HomeMy WebLinkAbout; 2003 CMWD Water Master Plan Update Part 1; 2003 CMWD Water Master Plan Update Part 1; 2003-03-01CARLSBAD MUNICIPAL WATER DISTRICT
WATER MASTER PLAN UPDATE
Prepared For:
City of Carlsbad
1635 Faraday Avenue
Carlsbad, California 92008
Prepared Bv:
DUDEK & ASSOCL\TES, INC.
605 Third Street
Encinitas, CA 92024
TEL (760) 942-5147
March 2003
ACKNOWLEDGMENTS
Dudek & Associates would like to express its sincere appreciation for the assistance and cooperation
provided by the management and staff of the City of Carlsbad during the completion and preparation of
this Master Plan Update. In particular, the efforts of the following individuals are acknowledged and
greatly appreciated:
Steven Jantz Project Manager/Associate Engineer
William Plummer Deputy City Engineer
Carrie Loya-Smalley Senior Civil Engineer
Kurt Musser Public Works Manager
Terry Smith Senior Civil Engineer
Pat Guevara Public Works Manager
Jim Ball Public Works Supervisor
Mark Biskup Associate Engineer
Casey Arndt Engineering Technician
Joe Adams Water System Operations
Pepper Godfrey Accounting Technician
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WATER MASTER PLAN UPDATE
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TABLE OF CONTENTS
Chapter Description Page
ACKNOWLEDGMENTS ii
TABLE OF CONTENTS iii
LIST OF TABLES v
LIST OF FIGURES vi
LIST OF APPENDICES vi
ANNOTATION vii
1 INTRODUCTION 1-1
1.1 BACKGROUND 1-1
1.2 SERVICE AREA OVERVIEW 1-1
1.3 PREVIOUS MASTER PLANS 1-2
1.4 2002 UPDATE SCOPE AND PURPOSE 1-2
2 EXECUTIVE SUMMARY 2-1
2.1 INTRODUCTION 2-1
2.2 EXISTING FACILITIES SUMMARY 2-1
2.3 EXISTING WATER DEMANDS 2-3
2.4 EXISTING SYSTEM EVALUATION 2-5
2.5 ULTIMATE DEMAND PROJECTIONS AND ANALYSIS 2-9
2.6 WATER QUALITY 2-14
2.7 SEAWATER DESALINATION 2-15
2.8 RECOMMENDED CAPITAL IMPROVEMENT PROGRAM 2-16
3 EXISTING SYSTEM DESCRIPTION 3-1
3.1 GENERAL 3-1
3.2 WATER SUPPLY 3-1
3.3 WATER DISTRIBUTION SYSTEM 3-2
3.4 INTER-TIE CONNECTIONS WITH OTHER AGENCIES 3-9
3.5 DAILY OPERATIONS 3-9
3.6 EMERGENCY SUPPLY OPERATIONS 3-11
3.7 WELL WATER AND SURFACE WATER SUPPLIES 3-11
3.8 WATER QUALITY 3-12
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WATER MASTER PLAN UPDATE ii March 2003
EXISTING WATER DEMANDS 4-1
4.1 HISTORICAL WATER CONSUMPTION 4-1
4.2 EXISTING WATER CONSUMPTION 4-2
4.3 DEMANDS PER PRES SURE ZONE 4-4
4.4 EXISTING SYSTEM PEAKING 4-6
4.5 EXISTING UNIT DEMANDS 4-11
EXISTING SYSTEM EVALUATION 5-1
5.1 DESIGN CRITERIA 5-1
5.2 HYDRAULIC MODEL DEVELOPMENT 5-5
5.3 MAXIMUM DAY DEMAND 24-HOUR SIMULATION 5-7
5.4 FIRE FLOW ANALYSIS 5-9
5.5 STORAGE ANALYSIS 5-11
ULTIMATE DEMAND PROJECTIONS AND ANALYSIS 6-1
6.1 CARLSBAD GROWTH DATABASE 6-1
6.2 GROWTH DATABASE UNIT WATER DEMANDS 6-3
6.3 ULTIMATE DEMAND PROJECTIONS 6-3
6.4 HYDRAULIC MODEL DEVELOPMENT 6-8
6.5 HYDRAULIC ANALYSIS RESULTS 6-11
6.6 STORAGE ANALYSIS 6-13
6.7 ULTIMATE SYSTEM OPERATIONS 6-15
6.8 SEAWATER DESALINATION 6-19
RECOMMENDED CAPITAL IMPROVEMENT PROGRAM 7-1
7.1 RECOMMENDED IMPROVEMENT PROJECTS 7-1
7.2 BASIS OF CONSTRUCTION COSTS 7-4
7.3 PHASED CAPITAL IMPROVEMENT PROGRAM 7-4
CONNECTION FEE UPDATE 8-1
8.1 BACKGROUND 8-1
8.2 GROWTH PROJECTIONS 8-2
8.3 WATER METER EDU CONVERSIONS 8-3
8.4 PROJECTED WATER METER EDUS 8-4
8.5 CAPITAL COSTS 8-5
8.6 CONNECTION FEE CALCULATIONS 8-5
8.7 WATER SYSTEM CASH FLOW ANALYSIS 8-7
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WATER MASTER PLAN UPDATE iii March 2003
LIST OF TABLES
Table 2-1 Summary of 2001 System Demands 2-4
Table 2-2 CMWD Planning and Performance Criteria Summary 2-5
Table 2-3 Existing Daily Storage Requirements 2-8
Table 2-4 City of Carlsbad Growth Database Summary 2-9
Table 2-5 Unit Demands for Ultimate Projections 2-10
Table 2-6 Summary of Proj ected Ultimate Demands 2-10
Table 2-7 SDCWA Max Day Supply in the Ultimate System Model 2-12
Table 2-8 Ultimate Daily Storage Requirements 2-14
Table 2-9 CMWD Recommended Capital Improvement Program *2-16
Table 3-1 SDCWA Aqueduct Connections 3-2
Table 3-2 Hydraulic Model Pipeline Summary 3-3
Table 3-3 Existing Reservoir Summary 3-5
Table 3-4 Pump Station Summary 3-6
Table 3-5 Control Valve Summary 3-7
Table 3-6 Other Agency Inter-ties 3-9
Table 4-1 Water Demand Categories 4-3
Table 4-2 2001 Water Demand by Categoiy 4-3
Table 4-3 Average Day Demand by Pressure Zone 4-5
Table 4-4 Summary of 2001 System Demands 4-6
Table 4-5 Historical Maximum Day Water Purchases 4-8
Table 4-6 Summary of Faraday Industrial Park Demand Analysis 4-14
Table 5-1 CMWD Planning and Performance Criteria 5-2
Table 5-2 Inflow for the Maximum Demand Day Simulation 5-8
Table 5-3 Nodes with Reduced Fire Flow Capacities 5-3
Table 5-4 Existing Daily Storage Requirements 5-11
Table 6-1 City of Carlsbad Growth Database Summary 6-2
Table 6-2 Unit Demands for Ultimate Projections 6-3
Table 6-3 Summary of Projected Ultimate Demands 6-4
Table 6-4 Future Phase II Recycled Water Demands in the Potable Water Service Area 6-7
Table 6-5 Existing and Ultimate Demands by Pressure Zone 6-9
Table 6-6 Existing Irrigation Demands Identified as Phase II Recycled Customers 6-10
Table 6-7 SDCWA Max Day Supply in the Ultimate System Model 6-12
Table 6-8 Ultimate Daily Storage Requirements 6-14
Table 7-1 CMWD Recommended Capital Improvement Program *7-4
Table 8-1 CMWD Existing Connection Fees 8-2
Table 8-2 Analysis Summary of Existing Commercial Meters 8-4
Table 8-3 Future Potable Water Meter EDUs 8-5
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Table 8-4 Capital Improvement Projects for the Water Cormection Fee Update 8-6
Table 8-5 Water Coimection Fee Calculation 8-7
Table 8-6 Updated Connection Fees 8-7
Table 8-7 Water Connection Fee Cash Flow Analysis 8-8
* Follows this page number.
