DEXTER WILSON ENGINEERING, INC.
WATER ● WASTEWATER ● RECYCLED WATER
CONSULTING ENGINEERS
2234 FARADAY AVENUE ● CARLSBAD, CA ● (760) 438-4422
SEWER SYSTEM ANALYSIS
FOR
NORTH CITY UNIVERSITY DISTRICT
November 24, 2021
i
TABLE OF CONTENTS
PAGE NO.
CHAPTER 1 INTRODUCTION ................................ ................................ ................... 1 PROJECT OVERVIEW ................................ ................................ .......... 1 DEVELOPMENT PLAN ................................ ................................ ......... 1 STUDY AREA ................................ ................................ ......................... 4 PURPOSE OF STUDY ................................ ................................ ........... 4
CHAPTER 2 DESIGN CRITERIA ................................ ................................ ............... 5 Sewage Generation and Peaking Factors ................................ ... 5 Gravity Sewers ................................ ................................ ............ 6
CHAPTER 3 SEWER FLOWS ................................ ................................ ..................... 7 Projected Sewer Flows ................................ ................................ 7 Sewer Flow Comparison ................................ ............................ 10
CHAPTER 4 EXISTING SEWER FACILITIES ................................ ........................ 12 Local Facilities ................................ ................................ .......... 12 Regional Facilities ................................ ................................ ..... 12
CHAPTER 5 RECOMMENDED SEWER FACILITIES ................................ ............ 14 Onsite Sewer Facilities ................................ ............................. 14 Hydraulic Analysis ................................ ................................ .... 15 Offsite Sewer Facilities ................................ ............................. 15 Local Improvements ................................ ...................... 15 Regional Improvements ................................ ................. 17
ii
LIST OF TABLES
PAGE NO.
TABLE 2-1 RECOMMENDED UNIT SEWER
GENERATION FACTORS ................................ ................................ ..... 6
TABLE 3-1 NORTH CITY UNIVERSITY DISTRICT PROJECTED
WASTEWATER GENERATION ................................ ............................ 7
TABLE 3-2 LAND USE COMPARISON BETWEEN
VALLECITOS WATER DISTRICT 2018 MASTER PLAN
AND 2021 NORTH CITY UNIVERSITY DISTRICT
SPECIFIC PLAN ................................ ................................ .................. 11
TABLE 5-1 NORTH CITY UNIVERSITY DISTRICT SPECIFIC PLAN
SEWER FLOW BY TRIBUTARY LOCATION/AREA ......................... 14
APPENDICES
APPENDIX A 2021 NORTH CITY UNIVERSITY DISTRICT SPECIFIC PLAN UNIT
COUNT AND LAND USE BREAKDOWN
APPENDIX B VALLECITOS WATER DISTRICT MASTER PLAN EXCERPT 2009
NORTH CITY UNIVERSITY DISTRICT MASTER PLAN
REFERENCE
APPENDIX C COMPUTER MODELING OUTPUT
APPENDIX D VALLECITOS WATER DISTRICT REFERENCE BACKGROUND
SEWER STUDIES
iii
LIST OF FIGURES
PAGE NO.
FIGURE 1-1 LOCATION MAP ................................ ................................ .................... 2
FIGURE 1-2 PROPOSED DEVELOPMENT PLAN ................................ .................... 3
FIGURE 4-1 EXISTING SEWER FACILITIES ................................ ........................ 13
FIGURE 5-1 PROPOSED ONSITE SEWER FACILITIES ................................ ....... 16
EXHIBIT
EXHIBIT A SEWER NODE DIAGRAM
DEXTER WILSON ENGINEERING, INC. PAGE 1
CHAPTER 1
INTRODUCTION
This report provides a sewer system analysis for the North City University District Specific Plan amendment project located in the City of San Marcos and Vallecitos Water District .
This report will provide information concerning projected sewage flows, ex isting facilities, and proposed major facilities, and onsite/offsite improvements necessary to provide adequate sewer service to the project.
PROJECT OVERVIEW
The University District project is situated in the heart of San Marcos (City), with parcels located on both the east and west sides of Twin Oaks Valley Road. The portion of the University District located east of Twin Oaks Valley Road is also known also as North City.
The site is bounded by State Route 78 and San Marcos Creek on the north, and Barham Drive and Discovery Hills on the south. Figure 1-1 provides a location map of the project.
DEVELOPMENT PLAN
The North City University District project encompasses a total of approximately 20 3 acres.
The development plan for the proje ct is mixed use with some open space areas. The residential component of the project proposes 3,400 multi -family residential units. The commercial component of the project includes approximately 2,000,000 square feet of office and retail space, 170 hotel rooms, and civic facilities. Figure 1-2 provides the proposed land use plan for the project.
