Meridian Consultants 3.0-1 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
3.0 PROJECT DESCRIPTION
This Supplemental Environmental Impact Report (EIR) evaluates the Approved Project based on recent
modifications and new information that has become available since the previous EIR was certified.
3.1 PROJECT LOCATION
The Approved Project is located in the community of Castaic, an unincorporated area of Los Angeles
County, California (Figure 3.0-1, Regional Location). The nearest city is Santa Clarita, about 5 miles
south; Castaic Lake is northeast, east of Interstate 5 (I-5); and the Los Padres National Forest is to the
north.
As shown on Figure 3.0-2, Local Vicinity Map, the eastern boundary of the School Site is approximately
2 miles west of the intersection of Parker Road and Sloan Canyon Road; and the southern boundary of
the School Site is approximately 2 miles north of the intersection of Hasley Canyon Road and Romero
Canyon Road. Regional access to the Project is from the I-5 via Hasley Canyon Road or Lake Hughes
Road/Sloan Canyon Road. Local access to the site is via Romero Canyon Road from Hasley Canyon Road
or Sloan Canyon Road to Baringer Road to Romero Canyon Road.
As illustrated in Figure 3.0-3, Project Access Routes, the East Access would be approximately 1 mile in
length, would follow Sloan Canyon Road, and would continue along Canyon Hill Road to the School Site
where it would connect to Valley Creek Road. The Southern Access is approximately 1.3 miles in length,
and extends from the School Site, and connects to Romero Canyon Road and then follows Baringer Road
to Sloan Canyon Road and continues south to Hillcrest Parkway. At the corner of Romero Canyon Road
and Baringer Road, Romero Canyon would extend approximately 100 feet south and terminate with a
gated emergency access to prevent nonemergency traffic from using Romero Canyon Road.
The Approved Project contains numerous parcels as shown in Figure 3.0-4, Project Parcel Map, and as
listed in Table 3.0-1, Project Assessor Parcels. In addition, as modified, the Approved Project will require
off-site grading on other parcels, including 3247-026-031 for the slopes west of the water tanks and
3247-062-000 for drainage improvements from properties to the north of the School Site.
3.2 PROJECT CHARACTERISTICS
The Approved Project has not substantially changed from that described in detail in the previously
certified EIR. The previously certified EIR considered the following components of the Approved Project:
the high school campus, other support facilities, and access roadways.
3.0 Project Description
Meridian Consultants 3.0-2 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
The School Site consists of approximately 198 acres; the high school campus would occupy
approximately 58 acres. An additional area on the School Site of nonusable area that would also be
graded for slopes, evaporation basins, roadways, and other support facilities (e.g., water tanks).
3.2.1 Description of the Approved Project
High School Campus
As described in the previously certified EIR, the Approved Project consists of a comprehensive high
school campus with approximately 250,000 square feet (sq. ft.) of building area, including several
classroom buildings, a library, a performing arts building, a multipurpose building, a physical education
building with gymnasium, and an administrative building (Figure 3.0-5, Approved Conceptual School
Site Plan).
The high school campus buildings are planned to be 1- and 2-stories tall. Athletic facilities would include
a 5,000-seat football/soccer stadium with a running track, tennis courts, basketball courts, baseball and
softball fields, and other play fields. The stadium and other fields would have nighttime lighting for
evening sports events. The tallest structures on the high school campus are likely to be the light poles at
the stadium, which typically reach 80 to 90 feet.
Other Support Facilities
Other facilities that are part of the Approved Project to be located on the School Site may include:
• Valley Creek Road. A perimeter roadway (Valley Creek Road) that will provide access on the School
Site to the high school campus from the East Access (Canyon Hill Road–Sloan Canyon Road), and the
Southern Access (Romero Canyon Road–Baringer Road–Sloan Canyon Road). Valley Creek Road will
be located on the eastern portion of the School Site and run primarily north and south.
• A helipad. The Los Angeles County Fire Department (LACoFD) has requested the grading of a pad on
which it could build a helipad to serve the Castaic area. Construction and operation of the helipad
would be the responsibility of the LACoFD. The District has agreed to include a 1.1-acre flat pad at
an elevation of 2,010 feet above mean sea level (amsl) to accommodate the County’s request.