LIST OF FIGURES
Figure 1 -1 CMWD Service Area * 1 -1
Figure 2-1 Existing Water System Schematic *2-l
Figure 2-2 CMWD Historical Demand Based on SDCWA Purchases 2-3
Figure 2-3 2001 Water Demand by Category 2-4
Figure 2-4 Maximum Day Demand Peaking Factor Curve 2-7
Figure 2-5 Historical Demands and Ultimate Demand Proj ections 2-11
Figure 2-6 Projected Ultimate Demands by Category 2-11
Figure 2-7 CMWD Ultimate System Hydraulic Profile *2-12
Figure 3-1 Existing System Hydraulic Profile *3-2
Figure 3-2 Pressure Zone Service Areas *3-3
Figure 3-3 San Luis Rey Groundwater Wells ^3-11
Figure 4-1 CMWD Historical Water Demand 4-2
Figure 4-2 2001 Water Demand by Category 4-4
Figure 4-3 CMWD Seasonal Demand Variations 4-7
Figure 4-4 Reservoir Levels and Diurnal Demand Curve for July 27, 2001 4-9
Figure 4-5 Reservoir Levels and Diurnal Demand Curve for August 3,2001 4-10
Figure 4-6 Demand Distribution for Singe Family Residential Accounts 4-12
Figure 4-7 Faraday Business Park 2001 -2002 Monthly Water Consumption 4-14
Figure 5-1 Existing System Hydraulic Model *5-5
Figure 5-2 Maximum Day Demand Peaking Factor Curve 5-7
Figure 6-1 City of Carlsbad Local Facility Management Zones 6-1
Figure 6-2 Historical Demands and Ultimate Demand Projections 6-5
Figure 6-3 Projected Ultimate Demands by User Category 6-5
Figure 6-4 Ultimate System Hydraulic Profile *6-8
Figure 6-5 Ultimate System Hydraulic Model *6-8
Figure 6-6 Reservoir Water Levels from the Maximum Day Demand Simulation 6-12
* Follows this page number
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WATER MASTER PLAN UPDATE V March 2003
LIST OF APPENDICES
Appendix A - Exhibits:
Exhibit 1 - Existing Distribution System (pipelines color-coded by zone)
Exhibit 2 - Proposed Ultimate Distribution System (pipelines color-coded by zone)
Exhibit 3 - Recommended CIP
Appendix B - Existing and Ultimate System Model and Analysis Results (on CD ROM)
ANNOTATION
The following abbreviations and acronyms were used in the preparation of this Master Plan:
ACP asbestos concrete pipe
ADD average day demand
AF Acre-feet
APN assessor parcel number
CCI construction cost index
cfs cubic feet per second
CIP capital improvement program
CMLC Concrete mortar lined and coated
CMWD Carlsbad Municipal Water District
CWA County Water Authority [San Diego]
DBP disinfection by-products
diam. Diameter
DIP ductile iron pipe
DOHS Department of Health Services [Califomia]
EDU equivalent dwelling unit
EIR Environmental Impact Report
FCV Flow control valve
fjps feet per second
GIS Geographical Infonnation System
gpd gallons per day
gpm gallons per minute
HCF htindred cubic feet
HGL hydraulic grade line
Hp Horsepower
hr Hour
HWL high water level
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If linear feet
LFMZ Local Facility Management Zone
in Inches
MCL Maximum contaminant level
MDD maximum day demand
MFDU multi-family dwelling unit
MG million gallons
mgd million gallons per day
MRDL Maximum residual disinfectant level
OMWD Olivenhain Municipal Water District
PF peaking factor
PRS Pressure reducing station
PRV pressure reducing valve
psi pounds per square inch
PSV pressure sustaining valve
SanGIS San Diego County Geographic Information System
SDCWA San Diego County Water Authority
SDWD San Dieguito Water District
SFDU single family dwelling unit
sqft square feet
TAP Tri-Agency Pipeline
TTHM total trihalomethanes
USGS United States Geologic Survey
VCP vitrified clay pipe
VFD variable frequency drive
VID Vista Irrigation District
VWD Vallecitos Water District
WRP Water Reclamation Plant
yr Year
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WATER MASTER PLAN UPDATE VII
Dudek & Associates, Inc.
March 2003
CHAPTER 1
INTRODUCTION
This Water Master Plan Update for the Carlsbad Municipal Water District (CMWD) evaluates the
existing water distribution system and its ability to meet projected demands. The most recent update to
the Water Master Plan was performed in 1997. Since the last Master Plan Update, a significant number of
residential, commercial and industrial developments have been constructed and future development has
been identified in the City's 2001 Growth Database. This current Master Plan presents an update ofthe
District's Water Master Plan for fhe planning period between 2001 and build-out ofthe District's service
area, which is anticipated to occur by 2020.
1.1 BACKGROUND
The first water supply to the Carlsbad area was obtained from the San Luis Rey River, in the City of
Oceanside. Wells were drilled in 1886 by the Carlsbad Land and Water Company, and a pipeline was
constmcted to transport the groundwater to Carlsbad. The wells continued to be the only supply for many
years. By the 1930's, summer demands exceeded the capacity of the wells. Lake Calavera was
constructed in 1936 to store excess well water in the winter for later use in the summer months.
However, the quantity and quality of the ground water gradually degraded, resulting in the need for a new
supply source to meet the area's growing water demand.
The Carlsbad Mimicipal Water District (CMWD) was formed in 1954 to bring imported Colorado River
water into the area. In 1990, the CMWD became a subsidiary district ofthe City of Carlsbad, with the
Mayor and City Coimcil acting as the CMWD's board. Operating under the Municipal Water District Act
of 1911, the CMWD supplies both potable and recycled water. The CMWD currently purchases 100% of
its water for the potable water system as treated water from the San Diego County Water Authority
(CWA). Water is supplied through the San Diego County Water Authority (SDCWA) aqueduct and the
Tri-Agency Pipeline (TAP). The population currently served is estimated at approximately 72,000.
1.2 SERVICE AREA OVERVIEW
The CMWD water service area covers approximately 85 percent of the City of Carlsbad and includes an
area of about 32 square miles. Water service to the southeast comer of the City is provided by the
Olivenhain Municipal Water District (OMWD). The Vallecitos Water District (VWD) provides service
to the Meadowlark area along the eastem City limit. The CMWD service area boundary and adjacent
district boundaries are shown on Figure 1-1.
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WATER MASTER PLAN UPDATE 1 -1 March 2003
LEGEND
CITY OF CARLSBAD BOUNDARY
CARLSBAD MUNICIPAL
WATER DISTRICT BOUNDARY
FIGURE 1-1
CARLSBAD MUNICIPAL WATER DISTRICT
WATER SERVICE AREA
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02-2003 Cartsbadwa11.mxd
The elevation of the CMWD service area varies from just under 700 feet at the eastem boundary to sea
level along the coast and lagoon shores. Water is supplied from four CWA aqueduct connections and
transported in separate fransmission mains to four locations along the eastem City boundary. Within the
CMWD service area, water is generally suppHed by gravity from east to west. The service area is
comprised of seventeen pressure zones, which extend from approximately the eastem service area
boundary and decrease in pressure west to the coast.
1.3 PREVIOUS MASTER PLANS
A summary ofthe two most recent Water Master Plans is provided in the sub-sections below.
1.3.1 1990 Water Master Plan
The 1990 Water Master Plan was prepared by MacDonald-Stephens Engineers, Inc. and adopted by the
Carlsbad City Council on January 29, 1991. In 1990, the existing average day demand was 14.6 MGD.
Flow projections were made based on the City of Carlsbad 1988 General Plan, and the ultimate average
day demand was projected to be 24.5 MGD. Reservoir "daily" and "emergency" storage criteria were
established in this Master Plan.
1.3.2 1997 Water Master Plan Update
The 1997 Water Master Plan Update was prepared by ASL Consulting Engineers and submitted as
Volume ni of the overall 1997 Master Plan Update. The purpose of this update was to incorporate
revised population projections to build-out ofthe City based on the 1994 General Plan and specific
project development plans. The 1997 Master Plan Update also incorporated a decrease in the average per
capita water consumption of approximately 15 percent from the last Master Plan, and the installation of
the 8.5MG Twin "D" reservoir. The ultimate average day demand was projected to be 25.4 MGD, which
included 1.34 MGD (1,500 AF per year) of recycled water demands.