DEXTER WILSON ENGINEERING, INC. PAGE 4
STUDY AREA
The entire project is within the boundaries of the Vallecitos Water District for sewer service.
There is an overall interceptor sewer to the north of the North City University District project that will provide sewer service to the area.
The project will sewer to this interceptor through three different existing sewer alignments.
The three gravity sewer alignments are through Discovery Street, Twin Oaks Valley Road under the 78 freeway, and Carmel Street/Industrial Street under the 78 freeway.
PURPOSE OF STUDY
This report serves as an overall update to the “Sewer System Analysis for San Marcos University District” by Dexter Wilson Engineering, Inc. dated February 2009. The purpose of this report is to provide a supporting document to the project environmental impact report and the North City - University District, Specific Plan Amendment to the City of San Marcos.
The facilities recommended and analyzed in this report must be compatible with the Vallecitos Water District Master Plan and the facility must be sized to take into account the ultimate needs of future development in the area. A hydraulic analysis will be prepared to evaluate the onsite and offsite sewer system for the project.
DEXTER WILSON ENGINEERING, INC. PAGE 5
CHAPTER 2
DESIGN CRITERIA
This chapter presents the design criteria used to evaluate recommended sewer system improvements for the San Marcos University District project. The criteria utilized in this study are in a ccordance with the Vallecitos Water District Vallecitos Water District 2018 Water, Wastewater, and Recycled Water Master Plan, unless otherwise noted. This report was prepared by Black & Veatch and is dated October 2018. The design criteria are used for evaluating the existing system as well as for design and sizing of proposed improvements to accommodate development in the study area.
Sewage Generation and Peaking Factors
Table 2 -1 presents the sewage generation factors used in projecting sewer flows for the project. Due to the mixed -use nature of the project, some of the sewer flow factors were adjusted from the District Master Plan based on conversations with the District as well as previous studies developed for the project . The source for t he sewer generation factors is footnoted in Table 2-1.
To convert average day sewer flows to peak flows, the following equations were utilized;
Peak Dry Weather Factor = 2.16 * (Average Dry Weather Flow) – 0.1618 Peak Wet Weather Factor = 2.78 * (Average Dry Weather Flow) – 0.087
DEXTER WILSON ENGINEERING, INC. PAGE 6
TABLE 2-1
RECOMMENDED UNIT SEWER
GENERATION FACTORS
Land Use Category Sewer Generation Factor
Mixed Use Residential 180 gpd/unit1
Residential (12-15 du/ac) 2,500 gpd/ac2
Residential (20-30 du/ac) 4,500 gpd/ac2
Hotel 125 gpd/room2
Office 1,200 gpd/ac2
Retail/Commercial 1,200 gpd/ac2
Civic 800 gpd/ac2
Parks 250 gpd/ac2
Open Space/Right-Of-Way 0
1 Per conversations with the VWD Engineering Department and previous North City University District studies.
2 Per VWD Master Plan.
Gravity Sewers
All gravity sewers have been designed to convey peak wet weather flow. For pipes with a diameter of 12-inches and smaller, the sewers have been designed to convey this flow when flowing half full (0.50 d/D). For pipes with a diameter of 15 -inches and larger, the sewers have been designed to convey peak wet weather flow when flowing three-fourths full by depth (0.75 d/D). Manning’s Equation with an “n” value of 0.013 was used to size and analyze all gravity sewers. All new sewers were designed to maintain a minimum velocity of two feet per second at design capacity to prevent the deposition of solids.
DEXTER WILSON ENGINEERING, INC. PAGE 7
CHAPTER 3
SEWER FLOWS
This chapter provides the projected sewer flows for the North City University District project.
A comparison of the current projected North City University District development to the North City University District development estimated in the 2018 VWD Master Plan for this property is also provided.
Appendix A presents the current Specific Plan land use breakdown by induvial planning area. Table 3-1 below calculates the projected wastewater generation from that current land use breakdown with the excep tion of the Zirpolo parcel. The Zirpolo parcel proposes 250 mixed-use residential units and thus other areas will decrease their mixed-use residential by 250 to keep the project’s residential units at 3,400. The mixed-use residential was deceased by 140 at Block 4, 25 at Block J, and 85 at Block X.
Projected Sewer Flows
Table 3 -1 provides a summary of projected Wastewater generation for the North City University District. The total projected average daily flow is 0.71 mgd. The projected maximum peak wet weather flow is 2.03 mgd.