Los Angeles County
Kern County
Ventura CountySanta Clarita
ThousandOaks
SimiValley
Moorpark
Oxnard
LosAngeles
Castaic
Lancaster
Palmdale
LakePiru
Castaic Lake5
5
14
405
10
10
210
60
110 710605
118 27
101
126
Pacific Ocean
138
138
2
150
Regional Location
FIGURE 3.0-1SOURCE: Castaic High School Draft EIR; Meridian Consultants, LLC – June 2013
029-001-13
APPROXIMATE SCALE IN MILES
1050 20
N
Legend:Project Site
Los Angeles County
Ventura County
CastaicLagoon
Cas
taic
C re
ek
Santa Clara River
Piru Creek
Hasley Cyn
Sloa
n C
yn
Rom
ero
Cyn
Santa Clarita
CastaicLakePiru
Castaic Lake
5
Local Vicinity Map
FIGURE 3.0-2SOURCE: Castaic High School Draft EIR; Meridian Consultants, LLC – June 2013
029-001-13
APPROXIMATE SCALE IN MILES
210 4
N
Legend:Project Site
Proposed GateBaringer
Hillcrest
Sloan Cyn
Sloa
n C
ynCyn Hill Rd
RomeroCyn
Option B
Harp Cyn Rd
Valley Creek
Valley Creek
Mandolin C
yn Rd
Qua
il Va
lley
The Old Rd
SchoolSite
East Access
Sou
ther
n A
cces
s
Valley Crest
Rom
ero
Cyn
Rd
Creek
Project Access Routes
FIGURE 3.0-3SOURCE: Castaic High School EIR; Planning Center - October 2012
029-001-13
APPROXIMATE SCALE IN FEET
250012500 5000
N
Legend:School Site
Existing Roadway (Dirt)
Southern Access Route
Existing Roadway (Paved)
East Access Route
Proposed RoadwayProposed Valley Creek Road
Rom
ero Cyn R
d
Man
do
lin C
yn R
d
Sloan Cyn Rd
Baringer RdRom
ero
Cyn
Rd
Slo
an C
yn R
d
Hillcrest Pkwy
Project Parcel Map
FIGURE 3.0-4SOURCE: Los Angeles County Assessor Office, 2014
029-001-13
N
Legend:
Southern Access Route
NOT TO SCALE
SCHOOLSITE
East Access
Southern Access
East Access RouteProject Site
Meridian Consultants 3.0-7 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-1 Project Assessor Parcels
Project Area Assessor Parcel
Number Address Property Owner Existing and Required
Off-site Easements
East Access
2865-018-033 28711 Sloan Canyon Road Russell Storm Drain Easement; Slope Easement, Permission t Enter & Construct
2865-018-039 Ramelli Storm Drain Easement & Drainage Acceptance
2865-018-040 28355 Sloan Canyon Road West Coast Association Church
Storm Drain Easement & Drainage Acceptance; existing easement for road and utility rights with “right to grant to others and/or to dedicate to public use”
2865-018-041 28343 Sloan Canyon Road Chesebrough Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; existing easement for road and utility rights with “right to grant to others and/or to dedicate to public use; current permission to enter and construct drainage inlet and outlet structures per street plans
2865-018-900 LA County Storm Drain Easement & Drainage Acceptance
2865-023-001 28553 Sloan Canyon Road Narr Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; Vacation of Existing Strom Drain Easement
2865-023-002 Narr Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; Vacation of Existing Strom Drain Easement
2865-023-004 28531 Sloan Canyon Road Narr Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; Vacation of Existing Strom Drain Easement
2865-023-006 28701 Sloan Canyon Road Allard Slope Easement, Permission t Enter & Construct
2865-023-011 29000 Sloan Canyon Road Osmond Slope Easement, Permission t Enter & Construct
2865-023-017 No address Narr Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; Vacation of Existing Strom Drain Easement; current permission to enter and construct drainage inlet and outlet structures per street plans
2865-023-019 No address Preach
2865-023-021 No address Preach
2865-023-024 28457 Sloan Canyon Road Hart Slope Easement, Permission t Enter & Construct; current permission to enter and construct drainage inlet and outlet structures per street plans
2865-023-025 No address Preach Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct; current permission to enter and construct drainage inlet and outlet structures per street plans
3.0 Project Description
Meridian Consultants 3.0-8 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Project Area Assessor Parcel
Number Address Property Owner Existing and Required
Off-site Easements 2865-023-900 28920 Sloan Canyon Road Castaic Elementary School
District Storm Drain Easement & Drainage Acceptance; Slope Easement, Permission t Enter & Construct;; current permission to enter and construct drainage inlet and outlet structures per street plans
3247-025-030 Tharaldson (Veir) Storm Drain Easement; Slope Easement, Permission t Enter & Construct
3247-026-019 Preach Storm Drain Easement; Slope Easement, Permission t Enter & Construct
3247-026-032 No address Jesser Family
3247-026-055 No address Gubrud Slope Easement, Permission t Enter & Construct; current permission to enter and construct drainage inlet and outlet structures per street plans
3247-026-056 No address Sprankle Slope Easement, Permission t Enter & Construct; current permission to enter and construct drainage inlet and outlet structures per street plans
School Site
3247-068-900
No address William S. Hart Union High School District None
3247-068-901
3247-068-902
3247-068-903
Tract 46443 D & A Daily Mortgage Storm Drain Easement; Slope Easement, Permission t Enter & Construct
3247-026-031 Diversified Capital Ventures
Slope Easement, Permission t Enter & Construct
Southern Access
3247-206-048 31233 Romero Canyon Road To be determined
3247-026-054 29645 Baringer Road To be determined
3247-026-053 29565 Baringer Road To be determined
3247-026-043 No address To be determined
3247-026-049 30910 Sola Canyon Road To be determined
3247-042-006 30910 Sloan Canyon Road To be determined
3247-042-015 30801 Sloan Canyon Road To be determined
3247-042-032 30758 Sloan Canyon Road To be determined
3247-042-019 30730 Sloan Canyon Road To be determined
3247-042-009 No address To be determined
3247-042-026 30706 Romero Canyon Road To be determined
3247-047-004 No address To be determined
3247-042-010 30771 Sloan Canyon Road To be determined
3247-042-011 No address To be determined
3247-042-012 30701 Sloan Canyon Road To be determined
3247-047-031 No address To be determined
3247-047-032 30469 Sloan Canyon Road To be determined Note: APN 3247-068-900 was formerly 3247-068-002, APN 3247-068-901 was formerly 3247-068-004, APN 3247-068-902 was formerly 3247-068-001, and APN 3247-068-903 was formerly 3247-068-004.