As part of the 1997 Master Plan Update, a separate investigation was made into using potential local
water resources, in addition to imported water, to increase the reliability ofthe water supply. The results
of this study were submitted as Volume II, Water Resources Potential. In 2000, an update was made to
the 1997 Master Plan water hydraulic model to reflect additions to the water distribution system.
1.4 2003 UPDATE SCOPE AND PURPOSE
Since the last Master Plan Update a significant number of residential, commercial and industrial
developments have been both constmcted and planned for fiiture constmction. The Carlsbad Mimicipal
Water Disttict, in its Notice to Proceed dated December 24, 2001, retained Dudek & Associates, Inc. to
provide engineering services necessary to analyze and evaluate existing and future requirements for
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WATER MASTER PLAN UPDATE 1-2 March 2003
continued reliable potable water service. The purpose of the Master Plan Update is to confirm
transmission main sizing, identify deficiencies in the system, and identify future capital improvement
projects based on updated ultimate demand projections.
In summary, the scope of work includes tasks to document and analyze existing facilities, develop unit
water demands and peaking factors, project ultimate water demands, and recommend facility and
operational improvements based on hydraulic analyses results. In this Master Plan Update ultimate water
demand projections are based on planned developments included in the City's recently compiled 2001
Growth Database. The Growth Database projects the number of additional single and multi-family units
and the number and size of non-residential buildings at buildout. At the direction of City staff, projected
Phase II recycled water demands are included in the ultimate potable water demand projections. To
analyze the water distribution system, the City's 2001 H2ONET computer model was updated and
enhanced to perform hydraulic analyses on the existing and ultimate water systems. The outcome of the
analyses is a recommended long-term capital improvement program (CIP) that will provide a water
distribution system capable of supplying the CMWD at build-out conditions.
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CHAPTER 2
EXECUTIVE SUMMARY
The Carlsbad Municipal Water Disfrict (CMWD) Water Master Plan Update documents the existing
water system facilities and demands, and identifies required improvements for build-out of the District's
service area, which is anticipated to occur by 2020. The water system analyses conducted as a part ofthis
project and documented in this report were performed to identify existing deficiencies in the system,
confirm facility sizing, and recommend a future capital improvement program (CIP) based on updated
ultimate demand projections.
2.1 INTRODUCTION
This Water Master Plan Update for the Carlsbad Municipal Water District (CMWD) evaluates the
existing water distribution system and its abiUty to meet projected demands. The CMWD water service
area covers approximately 85 percent of the City of Carlsbad and includes an area of about 32 square
miles. Water service to the southeast comer of the City is provided by the Olivenhain Municipal Water
Disfrict (OMWD). The Vallecitos Water Disttict (VWD) provides service to the Meadowlark area along
the eastem City limit.
The most recent update to the Water Master Plan was performed in 1997. Since that time, a significant
number of residential, commercial and industrial developments have been both constmcted and planned
for future constmction. In this current Water Master Plan Update, ultimate water demand projections are
based on planned developments included in the City's recently compiled 2001 Growth Database. The
Growth Database projects the number of additional single and multi-family units and the number and size
of non-residential buildings at buildout. At the direction of City staff, irrigation demands are included in
the ultimate potable water system under the conservative assumption that the planned Phase II Recycled
Water System is not constmcted.
2.2 EXISTING FACILITIES SUMMARY
For purposes of this Master Plan Update, the existing water system consists of facilities that were
operational as of December 2001. The facilities comprising the existing CMWD distribution system
include San Diego County Water Authority (SDCWA) tumouts, fransmission mains, distribution
pipelines, pressure reducing stations, storage reservofrs, pump stations, and inter-ties with adjacent water
agencies. The existing water distribution system is shown schematically on Figure 2-1 and illusttated on
the color wall map provided as Exhibit 1 in Appendix A.
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The CMWD imports water tiirough the SDCWA for their potable water needs. Water is suppUed to the
CMWD through four separate SDCWA freated water tumouts. Two of the tumouts, CWA No. 1 and
CWA No. 2, are dfrect connections to the SDCWA Second Aqueduct. CWA No. 1 supplies only the
CMWD, and CWA No. 2 supplies the Vallecitos Water Distiict (VWD) and the OUvenhain Municipal
Water Disttict (OMWD) in addition to the CMWD. Water supply to the CMWD from CWA No. 2 is
delivered through a VWD fransmission main. Connections No. 3 and No. 4 to the aqueduct system are on
the SDCWA owned and operated Tri-Agency Pipeline (TAP), which is also supplied from the SDCWA
Second Aqueduct. The TAP also serves the City of Oceanside and the Vista Irrigation District (VED).
The existing distribution system consists of 17 major pressure zones, which are suppHed by gravity from
over 50 pressure regulating stations. There are three pump stations within tiie disfribution system that are
used for emergency purposes only. The CMWD water distribution system is flexible in that supply from
the four aqueduct connections can be routed to different parts of the distribution system by making
changes to several key valve settings. This allows system operators to balance reservoir levels and
correct for discrepancies in the amount of water ordered versus the amount that is delivered through
service connections.
Water storage for tiie CMWD is provided by Maerkle Dam and 12 additional reservoirs within the
distribution system. Maerkle Dam is the major freated water storage facility for the CMWD, with a
capacity of approximately 600 acre-feet (195 MG). This reservofr is used to meet the City's requirement
to provide a minimum of ten days of emergency drinking water storage. Under normal operations, water
is supplied to Maerkle Dam from the SDCWA TAP No. 3 connection and then pumped into the adjacent
Maerkle Reservoir. From Maerkle Reservoir water is suppUed by gravity to the distribution system.
Currently the high pressure zones in the southeast portion ofthe service area (700, 680, 580S and 510)
cannot be suppHed with emergency water from the dam.
Water storage for fire flow and daily water operations is provided by eleven reservoirs (enclosed storage
tanks) within the disttibution system. The existing operational storage capacity is 51.5 MG, excluding
Maerkle Dam. Table 3-3 provides a summary ofthe storage facilities, including a small reservoir used as
a forebay for the Buena Vista Pump Station. All water storage is above ground except for the Maerkle
Dam and Maerkle Reservoir. The disfribution system reservofrs have been designed to be exfremely
flexible in thefr ability to ttansfer water throughout the District.
During planned shutdovras of the SDCWA aqueduct, which are normally scheduled for up to 10 days
during the winter, most of the CMWD is supphed from Maerkle Dam through the 490 Zone Maerkle
Reservofr. The 700, 680, 5 SON and 510 Zones are currently suppUed from the 700 Zone reservofrs (Santa
Fe II and La Costa Hi) and an inter-tie with the VID. A potable pump must be installed at the
VID/CMWD inter-tie to boost pressures to the CMWD 700 Zone.
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2.3 EXISTING WATER DEMANDS
As population expands and the northem coastal areas of San Diego County continue to develop, the
CMWD has experienced gradually increasing water demands. Historical water consumption over the past
ten years based on SDCWA water purchase records and the gain/loss of stored water in Maerkle Dam is
graphically illustrated on Figure 2-2. CMWD monthly water billing records for 2001 were obtained and
analyzed to establish the existing water demands and distribute water demands in the distribution system
hydraulic model. The total average rate of water supplied for 2001 based on CMWD billing records is
16.2 MGD and the average rate purchased is 16.8 MGD. The amount of water billed does not match the
volume of water purchased due to "unaccounted for" water. In most water distribution systems, the bulk
of "unaccounted for" water is due to system leakage, meter inaccuracies, and unmetered water
consumption from fire fighting, street cleaning, and construction uses. Water loss in the CMWD over the
past ten years has typically been between two and five percent.
Figure 2-2
CMWD HISTORICAL DEMAND BASED ON SDCWA PURCHASES
>-c/5
1 991 1 992 1 993 1 994 1 995 1 996 1 997 1 998 1 999 2000 2001 2002
[MAverage Day Demand MMax Day Demand (x.x) Max Day/ADD Peaking Factor |
The percentage of the total system demand based on water use categories is illustrated on Figure 2-3.
