park dedication fees for one dwelling unit
shall be paid in accordance with Chapter 19.52 of the Newport Beach Municipal
Code.
a1
City of Newport Beach
Planning Commission Resolution No. _
Page 11 of 15
11. Both project driveways and improvements at the comer of Cliff Drive and Santa
Ana Avenue shall be reviewed and approved by the City Traffic Engineer to insure
adequate sight distance is provided per City Standard STD - 110 -L. Slopes,
landscaping, walls and other obstructions shall be considered in line of site
requirements. Landscaping within the line of sight shall not exceed a height of
twenty-four inches. The sight distance requirement may be modified at non - critical
locations, subject to the approval of the Traffic Engineer.
12. Residences shall be designed in such a manner that allow vehicles exiting garage
spaces adequate space to turn around on site; backing out onto adjacent public
streets shall be prohibited.
13. Vehicular access shall be taken from either Cliff Drive or Santa Ana Avenue, and
access shall be prohibited from Avon Street.
14. All work conducted within the public right -of -way shall be approved under an
encroachment permit and all non - standard improvements within the public right -
of -way requires an encroachment agreement issued by the Public Works
Department.
15. Plantings within the public right -of -way along Santa Ana Avenue and Cliff Drive
shall be turf or other low planting that can accommodate pedestrian traffic.
16. The Map shall be prepared on the Califomia Coordinate System (NA083). Prior
to recordation of the Maps, the surveyorlengineer preparing the Maps shall
submit to the County Surveyor and the City of Newport Beach a digital - graphic
file of said Maps in a manner described in the Orange County Subdivision Code
and Orange County Subdivision Manual. The Maps to be submitted to the
City of Newport Beach shall comply with the City's CADD Standards.
Scanned images will not be accepted.
17. Prior to recordation of the Maps, the surveyof /engineer preparing the Maps shall
tie the boundary of the Maps into the Horizontal Control System established by
the County Surveyor in a manner described in Section s 7 -9 -330 and 7 -9 -337 of
the Orange County Subdivision Code and Orange County Subdivision Manual,
Subarticle 18. Monuments (one inch iron pipe with tag) shall be set On Each Lot
Comer unless otherwise approved by the Subdivision Engineer. Monuments
shall be protected in place if installed prior to completion of construction project.
18. All improvements shall be constructed as required by Ordinance and the Public
Works Department,
19. Upon submittal of building plans for plan check, a hydrology and hydraulic study
shall be submitted by the applicant, and approved by the City, to ascertain the
RY
City of Newport Beach
Planning Commission Resolution No.
Page 12 of 15
existing storm drain system along Avon Street has sufficient excess capacity to
accept all of the on -site storm runoff proposed for discharge into said system.
20. The design of all public facilities required to serve the development shall comply
with the City's Design Criteria, Standard Plans, and drawing submittal
requirements. All of the plan sheets shall be wet sealed, dated, and signed by the
California registered professionals responsible for the designs shown on said
plans.
21. A minimum 10 -foot radius cut -off easement for street and utilities purposes at the
Santa Ana Avenue/ Cliff Drive property comer shall be recorded as part of the
Map.
22. All private easements shall be recorded as part of the Map.
23. Full width sidewalks shall be constructed along the length of the Santa Ana
Avenue and Cliff Drive frontages.
24. An ADA compliant curb access ramp shall be constructed at the Santa Ana
Avenue /Cliff Drive return.
25. All proposed driveway flares (top of "X "s) shall maintain a minimum clear
distance of 5 -feet from the nearest power pole, pipe vents, above ground
facilities, or other public facilities.
26. All storm drain and sanitary sewer mains shall be installed with MacWrap
27. In accordance with the provisions of Chapter 13 of the Newport Beach Municipal
Code or other applicable section or chapter, a new street tree shall be planted
along the Cliff Drive frontage and existing street trees shall be protected in place
during the construction of subject project, unless otherwise approved by the
General Service Department and the Public Works Department through an
encroachment permit or agreement, if required.
28. Construction surety in a form acceptable to the City, guaranteeing the completion
of various required public improvements, shall be submitted to the Public Works
Department prior to encroachment permit issuance.
29. The developer shall be responsible for repairing and /or reconstruction of damage
done to the Santa Ana Avenue or Cliff Drive roadway pavement surrounding the
development site by private work.
30. Provisions shall be made to prevent proposed garages from being flooded by
storm runoff traveling on the inclined driveways.
Al
City of Newport Beach
Planning Commission Resolution No. _
Page 13 of 15
31. Each unit shall be served by individual water service and sewer lateral
connection to the public water and sewer systems.
32. All overhead utilities serving the development shall be undergrounded.
33. Vehicular traffic on Santa Ana Avenue shall be maintained throughout duration of
construction.
34. County Sanitation District fees shall be paid prior to issuance of any building
permits.
35. The applicant shall be responsible for the payment of all administrative costs
identified by the Planning Department within 30 days of receiving a final notification
of costs or prior to the release for recordation of the parcel map.
36. Prior to the issuance of any building permits, Public Works Department plan
check and inspection fee shall be paid.
37. Prior to issuance of grading or building permits, the project applicant shall have
an approved final Project Water Quality Management Plan (WQMP). The City of
Newport Beach requires all new development and significant redevelopment
projects to prepare and submit a WQMP to the City for review and approval.
38. Prior to the issuance of any grading permits, a Stormwater Pollution Prevention
Plan ( SWPPP) shall be prepared and approved by the City of Newport Beach as
the local permitting agency in accordance with the requirements of the Regional
Water Quality Control Board (RWQCB). The SWPPP shall include BMPs to
eliminate and /or minimize stormwater pollution prior to, and during construction.
The SWPPP shall require construction to occur in stages and stabilized prior to
disturbing other areas and require the use of temporary diversion dikes and basins
to trap sediment from run -off and allow clarification prior to discharge.
39. Prior to issuance of any grading permits, the project applicant shall document to
the City of Newport Beach Building Department that all facilities will be designed
and constructed to comply with current seismic safety standards and the current
City- adopted version of the Uniform Building Code.
40. Prior to issuance of any grading permits, an updated geotechnical report shall be
submitted with construction drawings for plan check. The Building Department
shall ensure that the project complies with the geotechnical recommendations
included in the report, as well as additional requirements, if any, imposed by the
Newport Beach Building Department.
56
City of Newport Beach
Planning Commission Resolution No. _
Page 14 of 15
41. Prior to the issuance of any grading permits, the applicant shall provide written
evidence to the Planning Director that a qualified archaeologist has been
retained to observe grading activities and conduct salvage excavation of
archaeological resources as necessary. The archaeologist shall be present at the
pre- grading conference, shall establish procedures for archaeological resources
surveillance, and shall establish, in cooperation with the applicant, procedures for
temporarily halting or redirecting work to permit the sampling, identification and
evaluation of the artifacts as appropriate. If additional or unexpected
archaeological features are discovered, the archaeologist shall report such
findings to the applicant and to the Planning Department. If the archaeological
resources are found to be significant, the archaeological observer shall
determine appropriate actions, in cooperation with the applicant, for exploration
and /or salvage. These actions, as well as final mitigation and disposition of the
resources, shall be subject to the approval of the Planning Director.
42. Prior to the issuance of the any grading permits, the applicant shall provide
written evidence to the planning director that a qualified paleontologist has been
retained to observe grading activities and conduct salvage fossils as necessary.
The paleontologist shall be present at the pre - grading conference, shall establish
procedures for paleontological resource surveillance, and shall establish
cooperation with the applicant, procedures for temporarily halting or redirecting
work to permit the sampling, identification and evaluation of fossils. If major
paleontological resources are discovered which require long term baiting or
redirecting of grading, the paleontologist. shall report such findings to the
applicant and to the Planning Department. The paleontologist shall determine
appropriate actions, in cooperation with the applicant, which ensure proper
exploration and /or salvage. These actions, as well as final mitigation and
disposition of the resources, shall be subject to the approval of the Planning
Director.
43. During construction of any proposed improvements, in accordance with Public
Resources Code 5097.94, if human remains are found, the Orange County
coroner must be notified within 24 hours of the discovery. if the coroner
determines that the remains are not recent, the coroner will notify the Native
American Heritage Commissions in Sacramento to determine the most likely
descendent for the area. The designated Native American representative then
determines, in consultation with the property owner, the disposition of the human
remains.
44. To the fullest extent permitted by law, the applicant shall indemnify, defend and
hold harmless City, its City Council, its. boards and commissions, officials,
officers, employees, and agents from and against any and all claims, demands,
obligations, damages, actions, causes of action, suits; losses, judgments, fines,
penalties, liabilities, costs and expenses (including without limitation, attorney's
5`
City of Newport Beach
Planning Commission Resolution No.
Page 15 of 15
fees, disbursements and court costs) of every kind and nature whatsoever which
may arise from or in any manner relate (directly or indirectly) to City's approval of
the General Plan Amendment No. 2005 -003 and Parcel Map No. 2005 -035;
and /or the City's related California Environmental Quality Act determinations.
�a
EXHIBIT 2
Slope Analysis
35
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EXHIBIT 5
Preliminary Geotechnical Investigation Reports
N
DAVID A. PURKIS, PE
Consulting Civil Engineer
May 6, 2005
Project No. 05 -1647
TO: Elan Enterprises Inc.
1380 Moorea
Laguna Beach, CA 92651
Attention: Kaveh Labijani
SUBJECT: Preliminary Geotechnical Investigation for Foundation Design
Residential Development of Lot 1 of 2961 Cliff Drive, Newport Beach,
California
INTRODUCTION
The results and recommendations, of our preliminary geotechnical investigation, pertinent to
proposed residential development of the subject property, are provided herein. The
investigation has addressed the distribution and engineering properties of earth materials in
order to develop appropriate conclusions regarding the proposed development and to
provide recommendations for design and construction. A topographic survey (Reference 1)
depicting the proposed development was used as a base map (Plate 1) to plot the locations
of exploratory excavations and geologic data for the subject site.
Conclusions and recommendations herein are pertinent to construction of a new single -
family residence as depicted on Plate 1. Grading and foundation plans are not available at
this time and will utilize portions of this report for their preparation. This office should
review these plans to determine the applicability of the contents of this report. This
investigation was conducted in conjunction with the adjacent lot (Lot 2 of 2%1 Cliff Drive).