TABLE 3-1
NORTH CITY UNIVERSITY DISTRICT
PROJECTED WASTEWATER GENERATION
Area Gross
Acres Land Use Quantity Equivalent
Acres1
Sewer
Generation
Factor
Avg. Water
Demand,
gpd
Scripps
1 8.5 Office
Mixed-Use Residential
150,000 SF
150 Units
8.5 Ac
--
1,200 gpd/Ac
180 gpd/unit
10,200
27,000
Subtotal Area 1 37,200
Shea/Lennar
(PA 3, 4, 5,
6, and 7) 2
44.1 Residential
(14.4 units/acre) 637 Units --- 2,500 gpd/Ac 110,250
DEXTER WILSON ENGINEERING, INC. PAGE 8
TABLE 3-1
NORTH CITY UNIVERSITY DISTRICT
PROJECTED WASTEWATER GENERATION
Area Gross
Acres Land Use Quantity Equivalent
Acres1
Sewer
Generation
Factor
Avg. Water
Demand,
gpd
Subtotal Area 2 110,250 Levitt North
3 6.1 Residential
(24.6 units/acre) 150 Units -- 4,500 gpd/Ac 27,450
Subtotal Area 3 27,450 Levitt South
4 15.5
Office
Mixed-Use Residential
Commercial
620,000 SF
523 Units
20,000 SF
15.0 Ac
--
0.5 Ac
1,200 gpd/Ac
180 gpd/unit
1,200 gpd/Ac
18,000
94,140
600
Subtotal Area 4 112,740 Block 1
5 5.3 Commercial
Office
89,000 SF
200,000 SF
1.6 Ac
3.7 Ac
1,200 gpd/Ac
1,200 gpd/Ac
1,920
4,440
Subtotal Area 5 6,360 Block 2
6 3.5 Mixed-Use Residential
Commercial
424 units
15,000 SF
---
3.5 Ac
180 gpd/unit
1,200 gpd/Ac
76,320
4,200
Subtotal Area 6 80,520
Block 3
7 6.0
Commercial
Mixed-Use Residential
Office
15,000 SF
50 units
80,000 SF
0.9 Ac
---
5.1 Ac
1,200 gpd/Ac
180 gpd/unit
1,200 gpd/Ac
1,080
9,000
6,120
Subtotal Area 7 16,200
Block 4
8 8.6
Mixed-Use Residential
Office
Retail
Hotel
60 units
450,000 SF
20,000 SF
170 Rooms
---
8.2 Ac
0.4 Ac
--
180 gpd/unit
1,200 gpd/Ac
1,200 gpd/Ac
125 gpd/room
10,800
9,840
480
21,250
Subtotal Area 8 42,370
Block C
9 5.3 Mixed-Use Residential
Commercial
196 Units
11,600 SF
--
5.3 Ac
180 gpd/unit
1,200 gpd/Ac
35,280
6,360
Subtotal Area 9 41,640
Block F
10 3.4 Mixed-Use Residential 270 Units --- 180 gpd/unit 48,600 Subtotal Area 10 48,600
Block J
11 2.2 Mixed-Use Residential
Office
35 units
100,000 SF
---
2.2 Ac
180 gpd/unit
1,200 gpd/Ac
6,300
2,640
DEXTER WILSON ENGINEERING, INC. PAGE 9
TABLE 3-1
NORTH CITY UNIVERSITY DISTRICT
PROJECTED WASTEWATER GENERATION
Area Gross
Acres Land Use Quantity Equivalent
Acres1
Sewer
Generation
Factor
Avg. Water
Demand,
gpd
Subtotal Area 11 8,940
PIMA/Block
K 12 1.6 Mixed-Use Residential
Office
66 units
21,900 SF
---
1.6 Ac
180 gpd/unit
1,200 gpd/Ac
11,880
1,920
Subtotal Area 12 13,800
Block X
13 5.1 Mixed-Use Residential 215 units --- 180 gpd/unit 38,700 Subtotal Area 13 38,700
Block Y and
Block Z
14 3.4 Mixed-Use Residential 50 units --- 180 gpd/unit 9,000 Subtotal Area 14 9,000
Cabinet
15 1.0 Commercial 1.0 Ac 1.0 Ac 1,200 gpd/Ac 1,200
Subtotal Area 15 1,500
Church
16 1.7 Mixed-Use Residential 150 units -- 180 gpd/unit 27,000 Subtotal Area 16 27,000
Mesa Rim
17 1.0 Commercial 28,200 SF 1.0 Ac 1,200 gpd/Ac 1,200
Subtotal Area 17 1,200
Quad
18 4.3 Mixed-Use Residential
Commercial
174 units
24,300 SF
--
4.3 Ac
180 gpd/unit
1,200 gpd/Ac
31,320
5,160
Subtotal Area 18 36,480
Urge
19 1.4 Commercial 20,000 SF 1.4 Ac 1,200 gpd/Ac 1,680
Subtotal Area 19 1,680
Zirpolo
20 4.70 Mixed-Use Residential 250 units -- 180 gpd/unit 45,000 Subtotal Area 20 45,000
Park
21 16.6 Parks 16.6 Ac 16.6 Ac 250 gpd/Ac 4,150
Subtotal Area 21 4,150
DEXTER WILSON ENGINEERING, INC. PAGE 10
TABLE 3-1
NORTH CITY UNIVERSITY DISTRICT
PROJECTED WASTEWATER GENERATION
Area Gross
Acres Land Use Quantity Equivalent
Acres1
Sewer
Generation
Factor
Avg. Water
Demand,
gpd
Open
Space/Right-
Of-Way
22 49 Open Space/Right-Of-
Way 49.0 Ac 49.0 Ac 0 gpd/Ac 0
Subtotal Area 22 0
TOTAL 203 710,480
1 Per the VWD Engineering Department, equivalent gross acres were calculated by proportionally splitting gross acreage by building square footage.