Residential water use accounts for 54 percent of the total water demand. Commercial/Industrial water use
and irrigation demands make up 17 and 23 percent, respectively, of the total water demand. It is noted
that the irrigation demands do not include users supplied from the CMWD Recycled Water System, as
recycled water users are identified with separate recycled water account types. However, supplemental
potable water is supplied to the recycled water system during peak demand periods at the "D" Tanks.
Agricultural water demands currently account for approximately five percent of the total water use.
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Figure 2-3
2001 WATER DEMAND BY CATEGORY
Single-Family
Residential
44%
Multi-Family
Residential
10%
Commercial/
Industrial
17%
Temporary
1%
Irrigation
23%
Agriculture
5%
Water demands are typically presented in terms of the average annual water consumption. Actual water
use, however, follows a widely varying pattem in which flows are sometimes well below or far greater
than "average". Flow variations are commonly expressed in terms of peaking factors, which are
multipliers to express the magnitude of variation from the average day demand (ADD). Peaking factors
are commonly used to express the system maximum and minimum month demand, the maximum day
demand (MDD), and the peak hour demand. The 2001 system demands are summarized in Table 2-1 and
described in detail in the following sub-sections.
Table 2-1
SUMMARY OF 2001 SYSTEM DEMANDS
Average Day 16.2 MGD 25.1 CFS
Minimum Month 8.0 MGD 12.4 CFS
Maximum Month 23.0 MGD 35.6 CFS
Maximum Day 26.5 MGD 41.0 CFS
Peak Hour 46.6 MGD 72.1 CFS
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2.4 EXISTING SYSTEM EVALUATION
HydrauUc computer simulations were performed to evaluate the existing water distribution system based
on comparisons with estabUshed and verified planning criteria. The hydrauUc analysis employs the use of
the HoONet® hydrauUc modeling software. The planning criteria, analysis methodology, hydrauUc
computer model and results of the hydraulic system analyses used in the evaluation of the water
distribution system relative to 2001 conditions are summarized in the sub-sections below.
2.4.1 Planning Criteria
The planning criteria for the evaluation of potable water facilities in the CMWD are based on existing
system performance characteristics, past criteria used by the Disfrict and current industry and area
standards. Planning criteria include standards for demand peaking factors, pressure zones, pipelines, fire
flows, and storage reservofrs. A summary of criteria that impact the design of water facilities is provided
in Table 2-2. These criteria are the basis for evaluating water system performance and determining
faciUties requfred to serve fiiture development.
Table 2-2
CMWD PLANNING AND PERFORMANCE CRITERIA SUMMARY
WATER DEMAND
PEAKING FACTORS
0.5 X ADD - Minimum Month Demand
1.5 X ADD - Maximum Month Demand
1.65 x ADD - Maximum Day Demand
2.9 x ADD - Peak Hour Demand
SYSTEM
PRESSURES
Static Pressures (based on the reservoir HWL):
60 psi - minimum desired
125 psi - maximum desired
150 psi - maximum allowed
Dynamic Pressures (with reservoir levels half fall):
40 psi - minimum allowable pressure during peak hour demands
20 psi - minimum allowable pressure for fire flows
25 psi —maximum desired pressure drop from static pressures
PIPELINES
8 fys - maximum allowable velocity at peak hour flow
5 ft./1000 ft - maximum desirable head loss at peak flow
10 ft./lOOO fl - maximum allowable head loss at peak flow
Dead-end water lines are to serve no more than 18 residences
FIRE FLOWS
Single-Family residential - 1,500 gpm for 2 hours
Multi-Family residential - 3,000 gpm for 2 hours
Industrial/Commercial/Institutional - 4,000 gpm for 4 hours
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WATER MASTER PLAN UPDATE 2-5
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March 2003
Table 2-2 (continued)
DAILY
STORAGE
Storage capacity in the distribution system equal to the total of the following based on
the reservoir service area:
Operational - 15% of Maximum Day Demand
Reserve - 100% of the Maximum May Demand
Fire Flow - Maximum fire flow for the required duration
EMERGENCY
STORAGE
10 days of storage based on the ADD
Emergency storage is contained in the Maerkle Dam
2.4.2 Hydraulic Model Development
Analysis ofthe water disttibution system is performed using the H2ONET® modeling, analysis and design
software developed by MWH Soft, Inc. H2ONET® provides a computer aided design (CAD) interface for
building and editing model facilities, and a hydrauUc analysis engine to perform extended period
simulations. An H2ONET® hydraulic computer model was developed for the CMWD in 1997 as part of
the 1997 Water Master Plan Update. This model was calibrated to 1997 conditions. In 1999, the model
was updated with pipeUnes for developments between 1997 and 1999. For this current Master Plan
Update, the 1999 model has been updated and enhanced to represent the 2001 water disfribution system.
New demands were input to the existmg system model based on 2001 water billing records. The process
of importing the billing data was performed using GIS techniques.
2.43 Maximum Day Demand 24-Hour Simulation
To assess performance of the existing disttibution system, system demands corresponding to a maximum
demand day were developed and input to the existing system model. The representative 24-hour
maximum day peaking curve for the CMWD, based on the flow analysis of two high demand days in
2001, is shown on Figure 2-4. Based on this representative curve and an existing system ADD of 16.2
MGD, the maximum day 24-hour demand analyzed is 26.7 MGD, and the peak hour demand is 47.0
MGD.
An extended period simulation was run to assess overall system performance and reservoir operations (the
ability to supply peak flows and refill after draining). Several simulation iterations were requfred to
properly adjust the SDCWA inflows and distribution system valves with variable settings. After the final
flow adjustments were made, reservoir levels were maintained between 25-75 percent fuU during the 24-
hour simulation with maximmn day demands.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 2-6 March 2003
Figure 2-4
MAXIMUM DAY DEMAND PEAKING FACTOR CURVE
0.0
m id nig hi 3:00 6:00 9:00 Noon 15:00
Time of Day
1 8:00 2 1 :00 m id n ig h t
Results of the 24-hour simulation were reviewed and analyzed. Low pressures were observed in the 680
Zone on Obelisco Court and near the 330 Zone in the vicinity of the Elm Reservoir. The low pressures
are a result of high elevations, and are not due to undersized facilities. High pressures were observed in
the 490 Zone transmission main in El Camino Real near Jackspar (175-185psi) and along an 8-inch
diameter pipeline in Paseo Cerro (140-160psi), located between Melrose Drive and the CMWD boundary
in the 700N Zone. In summary, analysis results indicate that the existing distribution system has adequate
capacity to supply peak summer demands. In the model simulation, flows entering the system and flow
adjustments to reservoirs were balanced by trial-and-error. In actual operations the flow entering the
system does not typically match the demand, and several flow adjustments are usually required by system
operators to balance reservoir levels.
2.4.4 Fire Flow Analysis
A fire flow analysis was performed on the existing system hydraulic model to determine the fire flow
capacity at each demand node. The fire flow simulation was mn with maximum day demands (ADD x
1.65) and the water level at reservoirs set to half full. The available fire flow was compared to the
required fire flow based on the meter account type (1,500 gpm for single-family, 3,000 gpm for multi-
family, or 4,000 gpm for commercial/industrial). Analysis results indicated that seven nodes could not
provide a residential fire flow of 1,500 gpm at a minimum pressure of 20 psi. Four nodes could not
provide the required multi-family fire flow of 3,000 gpm, and three demand nodes could not provide a
commercial/industrial fire flow of 4,000 gpm with a minimum 20 psi residual pressure. Pipeline
improvements will be required to deliver the required fire flow at these locations.
CMWD
WATER MASTER PLAN UPDATE 2-7
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March 2003
2.4.5 Storage Analysis
The requfred storage volume based on the criteria defined in Table 2-2 and 2001 demands was calculated
and compared to the capacity of the existing system reservoirs. Calculations to determine the required
daily storage volume are shown in Table 2-3. Based on these calculations, there is approximately 12.5
milUon gallons (MG) of excess storage capacity in the existing system. However, on a zone-by-zone
basis the 318 and 255 Zones are currently deficient in storage.