SCOPE OF WORK
The investigation included:
1. Geotechnical reconnaissance of the subject site.
2. One exploratory boring drilled with a truck mounted bucket auger.
3. Four exploratory trenches excavated by hand.
4. Core and bulk sampling of representative earth materials from the excavations.
5. Laboratory testing of representative samples.
6. Engineering and geotechnical analysis.
7. Preparation of this report and the accompanying illustrations.
2377 S. EL CAMINO REAL #203, SAN CLEMENTE, CA 92672 • 949.369.9701 • fax 949.661.1562
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ACCOMPANYING ILLUSTRATIONS AND APPENDICES
Figure 1 -
Site Location Map
Figure 2 -
Geologic Map (Morton & Miller, 1981)
Figure 3 -
Geologic Map (Fife, 1973)
Figure 4 -
Regional Fault Map
Figure 5 -
Active Fault Near - Source Zones Map
Figure 6 -
Seismic Hazard Zones Map
Figure 7 -
USGS Ground Acceleration Lookup Results
Figure 8 -
Typical Retaining Wall Subdrain Detail
Appendix A -
Logs of Exploratory Borings
Appendix B -
Exploration, Field and Laboratory Testing
Appendix C -
List of References
Appendix D -
Standard Grading Specifications
Appendix E -
Guidelines for General Site Maintenance
Plate I -
Geotechnical Plot Plan
Plate 2 -
Geotechnical Cross Sections
SITE DESCRIPTION
The subject site is an irregular shaped lot with an approximate area of 10,000 square feet
and is approximately half of a proposed lot split of the existing property. The site has a
relatively level pad area fronting Cliff Drive to the northeast and a descending slope to the
southwest. The current pad is at an approximate elevation of 70t feet above sea level. The
property is adjacent to Santa Ana Street to the northwest and residential property to the
southeast. The subject property is presently developed with a two-story residential structure
as depicted on Plate 1. The site is located at approximately N33.6r latitude by W 117.93°
longitude.
PROPOSED DEVELOPMENT
Based on Reference 1, the proposed development will consist of a multiple -level residence
with associated hardscape and landscape elements. The residence will have a lower level
requiring retaining walls that will daylight on the rear slope area.
fiat
Elan. Lot 1
May 6, 2005
Page 3
SURFACE DRAINAGE
The surface runoff associated with the site is essentially that which falls directly on the lot
as precipitation. Surface water collected on the site should be directed to the street or a
suitable storm drainage collection.
FIELD EXPLORATION
One exploratory boring and four exploratory trenches were excavated at the subject site to
the approximate depths and at the approximate locations shown in Appendix A and on Plate
1. Core and bulk samples obtained for laboratory testing and analysis. The excavations
were logged following excavation. The logs of the borings are included in Appendix A. A
more detailed description of the field sampling process is contained in appendix B.
LABORATORY TESTING
Laboratory testing consisted of moisture /density, maximum density/optimum moisture,
grain size, direct shear, expansion index and sulfate ion determinations. Testing procedures
and test results are contained in Appendix B. Certain of the results are also contained on
the trench logs in Appendix A.
GEOTECHNICAL CONDITIONS
GEOLOGIC SETTING
The City of Newport Beach is situated on the southwesterly slope of the San Joaquin Hills
that descends south to southwesterly to the Pacific Ocean with a coastal zone comprised of
wave -cut terraces that slope gently. The subject site is situated on the coastal terrace at
roughly 70 feet above sea level.
The terraces in the region of the subject site were cut in sedimentary bedrock, which has
been assigned to the Monterey or Capistrano Formation of Miocene age (Reference 4).
Wave - transported sediments (principally medium to fine sands) were deposited. on the
terraces as they were cut.
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EARTH MATERIALS
Based on a review of the literature, geologic maps, field observations and subsurface
exploration (Appendix A), the following geologic units were observed or noted:
Artificial Fill (Ai) I Residual Soils (Ors)
Surficial earth materials consisting of artificial fill and undifferentiated residual soils that
extend approximately 15 feet below the existing pad on the property. These soils are
reddish brown, silty sands that are moist and medium dense to dense. The upper portions
of these soils are not suitable for foundation support without reprocessing and
recompacting.
Marine Terrace Deposit (Otml
Lying beneath the surface soils are Marine Terrace Deposits consisting of gray brown fine
to coarse sands and silty sands. These materials are moist and dense to very dense.
Bedrock
Based on regional mapping, the bedrock underlying the site at depth is assigned to the
Monterey Formation or the Capistrano Formation, which are sedimentary rock of marine
origin and of Miocene age— The bedrock was not encountered in the exploratory
excavations.
Competent terrace deposits, certified fill and/or approved soils are suitable for support of
proposed building loads.
SURFICAL RUNOFF
No evidence of former uncontrolled runoff onto or from the site has been observed. The
proposed development on the relatively flat lot is not anticipated to adversely impact
surrounding properties, provided proper civil engineering design for the control of drainage
is implemented.
GROUND WATER
Groundwater was not encountered in any of the exploratory excavations made during this
investigation and is not anticipated to be a constraint to construction.
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LIQUEFACTION AND LANDSLIDES
The subject site is not located in a seismic hazard zone as depicted on Reference 5 by the
California Department of Conservation (refer to Figure 6). This reference depicts zones of
required investigation for Liquefaction or Earthquake - Induced Landslides in the Newport
Beach Quadrangle. Reference 8 defines these areas as: "Areas where historical occurrence
of liquefaction / landslide movement, or local geological, geotechnical and groundwater /
subsurface water conditions indicate a potential for permanent ground displacements such
that mitigation as defined in Public Resources Code section 2983 (c) would be required ".
However, the base of the slope near Pacific Coast Highway is depicted as a zone of potential
liquefaction. Site - specific exploration indicates that there is a lack of groundwater in the
upper 50 feet of the subject site, therefore, the potential for liquefaction is considered
remote.
No slumps or landslides that may impact the site were noted in the study area during our
investigation or on any of the reviewed referenced publications. The non - cohesive soils that
comprise the lower slopes may experience localized surficial instability. Surficial slope
conditions are not anticipated to be problematic to the proposed development provided
adequate setback of foundation elements as recommended herein are utilized in design and
construction.
SEISMIC CONSIDERATIONS
There are no active faults observed or previously mapped that pass through the site. The
nearest active fault is the Newport Inglewood Fault (NIF) [refer to Figure 41. The Newport-
Inglewood Fault Zone could produce an earthquake of magnitude 6.9 (Reference 11) with
local strong ground motion equivalent to at least VIII on the modified Mercalli Scale. The
Southern California area is susceptible to strong shaking from earthquakes originating from
the NIF, the Elsinore Whittier Fault, the San Jacinto Fault and the San Andreas Fault
(Figures 4 & 5).
A large earthquake, magnitude 6.3 occurred off Newport Beach on March 11, 1933, and
more recently a 4.6 to 4.9 magnitude earthquake occurred just offshore from Newport
Beach on April 7, 1989. Both of these earthquake epicenters were on the NIF. In Laguna
Beach a 4.5 magnitude earthquake occurred on October 27, 1969. The epicenter was
located 1000 feet offshore of Crescent Bay. From 1934 to 1937, earthquakes with
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epicenters west of Emerald Bay and magnitudes ranging from 1.5 to 2.0 were reported. In
1812, an earthquake of sufficient magnitude to destroy the mission occurred in San Juan
Capistrano.
The Probalistic Seismic Hazard Mapping Ground Motion website of the California
Geologic Survey returns a Peak Ground Acceleration value of 0.43g (alluvium site) for 10
percent probable exceedance in a 50 year period for the site's global coordinates (refer to
Figure 7).
The Active Fault Near - Source Zone Map, N -34 (Figure 5) indicates the site is located
approximately 1.5 Kilometers from the Newport Inglewood fault. The Newport Inglewood
fault is identified as a "Type B" fault, capable of a Moment Magnitude 6.9 earthquake.
In summary, this property is not subject to any special seismic hazards as compared to other
nearby residences in similar geologic environments. Ground rupture or liquefaction as a
result of seismic shaking is remote. There is no evidence of active faulting or ground
rupture on the site. Seismic design in accordance with the latest edition of the California
Building Code using the parameters provided in the recommendation section of this report
is considered appropriate.
C��l�•�C�7�T.�
1. A proposed residential development can be feasible and safe from a geotechnical
viewpoint provided it is done in accordance with the conclusions and
recommendations provided herein and that this office is retained during the design
and construction phases to assure conformance with these requirements.
2. A multiple story wood framed single- family residence is proposed for the subject
lot.
3. Earth materials underlying the proposed development area, as revealed in the
exploratory excavations and as depicted in literature consist of surficial soils and
Terrace Deposits atop bedrock of the Monterey or Capistrano Formations.
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Elan. Lot 1
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Page 7
4. Groundwater was not encountered at the site and is not anticipated to be a
development or construction constraint.
5. Unapproved soils in areas supporting structural elements should be removed and
recompacted to a minimum depth of two feet below the bottoms of proposed
footings.,
6. Competent approved native or certified fill soils will be suitable for support of
foundation elements. All slabs and footings should be designed in accordance with
the recommendations of this report to mitigate against substrata imperfections and
seismic shaking.
7. Results of laboratory tests indicate very low expansion potential for near surface
soils in accordance with Table 18 -I -B of the 2001 California Building Code (CBC).
8. Results of laboratory tests indicate a negligible sulfate exposure classification in
accordance with Table 19 -A-4 of the CBC.
9. Earth materials at the subject site should excavate readily with conventional
construction equipment.
10. Fault rupture across the property is not anticipated: Liquefaction is considered
remote.
11. Seismic design in accordance with the latest edition of the California Building Code,
using the parameters contained in the Seismic Design Section of the
Recommendations portion of this report, is considered appropriate.
12. Development of the subject site will not geotechnically adversely impact adjoining
properties provided the recommendations of this report are implemented in design,
construction and maintenance of the project.
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RECOMMENDATIONS
SITE PREPARATION
General: Except as modified by the recommendations presented in this report, all site
preparation and grading should be done in accordance with Appendix D. All significant
amounts of organic materials should be removed from areas to be graded. Any unsuitable
earth materials in the proposed construction area should be removed to a minimum depth of
2 feet below the bottom of proposed conventional footings and recompacted to the
recommended density. The recommended minimum density is 90 percent of the maximum
as determined using Test Designation ASTM D 1557 -00, A designated representative of
this office should approve in writing the bottom of all over - excavations prior to any fill
placement. The excavated onsite soils may be used for compacted fill provided they are
cleaned of deleterious materials in accordance with the recommendations of Appendix D.
Estimated Shrinkage and Subsidence: A shrinkage factor of 5 to 10 percent may be utilized
as an aid in estimating volume change of the materials during grading. It should be noted
that these numbers are estimates only as shrinkage and subsidence are difficult to estimate
accurately without extensive in -situ testing.