Meridian Consultants 3.0-9 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
• Water tanks. The Approved Project would include grading of a 0.46-acre pad for two above-ground
water tanks. The pad would be at the southwest corner of the School Site, west of the helipad.
Construction of one 750,000-gallon water tank would be included in the Approved Project with
water serving the new high school campus. The second water tank would serve future residential
development that is already approved for the surrounding area. Construction of the second tank is
not part of the Approved Project. The tank pad would be at an elevation of 2,050 amsl.
• Broadcasting facilities. If the district decides to include broadcasting facilities, then cellular,
television, and satellite transmission towers would potentially be located on one of the hilltops
outside the high school campus.
• Energy technology. The high school campus may also include advanced energy technology, such as
solar photovoltaic panels for electricity and storm water runoff storage facilities for dry weather
irrigation.
Access Routes
The previously certified EIR evaluated two separate access scenarios for providing access to the School
Site from both the north/east and south.
The Approved Project evaluated access routes from both Sloan Canyon and Romero Canyon roads, and
ultimately approved access from the east via Sloan Canyon Road–Canyon Hill Road (East Access) and
from the south via Sloan Canyon Road–Baringer Road–Romero Canyon Road/Valley Creek Road
(Southern Access). The access roads would be constructed within existing rights-of-way and easements.
East Access
Canyon Hill Road was selected as the preferred East Access route, and will provide a 44-foot-wide, two-
lane roadway improvement within a 60-foot right-of-way of Canyon Hill Road and Sloan Canyon Road
from the School Site to the current terminus of Sloan Road near the intersection of Quail Valley Road.
The roadway will include two 12-foot travel lanes with a 10-foot center lane, and 5-foot-wide Class II
bikes lanes in each direction.
Since the certification of the previous EIR, additional geotechnical testing has occurred, and further
refined plans have been prepared for the East Access alignment and configuration.
Approved Conceptual School Site Plan
FIGURE 3.0-5
029-001-13
SOURCE: RRC Architects, 2012
APPROXIMATE SCALE IN FEET
7503750 1500
N
Legend:
3.0 Project Description
Meridian Consultants 3.0-11 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Southern Access
The Southern Access is approximately 1.3 miles in length and will extend from the School Site and Valley
Crest Creek Road to Romero Canyon Road to Baringer Road, and then Sloan Canyon Road to Hillcrest
Parkway. The Southern Access route alignment (Sloan Canyon Road–Baringer Road–Romero Canyon
Road/Valley Creek Road) has not changed from that provided in the previously certified EIR.
The Southern Route will include a 28-foot-wide two-lane roadway with 14-foot travel lanes in each
direction within a 44-foot right-of-way of Baringer Road and Sloan Road to Hillcrest Parkway. The
Southern Access will include an 8-foot-wide Class III bike lane and an optional 8-foot-wide multiuse trail
on one side within the approved right-of-way. At the corner of Romero Canyon Road and Baringer Road,
Romero Canyon would extend approximately 100 feet south and terminate with a gated emergency
access to prevent nonemergency traffic from using Romero Canyon Road.
All public roadway improvements associated with the Approved Project would include a 5- to 6.5-foot
concrete sidewalk along one side of the road.
Valley Creek Road would bridge over Los Angeles County Romero Canyon flood plain limits about 300
feet north of the south School Site boundary. Roadway protection to reduce erosion along the east side
of Valley Creek Road would be installed underground for a length of approximately 600 feet starting 500
feet south of the site boundary and extending north.
Baringer Road would bridge over Los Angeles County Romero Canyon flood plain limits. Baringer Road
would intersect with Valley Creek Road at a 90-degree knuckle intersection. Two options are under
consideration for this intersection. Option 1 would locate the intersection would be about 400 feet
south of the south School Site boundary. Baringer Road would bridge the Romero Canyon natural
drainage; the bridge would be about 105 feet long. In Option 2 the west end of Baringer Road would be
shifted south about 95 feet. Baringer Road would cross Romero Canyon with a 50-foot-long bridge or a
concrete arch culvert.
