3.0 project description...3.0 project description meridian consultants 3.0-2 revised draft...

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


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


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


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



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





3247-042-026 30706 Romero Canyon Road 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.


• 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


7503750 1500

N

Legend:



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:



• 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


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


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



- 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



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.



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:



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.



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.



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)





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.


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.



Table 3.0-3 Estimated Grading Quantities – East Access Route

Phase



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.



Table 3.0-4 Estimated Grading Quantities - Southern Access Route

Phase



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.



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.



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.


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


Revised School Site Conceptual Grading Plan029-001-13


4002000 800

N

Project SiteLegend:


Revised Cut and Fill Areas - School Site and East Access Route029-001-13


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


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


029-001-13


10005000 2000

N

Legend:Project Site

Preliminary Construction Phasing Map


029-001-13


10005000 2000

N

Project SiteLegend:

ProposedGate

- East Access Route

- Valley Creek Route

- Southern Access Route

3.0 project description...3.0 project description meridian consultants 3.0-2 revised draft...

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