Sewer Flow Comparison
The VWD Master Plan relies on 2018 land use zoning in this area as a basis for converting land uses to projected water demands. Table 3-2 provides a land use comparison for this area based on the VWD Master Plan assumptions (2009 Specific Plan). Appendix B provides the excerpt from the VW D Master Plan which states the assumed development parameters for the North City University District project.
D
EXTER WILSON ENGINEERING, INC.
PAGE
11 TABLE 3
-
2 LAND USE COMPARISON
BETWEEN
VWD
2018
MASTER PLAN
AND
2021 NORTH CITY UNIVERSITY DISTRICT SPECIFIC PLAN
Land Use
VWD 2018 Master
Plan
Quanti
ties
1 2021 North City
University District
Specific
Plan Quantities
Difference
Multi
-
Family
Residential & Student
3,400 Units
3,400 Units
0 Specialty Retail /
Strip Commercial
1,000,000 SF
239,000 SF
-
761,000 SF
Hotel
450 Rooms
170 Rooms
-
280 Rooms
Corporate
Headquarters Office
638,000 SF
1,070,000 SF
+432,000 SF
Medical Office
300,000 SF
150,000 SF
-
150,000 SF
Standard Commercial
Office
638,000 SF
537,000 SF
-
101,000 SF
Market
0 39,000 SF
+39,000 SF
1 VWD 2018 Master Plan quantities based on 20
09 North City University District
Specific
Plan quantities
.
In comparing
the land use
breakdowns between the 2009 and 2021 North City University District Specific Plans
, the current land use plan would
decrease
projected average
sewer
generation
by approximately
0.3 5
mgd.
This 0.3
5 mgd is the is the difference between the
sewer generation
projected in the “Sewer System Analysis for San Marcos University District” by Dexter Wilson Engineering, Inc. dated February 2009 (1. 06 mgd) and this current
study supporting the 2021 North City University District Specific Plan (
0.7 1
mgd).
DEXTER WILSON ENGINEERING, INC. PAGE 12
CHAPTER 4
EXISTING SEWER FACILITIES
This chapter provides a description of existing sewer facilities in the vicinity of the North City University District project. Figure 4-1 provides the location of major sewer facilities in the area.
Local Facilities
There is an existing 18-inch sewer line in Twin Oaks Valley Road. This line increases to 21- inch as it conveys flow north and crosses State Route 78. There is also a parallel 8 -inch diameter gravity sewer in Twin Oaks Valley Road that connects into the project’s existing 15-inch diameter sewer connection to the existing 21-inch diameter line, just south of State Route 78. There is 12-inch sewer line in Barham Drive that increases to 15-inch as it conveys flow westerly and connects to the 18-inch line in Twin Oaks Valley Road. There is also a 12- inch gravity sewer line at Discovery Street that conveys flow easterly to the line in Twin Oaks Valley Road. In the northeastern corner of the project at and near the Camel Street and Industrial Street intersection, there are some existing 8 -inch diameter gravity sewer lines that serve adjacent and contingent development.
Regional Facilities
The gravity sewer interceptor located north of the North City University District project conveys flow westerly to District Lift Station Number 1 near the intersection of San Marcos Boulevard and Pacific Street. From this location, the District has the option of pumping through Lift Station Number 1 to their Meadowlark Treatment Plant or sewage can flow by gravity through the Distr ict land outfall to the Encina Wastewater Authority. The Encina plant is currently rated for a capacity of 40.5 mgd and the Vallecitos Water District has capacity rights of 10.5 mgd (liquid and solid).