Table 2-3
EXISTING DAILY STORAGE REQUIREMENTS
RESERVOIR Service
Zones;
Existinq Demand sraae Reai jire ments Reservoir
Capacity
Surplus/
Deficit RESERVOIR Service
Zones;
ADD
(MGD)
IKDD
(MGD)
Operational
(15xMDD»
Fire Reserve
(1 MDD) Total
Reservoir
Capacity
Surplus/
Deficit
La Costa
High
700S
680
5808
510
0.04
0.41
0.07
0.20
0.07
0.68
0.12
0.33
0.2 MG 0.96 MG 1.2 MG 2.3 MG 6.0 MG 3.7 MG
Santa Fe II
700N
550
430
0.72
2.47
0.17
1.19
4.08
0.28
0.8 MG 0.96 MG 5.5 MG 7.3 MG 9.0 MG 1.7 MG
Maerkle Res.
490
285
198
0.02
0.16
0.08
0.03
0.26
0.14
0.1 MG 0.96 MG 0.4 MG 1.5 MG 10.0 MG 8.5 MG
TAP
580<^'
446
349
0.41
1.65
0.08
0.68
2.72
0.13
0.5 MG 0.96 MG 3.5 MG 5.0 MG 6.0 MG 2.5 MG
D3 375 1.91 3.15 0.5 MG 1.92 MG 3.2 MG 5.5 MG 8.5 MG 3.0 MG
La Costa Lo 318 3.00 4.95 0.7 MG 0.96 MG 5.0 MG 6.7 MG 1.5 MG -5.2 MG
Ellery 330 1.15 1.90 0.3 MG 0.96 MG 1.9 MG 3.1 MG 5.0 MG 1.9 MG
Elm
Skyline
"E" Res.
255 3.70 6.11 0.9 MG 0.96 MG 6.1 MG 8.0 MG 4.5 MG -3.5 MG
TOTALS 16.2 26.8 4.0 MG 8.6 MG 26.8 MG 39.5 MG 50.5 MG 12.5 MG
(1) Equal to the volume of water based on the largest fire flow within the tank service area (flow rate times duration). For
large service areas, the fire flow storage was increased based on the potential for multiple fires.
(2) The 580 Zone has no available storage but can be supplied from the TAP Res. through the Calavera Pump Station.
The CMWD emergency storage policy is to provide 10 days of average water use. Based on the existing
ADD of 16.2 MGD, the required storaege volume is 162 MG. Maerkel Dam, which has a storage
capacity of 195 MG, currently provides the requfred storage volume for the District.
CMWD
WATER MASTER PLAN UPDATE 2-8
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March 2003
2.5 ULTIMATE DEMAND PROJECTIONS AND ANALYSIS
The CMWD ultimate demand is projected based on existing demands, future water demands calculated
from the Growth Database, and future irrigation demands obtained from recycled water projections. A
hydrauUc analysis is performed with projected ultimate maximum day demands to verify and size the
future facilities, and to identify any additional faciUties required to serve the CMWD at buildout.
2.5.1 Carlsbad Growth Database
Build-out projections for the City of Carlsbad have been recently updated and compiled into a Growth
Database, which is maintained by the City. Most of the projected growth in the CMWD is associated
with known, plaimed developments in the eastem portion ofthe City. The remainder of the fiiture growth
in the City of Carlsbad includes smaller developments and "infill" of established neighborhoods and
commercial areas, generally located in the westem portions of the City. The growth potential data in the
Carlsbad Growth Database used for this Master Plan Update is summarized by Local Facility
Management Zone (LFMZ) in Table 2-4.
Table 2-4
CITY OF CARLSBAD GROWTH DATABASE SUMMARY
LFMZ
Nff.
No. of R BB. Units Non-Residential Comments LFMZ
Nff. SFDU MFOU
Non-Residential Comments
1 430 0 0 Downtown area; Unit counts from 5/15/02 LFMZ 1 update
2 25 146 39,656 3 second dwelling units counted as MFU
3 13 0 193,251
4 0 0 50,000
5 0 0 4,137,974 Includes Faraday Business Park and airport
6 185 c 89.988 Futeire church assumed at 9>100 sqfl(25% coverage)
7 345 436 32,670 Calavera unit counts from 7/15/02 update; Future elem.school
8 186 544 6,000 Kelly Ranch
9 41 0 428,100
10 750 320 0 Villages of La Costa; Future elementary school
11 1,266 275 622,972 Villages of La Costa
12 55 0 -20,000 Futurs church assumed Bt 20,000 sqft
13 0 18 1,482,142 24 room hotel expansion assumed at 1 hotel unit =.75 MFDU
14 711 411 229,166 Unit counts from Robertson Ranch update; Future High School
15 807 158 303,798 Sycamore Creek; 8 second dwelling units counted as MFDU
16 0 0 1,921,000 Carlsbad Oaks North BP; Building area from 8/01/02 update
17 523 100 2,511,000 Bressi Ranch; 40,000 sqft for private school & daycare/church
18 308 0 2,262,817 140 condos counted as SFDU
19 218 78 69,520 61 condos counted as SFU; 78 timeshares counted as MFDU
20 687 24 73,450
21 185 210 0
22 168 286 53.280 149 condos counted as SFU
23 0 264 507,000 Includes assisted living project (non-res & MFOUs)
24 32 0 0
25 130 0 0
Totals 7,065 3,270 15,033,784
Note: shaded rows Indicate LFMZs with parcels outside ofthe CMWD
CMWD
WATER MASTER PLAN UPDATE 2-9
Dudek & Associates, inc.
March 2003
The unit demands developed to project ultimate water demands from buildout data in the Growth
Database are Usted in Table 2-5. These water demands were reviewed and approved by CMWD Staff.
Table 2-5
UNIT DEMANDS FOR ULTIMATE PROJECTIONS
LAND USE TYPE PROJECTED WATER
USE FACTOR DEVELOPMENT UNIT
Single-Family
Residential 550 gallons per day per dwelling unit
Multi-Family
Residential 250 gallons per day per dwelling unit
Non-Residential 2,300 gallons per day per 10,000 square feet of
building area
2.5.2 Ultimate Demand Projections
Ultimate demand projections are based on build-out conditions for the CMWD, which is projected to
occur by the year 2020. The CMWD is surrounded by four neighboring disfricts, and there is no
expectation of altering the current district boundary in the future The projected ultimate demand under
various peaking conditions is Usted in Table 2-6.
Table 2-6
SUMMARY OF PROJECTED ULTIMATE DEMANDS
Average Day 23.9 MGD 37.0 CFS
Minimum Monib 12.0 MGD 18.5 CFS
Maximum Month 35.9 MGD 55.5 CFS
Maximum Day 39.4 MGD 61.0 CFS
Peak Hour 69.3 MGD 107.2 CFS
The scope ofwork for this Master Flan Update states that "ultimate demand projections are to be based on
the assumption that the plaimed Phase II expansion of the CMWD Recycled Water System is not
constmcted". To estimate ultimate demands, demand projections for future development identified in the
Growth Database and irrigation demands identified from the 1999 Recycled Water Master Plan are added
to existing system demands. The projected ultimate demand is illusfrated together with historical
demands on Figure 2-5. An estimate ofthe ultimate water use by category is provided in Figure 2-6.
CMWD
WATER MASTER PLAN UPDATE 2-10
Dudek & Associates, Inc.
March 2003
Figure 2-5
HISTORICAL DEMANDS AND ULTIMATE DEMAND PROJECTIONS
26
24
22
20 -T3 C
(T3
E
0)
o
™ 18
3 C
C <
14
12
10
23.9
Pfojected^emands
without operation of Phase II
Recycled water system
21.2
Projected demands
assuming operation of Phase II
Recycled water system
Historical water
consumption based on CWA
deliveries
1990 1995 2000 2005 2010 2015 2020
Figure 2-6
PROJECTED ULTIMATE DEMANDS BY CATEGORY
Single-Family
Residential
42%
IVIulti-Family
Residential
9% Commercial/
Industrial
23%
Temporary
1% Agriculture
1%
Irrigation
(Phase II Recycled)
12%
Irrigation
12%
CMWD
WATER MASTER PLAN UPDATE 2-11
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March 2003
2.5.3 Ultimate System Hydraulic Analysis
The ultimate system H2ONET® model was developed from tiie existing system model, layout plans for
planned developments, and current CMWD CEP projects. The hydraulic profile of tiie ultimate system as
modeled is provided in Figure 2-7. The ultimate system model includes only the existing storage
faciUties, however additional storage faciUties are recommended to satisfy the requfred storage criteria
(discussed in the next section). A new pump station was added to the model to supply the 700 Zone from
the 490/550 Zone under the emergency supply scenario from Maerkle Dam.