STRUCTURAL SETBACK
The bottom of all residence foundation elements should be of sufficient depth to meet the
requirements of the 2001 California Building Code. The lateral distance between the lowest
outside edge of the foundation element and the descending slope face must be a minimum
of one -third the total height of the slope or 40 feet, whichever is greater.
CONTINUOUS FOOTINGS
Bearing Capacity: The allowable bearing capacity of conventional strip footings having a
minimum width of 15 inches and founded a minimum of 24 inches below lowest adjacent
grade in approved earth materials should not exceed 1,500 pounds per square foot. This
value may be increased by one -third for short duration loading as may result from wind or
seismic action. The bottoms of all footings should be placed upon a level surface.
Lateral Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of footings. For footings cast against approved earth materials, the
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lateral bearing resistance may be computed using a value of 200 pounds per square foot,
which may be increased by 200 psf for each additional foot of depth, but should not exceed
3000 pounds per square foot. A coefficient of friction of 0.35 may be used in computing
the frictional resistance.
It should be noted that these allowable earth material resistance parameters appropriately
reflect a factor -of- safety of 1.5.
Footing Reinforcement: A minimum of two No. 5 bars should be placed at the top and
bottom of continuous footings in order to minimize tension cracks during seismic shaking
due to subsurface imperfections.
Footing Geometry: Exterior footings should be embedded a minimum of 24 inches below
lowest adjacent grade in competent earth materials.
Garage O nines: Footing steel and geometry should be continuous across garage door
openings.
Settlement: Total settlement due to structural loads is estimated not to exceed 1/4 inch for
footings supported on approved earth materials. Differential settlements due to structural
loads will be similar to total settlements and can be estimated to be approximately 1/4 inch
over a horizontal distance of 20 feet. It is expected that settlements, should they occur, will
do so essentially as the loads are applied. Potential settlement due to liquefaction under a
strong seismic event is estimated to be approximately 1/4 inch.
ISOLATED PAD FOOTINGS
Bearing Capacity: The allowable bearing capacity of soils supporting pad footings founded
a minimum of 18 inches below lowest adjacent grade in approved earth materials is 1,500
pounds per square. foot, increased by 20 percent for each additional foot of depth and/or
width beyond I foot to a maximum of 4,500 pounds per square foot. This value may be
increased by one -third for short duration loading as may result from wind or seismic action.
The bottoms of all footings should be placed upon a level surface.
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Lateral Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of footings. For footings cast against approved earth materials, the
lateral bearing resistance may be computed using a value of 200 pounds per square foot,
which may be increased by 200 psf for each additional foot of depth, but should. not exceed
3000 pounds per square foot. A coefficient of friction of 0.35 may be used in computing
the frictional resistance.
It should be noted that these allowable earth material resistance parameters appropriately
reflect a factor -of- safety of 1.5.
Pad Footing Reinforcement: A minimum grid of No. 5 bars @6 16" on- center each -way
should be placed on chairs at the bottom of pad footings
Pad Footing Geometry: Pad footings should be a minimum of 24 inches square and a
minimum of 24 inches below lowest adjacent grade in competent earth materials.
CAISSONS
Vertical Bearing Capacity and Settlement: The end bearing component of the allowable
bearing capacity of cast -in -place concrete caissons founded in approved soil is 1500 pounds
per square foot with an allowable increase of 20 percent for each additional foot of width
and /or depth beyond the minimum of 1 foot not to exceed 4500 pounds per square foot.
These values may be increased, by one -third for short duration loading as may result from
wind or seismic action. The frictional component of the allowable bearing capacity is 250
pounds per square foot and may be taken only in competent terrace deposits below a depth
of 8-feet.
Lateral Load :.Caissons cast against creep prone soils should be designed to resist a lateral
load equal to 1000 pounds per linear foot of creep prone materials. For design purposes
the creep zone should be computed to a depth of 4 feet below the slope surface.
La Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of caissons. For caissons cast against approved undisturbed native
materials, the lateral bearing resistance may be computed using a value of 200 pounds per
square foot per foot of depth below natural grade which may be increased by 200 pounds
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Elan. Lot 1
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Page l l
per square foot for each additional foot of depth, but should not exceed 3000 pounds per
square foot. These values may be doubled for isolated conditions, defined as a minimum of
3 diameters between caissons. A coefficient of friction of 0.35 may be used in computing
the frictional resistance. It should be noted that these resistant parameters appropriately
reflect a factor -of- safety of 1.5.
Caisson.Geometly:. Caissons should be a minimum of 24-inch diameter to facilitate down -
hole inspection during the construction and should be provided with sufficient steel to meet
requirements as reinforced concrete members. The structural foundation engineer will
generate the anticipated depths of caissons based on structural load requirements. Actual
depths of caissons may be adjusted in the field after caisson excavations are examined by
the geotechnical consultant.
Construction Considerations: No steel or concrete should be placed in caisson excavations
until the holes are observed and approved in writing by the geotechnical consultants. All
caisson excavations should be thoroughly cleaned of loose soil and debris. Should
substantial volumes of groundwater be encountered, approved special drilling and
installation strategies will be needed. Provisions should be made to temporarily case
excavations should caving soils be encountered during construction and for downhole
inspection if needed. Caissons should not be excavated within 6 feet (edge to edge) of
another caisson excavation unless that caisson has been filled with concrete for more than
24 hours.
RETAINING WALLS
Lateral Loading on Retaining Walls: The lateral loads acting on cantilevered retaining walls
backfilled with approved non - expansive granular materials such as compacted sands or
gravel, having a width equal to or greater than half the retained height, can be computed
using an active pressure.force equal to an equivalent fluid pressure of 35 pounds per square
foot per foot of depth for level backfill and 50 pounds per square foot per foot of depth for
2 :1 (horizontal: vertical) sloping backfill. These values should be increased by 50 percent
for walls structurally restrained. The on -site soils are not suitable for backfill against the
wall.
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Surcharge loading: Lateral loads acting on retaining walls due to structural or vehicular
surcharges should be superimposed atop the earth pressures.
Lateral Resistance Design Values: Lateral loads may be resisted by passive pressure forces
and friction acting on the bottom of footings. For footings cast against approved soils, the
lateral bearing resistance may be computed using a value of 200 pounds per square foot,
which may be increased by 200 psf for each additional foot of depth, but should not exceed
3000 pounds per square foot. A.coefficient of friction of 0.35 may be used in computing
the frictional resistance. It should be noted that these resistant parameters appropriately
reflect a factor -of -safety of 1.5.
In addition to the soil loading, the retaining walls should be designed to support any
adjacent structural or vehicular surcharge loading that occurs within a 45- degree plane of the
base of the wall.
Vertical Bearing Design Values: The allowable bearing capacity of soils supporting
retaining wall footings founded atop approved earth materials is 1,500 pounds per square
foot, increased by 20 percent for each additional foot of depth and/or width beyond 1 foot to
a maximum of 4,500 pounds per square foot. This value may be increased by one -third for
short duration loading as may result from wind or seismic action. The bottoms of all
footings should be placed upon a level surface.
S ins• A recommended drainage design for achieving control of seepage forces behind
retaining walls is shown on Figure 8. This design consists of single sized gravel wrapped
with geotextile fabric separator or graded washed gravel placed in contact with undisturbed
native material. Collection is with a flinch diameter perforated pipe embedded at the base of
the gravel tied to a 4 -inch diameter non - perforated outlet pipe which discharges at
convenient locations selected during foundation plan review. The pipe should be placed
such that the gradient is not less than 0.01 ft. /ft. The fabric wrapped gravel envelope should
be placed at a similar gradient. The drain should have a minimum of 2 cubic feet per foot of
gravel.
All subdrain pipes should be SDR -35 or approved equivalent. Perforations may be either
bored holes not less than 3/16 -inch or larger than 1/2 -inch diameter or 1/8 -inch slots placed
-11
Elan. Lot 1
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Page 13
on the bottom one -third of the pipe perimeter. If the pipe is to be bored, a minimum of 5
holes should be uniformly placed per foot of length. Slots should not exceed 2 inches in
length and total length of slots should not be less than 50 percent of the pipe length.
The geotextile filter fabric should be in accordance with Orange County Standard Plan 808.
The fabric pore spaces should be between 30 and 100 mesh openings. The fabric should be
placed such that a minimum lap of 6 inches exists at all splices. The fabric wrapped gravel
envelope should consist of 112 -inch minimum single size drain rock. All subdrain
installations should be inspected by this office or designated representative.
Waterproofing All interior building retaining walls should be protected from moisture
penetration with a suitable waterproofing method specified by the project architect or a
qualified experienced professional.
Wall Backfill: Approved on -site soils may be used for the select backfill zone that is
adjacent to the wall. Approved self- compacting gravel backfill may be placed in quantity
behind the walls. All other materials should be.placed in 6 to 8 inch loose lifts and
mechanically compacted to at least 90 percent of ASTM - 1557 -00 maximum density.
Notification of this office is required prior to all retaining wall backfill operations.
SEISMIC DESIGN
Seismic Design in accordance with the 2001 California Building Code, should use the
following criteria:
2001 CBC Table No.
Factor
16-I
Seismic Zone Factor, Z
0.40
16-J
Soil Profile Type
Sd
16 -Q
Seismic Coefficient, Ca
0.44 Na
16 -R
Seismic Coefficient, Cv
0.64 Nv
16 -S
Near - Source Factor, Na
1.3
16 -T
Near- Source Factor, Nv
1.6
16 -U
Seismic Source type
B
/I?-
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CONCRETE
Results of site specific Sulfate Ion Tests indicate a "Negligible" sulfate exposure
classification in accordance with Table 19 -A-4 of the 1997 UBC (2001 CBC). While no
requirements are imposed by the Uniform Building Code, the use of Type V Cement for all
concrete in contact with earth materials is considered prudent.
TEMPORARY EXCAVATIONS
All temporary excavations should be in accordance with CaIOSHA requirements and
applicable governing agency grading and building codes. Any excavation over 5 feet in
height should be constructed at a 1:1 (horizontal: vertical) slope, or shored. Any excavations
that extend below an imaginary 1:1 plane projected from the bottom of any existing
structure footing or utility should also be shored or slot cut.