DEXTER WILSON ENGINEERING, INC. PAGE 14
CHAPTER 5
RECOMMENDED SEWER FACILITIES
This chapter presents the recommended sewer system improvements necessary to provide sewer service to the North City University District project.
Onsite Sewer Facilities
The North City University District can be served by the construction of onsite gravity sewers and connection to the existing system at several locations. The eastern portion of the project proposes to connect to an existing 8-inch diameter gravity sewer line in Carmel Street. The majority of the project proposes to connect to the existing gravity sewer lines in Twin Oaks Valley Road. The western portion of the project will convey flow to the intersection of Discovery Street and Grand Avenue. From this location , approximately 1,000 to 2,000 feet of offsite sewer line will be necessary to convey flow westerly to the existing 16-inch diameter sewer line in Craven Road.
Table 5-1 below shows the sewer flow distribution totals by tributary location.
TABLE 5-1
2021 NORTH CITY UNIVERSITY DISTRICT SPECIFIC PLAN
SEWER FLOW BY TRIBUTARY LOCATION/AREA
Tributary Outlet Project Area(s)1 Total Average
Sewer Flow, gpd
Carmel Street Block F (60%), Block Y, Block Z, and Zirpolo Parcel 83,160
Twin Oaks Valley Road
Church, Cabinet, Quad, Block X, Block J,
Block K, PIMA, Block C, Mesa Rim, Urge,
Block F (40%), Block 2, Block 1, Block 3, Block
4, Levitt North, Levitt South, and Shea/Lennar
(PA 3 East, 116 units)
495,565
Discovery Street Shea Lennar, Park, and Scripps 131,755 1 Refer to Table 3-1 for project area breakdown.
DEXTER WILSON ENGINEERING, INC. PAGE 15
Hydraulic Analysis
A preliminary hydraulic analysis has been performed to estimate proposed onsite sewer line sizing and confirm existing sewer line capacities . Projected flows have been split based on the current development plan and pipe slopes have been estimated either based on preliminary street grades , derived from As -Built drawings, or sourced from existing VWD hydraulic studies for the project.
Existing sewer flows and offsite gravity sewer pipe slopes through the site were based on two Draft Technical Memorandum s prepared by VWD. These two memorandums were titled “University District San Marcos East & West and Discovery Village North and South Sewer Study” dated June 10, 2019 and “Discovery Village West & East Water and Sewer Study” dated September 22, 2021.
Figure 5-1 graphically shows the location of onsite sewer facilities.
Offsite Sewer Facilities
The previous study “Sewer System Analysis for San Marcos University District” by Dexter Wilson Engineering, Inc. dated February 2009 evaluated the impacts of the original North City University District project. The study identifie d local and regional improvements to provide service to the project. Since that time, several local and regional improvements have already been made and implemented by the District.
Local Analysis and Improvements. The eastern portion of the project will convey flows through an existing 8 -inch sewer line in Carmel Street. This line conveys flow northerly across State Route 78 and connects into a 12-inch line. The hydraulic analysis indicates that one section of this alignment flows above a 0.5 d/D ratio with additional flows from the project.
The middle portion of the project will convey flow to an existing 21 -inch sewer line in Twin Oaks Valley Road that conveys flow northerly across State Route 78 before connecting into a regional interceptor. The maximum d/D ratio within this portion is 0.63 counting for existing peak flows as well as development of the project.
DEXTER WILSON ENGINEERING, INC. PAGE 17
The western portion of the project will require an offsite sewer line to convey flow to the existing 16-inch gravity sewer line in Craven Road. Our analysis indicates that a 12 -inch offsite sewer gravity sewer line is required.
Regional Analysis and Improvements. At time of the 2009 study, t here was an approximately 7,000 foot section of existing interceptor from Grand Avenue to Lift Station Number 1 that was identified for replacement in the District Master Plan. This interceptor has been ultimately replaced since that time with a 42-inch diameter sewer interceptor.
The District is also planning to construct a parallel and replace select land outfall segments from Lift Station Number 1 to the Encina Wastewater Authority to accommodate ultimate development. The District is planning on 30-inch to 48 -inch parallel and new outfall pipelines to accommodate buildout flows per the Master Plan
As mentioned previously in this report, t hese District proposed improvements incorporate the North City University District project.
The District currently has 7. 67 mgd of liquid treatment capacity at Encina and 5.0 mgd at the Meadowlark Treatment Plant for a total of 12.67 mgd. The 2018 Master Plan projected ultimate flows for the District to be 1 4.40 mgd. The District will be required to purchase additional capacity in the Encina System.