Projected demands were input to the ultimate system model using a multi-step process. HydrauUc
analysis ofthe ultimate system was performed to size and verify proposed future faciUties. The ultimate
system model was analyzed under botii maximum day demand and emergency supply scenarios. Several
iterations of the ultimate system model were developed as proposed faciUties were added or modified
based on analysis results. The final ultimate system model is illustrated on Exhibit 2 in Appendix A
Maximum Day Demand 24-Hour Simulation - Projected demands corresponding to an ultimate system
maximum demand day were developed and input to the ultimate system model to identify and size future
facilities. Several simulation iterations were required to properly adjust the SDCWA inflows, distribution
system valves with variable settings, and pressure settings for new pressure reducing valves.. The final
SDCWA inflows modeled at tiie aqueduct connections are shown in Table 2-7. Supply from SDCWA
Coimection No. 3 (Supply to Maerkle Reservofr/Dam) was maximized based on the increased
fransmission capacity of the 490 Zone and the benefit of increased cfrculation in Maerkle Dam. It is
noted tiiat the supply from SDCWA Connection No. 2 is at the existing rated capacity, and the supply
from the Maerkle Connection is nearly at capacity.
Table 2-7
SDCWA MAX DAY SUPPLY IN THE ULTIMATE SYSTEM MODEL
San Diego County Water
Authority Connection
Rated Capacity* Supply in Ultimate System Mode
with Max Day Demands San Diego County Water
Authority Connection (MGD) fcfs) (MGD) (cfs)
CWA No. 1 (Palomar Airport
Road Connection) 23.3 36.0 16.2 25.0
CWA No. 2 8.6 13.3 8.6 13.3
TAP No. 3
(Maerkle Connection) 11.6 18.0 11.0 17.1
TAP No. 4
(TAP Connection) 8.7 13.5 5.1 7.8
TOTALS 52.2 80.8 40.9 63.3
' Rated capacity for Conn. No. 1, 3 and 4 is the capacity of the SDCWA meter at the tumout, minus 10%.
Rated capacity for Conn. No. 2 is based on a contractual agreement with VWD, OMWD, and Carisbad.
CMWD
WATER MASTER PLAN UPDATE 2-12
Dudek & Associates, Inc.
March 2003
O O CN
cn
x>
I
E
-C
u
I
I
O X)
CL
3DCWA TAP SIXWA SECOND AQUEDUCT
TAP CONNECnON
®klABRKLE \CONNECTK)N
PALOiUK
J AJWORTRO IPARl
COfneCTKH
tl
IHAERKLE J J
UAERKLEII I I RESERVOIR PUMP STA. 1SUG
SECOND AQUEDUCT
CCHNECVOH
THROUOHVWl
SANTA FEI,
RESERVOIfi
3.0 MG
LA COSTA HI RESERVOIR 6.0 MG
4 1
MO
3
s
LEGEND
EXISTING FACILITIES:
<1> SDCWA FLOW CONTROL • NORMALLY CLOSED VALVE
PRV OR PRV/PSV COMBINA TION PUItlPSTAVON
PSV
CHECKVALVE
BUTTERFLY VALVE
PLUG VALVE
I J-BASt ELEV. STORAGE RESERVOIR
PRIMARYSUPPLY
EMERGENCY OR BACK-UP SUPPL Y
NOTE:
VAL VE ID NUMBERS CORRESPOND TO ID NUMBERS IN THE
CONTROL VALVE SUMMARY TABLES.
PROPOSED FACILITIES:
NEW OR UPGRADED PUMP STATION
^ NEW OR UPGRADED PRV/PSV
I I NEW STORAGE RESERVOIR • LBASE El£V.
FIGURE 2-7
CARLSBAD MUNICIPAL WATER DISTRICT
ULTIMATE SYSTEM HYDRAULIC PROFILE
DUDEK & ASSOCIATES, INC.
Model results from the maximum day demand simulation were reviewed to assess system operations and
reservofr performance. The existing reservoirs in the ultimate system were able to supply operational
storage and refiU.
Emergencv Supplv Scenario - The ultimate system model was analyzed under an emergency supply
scenario, with average day demands suppUed from the Maerkle Dam. In tiiis simulation, the bypass at the
Maerkle Confrol Valve was opened to create an integrated 490-550 zone and tiie Calavera Hills Pump
Station was operated to supply the 580 Zone. The capacity ofthe proposed 700 Zone emergency supply
pump station was set equal to the average day demand of the 700, 680 580S and 510 Zones, which is
approximately 3.6 MGD or 2,500 gpm.
A 24-hour simulation was run, and model results indicated that average day demands could be suppUed to
the entire disfribution system from Maerkle Reservoir. However, the capacity of the Maerkle Reservofr
Pump Station, which supplies Maerkle Reservofr from Maerkle Dam, wiU have to be increased to
approximately 16,500 gpm (23.9 MGD). Altiiough pressures in the 550 Zone dropped by approximately
25 psi, analysis results indicate that the required 40 psi minimum pressure could be maintained.
2.5.4 Storage Analysis
The required storage volume based on projected ultimate demands is calculated and compared to the
capacity of the existing system reservoirs. Calculations to determine the requfred storage volume are
shown in Table 2-8. Based on these calculations, there is projected to be a storage deficit of
approximately 4.5 milUon gaUons (MG) in tiie ultimate system. Additionally, tiie District is considering
the removal ofthe 1.5 MG "E" Reservofr from the system, which does not operate together with the otiier
two 255 Zone reservofrs due to its elevation.
The CMWD emergency storage poUcy is to provide 10 days of average water use. Based on the projected
ultimate average aimual demand of 23.9 MGD, the required storage volume is 239 MG. If demands
identified as being suppUed from the future Phase II Recycled Water System are not included, the
projected ultimate demand is approximately 21.2 MGD, and 212 MG of emergency storage wiU be
required. Maerkle Dam is reported to have a storage capacity of 195 MG. Therefore, additional storage
wiU need to be constructed to comply with the CMWD emergency storage poUcy.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 2-13 March 2003
Table 2-8
ULTIMATE DAILY STORAGE REQUIREMENTS
RESERVOIR Service
Zones
Projected Demand St« jraqe Reau rements Reservoir
Capacity
Available
Emergency
Capacitv
RESERVOIR Service
Zones (MGD)
MDD
(MGD)
Operational
f.15xMDD)
Fire Reserve
(1 MDD) Totai
Reservoir
Capacity
Available
Emergency
Capacitv
Santa Fe II
&
La Costa
High
700
680
580S
510
550
430
2.80
0.42
0.06
0.31
3.86
0.21
4.61
0.70
0.10
0.52
6.38
0.35
1.9 MG 2.88 MG 12.7 MG 17.4 MG 15.0 MG -2.4 MG
Maerkle Res.
490
285
198
0.36
0.14
0.08
0.60
0.24
0.13
0.1 MG 0.96 MG 1.0 MG 2.1 MG 10.0 MG 7.9 MG
TAP
580<2>
446
349
0.51
2.25
0.09
0.85
3.71
0.15
0.7 MG 0.96 MG 4.7 MG 6.4 MG 6.0 MG -0.4 MG
03 375 4.02 6.64 1.0 MG 1.92 MG 6.6 MG 9.6 MG 8.5 MG -1.1 MG
La Costa Lo 318 3.60 5.94 0.9 MG 0.96 MG 5.9 MG 7.8 MG 1.5 MG -6.3 MG
Ellery 330 1.10 1.82 0.3 MG 0.96 MG 1.8 MG 3.0 MG 5.0 MG 2.0 MG
Elm
Skyline
"E" Res.