3.2.2 Modifications to the Approved Project
Several aspects of the Approved Project have been modified based on comments from the Division of
the State Architect (DSA), the California Geological Survey (CGS), and the County of Los Angeles
Department of Public Works (LACDPW).
High School Campus
The changes to the high school campus from the Approved Project are illustrated in Figure 3.0-6,
Revised Conceptual School Site Plan. These include the following:
3.0 Project Description
Meridian Consultants 3.0-12 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
• Grades have been changed on the slopes to the west of the high school campus and additional
benches were added.
• The channel inlet north of the high school campus has been enlarged to accommodate flow.
• The parking lot has been reconfigured and curb cuts for street access relocated.
• The main channel is now concrete lined.
• Basketball courts have been relocated.
• Additional fencing has been added along basins and channels.
• The northern slopes have been extended to provide for remedial geotechnical grading.
• The water quality management basin is now one basin.
• The access road has been extended at the terminus of Valley Creek Road to both the proposed
channel at the northern boundary as well as joining existing dirt access road.
School Site
Figure 3.0-7, Comparison of Prior and Revised Grading Areas – School Site, shows the previous and
current areas of disturbance during grading of the School Site. Changes to the grading plan since the
previously certified EIR include the following:
• Tank Site (see area “A” on Figure 3.0-7)
- Subsurface geologic conditions require the relocation of the tank to the west. As a result, there will be an off-site encroachment of a cut slope of approximately 2 acres.
- The finished slopes beneath the tank pad have been redesigned to be buttresses to provide additional geologic stability; the number of benches has been increased.
- Additional slope drainage has been added. - An increased grading envelope will allow a 2:1 slope to be constructed west of the water tanks.
• Mudflow Source in East-Draining Tributary Canyon (see area “B” on Figure 3.0-7)
- The County hydrology approval process has identified a significant volume of mudflow material in this area. There is the potential over time that some or all of this material would make its way down the drainage course.
Revised Conceptual School Site Plan
FIGURE 3.0-6
029-001-13
SOURCE: RRC 2013
APPROXIMATE SCALE IN FEET
5002500 1000
N
TOTAL OFFSITEAREA = 5.83 Ac
Comparison of Prior and Revised Grading Areas - School Site
FIGURE 3.0-7SOURCE: Sikland Engineers - 2014
029-001-13
APPROXIMATE SCALE IN FEET
15007500 3000
N
RevisedGrading
Footprint -School Site
PriorGradingFootprint
School Site
Area “F”Tract 46443
Area “G”
East Slopes
South Slopes
Area “I”
Area “H”
Channel Outlet
Area “A”
TankSite
Area “B”
EastDrainingTributaryCanyon
Area “C”
Area “D”
GeologicRemediation
Area
Area “E”
Landslide andNatural Slope North of
Geologic Remediation Area
NorthButtress
Legend:Area “ ” as described in text
3.0 Project Description
Meridian Consultants 3.0-15 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
- A redesign has been done to accommodate some of the material in place (+/- 20,000 cubic yards [cu. yds.]) and will utilize an access road in the area to act as a spillway to contain mudflow materials away from the high school campus. This mudflow containment capacity required additional grading.
• Geologic Remediation Area (see area “C” on Figure 3.0-7)
- The County LACDPW review has requested required the following changes:
• Additional surface drainage facilities • More concrete details in the overflow facilities within the catchment area
• Landslides and Natural Slope North and West of Geologic Remediation Area (see area “D” on Figure 3.0-7)
- The County LACDPW hydrology approval process has identified a significant volume of potential mudflow material in this area. There is the potential over time that some or all of this material would make its way down the drainage course.
- A redesign has been done to contain mudflow material away from the high school campus.
- Additional drainage facilities have been added to protect slope surfaces from erosion.
• North buttress (see area “E” on Figure 3.0-7)
- A clay bed was discovered during a subsequent geologic investigation that required buttressing of the slope.
- The back cut for the slope may extend beyond the easement area along the northern property line; the buttress involves significantly more grading in this area.
• TM 46443 (see area “F” on Figure 3.0-7)
- The approved grading plan for this tract included the removal of approximately 10-feet-deep alluvial. Current information and County requirements will include full depth alluvial removals of 20 feet or more.
• East slopes (see area “G” on Figure 3.0-7)
- Slope drainage devices have been added and modified.
• Channel outlet (see area “H” on Figure 3.0-7)
- At the request of the County, tThe channel has been redesigned to outlet on the east side of Valley Creek Road. This is a change to the drainage concept, which results in fewer buried
3.0 Project Description
Meridian Consultants 3.0-16 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
drainage structures and additional outlet structures. The prior design included a trapezoidal channel alignment that crosses Valley Creek Road from east to west using a 60-inch diameter reinforced concrete pipe (RCP), that outlets to a proposed riprap channel, then crosses back to the east using a box culvert and outlets to existing natural canyon. The redesigned alignment provides for the trapezoidal channel to be straight and follows the street alignment going south, then outlets through a long riprap and connects to the existing natural canyon.