APPENDIX A
2021 NORTH CITY UNIVERSITY DISTRICT SPECIFIC PLAN
UNIT COUNT AND LAND USE BREAKDOWN
APPENDIX B
VWD MASTER PLAN EXCERPT
2009 NORTH CITY UNIVERSITY DISTRICT MASTER PLAN REFERENCE
Vallecitos Water District | 2018 WATER, WASTEWATER, AND RECYCLED WATER MASTER PLAN BLACK & VEATCH | Land Use and Population 2-11
approximately 370 multi-family residential units, 44,000 sf of commercial space, 5,400 sf of live/work space, and 5,000 sf of restaurants or food establishments.
2.1.3.8 Parkview Homes
The City of San Marcos General Plan (adopted February 2012) identifies Parkview Homes as an adopted SPA. This development is located on Autumn Drive between Knoll Road and Pico Avenue.
Its permitted planned development includes 84 apartment units and 6,490 square feet of retail space.
2.1.3.9 Richmar
The City of San Marcos General Plan (adopted February 2012) identifies the Richmar development as an adopted SPA. The Westlake Village (Completed 2010) and Autumn Terrace (Completed 2010) SPAs are also within the Richmar Specific Plan. The Richmar project is located along Richmar Avenue in the City of San Marcos. Its permitted planned development is 291 multi-family units, approximately 10,000 sf of office space, and approximately 50,000 of commercial space. The development (including Westlake Village and Autumn Terrace) covers approximately 64.35 acres.
2.1.3.10 San Elijo Hills
San Elijo Hills is a planned community development on San Elijo Road, east of Rancho Santa Fe Road and the “Old Creek Ranch” SPA. The City of San Marcos General Plan (adopted February 2012) identifies this development as an adopted SPA. Its permitted planned development includes 2,496 single-family dwelling units, 972 multi-family dwelling units, and approximately 544,500 sf of commercial space.
2.1.3.11 San Marcos Highlands
The City of San Marcos General Plan (adopted February 2012) identifies San Marcos Highlands as an adopted SPA that encompasses 262 acres. This project is partially located within the City of San Marcos and partially falls within unincorporated areas of San Diego County. The project is located at the north end of Las Posas Road north of Borden Road. Its permitted planned development includes 189 single-family residential units over approximately 107 acres.
2.1.3.12 University District
The University District is a 195-acre planned development near California State University – San Marcos. It is located on both sides of Twin Oaks Valley Road, bounded by State Route 78 and San Marcos Creek on the north, and Barham Drive and Discovery Hills to the south. The University District Specific Plan was approved by the City of San Marcos in 2009.
The City of San Marcos General Plan (February 2012) identifies the University District as an adopted SPA. Its permitted planned development includes 1,000,000 square feet (sf) of commercial space, 938,000 sf of office space, 30,000 sf of civic/community space, 2,600 multi-family residential units, 800 student housing units, and 450 hotel rooms.
2.2 POPULATION AND PROJECTIONS
Planned land use data, as described above, was used to determine water demand and wastewater generation projections under build-out, or ultimate conditions. Population growth estimates provided the basis for determining water demand and wastewater generation projections in the
APPENDIX C
COMPUTER MODELING OUTPUT
The following conditions were modeled:
1. Average Day Demand.
2. Peak Hour Demand.
3. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 824.
4. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 825.
5. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 910.
6. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 933.
7. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 917.
8. Maximum Day Demand plus 2,500 gpm Fire Flow at Node 942.
DATE:
FOR:
SHT
1 OF
3 BY:
M.G.D.
G.P.M.
C.F.S.
60% of Block F
16 14
29,160
29,160
3.83 111,593
3.78 110,254
0.110
77 0.171
8 1.00
0.065388
0.17333
0.26 0.1623
2.37 14
12 0
29,160
3.83 111,593
3.78 110,254
0.110
77 0.171
8 1.00
0.065388
0.17333
0.26 0.1623
2.37 Block Y, & Z
12 10
9,000
38,160
3.66 139,816
3.69 140,946
0.141
98 0.218
8 1.00
0.083591
0.19333
0.29 0.1890
2.60 Ex. Commercial
10 8
6,000
44,160
3.58 158,022
3.65 161,048
0.161
112
0.249
8 1.00
0.095513
0.20667
0.31 0.2074
2.70 8
6 0
44,160
3.58 158,022
3.65 161,048
0.161
112
0.249
8 0.30
0.174381
0.28667
0.43 0.3229
1.74 CL-1, Zirpolo Parcel 250 Units
6 4
45,000
89,160
3.19 284,765
3.43 305,879
0.306
212
0.473
8 0.30
0.331203
0.42000
0.63 0.5210
2.04 CL-2, 62 gpm peak ex. flow*
4 2
28,500
117,660
3.05 359,298
3.35 394,030
0.394
274
0.610
8 1.20
0.213326
0.32000
0.48 0.3727
3.68 * Ex. Peak Flows Sourced from "UDSM East & West and Discovery Village North & South - Sewer Study Draft Technical Memorandum June 10, 2019 TOTAL AVG.