255 4.07 6.72 1.0 MG 0.96 MG 6.7 MG 8.7 MG 4.5 MG -4.2 MG
TOTALS 23.9 39.4 5.9 MG 9.6 MG 39.4 MG 55.0 MG 50.5 MG -4.5 MG
(1) Equal to the volume of water basecJ on the largest fire flow within the tank service area (flow rate times duration). For
large service areas, the fire flow storage was increased based on the potential for multiple fires.
(2) The 580 Zone has no available storage but can be supplied from the TAP Res. through the Calavera Pump Station.
2.6 WATER QUALITY
Maerkle Dam provides storage capacity for daily operational needs and suppUes the distribution system
when imported water is not available from the SDCWA (due to aqueduct and treatment plant shutdowns).
The dam is also used to maintain sufficient local storage to meet the City's "Growth Management
Requfrement", which states that the CMWD is to maintain 10 days of storage for the distribution system.
These storage requirements, however, are affecting CMWD's ability to maintain water quality in Maerkle
Dam.
The freated water purchased from the SDCWA uses chloramines as the secondary or residual disinfectant.
The water therefore contains low concentrations of ammonia, which serves as a potential source of
reduced nifrogen. Due to the presence of ammonia combined with the long residence time in Maerkle
Dam, additional freatment of the water is required to avoid water quality compUcations due to
nitrification. Nifrification is the result of biological conversion of ammonia to nitrite, which represents
an oxidant demand. Historically, CMWD practiced breakpoint chlorination to remove the ammonia and
produce a free chlorine residual in the reservoir influent water. However, this practice formed high
concenfrations of disinfection byproducts (DBPs) and may have adverse consequences for water system
CMWD
WATER MASTER PLAN UPDATE 2-14
Dudek & Associates, Inc.
March 2003
operation and compliance with tiie newly effective Stage 1 Disinfectants and Disinfection Byproducts
(D/DBP) Rule and tiie soon to be proposed Stage 2 D/DBP Rule.
To address both the elevated DBP formation and the potential for nitrification, CMWD requested an
amendment to its "Domestic Water Supply Pemiit" to test the use of chlorine dioxide for confrol of DBP
formation and nitrification. An amendment was issued on June 5, 2002 by the Califomia Department of
Healtii Services (DOHS) under permit amendment 05-14-02PA-002. On June 19, 2002, CMWD
discontinued its current practice of breakpoint chlorination and began testing the use of chlorine dioxide
to reduce organohaUde DBP formation and produce a new byproduct, chlorite, to conttol nitrification.
Monitoring results for chlorine dioxide in the unblended Maerkle Dam effluent feed show very steady,
predictable, and satisfactory results. The chlorite dioxide residual in the reservoir effluent is well below
0.64 mg/L (80% of Maximum Residual Disinfectant Level) and the daily chlorite level in the reservoir
effluent was well below 0.80 mg/L (80% of tiie Maximum Contaminant Level). The weekly nifrite level
in the reservofr effluent has stayed below 0.010 mg/L witii a stable chloramine residual being observed
(-1.0 mg/L), even after several months of detention in the reservoir.
With the cessation of breakpoint chlorination, the concenttation of total trihalomethanes (TTHM) in tiie
Maerkle Dam effluent is rapidly decreasing, and distribution system concenfrations also appear to be
decreasing. TTHM in the Maerkle Dam effluent have now approached the influent concentrations found
in the treated water supply from the SDCWA. For tiiese reasons, CMWD plans to continue tiie use of
chlorine dioxide. This results in the need for a permanent installation of a chlorine dioxide generator and
chemical storage facility. A decision on the permanent instaUation wiU be delayed until after the seawater
desalination project has been decided upon, which calls for desalinated water to be stored at Maerkle Dam
(discussed in the next section).
2.7 SEAWATER DESALINATION
A feasibiUty study has been prepared by a private company for a future 50 MG seawater desalination
faciUty adjacent to the Encina Power Plant. The plant could eventuaUy be expanded to a lOOMG facility.
The high quality drinking water would be sold based on long-term water sales agreements, and a draft
water purchase agreement has been submitted to the SDCWA for thefr consideration. The proposed
desalination plant would deliver desalinated water to CMWD, the City of Oceanside, VID, VWD, and tiie
SDCWA. Desalinated water would be pumped from the desalination facility in a new 48-inch diameter
pipeline to Maerkle Dam and Maerkle Reservoir prior to disfribution to the various use areas. Maerlde
Dam would therefore be converted to a desalinated water storage faciUty.
CMWD is currently conducting its own intemal evaluation of the desaUnation study separate from the
Water Master Plan Update. SDCWA staff is also reviewing the feasibiUty study and is in discussion with
staff at Carlsbad and Oceanside over coordinating technical review of the proposal. CMWD has
expressed concem over the mixing of desalinated water witii imported water from the SDCWA, and the
CIVIWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 2-15 March 2003
effect of changing supply sources on customers. Specifically, changes in taste, mineral content, and the
overaU water hardness may adversely affect customers who, under various seasonal supply scenarios,
would be delivered either desalinated water, imported water, or a mixture of botii suppUes. The CMWD
has therefore requested first rights to the desalinated water in order to supply aU of its customers from a
single source.
If the desalination plant is constmcted there wiU be numerous impacts to the City of Carlsbad and the
operation of the CMWD distribution system. In addition to new pipelines, a new pump station will be
required at Maerkle Dam to pump desalinated water back into the SDCWA tri-agency pipeline and an
additional CMWD pumping facility would be requfred to supply the upper zones with desaUnated water
from Maerkle Reservoir. Emergency storage rights for the water in Maerkle Dam wiU need to be
negotiated. The potential impacts of changing the water supply to a desalinated source also need further
investigation.
2.8 RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
Water distribution system improvements are recommended to supply fiiture demands and improve system
reUabiUty. The recommended CIP includes the CMWD-funded projects proposed for build-out of the
water distribution system, which is projected to occur by the year 2020. The proposed improvements are
iUustrated on Exhibit 3 in Appendix A and are summarized by phase with an opinion of probable
constmction cost in Table 2-9. The projects have been grouped into phases to address proposed
improvements to the existing distribution system in Phase I, improvements to provide an emergency
water supply to the entire distribution system from Maerkle Dam in Phase II, and improvements required
for fiiture development in Phase III. These phases should provide the CMWD with a long range planning
tool to keep up with growth and provide for expansion of the water distribution system in an orderly
manner. It is noted that phasing for recommended improvement projects may be accelerated or deterred
to account for changes in development schedules, availability of land or rights-of-way for constmction,
fimding limitations, and other considerations that cannot be predicted at this time.
Fourteen projects are recommended to increase the available fire flow capacity in the existing system.
The majority ofthe recommended fire flow projects consists of replacing older 6-inch diameter pipelines
with larger diameter pipelines. Four projects are recommend to increase the reUabiUty of the existing
system, based on the CMWD requirement that no more than 18 houses are to be served from a dead-end
water Une. Several water system improvements are required to supply the entire distribution system from
storage in Maerkle Dam. These projects include increasing the capacity ofthe Maerkle Pump Station,
constmcting a second fransmission main from Maerkle Reservoir to the 490 Zone distribution system to
increase capacity, construction of additional deUvery mains and reducing stations to supply tiie 446 and
375 Zones from the 490 Zone, replacement ofthe existing 20-inch diameter pipeline in El Camino Real
upsfream of the Maerkle Confrol Vault with a 30-inch diameter pipeline, and constmction of an
emergency pump station to supply the 700 Zone from the 490 Zone.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 2-16 March 2003
Several transmission main capacity improvements are recommended in the ultimate distribution system to
supply future demands. Generally, distribution pipelines 12-inches in diameter and smaUer required to
serve future development projects are considered developer-fimded projects. Larger pipelines are
included in the CIP. In some cases, both the developer and the CMWD wiU share pipeline project costs.
Transmission system capacity improvements are recommended for the 700 Zone to supply increased
demands and also to integrate the existing 700N and 700S Zones into a single zone.