• South slopes (see area “I” on Figure 3.0-7)
- All of the south slopes have become buttresses to provide additional stability for landslide mitigation.
To accommodate drainage requirements on the School Site, the area, located in the western portion of
the site (Mudflow Source in East-Draining Tributary Canyon [see Figure 3.0-7]), previously consisted of a
private bulked flow inlet designed to carry bulked flows of approximately 71.2 cubic feet per second
(cfs) of flow, including approximately 3,200 cu. yds. of debris. The access road has been redesigned to
raise it to account for the possibility of a surficial slope failure, and creates a higher berm with a capacity
to carry greater than the approximate event mud flow of approximately 20,000 cu. yds.), while assuming
that the private bulked flow inlet would be plugged. The downstream portion of the same access road
has been redesigned to act as an emergency overflow with a slope of 10 percent; this is in addition to
the separate emergency debris tower and overflow pipes.
The previous design for the Approved Project at the School Site utilized a two-tier pad for evaporation
with a retention basin located northeast of the pad. The Approved Project has been modified to include
a new configuration brings the previous two level design into a single basin with a flat bottom elevation
at 1,825 feet amsl. The retention basin has been relocated to the grading cut location at the southwest
corner of the pad, adjacent to the helipad slopes. The east side of the basin pad is lined with a 3-foot-
high berm; the bottom first 10 inches of the berm is the required design capacity to retain storm water
volume for both retention and evaporation. The depth and capacity beyond the first 10 inches has been
designed to detain and control the flow such that the overall proposed condition flow does not exceed
the existing condition flow at the School Site boundary.
Access Routes
The access route alignments have not changed since the certification of the prior EIR. The Southern
Access is as proposed and described for the Approved Project; detailed engineering studies on the
design have yet to be completed. However, to respond to comments from LACDPW, modifications have
been made to the drainage proposed for the Eastern Access route.
3.0 Project Description
Meridian Consultants 3.0-17 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
As currently designed, the East Access route will implement drainage improvements along the East
Access roadway to accommodate stormwater flow from within the local drainage area and prevent
runoff onto adjacent properties. In compliance with Los Angeles County requirements, the Approved
Project has been designed to include debris basins.
As considered in previously certified EIR, the Approved Project was to implement a previous design by
Los Angeles County approved in 2005 as part of Tract 46443 for a portion of the East Access route
adjacent the property owned by the Castaic Elementary School District and for a future elementary
school site (28920 Sloan Canyon Road; APN 2865-023-900). As shown on Figure 3.0-8, Drainage
Improvements Along East Access Route, the previously considered design included the use of culverts
along Sloan Canyon Road to channel storm water runoff from the west to the east.
As currently proposed, the modifications to the Approved Project (see Figure 3.0-8), include the
drainage improvements for the East Access roadway include a single debris basin at the northeast
corner of the proposed elementary school property located on the south side of Sloan Canyon Road.
This debris basin is designed to accommodate the consolidated total debris volume of the previously
approved design for Tract No. 46335 along Sloan Canyon Road. The debris basin will serve a total
upstream tributary area of 138.8 acres, and contain a total debris volume of 13,870 cu. yds. as required
by LACDPW. The inlet pipe has been designed to accommodate the 50-year, burned discharge of 286
cubic feet per second (cfs).
Additional small debris basins may be necessary along Sloan Canyon Road, as well as modifications
and/or relocation of proposed roadway culvert under-crossings. Grading associated with these basins
and under-crossings are included within the disturbed grading acreage.
To facilitate access, the District will extend an existing dirt roadway from Sloan Canyon Road to the
School Site. The new road (Canyon Hill Road) will provide public access along the to the High School
campus in an east to west fashion. While the District is considering various options for the roadway,
subject to approval by the County, the volume of grading required and the areas to be disturbed are
based on grading for the full width right-of-way (80 feet). Adjacent to the Canyon Hill Road, surface
water flows from the existing natural tributary area on the north side of the road will be conveyed
through the 36-inch diameter culvert crossing the road into the existing natural channel. A series of five
culverts will run under the proposed Sloan Canyon Road to convey flows to the existing natural channel
and watershed of Sloan Canyon Creek. In addition to the standard inlet and outlet structures containing
grouted riprap pads, the five crossing structures will include:
3.0 Project Description
Meridian Consultants 3.0-18 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
a) A 42-inch concrete pipe with an inlet headwall (7.63 feet in height and 11 feet in length), and an
outlet headwall (8 feet in height and 12 feet in length).
b) A 42-inch concrete pipe with an inlet headwall (9 feet in height and 10-inches in length), and an
outlet headwall (4.4 feet in height and 12 feet in length). (optional future)
c) A 5-foot by 3-foot single concrete box, with an inlet headwall (5.25 feet in height and 12 feet in
length), and an outlet headwall (7 feet in height and 12 feet in length).
d) a 42-inch concrete pipe with an inlet headwall ( 5.5 feet in height and 6 feet in length), and an
outlet headwall ( 5.5 feet in height and 10 feet in length).
e) a 42-inch concrete pipe, with an inlet headwall height of (5.5 feet in height and 10 feet in
length), and an outlet headwall (6 feet in height and 12 feet in length).