The contractor is entirely responsible for the job site conditions during the entire course of
construction, including insuring lateral support to and protection of existing structures and
property
DRIVEWAY AND HARDSCAPE SLABS
Subgrade soils beneath driveway and hardscape flatwork elements should be overexcavated
a minimum of 12 inches below the bottom of the element and recompacted to at least 90
percent of maximum density as determined by test designation ASTM 1557 -00. Exterior
slabs should have a minimum thickness of 4 inches and be reinforced with a minimum of
#3 bars at 12 inches on- center each -way located at the center of the slab. The outer 8 -inch
edge of driveways and patio slabs should be thickened to a minimum of 8 inches.
HARDSCAPE FOOTINGS
All hardscape elements supported on footings should be founded entirely in approved soils.
Footings founded in soils may be designed for a vertical allowable bearing capacity of 1,500
pounds per square foot. These values may be increased by one -third for short duration
loading, as may result from wind or seismic action. Lateral loads may be resisted by a
passive pressure force equal to 150 pounds per square foot for footings founded in
approved soils. A friction coefficient of 0.25 may be used for soil. The bottoms of all
footings should be placed upon a level surface. All hardscape footings should be reinforced
with a minimum of four number 4 bars, two top and two bottom.
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Page 15
SWIMMING POOL AND SPA
The structural design of swimming pool and spa shells should meet the requirements of
Section 1919 of the 1997 Uniform Building Code. Care should be taken during excavation
of the pool and /or spa to minimize disturbance of support soils. If a transition in support
conditions is exposed during excavation, then the entire base of the support soils should be
overexcavated and recompacted a minimum of 2 feet below the bottom of the proposed
shell. Observations and/or tests should be performed by the geotechnical consultants to
verify that exposed soil conditions are consistent with design assumptions.
Bearing Capacity: The allowable bearing capacity of approved soils supporting pool and spa
shells is 1,500 pounds per square foot, increased by 20 percent for each additional foot of
depth beyond I foot to a maximum of 4,500 pounds per square foot.
Settlement: Total settlement due to structural loads is estimated not to exceed 1/4 inch.
Differential settlements can be estimated to be approximately 114 inch over a horizontal
distance of 20 feet. It is expected that settlements, should they occur, will do so essentially
as the loads are applied.
Lateral loads: Pool walls should be designed to withstand lateral soil loads equal to an
equivalent fluid pressure of 55 pounds per square foot per foot of depth for walls gunited or
cast against excavations in existing soils. These values should be increased by 50 percent
for walls structurally restrained. In addition to the soil loading, the pool or spa walls should
be designed to support any adjacent structural surcharge loading that occurs within a 45-
degree plane of the base of the wall.
Lateral resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of the pool or spa. For pools cast against approved soils, the lateral
bearing resistance may be computed using a value of 200 pounds per square foot, which
may be increased by 200 psf for each additional foot of depth, but should not exceed 3000
pounds per square foot. Lateral resistance should not be taken for any soils subject to slope
creep (within 4 feet of slope surface). A coefficient of friction of 0.25 may be used in
computing the frictional resistance. It should be noted that these resistant parameters
appropriately reflect a factor -of- safety of 1.5.
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May 6, 2005
Page 16
Setback: The swimming pool and /or spa should be founded in competent earth materials
such that a minimum horizontal distance between the outer lowermost portion of the pool
foundation and the descending slope face is at least one -sixth the height of the slope or 20
feet, whichever is less. Caisson support may be needed for the proposed pool.
LANDSCAPING
Landscaping and irrigation should implemented in a manner that mitigates the impact on
foundation and hardscape elements and the earth materials supporting these elements.
Trees or bushes that develop large root systems or that require significant water should be
avoided near foundations and hardscape flatwork. Variations in moisture content can
severely impact the characteristics and strength of earth materials. Planter areas adjacent to
structures should be designed such that foundation support soils are protected from
saturation. Drainage patterns approved for the project should be maintained throughout the
life of the project. Slopes and graded areas should be planted as soon as is practical with
suitable ground cover and plants as recommended by an experienced landscape design
professional and/or is in accordance with the governing jurisdictional agency.
UTILITY TRENCHES
Utility trenches should be backfilled with clean sand, gravel, or approved soils. The soil
materials should be compacted to a density at least equal to 90 percent of the maximum
density as determined by test designation ASTM 1557 -00. Contractors should keep
detailed records /map of the location and depths of all underground utility lines installed.
Notification of this office is required prior to any utility line backfill operations.
DRAINAGE RUNOFF
Water should not be permitted to pond adjacent to the structure. All runoff water should
drain positively (solid pipe) to the street or alley.
ROOF DRAINAGE
The finished structure should be equipped with eaves, troughs and downspouts that collect
roof runoff and conduct it to pipes or other non - erosive drainage devices through which it
can be directed to the street or alley.
'5
Elan. Lot 1
May 6, 2005
Page 17
REVIEW
The undersigned should review and approve in writing the final project grading and
foundation plans to confirm compliance with the geotechnical recommendations.
FIELD INSPECTIONS
Observations and tests should be made during construction to confirm the project
geotechnical recommendations are properly implemented. These inspections should occur:
following excavations for all overexcavation bottoms prior to placement of fill, during any
fill placement and compaction, following retaining wall subdrain installation, during
retaining wall backfill operations, during all utility trench backfill placement and compaction;
during caisson excavations, following footing excavations prior to steel placement, and
following slab subgrade preparation. The above inspections and testing conducted during
construction; as well as, attending pre -grade meetings or responses to agency review items
are beyond the scope and budget of this investigation and will be billed on a time and
materials basis in accordance with our most recent Fee Schedule. Timely notification (48
hours) of the geotechnical phases of construction is the responsibility of the client or their
representative.
The above construction inspections do not supersede or replace any normally required
certified independent inspections or agency inspections.
PRE - CONSTRUCTION MEETING
A pre- construction conference should be held with representatives of the owner, contractor,
architect, civil engineer, soil engineer, geologist and building official representative prior to
commencement of grading to clarify any questions relating to the intent of these
recommendations and to coordinate the necessary construction inspections.
MAINTANENCE AND FUTRE INPROVEMENTS
Throughout the life of the project, regular site maintenance should be conducted to insure
that drainage components are clean of obstructions and that they properly control surface
waters. Any alteration of drainage patterns or landscape features may result in adverse
conditions that can affect the performance of the proposed development. Landscaping
installations should be maintained in a manner that does not allow water to pond near sloped
'I IP
Elan. Lot 1
May 6, 2005
Page 18
areas or in areas adjacent to structures, and that generally protects the surface of slopes from
erosional damage. Site and slope maintenance guidelines are attached in Appendix F.
The recommendations of this report are specific to the current scope of the project as
discussed herein. Any future proposed improvements or changes to site conditions would
require additional geotechnical evaluation and possibly additional investigation.
CLOSURE
This investigation was conducted in accordance with generally accepted practice in the
geotechnical field, as currently practiced in this or similar localities. Proper implementation
of the recommendations of this report should provide suitable performance for the lifetime
of the project. No expressed or implied warranty is made regarding the use of the contents
of this report. The conclusions and recommendations presented in this report are based on
surface and subsurface conditions encountered and the present state of geotechnical
knowledge. The results of and conclusions drawn from observations made, tests conducted
and information obtained for this report, are believed to be representative of the site
conditions impacting the proposed project. Subsurface conditions may vary between
observation points. Should conditions be revealed that are at variance with the findings of
this report, such conditions will need to be evaluated by the geotechnical consultants with
supplemental recommendations possibly resulting. As site , geotechnical conditions may
alter with time, the recommendations presented in this report are considered valid for a
period of one year from the report date.
This, report is intended for the specific currently proposed development by our client and is
to be used only as necessary to obtain permits and for the design and construction of said
development. Changes in the proposed land use or development may require supplemental
investigations or recommendations. This report is intended for the sole use of our client in
conjunction with the undersigned and may not be assigned or transferred, or any portion
thereof be assigned or transferred, to a third party without written permission and consent
from this office. Any independent use of this report, in any form, is not valid unless
specific, written verification of the applicability of the recommendations is obtained from
this office.
/)I
Elan. Lot 1
May 6, 2005
Page 19
Thank you for the opportunity to be of service. If you have any questions, please call.
Respectfully Submitted,
GOC/3�
David A. Purkis
Civil Engineer (RCE 42810) . .
Expires 3 -31 -06
A.
Distribution:
Addressee (5) w No.42810
d Fxp.03 -31.06
l�l !
Ian S. Kennedy
Engineering Geologist (CEG 1057)
Expires 1 -31 -06
r--
NO. 1057
CERTIFIED
V'4GF';EERi't
'J�
DAVID A. PURKIS, PE
Consulting Civil Engineer
May 6, 2005
Project No. 05 -1647
TO: Elan Enterprises Inc.
1380 Moorea
Laguna Beach, CA 92651
Attention: Kaveh Lahijani
SUBJECT: Preliminary Geotechnical Investigation for Foundation Design
Residential Development of Lot 2 of 2961 Cliff Drive, Newport Beach,
California
INTRODUCTION
The results and recommendations of our preliminary geotechnical investigation, pertinent to
proposed residential development of the subject property, are provided herein. The
investigation has addressed the distribution and engineering properties of earth materials in
order to develop appropriate conclusions regarding the proposed development and to
provide recommendations for design and construction. A topographic survey (Reference 1)
depicting the proposed development was used as a base map (Plate 1) to plot the locations
of exploratory excavations and geologic data for the subject site.
Conclusions and recommendations herein are pertinent to construction of a new single -
family residence as depicted on Plate 1. Grading and foundation plans are not available at
this time and will utilize portions of this report for their preparation. This office should
review these plans to determine the applicability of the contents of this report. This
investigation was conducted in conjunction with the adjacent lot (Lot 1 of 2961 Cliff Drive).
SCOPE OF WORK
The investigation included:
1. Geotechnical reconnaissance of the subject site.
2. One exploratory boring drilled with a truck mounted bucket auger.
3. Four exploratory trenches excavated by hand.
4. Core and bulk sampling of representative earth materials from the excavations.
5. Laboratory testing of representative samples.
6. Engineering and geotechnical analysis.
7. Preparation of this report and the accompanying illustrations.
2377 S. EL CAMINO REAL #203, SAN CLEMENTE, CA 92672 - 949.369.9701 • fax 949.661.1562
H
Elan. Lot 2
May 6, 2005
Page 2
ACCOMPANYING ILLUSTRATIONS AND APPENDICES
Figure 1
Site Location Map
Figure 2
Geologic Map (Morton & Miller, 1981)
Figure 3 -
Geologic Map (Fife, 1973)
Figure 4 -
Regional Fault Map
Figure 5 -
Active Fault Near - Source Zones Map
Figure 6 -
Seismic Hazard Zones.Map
Figure 7 -
USGS Ground Acceleration Lookup Results
Figure 8 -
Typical Retaining Wall Subdrain Detail
Appendix A -
Logs of Exploratory Borings
Appendix B -
Exploration, Field and Laboratory Testing
Appendix C -
List of References
Appendix D -
Standard Grading Specifications
Appendix E -
Guidelines for General Site Maintenance
Plate 1 -
Geotechnical Plot Plan
Plate 2 -
Geotechnical Cross Sections
SITE DESCRIPTION
The subject site is an irregular shaped lot with an approximate area of 10,000 square feet
and is approximately half of a proposed lot split of the existing property. The site is
comprised of sloping ground, descending from Santa Ana Avenue on the northwest to
Avon Street below. Lot 1 of 2961 Cliff Drive, which is proposed to be developed in
conjunction with the subject lot, is to the northeast. The subject property is presently
undeveloped with grasses and some trees on it. The site is located at approximately
N33.62° latitude by W117.93' longitude.