DRY WEATHER
FLOW (gpd)
PEAK DWF
FACTOR
Dexter Wilson Engineering, Inc.
IN-LINE
FLOW
PEAK DWF
(gpd)
PEAK
WWF
FACTOR
VELOCITY
(f.p.s.)
Exhibit A
DEPTH K'
(1)
LINE
SIZE
(inches)
EST.
SLOPE
(%)
C
a
for
Velocity
(3)
dn/D
(2)
REFER TO PLAN SHEET:
dn (feet)
SEWER STUDY SUMMARY
PEAK FLOW (DESIGN FLOW)
11/16/2021
JOB NUMBER:
PEAK WWF
(gpd)
University District Specific Plan Project 2021 Update City of San Marcos (Carmel Undercrossing)
COMMENTS
TO
FROM
1 K' based on n = 0.013
2 dn/D using K' in Brater King Table 7-14
3 From Brater King Table 7-4 based on dn/D
\\ARTIC\Eng\887004\2021-11-16 San Marcos University District 2021 Update Carmel Undercrossing.xlsx Full Layout
DATE:
FOR:
SHT
2 OF
3 BY:
M.G.D.
G.P.M.
C.F.S.
Summit Church, Cabinet (Durner), Quad
158
156
64,680
64,680
3.36 217,591
3.53 228,180
0.228
158
0.353
8 3.40
0.073391
0.18000
0.27 0.1711
4.64 Block J & K & PIMA
152
148
22,740
22,740
3.98 90,597
3.86 87,861
0.088
61 0.136
8 1.00
0.052107
0.15333
0.23 0.1365
2.24 50% of Block C
150
148
20,820
20,820
4.04 84,140
3.89 81,062
0.081
56 0.125
8 1.00
0.048075
0.14667
0.22 0.1281
2.20 Mesa Rim & Urge & 40% of Block F
160
156
22,320
22,320
4.00 89,193
3.87 86,378
0.086
60 0.134
8 1.00
0.051228
0.15333
0.23 0.1365
2.20 156
154
0 87,000
3.21 278,971
3.44 299,107
0.299
208
0.463
12 1.82
0.044598
0.21000
0.21 0.1199
3.86 50% of Block C & Block X
154
148
59,520
146,520
2.95 431,826
3.29 481,403
0.481
334
0.745
12 0.73
0.113338
0.34000
0.34 0.2355
3.16 50% of Block 2
148
146
40,260
230,340
2.74 630,945
3.16 727,592
0.728
505
1.126
12 1.00
0.146358
0.39000
0.39 0.2836
3.97 Block 1
146
144
6,360
236,700
2.73 645,516
3.15 745,912
0.746
518
1.154
15 0.80
0.092522
0.38750
0.31 0.2074
3.56 144
136
0 236,700
2.73 645,516
3.15 745,912
0.746
518
1.154
15 0.83
0.090834
0.38750
0.31 0.2074
3.56 50% of Block 2 & Block 3
142
140
56,460
56,460
3.44 194,161
3.57 201,551
0.202
140
0.312
8 1.00
0.119533
0.23333
0.35 0.2450
2.86 140
138
0 56,460
3.44 194,161
3.57 201,551
0.202
140
0.312
12 0.50
0.057336
0.24000
0.24 0.1449
2.15 138
136
0 56,460
3.44 194,161
3.57 201,551
0.202
140
0.312
12 0.50
0.057336
0.24000
0.24 0.1449
2.15 Shea/Lennar (PA 3 East), Levitt North & South
172
170
160,267
160,267
2.90 465,537
3.26 522,477
0.522
363
0.808
10 1.00
0.170901
0.35833
0.43 0.3229
3.61 170
108
0 160,267
2.90 465,537
3.26 522,477
0.522
363
0.808
8 1.00
0.309865
0.40000
0.60 0.4920
3.70 136
134
0 293,160
2.63 772,291
3.09 906,800
0.907
630
1.403
15 0.50
0.142275
0.48750
0.39 0.2836
3.17 Block 4
134
132
42,370
335,530
2.58 864,812
3.06 1,025,741
1.026
712
1.587
15 0.50
0.160936
0.51250
0.41 0.3032
3.35 132
108
0 335,530
2.58 864,812
3.06 1,025,741
1.026
712
1.587
15 0.50
0.160936
0.51250
0.41 0.3032
3.35 Ex. 2,090 gpm Peak Flow*
108
106
1,008,200
1,503,997
2.02 3,041,040
2.68 4,035,258
4.035
2802
6.244
21 0.30
0.333225
1.10250
0.63 0.5210
3.91 106
104
0 1,503,997
2.02 3,041,040
2.68 4,035,258
4.035
2802
6.244
21 2.50
0.115432
0.61250
0.35 0.2450
8.32 CA 78 Undercrossing
104
102
0 1,503,997
2.02 3,041,040
2.68 4,035,258
4.035
2802
6.244
21 0.50
0.258115
0.94500
0.54 0.4330
4.71 Proj. Flow:
495,797
* Ex. Peak Flows and Slopes Sourced from " Discovery Village West & Discovery Village East Water and Sewer Study Draft Technical Memorandum September 22, 2021 11/16/2021
JOB NUMBER:
Exhibit A
DEPTH K'
(1)
LINE
SIZE
(inches)
EST.