In addition to culverts, two debris basins are proposed to control sediment. The first basin is located on
the Castaic Union Elementary School District property, while the second is located slightly downstream
on the Allard property. Both basins outlet into the proposed storm drain system that runs within Sloan
Canyon Road and outlets in the existing storm drain per Planned Development (PD) Permit No. 1558.
LACFCD will be responsible for future maintenance of the following structures including:
a) all catch basins with laterals;
b) the one culvert crossing along Valley Creek Road;
c) the main concrete trapezoidal channel (that runs from north to south, adjacent and parallel,
northerly and easterly of Valley Creek Road);
d) a ten foot by four foot reinforced concrete box lateral with bulked flow inlet (located northeast
of the site); and e) the terminus riprap channel that outlets into Romero Canyon Creek (located
about 340 feet north of the south site boundary).
All other stormwater infrastructure will be privately maintained by the District.
3.2.3 Construction
Grading
The concept grading plan for the Approved Project has been revised based on the additional
geotechnical testing and evaluations completed, and comments from CGS and LACDPW.
3.0 Project Description
Meridian Consultants 3.0-19 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
The concept grading plan for the School Site is provided in Figure 3.0-9, Revised School Site Conceptual
Grading Plan. The cut and fill areas for the School site and the East Access roadway are shown in Figure
3.0-10, Revised Cut and Fill Areas – School Site and East Access Route.
Previously, approximately 136.01 acres were to be graded for the School Site with an additional 5.83
acres to be graded off site (a total of approximately 141.84 acres); the revised grading plan for the
School Site estimate 136.84 acres to be graded on site with an additional 11.23 acres graded off site (for
a total of approximately 148.07 acres). As such, the revised grading plan will increase grading by
approximately 6.23 acres
For the East Access roadway, the previous estimate for the Approved Project’s grading was
approximately 45 acres; the revised grading plan for the East Access roadway indicates approximately
68.4 acres will be disturbed during grading (an increase of approximately 23.4 acres). Figure 3.0-11,
Conceptual Grading Plan – East Access Route, illustrates the grading area.
The area to be graded for the Southern Access has not changed from the Approved Project and is
approximately 11.5 acres in total area. The location of the grading areas for the Southern Access are the
same as noted in the previously certified EIR and are shown in Figure 3.0-12, Conceptual Grading Plan –
Southern Access Route.
The total estimated grading quantities identified in the previously certified EIR and the revised estimates
for the School Site are provided in Table 3.0-2, Estimated Grading Quantities – School Site.
The estimated grading quantities for the roadways, including the East Access and Southern Access
routes, are provided in Table 3.0-3, Estimated Grading Quantities – East Access Route, and Table 3.0-4,
Estimated Grading Quantities – Southern Access Route, respectively. The total estimated grading
volumes for the Southern Access route have not changed at this time.
The roadway and sidewalk paving areas have not been revised as the total paved area and sidewalks
have remained the same as presented previously for the Approved Project. A summary of the paving
areas is provided in Table 3.0-5, Estimated Access Routes Pavement Quantities.
The total estimated grading quantities, including the School Site and the access routes, is provided in
Table 3.0-6, Total Project Estimated Grading Quantities.
Construction Equipment
The construction equipment anticipated for site clearing, grading, and construction has been revised to
account for the modifications to the Approved Project. The previously certified EIR and changed
equipment lists are provided in Table 3.0-7, Anticipated Construction Equipment.
3.0 Project Description
Meridian Consultants 3.0-20 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Overall, the Approved Project’s related construction activities would take approximately 2.5 to 3 years
to complete. Construction would start with grading and compaction of the site and roadways, followed
by any necessary utility trenching. The footings, buildings, and utilities would then be constructed. The
area surrounding the new buildings would be covered with concrete and asphalt, and curb cuts.
Construction Schedule
Figure 3.0-13, Preliminary Construction Phasing Map, shows the anticipated sequencing of work for
grading and construction of the Approved Project. The Approved Project’s construction schedule
includes the following phases (the sequencing of the phase may differ):
• Phase 1: Grading and construction of the East Access from Sloan Canyon Road from Quail Valley
Road to pump station no. 3
• Phase 1B: Grading and construction of the East Access from Canyon Hill Road from pump station no.