PROPOSED DEVELOPMENT
Based on Reference 1, the proposed development will consist of a multiple -level residence
with associated hardscape and landscape elements. The approximate location of the
proposed residence is depicted on Plates 1 & 2.
Elan. Lot 2
May 6, 2005
Page 3
SURFACE DRAINAGE
The surface runoff associated with the site is essentially that which falls directly on the lot
as precipitation. Surface water collected on the site should be directed to the street or a
suitable storm drainage collection.
INVESTIGATION
FIELD EXPLORATION
One exploratory boring and four exploratory trenches were excavated at the subject site to
the approximate depths and at the approximate locations shown in Appendix A and on Plate
1. Core and bulk samples obtained for laboratory testing and analysis. The excavations
were logged following excavation. The logs of the borings are included in Appendix A. A
more detailed description of the field sampling process is contained in appendix B.
LABORATORY TESTING
Laboratory testing consisted of moisture /density, maximum densityloptimum moisture,
grain size, direct shear, expansion index and sulfate ion determinations. Testing procedures
and test results are contained in Appendix B. Certain of the results are also contained on
the trench logs in Appendix A.
GEOTECHNICAL CONDITIONS
GEOLOGIC SETTING
The City of Newport Beach is situated on the southwesterly' slope of the San Joaquin Hills
that descends south to southwesterly to the Pacific Ocean with a coastal zone comprised of
wave -cut terraces that slope gently. The subject site is situated on the coastal terrace at
roughly 70 feet above sea level.
The terraces in the region of the subject site were cut in sedimentary bedrock, which has
been assigned to the Monterey or Capistrano Formation of Miocene age (Reference 4).
Wave - transported sediments (principally medium to fine sands) were deposited on the
terraces as they were cut.
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EARTH MATERIALS
Based on a review of the literature, geologic maps, field observations and subsurface
exploration (Appendix A), the following geologic units were observed or noted:
Artificial Fill (Af) ! Residual Soils (Qrs)
Surficial earth materials consisting of artificial fill and undifferentiated residual soils that
extend approximately 15 feet below the existing pad on the property. These soils are
reddish brown, silty sands that are moist and medium dense to dense. The upper portions
of these soils are not suitable for foundation support without reprocessing and
recompacting.
Marine Terrace Deposit (Ot m)
Lying beneath the surface soils are Marine Terrace Deposits consisting of gray brown fine
to coarse sands and silty sands. These materials are moist and dense to very dense.
Based on regional mapping, the bedrock underlying the site at depth is assigned to the
Monterey Formation or the Capistrano Formation, which are sedimentary rock of marine
origin and of Miocene age. The bedrock was not encountered in the exploratory
excavations.
Competent terrace deposits, certified fill and /or approved soils are suitable for support of
proposed building loads.
SURFICAL RUNOFF
No evidence of former uncontrolled runoff onto or from the site has been observed. The
proposed development on the relatively flat lot is not anticipated to adversely impact
surrounding properties, provided proper civil engineering design for the control of drainage
is implemented.
GROUND WATER
Groundwater was not encountered in any of the exploratory excavations made during this
investigation and is not anticipated to be a constraint to construction.
G f I
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LIQUEFACTION AND LANDSLIDES
The subject site is not located in a seismic hazard zone as depicted on Reference 5 by the
California Department of Conservation (refer to Figure 6). This reference depicts zones of
required investigation for Liquefaction or Earthquake - Induced Landslides in the Newport
Beach Quadrangle. Reference 8 defines these areas as: "Areas where historical occurrence
of liquefaction / landslide movement, or local geological, geotechnical and groundwater/
subsurface water conditions indicate a potential for permanent ground displacements such
that mitikation as defined in Public Resources Code section 2983 (c) would be required ".
However, the base of the slope near Pacific Coast Highway is depicted as a zone of potential
liquefaction. Site - specific exploration indicates that there is a lack of groundwater in the
upper 50 feet of the subject site, therefore, the potential for liquefaction is considered
remote.
No slumps or landslides that may impact the site were noted in the study area during our
investigation or on any of the reviewed referenced publications. The non - cohesive soils that
comprise the lower slopes may experience localized surficial instability. Surficial slope
conditions are not anticipated to be problematic to the proposed development provided
adequate setback of foundation elements as recommended herein are utilized in design and
construction.
SEISMIC CONSIDERATIONS
There are no active faults observed or previously mapped that pass through the site. The
nearest active fault is the Newport Inglewood Fault (NIF) [refer to Figure 41. The Newport-
Inglewood Fault Zone could produce an earthquake of magnitude 6.9 (Reference 11) with
local strong ground motion equivalent to at least VIII on the modified Mercalli Scale. The
Southern California area is susceptible to strong shaking from earthquakes originating from
the NIF, the Elsinore Whittier Fault, the San Jacinto Fault and the San Andreas Fault
(Figures 4 & 5).
A large earthquake, magnitude 6.3 occurred off Newport Beach on March 11, 1933, and
more recently a 4.6 to 4.9 magnitude earthquake occurred just offshore from Newport
Beach on April 7, 1989. Both of these earthquake epicenters were on the NIF. In Laguna
Beach a 4.5 magnitude earthquake occurred on October 27, 1969. The epicenter was
located 1000 feet offshore of Crescent Bay. From 1934 to 1937, earthquakes with
Elan. Lot 2
May 6, 2005
Page 6
epicenters west of Emerald Bay and magnitudes ranging from 1.5 to 2.0 were reported. In
1812, an earthquake of sufficient magnitude to destroy the mission occurred in San Juan
Capistrano.
The Probalistic Seismic Hazard Mapping Ground Motion website of the California
Geologic Survey returns a Peak Ground Acceleration value of 0.43g (alluvium site) for 10
percent probable exceedance in .a 50 year period for the site's global coordinates (refer to
Figure 7).
The Active Fault Near - Source Zone Map, N -34 (Figure 5) indicates the site is located
approximately 1.5 Kilometers from the Newport Inglewood fault. The Newport Inglewood
fault is identified as a "Type B" fault, capable of a Moment Magnitude 6.9 earthquake.
In summary, this property is not subject to any special seismic hazards as compared to other
nearby residences in similar geologic environments. Ground rupture or liquefaction as a
result of seismic shaking is remote. There is no evidence of active faulting or ground
rupture on the site. Seismic design in accordance with the latest edition of the California
Building Code using the parameters provided in the recommendation section of this report .
is considered appropriate.
CONCLUSIONS
1. A proposed residential development can be feasible and safe from a geotechnical
viewpoint . provided it is done in accordance with the conclusions and
recommendations provided herein and that this office is retained during the design
and construction phases to assure conformance with these requirements.
2. A multiple story wood framed single - family residence is proposed for the subject
lot.
3. Earth materials underlying the proposed development area, as revealed in the
exploratory excavations and as depicted in literature consist of surficial soils and
Terrace Deposits atop bedrock of the Monterey or Capistrano Formations.
,�A
Elan. Lot 2
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Page 7
4. Groundwater was not encountered at the site and is not anticipated to be a
development or construction constraint.
5. Unapproved soils in areas supporting structural elements should be removed and
recompacted to a minimum depth of two feet below the bottoms of proposed
footings.
6. Competent approved native or certified fill soils will be suitable for support of
foundation elements. All slabs and footings should be designed in accordance with
the recommendations of this report to mitigate against substrata imperfections and
seismic shaking.
7. Results of laboratory tests indicate very low expansion potential for near surface
soils in accordance with Table 18 -1 -B of the 2001 California Building Code (CBC).
8. Results of laboratory tests indicate a negligible sulfate exposure classification in
accordance with Table 19 -A-4 of the CBC.
9. Earth materials at the subject site should excavate readily with conventional
construction equipment.
10. Fault rupture across the property is not anticipated. Liquefaction is considered
remote.
11. Seismic design in accordance with the latest edition of the California Building Code,
using the parameters contained in the Seismic Design Section of the
Recommendations portion of this report, is considered appropriate.
12. Development of the subject site will not geotechnically adversely impact adjoining
properties provided the recommendations of this report are implemented in design,
construction and maintenance of the project.
0
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Page 8
SITE PREPARATION
General: Except as modified by the recommendations presented in this report, all site
preparation and grading should be done in accordance with Appendix D. All significant
amounts of organic materials should be removed from areas to be graded. Any unsuitable
earth materials in the proposed construction area should be removed to a minimum depth of
2 feet below the bottom of proposed conventional footings and recompacted to the
recommended density. The recommended minimum density is 90 percent of the maximum
as determined using Test Designation ASTM D 1557 -00. A designated representative of
this office should approve in writing the bottom of all over - excavations prior to any fill
placement. The excavated onsite soils may be used for compacted fill provided they are
cleaned of deleterious materials in accordance with the recommendations of Appendix D.
Estimated Shrinkage and Subsidence: A shrinkage factor of 5 to 10 percent may be utilized
as an aid in estimating volume change of the materials during grading. It should be noted
that these numbers are estimates only as shrinkage and subsidence are difficult to estimate
accurately without extensive in -situ testing.
STRUCTURAL SETBACK
The bottom of all residence foundation elements should be of sufficient depth to meet the
requirements of the 2001 California Building Code: The lateral distance between the lowest
outside edge of the foundation element and the descending slope face must be a minimum
of one -third the total height of the slope or 40 feet, whichever is greater.
CONTINUOUS FOOTINGS
Bearing Capacity: The allowable bearing capacity of conventional strip footings having a
minimum width of 15 inches and,founded a minimum of 24 inches below lowest adjacent
grade in approved earth materials should not. exceed 1,500 pounds per square foot. This
value may be increased by one -third for short duration loading as may result from wind or
seismic action. The bottoms of all footings. should be placed upon a level surface.