SLOPE
(%)
C
a
for
Velocity
(3)
dn/D
(2)
PEAK WWF
(gpd)
University District Specific Plan Project City of San Marcos (Twin Oaks Valley Road)
COMMENTS
TO
FROM
REFER TO PLAN SHEET:
TOTAL AVG.
DRY WEATHER
FLOW (gpd)
PEAK DWF
FACTOR
Dexter Wilson Engineering, Inc.
IN-LINE
FLOW
SEWER STUDY SUMMARY
PEAK DWF
(gpd)
PEAK
WWF
FACTOR
VELOCITY
(f.p.s.)
PEAK FLOW (DESIGN FLOW)
dn (feet)
1 K' based on n = 0.013
2 dn/D using K' in Brater King Table 7-14
3 From Brater King Table 7-4 based on dn/D
\\ARTIC\Eng\887004\2021-11-16 San Marcos University District 2021 Update Twin Oaks Valley Road.xlsx Full Layout
DATE:
FOR:
SHT
3 OF
3 BY:
M.G.D.
G.P.M.
C.F.S.
Shea/Lennar (PA-4)
212
210
18,081
18,081
4.13 74,758
3.94 71,267
0.071
49 0.110
10 0.50
0.032967
0.15833
0.19 0.1039
1.53 Shea/Lennar (PA-3 West)
210
208
18,081
36,162
3.70 133,654
3.71 134,193
0.134
93 0.208
10 0.50
0.062076
0.20833
0.25 0.1535
1.95 Shea/Lennar (PA-5, PA-6, and PA-7)
208
206
54,243
90,405
3.19 288,094
3.43 309,777
0.310
215
0.479
10 0.50
0.143298
0.32500
0.39 0.2836
2.43 Scripps & Park
206
204
41,350
131,755
3.00 395,041
3.32 436,910
0.437
303
0.676
10 0.50
0.202109
0.39167
0.47 0.3627
2.68 Connection to Ex. Sewer
204
202
0 131,755
3.00 395,041
3.32 436,910
0.437
303
0.676
12 0.50
0.124290
0.36000
0.36 0.2546
2.66 131,755
* 0.5% Min. Slope Sourced from " Discovery Village West & Discovery Village East Water and Sewer Study Draft Technical Memorandum September 22, 2021
PEAK DWF
(gpd)
PEAK
WWF
FACTOR
VELOCITY
(f.p.s.)
PEAK FLOW (DESIGN FLOW)
dn (feet)
TOTAL AVG.
DRY WEATHER
FLOW (gpd)
PEAK DWF
FACTOR
Dexter Wilson Engineering, Inc.
IN-LINE
FLOW
SEWER STUDY SUMMARY
11/16/2021
JOB NUMBER:
Exhibit A
DEPTH K'
(1)
LINE
SIZE
(inches)
EST.
SLOPE*
(%)
C
a
for
Velocity
(3)
dn/D
(2)
PEAK WWF
(gpd)
University District Specific Plan Project 2021 Update City of San Marcos (Discovery)
COMMENTS
TO
FROM
REFER TO PLAN SHEET:
1 K' based on n = 0.013
2 dn/D using K' in Brater King Table 7-14
3 From Brater King Table 7-4 based on dn/D
\\ARTIC\Eng\887004\2021-11-16 San Marcos University District 2021 Update Discovery Road West.xlsx Full Layout
APPENDIX D
VALLECITOS WATER DISTRICT
REFERENCE BACKGROUND SEWER STUDIES
EXHIBIT A
NODE AND PIPE DIAGRAM