3 to the terminus of the future Mandolin Canyon Road
• Phases 2A and 2B: Grading and construction of Canyon Hill Road from the terminus of Mandolin
Road to the School Site and the intersection of the Valley Creek Road
• Phase 2: Grading of the School Site and subsequent construction of the high school campus and
other facilities (grading associated with geotechnical remediation and removals may occur
separately)
• Phase 3: Grading and construction of the future Southern Access route from the School Site from
Valley Creek Road to Baringer Road to Sloan Canyon Road to Hillcrest Parkway
While the Approved Project includes all the Phases noted previously, this Supplemental EIR only
considers changes to the Approved Project, which involve the East Access along Canyon Hill Road and
the School Site (Phases 1, 2A, 2B, and 2). For the construction of the Southern Access (Phase 3), the
Supplemental EIR relies on the information as presented in the previously certified EIR as the
information available has not changed.
The estimated time frame for grading and pavings include:
• Phase 1: 2 months (30 days grading; 10 days paving and curb and gutter)
• Phase 1B: 2 months (30 days grading; 10 days paving and curb and gutter)
• Phases 2A and 2B: 2 months (30 days grading; 10 days paving and curb and gutter)
3.0 Project Description
Meridian Consultants 3.0-21 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
• Phase 2: 12 months (200 days grading; 60 days paving and curb and gutter)
• Phase 3: 6 months (80 days grading; 40 days paving and curb and gutter)
The estimated construction time for the high school campus and other structures is approximately 18 to
24 months after the completion of site grading.
Driveways and final road improvements would be constructed. Finally, landscaping, site fencing, and any
finishing work would be completed.
Meridian Consultants 3.0-22 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-2 Estimated Grading Quantities – School Site
Phase
Previously Certified EIR Quantities (cu. yds.)
Revised Quantities (cu. yds.)
Area Cut Area Fill Area Cut Area Fill
Phase 2
C1 1,140,000 F1 3,788,800 C1 1,160,000 F1 3,988,000 C2 691,100 F2 98,200 C2 718,000 F2 312,000 C3 905,400 F3 61,900 C3 1,060,000 F3 76,000 C4 559,900 – C4 606,000 – C5 296,400 – C5 300,000 –
Subtotal 3,592,800 3,948,900 3,844,000 4,376,000 Removal &
recompaction 1,100,000 1,100,000 2,400,000 2,400,000 Total 4,692,800 5,048,900 6,244,000 6,776,000a Bulking factor 150,000 – 190,000 – Total School Site 4,842,800 5,048,900 6,434,000 6,776,000
Note: cu. yds. = cubic yards. a Excess fill will be transported from the East Access cut materials. Grading will be balanced within the School Site and East Access Grading areas; no import or export will occur from off-site.
3.0 Project Description
Meridian Consultants 3.0-23 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-3 Estimated Grading Quantities – East Access Route
Phase
Previously Certified EIR Quantities (cu. yds.)
Revised Quantities (cu. yds.)
Area Cut Area Fill Area Cut Area Fill
Phase 1 Sloan to Quail 0 0 Sloan to Quail 52,000 63,500
Phase 1B, 2A, & 2B
C6 371,000 F4 59,800 C6 46,000 F4 60,000 C7 390,300 F5 108,000 C7 622,000 F5 181,000 C8 3,700 – C8 63,000 – C9 18,900 – C9 21,000 –
C10 5,000 – C10 6,200 – C11 146,000 F6 253,200 C11 149,000 F4 262,200
Subtotal 934,900 421,000 959,200 566,700 Removal &
recompaction 200,000 200,000 800,000 800,000 Total 1,134,900 621,000 1,759,200a 1,366,400 Bulking factor 30,000 – 55,000 – Total East Access Route 1,164,900 621,000 1,814,200 1,366,400
Note: cu. yds. = cubic yards. a Excess cut will be transported and used as fill to School site. Grading will be balanced within the School Site and East Access Grading areas; no import or export will occur from off-site.
3.0 Project Description
Meridian Consultants 3.0-24 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-4 Estimated Grading Quantities - Southern Access Route
Phase
Previously Certified EIR Quantities (cu. yds.)
Revised Quantities (cu. yds.)
Area Cut Fill Cut Fill
Phase 3
Valley Creek Road to Baringer Road 10,000 8,000 10,000 8,000 Baring Road to Sloan Canyon 97,000 99,000 97,000 99,000 Sloan Canyon Road to Hillcrest Parkway 90,000 116,000 90,000 116,000 Hillcrest Parkway widen 400 to Sloan Canyon Road 10,000 4,000 10,000 4,000 Romero Canyon Road south of Baringer (improvements for gated emergency access) 3,000 3,000 3,000 3,000
Subtotal 210,000 230,000 210,000 230,000 Removal & recompaction, and 3 percent bulking
factor 320,000 300,000 320,000 300,000
Total Southern Access Route 530,000 530,000 530,000 530,000 Note: cu. yds. = cubic yards.
3.0 Project Description
Meridian Consultants 3.0-25 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-5 Estimated Access Routes Paving Quantities
Phase Access Route Site Area
Previously Certified EIR Paving (sq. ft.)
Changed Paving (sq. ft.)