Lateral Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of footings. For footings cast against approved earth materials, the
CA(_Q
Elan. Lot 2
May 6, 2005
Page 9
lateral bearing resistance may be computed using a value of 200 pounds per square foot,
which may be increased by 200 psf for each additional foot of depth, but should not exceed
3000 pounds per square foot. A coefficient of friction of 0.35 may be used in computing
the frictional resistance.
It should be noted that these allowable earth material resistance parameters appropriately
reflect a factor -of- safety of 1.5.
Footing Reinforcement: A minimum of two No. 5 bars should be placed at the top and
bottom of continuous footings in order to minimize tension cracks during seismic shaking
due to subsurface imperfections.
Footing Geometry: Exterior footings should be embedded a minimum of 24 inches below
lowest adjacent grade in competent earth materials.
Garage Openings Footing steel and geometry should be continuous across garage door
openings.
Settlement: Total settlement due to structural loads is estimated not to exceed 1/4 inch for
footings supported on approved earth materials. Differential settlements due to structural
loads will be similar to total settlements and can be estimated to be approximately 1/4 inch
over a horizontal distance of 20 feet. It is expected that settlements, should they occur, will
do so essentially as the loads are applied. Potential settlement due to liquefaction under a
strong seismic event is estimated to be approximately 1/4 inch.
ISOLATED PAD FOOTINGS
Bearing Capacity: The allowable bearing capacity of soils supporting pad footings founded
a minimum of 18 inches below lowest adjacent grade in approved earth materials is 1,500
pounds per square foot, increased by 20 percent for each additional foot of depth and/or
width beyond I foot to a maximum of 4,500 pounds per square foot. This value may be
increased by one -third for short duration loading as may result from wind or seismic action.
The bottoms of all footings should be placed upon a level surface.
%I
Elan. Lot 2
May 6, 2005
Page 10
Lateral Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of footings. For footings cast against approved earth materials, the
lateral beating resistance may be computed using a value of 200 pounds per square foot,
which. may be increased by 200 psf for each additional foot of depth, but should not exceed
3000 pounds per square foot. A coefficient of friction of 0.35 may be used in computing
the frictional resistance.
It should be noted that these allowable earth material resistance parameters appropriately
reflect a factor -of- safety of 1.5.
Pad Footing Reinforcement A minimum grid of No. 5 bars @ 16" on- center each -way
should be placed on chairs at the bottom of pad footings
Pad Footing Geometry Pad footings should be a minimum of 24 inches square and a
minimum of 24 inches below lowest adjacent grade in competent earth materials.
CAISSONS
Vertical Bearing Cap-a-613! and Settlement: The end bearing component of the allowable
bearing capacity of cast -in -place concrete caissons founded in approved soil is 1500 pounds
per square foot with an allowable increase of 20 percent for each additional foot of width
and/or depth beyond the minimum of 1 foot not to exceed 4500 pounds per square foot.
These values may be increased by one -third for short duration loading as may result from
wind or seismic action. The frictional component of the allowable bearing capacity is 250
pounds per square foot and may be taken only in competent terrace deposits below a depth
of 8 feet.
Lateral Loads: Caissons cast against creep prone soils should be designed to resist a lateral
load equal to 1000 pounds per linear foot of creep prone materials. For design purposes
the creep zone should be computed to a depth. of 4 feet below the slope surface.
Lateral Resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of caissons. For caissons cast.against approved undisturbed native
materials, the lateral bearing resistance may be computed.using a value of 200 pounds per
square foot per foot of depth below natural grade which may be increased by 200 pounds
Elan. L.ot 2
May 6, 2005
Page I1
per square foot for each additional foot of depth, but should not exceed 3000 pounds per
square foot. These values may be doubled for isolated conditions, defined as a minimum of
3 diameters between caissons. A coefficient of friction of 0.35 may be used in computing
the frictional resistance. It should be noted that these resistant parameters appropriately
reflect a factor -of -safety of 1.5.
Caisson Geometry: Caissons should be a minimum of 24 -inch diameter to facilitate down -
hole inspection during the construction and should be provided with sufficient steel to meet
requirements as reinforced concrete members. The structural foundation engineer will
generate the anticipated depths of caissons based on structural load requirements. Actual
depths of caissons may be adjusted in the field after caisson excavations are examined by
the geotechnical consultant.
Construction Considerations: No steel or concrete should be placed in caisson excavations
until the holes are observed and approved in writing by the geotechnical consultants. All
caisson excavations should be thoroughly cleaned of loose soil and debris. Should
substantial volumes of groundwater be encountered, approved special drilling and
installation strategies will be needed. Provisions should be made to temporarily case
excavations should caving soils be encountered during construction and for downhole
inspection if needed. Caissons should not be excavated within 6 feet (edge to edge) of
another caisson excavation unless that caisson has been filled with concrete for more than
24 hours.
RETAINING WALLS
Lateral Loading on Retaining Walla: The lateral loads acting on cantilevered retaining walls
backEilled with approved non - expansive granular materials such as compacted sands or
gravel, having a width equal to or greater than half the retained height, can be computed
using an active pressure force equal to an equivalent fluid pressure of 35 pounds per square
foot per foot of depth for level backfill and 50 pounds per square foot per foot of depth for
2:1 (horizontal: vertical) sloping backfill. These values should be increased by 50 percent
for walls structurally restrained. The on -site soils are not suitable for backfill against the
wall.
Elan. Lot 2
May 6, 2005
Page 12
Surcharge loading: Lateral loads acting on retaining walls due to structural or vehicular
surcharges should be superimposed atop the earth pressures.
Lateral Resistance Design Values: Lateral loads may be resisted by passive pressure forces
and friction acting on the bottom of footings. For footings cast against approved soils, the
lateral bearing resistance may be computed using a value of 200 pounds per square foot,
which may be increased by 200 psf for each additional foot of depth, but should not exceed
3000 pounds per square foot. A coefficient of friction of 0.35 may be used in computing
the frictional resistance. It should be noted that these resistant parameters appropriately
reflect a factor -of- safety of 1.5.
In addition to the soil loading, the retaining walls should be designed to support any
adjacent structural or vehicular surcharge loading that occurs within a 45- degree plane of the
base of the wall.
Vertical Bearing Design Values: The allowable bearing capacity of soils supporting
retaining wall footings founded atop approved earth materials is 1,500 pounds, per square
foot, increased by 20 percent for each additional foot of depth and /or width beyond 1 foot to
a maximum of 4,500 pounds per square foot. This value may be increased by one -third for
short duration loading as may result from wind or seismic action. The bottoms of all
footings should be placed upon a level surface.
Subdrains: A recommended drainage design for achieving control of seepage forces behind
retaining walls is shown on Figure 8. This design consists of single sized gravel wrapped
with geotextile fabric separator or graded washed gravel placed in contact with undisturbed
native material. Collection is with a flinch diameter perforated pipe embedded at the base of
the gravel tied to a 4 -inch diameter non - perforated outlet pipe which discharges at
convenient locations selected during foundation plan review. The pipe should be placed
such that the gradient is not less than 0.01 ft. /ft. The fabric wrapped gravel envelope should
be placed at a similar gradient. The drain should have a minimum of 2 cubic feet per foot of
gravel.
All subdrain pipes should be SDR -35 or approved equivalent. Perforations may be either
bored holes not less than 3/16 -inch or larger than 1/2 -inch diameter or 1/8 -inch slots placed
Elan. Lot 2
May 6, 2005
Page 13
on the bottom one -third of the pipe perimeter. If the pipe is to be bored, a minimum of 5
holes should be uniformly placed per foot of length. Slots should not exceed 2 inches in
length and total length of slots should not be less than 50 percent of the pipe length.
The geotextile filter fabric should be in accordance with Orange County Standard Plan 808.
The fabric pore spaces should be between 30 and 100 mesh openings. The fabric should be
placed such that a minimum lap of 6 inches exists at all splices. The fabric wrapped gravel
envelope should consist of 112 -inch minimum single size drain rock. All subdrain
installations should be inspected by this office or designated representative.
Waterproofing: All interior building retaining walls should be protected from moisture
penetration with a suitable waterproofing method specified by the project architect or a
qualified experienced professional'.
Wall Backfill: Approved on -site soils may be used for the select backfill zone that is
adjacent to the wall. Approved self - compacting gravel backfill may be placed in quantity
behind the walls. All other materials should be placed in 6 to 8 inch loose lifts and
mechanically compacted to at least 90 percent of ASTM - 1557 -00 maximum density.
Notification of this office is required prior to all retaining wall backfill operations.
SEISMIC DESIGN
Seismic Design in accordance with the 2001 California Building Code, should use the
following criteria:
2001 CBC Table No.
Factor
16 -I
Seismic Zone Factor, Z
0.40
16 -J
Soil Profile Type
Sd
16 -Q
Seismic Coefficient, Ca
0.44 Na
16 -R
Seismic Coefficient, Cv
0.64 Nv
16 -S
Near- Source Factor, Na
1.3
16-T
Near - Source Factor, Nv
1.6
16-U
Seismic Source type
B
Flan. Lot 2
May 6, 2005
Page 14
CONCRETE
Results of site specific Sulfate Ion Tests indicate a "Negligible" sulfate exposure
classification in accordance with Table 19 -A -4 of the 1997 UBC (2001 CBC). While no
requirements are imposed by the Uniform Building Code, the use of Type V Cement for all
concrete in contact with earth materials is considered prudent.
TEMPORARY EXCAVATIONS
All temporary excavations should be in accordance with CalOSHA requirements and
applicable governing agency grading and building codes. Any excavation over 5 feet in
height should be constructed at a 1:1 (horizontal: vertical) slope, or shored. Any excavations
that extend below an imaginary 1:1 plane projected from the bottom of any existing
structure footing or utility should also be shored or slot cut.
The contractor is entirely responsible for the job site conditions during the entire course of
construction, including insuring lateral support to and protection of existing structures and
property.
DRIVEWAY AND HARDSCAPE SLABS
Subgrade soils beneath driveway and hardscape flatwork elements should be overexcavated
a minimum of 12 inches below the bottom of the element and recompacted to at least 90
percent of maximum density as determined by test designation ASTM 1557 -00. Exterior
slabs should have a minimum thickness of 4 inches and be reinforced with a minimum of
#3 bars at 12 inches on- center each -way located at the center of the slab. The outer 8 -inch
edge of driveways and.patio slabs should be thickened to a minimum of 8 inches.
HARDSCAPE FOOTINGS
All hardscape elements supported on footings should be founded entirely in approved soils.
Footings founded in soils may be designed for a vertical allowable bearing capacity of 1,500
pounds per square foot. These values may be increased by one -third for short duration
loading, as may result from wind or seismic action. Lateral loads may be resisted by a
passive pressure force equal to 150 pounds per square foot for footings founded in
approved soils. A friction coefficient of 0.25 may be used for soil. The bottoms of all
footings should be placed upon a level surface. All hardscape footings should be reinforced
with a minimum of four number 4 bars, two top and two bottom.
A
Elan. Lot 2
May 6, 2005
Page 15
SWIMMING POOL AND SPA
The structural design of swimming pool and spa shells should meet the requirements of
Section 1919 of the 1997 Uniform Building Code. Care should be taken during excavation:
of the pool and/or spa to minimize disturbance of support soils. If a transition in support
conditions is exposed during excavation, then the entire base of the support soils should be
overexcavated and recompacted a minimum of 2 feet below the bottom of the proposed
shell. Observations and /or tests should be performed by the geotechnical consultants to
verify that exposed soil conditions are consistent with design assumptions.
Bearing Caoacity: The allowable bearing capacity of approved soils supporting pool and spa
shells is 1,500 pounds per square foot, increased by 20 percent for each additional foot of
depth beyond 1 foot to a maximum of 4,500 pounds per square foot.
Settlement: Total settlement due to structural loads is estimated not to exceed 114 inch.
Differential settlements can be estimated to be approximately 1/4 inch over a horizontal
distance of 20 feet. It is expected that settlements, should they occur, will do so essentially
as the loads are applied.
Lateral loads: Pool walls should be designed to withstand lateral soil loads equal to an
equivalent fluid pressure of 55 pounds per square foot per foot of depth for walls gunited or
cast against excavations in existing soils. These values should be increased by 50 percent
for walls structurally restrained. In addition to the soil loading, the pool or spa walls should
be designed to support any adjacent structural surcharge loading that occurs within a 45-
degree plane of the base of the wall.
Lateral resistance: Lateral loads may be resisted by passive pressure forces and friction
acting on the bottom of the pool or spa. For pools cast against approved soils, the lateral
bearing resistance may be computed using a value of 200 pounds per square foot, which
may be increased by 200 psf for each additional foot of depth, but should not exceed 3000
pounds per square foot. Lateral resistance should not be taken for any soils subject to slope
creep (within 4 feet of slope surface). A coefficient of friction of 0.25 may be used in
computing the frictional resistance. It should be noted that these resistant parameters
appropriately, reflect a factor -of- safety of 1.5.
0
Elan. Lot 2
May 6, 2005
Page 16
Setback : The swimming pool and /or spa should be founded in competent earth materials
such that a minimum horizontal distance between the outer lowermost portion of the pool
foundation and the descending slope face is at least one -sixth the height of the slope or 20
feet, whichever is less. Caisson support may be needed for the proposed pool.
LANDSCAPING
Landscaping and irrigation should implemented in a manner that mitigates the impact on
foundation and hardscape elements and the earth materials supporting these elements.
Trees or bushes that develop large root systems or that require significant water should be
avoided near foundations and hardscape flatwork. Variations in moisture content can
severely impact the characteristics and strength of earth materials. Planter areas adjacent to
structures should be designed such that foundation support soils are protected from
saturation. Drainage patterns approved for the project should be maintained throughout the
life of the project. Slopes and graded areas should be planted as soon as is practical with
suitable ground cover and plants as recommended by an experienced landscape design
professional and/or is in accordance with the governing jurisdictional agency.
UTILITY TRENCHES
Utility trenches should be backfilled with clean sand, gravel, or approved soils. The soil
materials should be compacted to a density at least equal to 90 percent of the maximum
density as determined by test designation ASTM 1557 -00. Contractors should keep
detailed records /map of the location and depths of all underground utility lines installed.
Notification of this office is required prior to any utility line backfill operations.
DRAINAGE RUNOFF
Water should not be permitted to pond adjacent to the structure. All runoff water should
drain positively (solid pipe) to the street or alley.
ROOF DRAINAGE
The finished structure should be equipped with eaves, troughs and downspouts that collect
roof runoff and conduct it to pipes or other non- erosive drainage devices through which it
can be directed to the street or alley.
q.A
Elan. Lot 2
May 6, 2005
Page 17
REVIEW
The undersigned should review and approve in writing the final project grading and
foundation plans to confirm compliance with the geotechnical recommendations.
FIELD INSPECTIONS
Observations and tests should be made during construction to confirm the project
geotechnical recommendations are properly implemented. These inspections should occur:
following excavations for all overexcavation bottoms prior to placement of fill, during any
fill placement and compaction, following retaining wall subdrain installation, during
retaining wall backfill operations, during all utility trench badriill placement and compaction,
during caisson excavations, following footing excavations prior to steel placement, and
following slab subgrade preparation. The above inspections and testing conducted during
construction; as well as, attending pre -grade meetings or responses to agency review items
are beyond the scope and budget of this investigation and will be billed on a time and
materials basis in accordance with our most recent Fee Schedule. Timely notification (48
hours) of the geotechnical phases of construction is the responsibility of the client or their
representative.
The above construction inspections do not supersede or replace any normally required
certified independent inspections or agency inspections.
PRE- CONSTRUCTION MEETING
A pre - construction conference should be held with representatives of the owner, contractor,
architect, civil engineer, soil engineer, geologist and building official representative prior to
commencement of grading to clarify- any questions relating to' *the intent of these
recommendations and to coordinate the necessary construction inspections.
MAINTANENCE AND FUTRE IMPROVEMENTS
Throughout the life of the project, regular site maintenance should be conducted to insure
that drainage components are clean of obstructions and that they properly control surface
waters. Any alteration of drainage patterns or landscape features may result in adverse
conditions that can affect the performance of the proposed development. Landscaping
installations should be maintained in a manner that does not allow water to pond near sloped
(0 .
Elan. Lot 2
May 6, 2005
Page 18
areas or in areas adjacent to structures, and that generally protects the surface of slopes from
erosional damage. Site and slope maintenance guidelines are attached in Appendix F.
The recommendations of this report are specific to the current scope of the project as
discussed herein. Any future proposed improvements or changes to site conditions would
require additional geotechnical evaluation and possibly additional investigation.
CLOSURE
This investigation was conducted in accordance with generally accepted practice in the
geotechnical field, as currently practiced in this or similar localities. Proper implementation
of the recommendations of this report should provide suitable performance for the lifetime
of the project. No expressed or implied warranty is made regarding the use of the contents
of this report. The conclusions and recommendations presented in this report are based on
surface and subsurface conditions encountered and the present state of geotechnical
knowledge. The results of and conclusions drawn from observations made, tests conducted
and information obtained for this report, are believed to be representative of the site
conditions impacting the proposed project. Subsurface conditions may vary between
observation points. Should conditions be revealed that are at variance with the findings of
this report, such conditions will need to be evaluated by the geotechnical consultants with
supplemental recommendations possibly resulting. As site geotechnical conditions may
alter with time, the recommendations presented in this report are considered valid for a
` period of one year from the report date.
This report is intended for the specific currently proposed development by our client and is
to be used only as necessary to obtain permits and for the design and construction of said
development. Changes in the proposed land use or development may require supplemental
investigations or recommendations. This report is intended for the sole use of our client in
conjunction with the undersigned and may not be assigned or transferred, or any portion
thereof be assigned or transferred, to a third party without written permission and consent
from this office. Any independent use of this report, in any form, is not valid unless
specific, written verification of the applicability of the recommendations is obtained from
this office.
33
Elan. Lot 2
May 6, 2005
Page 19
Thank you for the opportunity to be of service. If you have any questions, please call.
Respectfully Submitted,
Q cp'e
David A. Purkis
Civil Engineer (RCE 42810)
Expires 3 -31 -06 r
Distribution:
Addressee (5)
Ia� n
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5. Kennedy
Engineering Geologist (CEG 1057)
Expires 1 -31 -06
ro, j057 '
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Local Hydrology/ Hydraulic Report March 2004
Hydrology /Hydualic Report
For:
The Mirsafavi Residence
Cliff Drive
Newport Beach, CA
Tentative Parcel Map No. 2005 -206
Prepared by:
GILBERT ENGINEERING & ASSOCIATES. INC.
2 Merriweather Place
Ladera Ranch, California 92694
. (949) 218 -8075
Project Number:
187.000
Supervising Engineer:
R. William Gilbert, P.E.
RCE No. 53251
Date Prepared:
March 2006
Mirsafavi Residence
Beach, CA
K31
Local Hydrology/ Hydrauflc Report March 3006
Table of Contents
1. Introduction ..................................... ............................... 1
Geographic Setting .................................. ............................... l
Purpose of This Report ...............:............... ..............................1
References................................................. ............................... l
Project Site Location Map ........................ ..............................2
11. Existing Topographic & Hydrologic Conditions ...... 3
ExistingTopography ................................... ..............................3
Existing Drainage Pattern ......................... ..............................3
Existing Storm Drain Facilities .................... ..............................3
Exisfing Conditions ..................................... ..............................3
Ill. Proposed Storm Drain Facilities ... ............................... 4
IV. Hydrology Study (Local Storm Drains) ............................ 4
Storm Frequency
Methodology.............................................. ..............................4
V Local Area Drain Pipe Sizing ......... ............................... 4
VI.Design Criteria ....................................... ..............................4
Excerpts from Grange County Design Manual
V11. Results & Conclusions ..................... ............................... 7
Vlll. Appendices ........................................ ..............................8
Appendix 1- Figure 4-5, Runoff /Acre for Graphic Method
Appendix 2- Local Area Drain Pipe Size Calculations .
Appendix 3- Local Hydrology Map (In Pocket)
MirsafaW Residence - Newport Beach, CA
5nD
Local Hydrology/ Hydraulic Report
1. Introduction
Geographic Setting
The Study area consists of 2 private residential lots. The northern lot, Lot
1 is 0.34 acres± and the southern lot, Lot 2 is 0.42 acres±. The lots are
located south of Cliff Drive, east of Santa Ana Ave. and north of Avon
Street. East of the two lots is an existing private residence.
Purpose of This Report
The purpose of this report is to accomplish the following objectives:
1. To determine the storm water discharges generated within local
drainage areas within the project.
2. To support the design of "local" storm drains, consisting of laterals
and catch basins, as submitted with this report.
3. To demonstrate that the "storm water" and "Flood" protection goals
as outlined in Addendum No. 1 to the O.C. P.F. &R.D. Design
Manual have been met.