Roadway Sidewalk Roadway Sidewalk 1 Sloan Canyon, Canyon Hill to Quail Valley 108,000 13,500 108,000 13,500
1A, 2A, & 2B Canyon Hill Road 104,000 13,000 104,000 13,000
Phase 3
Valley Creek Road to Baringer Road 24,000 3,000 24,000 3,000 Baringer Road to Sloan Canyon Road 61,600 11,000 61,600 11,000 Sloan Canyon Road to Hillcrest Parkway 126,000 22,500 126,000 22,500 Hillcrest Parkway widen 400 feet to Sloan Canyon Road 11,120 2,000 11,120 2,000 Romero Canyon Road south of Baringer Road (improvements for gated emergency access) 31,200 0 31,200 0
Total 465,920 65,000 465,920 65,000 Note: sq. ft. = square foot.
3.0 Project Description
Meridian Consultants 3.0-26 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-6 Total Project Estimated Grading Quantities
Area
Previously Certified EIR Grading Plans
(cu. yds.) Revised Grading Plans
(cu. yds.) Cut Fill Cut Fill
School site 4,850,000 5,100,000 6,434,000 6,776,000
Subtotal 4,850,000 5,100,000 6,434,000 6,776,000
East Access route 930,000 680,000 1,814,200 1,366,400
Southern Access route 530,000 530,000 530,000 530,000
Subtotal 1,460,000 1,210,000 2,344,200 1,896,400
Consolidation as a result of recompaction 105,800a
Total1 6,310,000 6,310,000 8,778,200 8,672,400 8,778,200
Note: cu. yds. = cubic yards. a Excess cut will be consolidated at part of recompaction efforts; cut and fill will be balanced on site. 1 - Grading will be balanced within the School Site and East Access Grading areas; no import or export will occur from off-site.
Meridian Consultants 3.0-27 Revised Draft Supplemental EIR for Castaic High School 029-001-13 April June 2014
Table 3.0-7 Anticipated Construction Equipment
Phase Equipment Type and
Phase
Previously Certified EIR
Estimate
Revised Equipment
Estimate
Site preparation/clearing
Grader 1 1 Dozer 3 3 Loader 1 1
Dump truck 2 2 Water truck 2 2
Grading – East Access and Southern Access (Phases 1, 1B,
2A, 2B, and 3)
Scraper 8 8 Dozer 5 5 Blade 2 2
Loader 1 1 Compactor 2 2 Water truck 4 4
Grading – School Site (Phase 2)
Scraper 8 14 Dozer 5 5 Blade 2 2
Loader 1 1 Compactor 2 2 Water truck 4 4
Trenching and utilities Excavator 2 2
Loader 2 2
Building construction
Crane 1 1 Forklift 2 2 Loader 1 1
Backhoe 1 1 Rough terrain forklift 2 2
Concrete truck 2 2 Concrete pump 1 1
Water truck 1 1 Generator 3 3
Paving
Paver 1 1 Roller 2 2
Concrete truck 8 8 Concrete pump 1 1
Truck (asphalt) S-10 8 8 Water truck 2 2
FIGURE 3.0-8SOURCE: Sikand Engineering - 1988; Sikand Engineering - 2014.
Drainage Improvements Along East Access Route029-001-13
Proposed Hydrology
N
ProposedDebrisBasin
PreviouslyApprovedCulverts
forTract46443
Sikland Engineering - 1988Approved Hydrology Tract 46443
ProposedStormDrainProposed
Culvert
FIGURE 3.0-9SOURCE: Sikland Engineers - 2014
Revised School Site Conceptual Grading Plan029-001-13
APPROXIMATE SCALE IN FEET
4002000 800
N
Project SiteLegend:
FIGURE 3.0-10SOURCE: Sikland Engineers - 2014
Revised Cut and Fill Areas - School Site and East Access Route029-001-13
APPROXIMATE SCALE IN FEET
5002500 1000
N
Project SiteLegend:
Cut AreasFill Areas
School Site
East Access Route
East Access Grading area as presented in previously certified EIR
East Access Grading Area as revised
APPROXIMATE SCALE IN FEET
5002500 1000
N
Project SiteLegend:
Cut AreasFill Areas
Conceptual Grading Plan – East Access Route
FIGURE 3.0-11SOURCE: Castaic High School EIR; Planning Center 2012and Sikland Engineers - 2014
029-001-13
N
Site Boundary 0 1,000
Conceptual Grading Plan - Southern Access Route
FIGURE 3.0-12SOURCE: Sikland Engineers - 2012
029-001-13
APPROXIMATE SCALE IN MILES
10005000 2000
N
Legend:Project Site
Preliminary Construction Phasing Map
FIGURE 3.0-13SOURCE: Sikland Engineers - 2013
029-001-13
APPROXIMATE SCALE IN FEET
10005000 2000
N
Project SiteLegend:
ProposedGate
- East Access Route
- Valley Creek Route
- Southern Access Route