References
• O.C. P.F. &R.D. Hydrology Manual
• O.C. P.F.&R.D. Design Manual
Mirsafavi Residence Newport Beach, CA
0
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W271
Project Site Loca ■ ■on Ma
Thomas Brothers, 200,
Residence
Newport
//
Local Hydrology►/ Hydraulic Report
II. Existing Topographic & Hydrologic Conditions
Existing Topography
The site has an existing house on the northern end of the lot which will
be tom down. Behind the house is a large natural slope which
continues down to Avon St.
Existing Drainage Pattern
The site drainage presently sheet flows across the property, to the
south, and down the hill where it makes its way into a small rectangular
toe of slope drain which daylights into Avon Street, just east of the
parcel. On the northern end of the site a small portion of drainage
from the existing front yard, drains into Cliff Drive and travels down
Santa Ana Ave.
Existing Storm Drain Facilities
All onsite drainage sheet flows around the existing house and down
the hill behind it with the exception of the front yard area which flows
into Cliff Drive.
Existing Conditions
Currently there are no signs of erosion on the site.
III. Proposed Storm Drain Facilities
The front yard of LOT 1 will be collect via area drains and will outlet on
the northwest side of the lot via curb outlet into Santa Ana Ave using
the City Standard 184-L. Bottomless trench drains will also be
incorporated at the driveways.
The backyard and easterly side yard will be collected in a v -ditch and
will travel down the eastern property line through LOT 2 in a drainage
easement. Prior to crossing Lot 2 there will be a BMP water filter device
that will clean the storm water before sending it into Lot 2.
All of Lot 2 will also be collected by area drains and drain into the
some v -ditch on the eastern side of the property. The southern
property line will also have a v -ditch which will connect with the
eastern v- ditch. At the bottom of the hill the two v- ditches confluence
and at this point another BMP water filter device will be placed to
clean the storm water at the south eastern comer of the property. The
Residence — Newport Beach, CA
tib3
Local HydrolM / Hydraulic Report
two v- ditches will connect to the existing rectangular drain behind the
retaining wall on Avon Ave. From the point of connection, the existing
rectangular drain will be enlarged to accommodate the flow from the
two lots. The rectangular drain will continue to daylight into Avon Ave.
as it currently does.
IV. Hydrology Study (Local Storm Drains)
Storm Frequency
The storm frequency for this study is based on the 10 year storm
Methodology
This study was prepared in conformance with the Orange County
Local Drainage Manual and the Hydrology Manual. Due to the small
size of the private residence Method 11 (Graphic Method) was used
to size the volume of runoff that would be released into the rip rap
structure, Based on Figure 4-5 of the Local Drainage Manual a Q10
of 3.2 cfs was calculated per acre. The acreage tributary to the
rectangular drain equals 0.76 acres, giving a total drain flow of 2.28
cfs. Ql = 0.19 cfs, Q2 = 0.90cfs and Q3 = 1.34cfs.
The hydraulic analysis was performed using the Heastead Methods
FlowMaster computer program which uses Manning's formula Q =
A *1.486 /n *R2/3 *S112. The roughness coefficient n--0.13 for the
concrete ditches and n =0.10 for the PVC pipe.
V. Local Area Drain Pipe Sizing
Local PVC pipes and V- ditchs were sized using a Q =3.2 cfs per acre to
obtain the Q for an area. Then the maximum 0}0 capacity for a 4"
pipe at a 1% (minimum) slope was calculated along with maximum
capacity for a v -ditch and the existing rectangular drain along with a
larger proposed drain. The full flow of a 4" PVC pipe at s= 0.0100
grade will carry Q=0.24 cfs. The proposed Al area only has Q, =0.19
cfs. Therefore a 4" pipe will be sufficient. A proposed 2' wide by V
deep V -ditch flowing at s= 0.0100 grade will carry 5.72cfs which is
greater than the entire site runoff at OT- 2.43cfs. The v- ditches flow at a
much steeper grade so they can handle much higher Q's. For
example at v -ditch flowing at a slope of s=0.0500 will carry a
Q= 12.78cfs. Because none of the ditches are less than s= 0.0100 the v-
Mirsafavi Residence Newport Beach, GA
FDA
Local Hydrology/ Hydraulic Report
ditch size is sufficient. The existing rectangular channel at the bottom
of the hill which will pick up the Qr= 2.43cfs from the project can only
handle 2.27cfs at a s= 0.0100 grade. Therefore we recommend that
the rectangular drain be replace by a 2' wide by V deep concrete
drain which will handle upto Qr =14.40 cfs at a s= 0.0100 grade.
VI. Design Criteria
The proposed storm drain systems will be designed so as to be
consistent with the following goals and guidelines:
A. All buildings shall be protected from flooding during a 100 -year
frequency storm because the site is not in a flood zone and
overflow protection well be designed into the project.
B. 1. Onsite design storm is based on a 10 -year frequency. In sump
conditions for catch basins and the connecting storm drains
also use a 10 -year frequency.
2. Offsite design storm frequency, subject to individual review by
the City, should be in accordance with the O.C. P.F. &R.D.
Hydrology Manual.
C. 1. Velocity should not exceed 20 FPS in P.V.0 pipe and standard
wall R.C.P.
2. Where velocity exceeds 20 FPS, a special wall R.C.P. with a
minimum of I'/-inch steel clearance on the inside surface shall
be used.
3. Maximum velocity in special cover R.C.P. shall be 45 FPS.
D. On arterial highways, one jij 12' lane each direction should be
clear of water, with a 10 -year storm. In sump conditions, a 25 -year
storm event shall be used.
E. On local streets, flow should not exceed top of curb, for a 10 -year
storm event, and in sump conditions, a 25 -year storm event shall be
used.
F. Cross gutter is not allowed at any through street.
G. Catch basins are to be constructed at all four corners of arterial
highway intersections.
H. Open cut is not allowed at any existing arterial highway. Pipe must
be jacked across street.
Mftafavi Residence Newport Beach. CA
jP5
Local Hydrology/ Hydraulic Report
I. Maximum W.S. in CB's for design conditions shall be 0.5' below inlet
(FL.) elevation.
J. Once water is picked up in a storm drain, it should remain in the
system.
K. Pipe size may not be decreased downstream without the City's
approval.
L. Branching of flow is not allowed. .
M. Provide hydraulic and energy grade line calculations and plot of
hydraulic grade line on plans with table of appropriate hydraulic
data.
N. The ratio of normal velocity to critical velocity should be less than
0.9 or greater than 1.2.
O. All pipes and conduits laid parallel to the roadway shall be placed
at least 30" below the roadway surface. However, when pipe
depth is in excess of 10' (measured from top of pipe to ground
surface), the City's approval is required prior to the initial design of
the system.
P. Junction structures should be designed according to the O.C.
P.F.S,R.D. "Design Manual" or utilize City of Newport Beach
Standard Plans.
Q. Storm Drain Easement width shall be determined in the following
manner:
1. D = 36" or smaller - Distance from top of pipe to ground level
times 1.5 + diameter of pipe +2.0' (When cover exceeds 10', use
2 below.)
2. D = 39" or greater - a. Distance from bottom of pipe to ground
level times 2.0 + diameter of pipe + 2.0'.
In any case, the width of easement shall not be less than 10.0' in
width.
R. Storm drain shall be located at the center line of the easement.
S. Easement shall be exclusively for storm drain purposes.
T. Storm drain with high fills:
1. Fill Greater than 40 Feet
Storm drains which are installed with cover greater than 40 feet
shall have a diameter a minimum of 12 inches larger than that
required for hydraulic adequacy and shall be constructed using
pre - stressed concrete pipe."
Newport Beach, CA
10 (D
Local Hydrology/ Hydraulic Report
Storm drains which are installed with cover between 30 and 40
feet shall have a diameter a minimum of 12 inches larger than
that required for hydraulic adequacy and shall be constructed
using pre- stressed concrete pipe if the subgrade of the pipe is in
a fill area' If subgrade is in native soil, reinforced concrete pipe
may be used.
3. Fill Between 20 and 30 Feet
Storm drains which are installed with cover between 20 and 30
feet shall be constructed using reinforced concrete pipe. A
pipe diameter greater than that required for hydraulic
adequacy may be required if, in the opinion of the City
Engineer's staff, the particular conditions involved warrant the
larger size.
4. Fill Less Than 20 Feet
Normal criteria for storm drain design shall be followed.
Exceptions may be made for a roadway crossing of a natural
watercourse which will remain undisturbed with future
development.
VII. Results and Conclusions
This report's purpose was to size the proposed storm drain system
only. The drainage patterns or direction of flow did not change
from the existing to the proposed.
Based on our calculations, it is our opinion that the proposed storm
drain system designed to a Qt0 Storm Frequency is adequate to
transport the drainage off site and that for a. 010() storm frequency
there should be no damage to the proposed structures.
Mirsafavi Residence Newport Beach. CA
161
Local Hydrology/ Hydraulic Report
VIII. Appendices
Appendix I - Figure 45, Runoff /Acre for Graphic Method
Appendix 2 - Area Drain Pipe Size Calculations
Appendix 3 - Local Hydrology Map
Mirs0avi Residence Newport Beach, CA
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Table
Ruling Table for Circular Channel
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Constiaii Data
Manni w coamdert 0.010
Depth 0.33 it
Diameter 0.33 it
RaWM Table
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(tttit)
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0.030000
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0.040000
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Solve For
Discharge
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Depth 1.00 it
Left Side Slope 1.00 M: V
Fwd Side Slope 1.00 H: V
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Channel
slope Discharge
(f 1110 (frig)
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5.72
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8.08
0.030000
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0.040000
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Solve For Discharge
Input Data
MaM*W Coefkkwd
0.013
charnel Slope
0.010000 f"
Depth
0.50 It
Bottomttyicth
1.00 ft
Results
Drsdrarge
227
MIS
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0.50
fP
Wetted Perlmetw
2.00
ft
Top WkrIh
1.00
ft
Critical Depth
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Cry Stops
0.008044 Mft
VelocitY
4.54
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Velocity Heat
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Speck Energy
0.82
ft
Froude Number
1.13
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Method Marr767g's Formula
Solve For Discharge _
Input Data
MNW*W Coefficient 0.013
Charnel Slope 0.010000 R/ft
D"M 1.00 It
Bottom Width 2.00 It
Results
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14.40
Refs
Flow Area
240
ft'
Wetted Perimeter
4.00
It
Top Width
2.00
It
Critical Depth
1.17
It
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Froude Number
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