Based on projected ultimate demands and the planned removal of the "C" Reservoir form the potable
water distribution system, there will be a daily storage deficit of approximately 4.5 MG within the
distribution system. The storage deficit wiU increase by an additional 1.5 MG if the CMWD decides to
remove the "E" Reservofr from service. It is recommended that the daily storage deficit be met by
constmcting an additional reservoir at the D3 Reservoir site, where there is afready a reservoir pad in
place on District-owned property. To operate efficiently in the distribution system, it is recommended
that a "twin" reservoir be constmcted with the same dimensions and capacity as the existing 8.5 MG D3
Reservoir.
During completion of this planning docmnent. City Staff decided that the 10-day emergency storage
requirement is to be calculated based on the projected ultimate ADD without Phase II recycled water
demands. To meet the future emergency storage deficit, constmction of an additional reservoir adjacent
to Maerkle Dam was recommended in the last Master Plan. This previous storage solution has been
carried forward at the request of District Staff, and a buried reservoir with a capacity of 15 MG is
recommended to provide the requfred 10-days of emergency storage at build-out conditions (CIP No. 28).
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 2-17 March 2003
Table 2-9
CMWD RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
Label Zone Description/Location Project Type Existing
Diam.
New
0am.
Pipeline
Lenoth
Unit Cost
Estinisite'
35%
Conilnaencf
Total Constr.
Cost* Benefit/Comments
PHASE 1 - EXISTING SYSTEM IMPROVEMENTS
F 1 330 Upsize 6" and 4" PL in Jeanne Place to
end of cul-de-sac
Pipeline
Replacement 6-in. 8-in. 600' $95 /linear ft. $33 $ 76,800 Upsize to provide Residential fire flow
F 2 446 Upsize 6" PL in Nob Hill Drive to end of cul
de-sac
Pipeline
Replacement 6-in. 8-in. 650' $95 /linear ft. $33 $ 83,200 Upsize to provide Residenlial fire flow
F 3 446 Upsize 6" PL in Holly Brae Lane and Alder
Ave east of Skyline Dr.
Pipeline
Replacement 6-in. 8-in. 890' $95 /linear ft. $33 $ 114,000 Upsize to provide Residential fire flow
F 4 446 Upsize 6" PL in Falcon Dr. east of Donna
Dr. to cul-de-sac
Pipeline
Replacement 6-in. 8-in. 870' $95 /linear ft. $33 $ 111,400 Upsize to provide Residential fire flow
F 5 255 Upsize 6" PL in Cynthia Ln & Gregory Dr,
from Knowles Av to cul-de-sac
Pipeline
Replacement 6-in. 8-in. 710' $95 /linear ft. $33 $ 90,900 Upsize to provide Residenfial fire fiow
F 6 330
Upsize 6" PL In Tamarack Av from
Highland Drive west to Adair St., and in
Adair St to cul-de-sac
Pipeline
Replacement 6-in. 8-in. 1250' $95 /linear ft. $33 $ 160,100 Upsize to provide Residenfial and Multi-family
fire flow
F 7 330 Upsize 6" PL in Highland Dr. from Yourell
Ave to Ratcliff
Pipeline
Replacement 6-in. 8-in. 700' $95 /linear ft. $33 $ 89,600 Upsize to provide Residenfial fire flow
F 8 580
Switch supply to hydrants at the Calavera
Rec. center from the 580 Zone to the 446
Zone
New
Connection to
Fire Hydrants
NA NA NA $25,000 L.S. $8,750 $ 33,750
The 580 Zone has no storage. Modify system
to provide Comm/Ind fire flow to recreafion
center from the 446 Zone and TAP Reservoir
F 9 330 Upsize 6" PL from Chestnut Ave at
Woodland Wav to the end of Woodland
Pipeline
Replacement 6-in. 8-in. 560' $95 /linear ft. $33 $ 71,700 Upsize to provide MulU-Family fire flow
F 10 255 Upsize 6" PL in Garfield from Chinquapin
Ave to end of cul-de-sac
Pipeline
Replacement 6-in. 8-in. 846' $95 /linear ft. $33 $ 108,300 Upsize to provide Comm/Ind fire flow
F 11 255 Upsize 6" PL in Arland Road from
Hicjhland to Buena Vista Way
Pipeline
Replacement 6-in. 12-in. 780' $116/linear ft. $41 $ 121,900 Upsize to provide Comm/Ind flre flow
F 12 330 Install parallel pipeline in Highland Dr.
from Hillside Dr. south to Adams St.
New
Watermain 6-in. 8-in. 2400' $95 /linear ft. $33 $ 307,300 Upsize to provide Residential fire flow &
provide redundant supply
F 13 255 Install parallel pipeline in Cove Drive from
Park Drive to end.
New
Watermain 6-in. 10-in. 1300' $106/linear ft. $37 $ 185,700 Upsize to provide MulU-Family fire fiow &
provide redundant supply
F 14 680 High elevation areas in the vinicity of
Obelisco Place/Circle
emergency
pump NA NA NA $75,000 L.S. $26,250 $ 101,250 Install emergency pump to boost pressures &
provide the req'd fire flow @ 20psi
2 255 Parallel existing. 8" PL in Crestview Drive
south of El Camino Real
New
Watemain 8-in. 8-in. 600' $95 /linear ft. $33 $ 76,800 Provides redundant supply fo exisfing
residential area
3 255 El Camino Real south from Kelly Drive to
Lisa Street
New
Watemtain NA 10-in. 1500' $106/linear ft. $37 $ 214,300 Provides looping to improve pressures and
reliability
16 550 El Camino Real from Palomar Airport
Road south to Cassia Road
Watemiain
Replacement 20-in. 24-in. 6100' $240 /linear ft. $84 $ 1,976,400 Replace existing pipeline and provide
Increased flow c:apacity
17 375 Poinsettia Lane west from Skimmer Ct. to
Blackrail Rd.
New
Watermain NA 12-in. 4500' $116/linear n. $41 $ 703,000 Completes 375 Loop along Poinsettia Lane;
Increase capacitv to/from the D3 Reservoir
18 550 Poinsettia Road, 1100 feet east of
Blackrail Kd.
Watermain
Replacement 18-in. 30-in. 1100' $250 /linear ft. $88 $ 371,300 Increase supply to 550 Zone and D3 Reservoir
19 550 Aviara Pky at Plum Tree north to Mariposa
St, then east to Sapphire Dr.
New
Watermain NA 8-in. 3100' $95 /linear ft. $33 $ 397,000 Provide redundant supply to residential
development
21 680 Intersection of El Fuerte and Corintia SL New 700 =>
680 PRS NA NA NA $100,000 L.S. $35,000 $ 135,000 Provide redundant supply to 680, 580S and
510 Zones
22 318 Carisbad Boulevard from Avenida Encinas
south to the District boundary
New
Watermain NA 12-in. 4900' $116/linear ft. $41 $ 765,500 Provide 2-way emergency conn w/SDWD 240
Zone; can supply to 318 Zone west of 1-5
WATER MASTER PLAN UPDATE March 2003
Table 2-9 (continued)
Zone Description/Location Project Type Existing
Diani
Pipeline
Lennlh
Unit Cost
Estimate*
35%
Continaencv
Total Constr.
Cosf Benefit/Comments
PHASE 1 - EXISTING SYSTEM IMPROVEMENTS (continued)
24 550 Parallel exisfing PL in PoinsetUa Road
from Ambrosia Ln. to Blackrail Rd.
New
Watermain
18-in &
30-in 12-in. 2000' $116/linear ft. $41 $ 312,400 Provide redundant supply to residential
developments
26 700 Palomar Airport Road west of SDCWA
Connection #1
Watemiain
Replacement 20-in. 30-in. 1500' $250 /linear ft. $88 $ 506,300 Reduce velocity & provide increased capacity
from SDCWA #1 Connecfion into 700 Zone.
31 490 El Camino crossing at Kelly Dr. New
watermain NA 12-in. 300 $124 /linear ft. $43 $ 50,200 Increase supply to the 255 Zone directly from
the 490 Zone thru the Kelly PRS
32 NA Abandonment of 9 wells at the Foussart
well field
well
abandonment NA NA NA $150,000 LS. $52,500 $ 202,500 Abandon wells per State standards; removal of
pumps, structures & restoration of property
33 NA Lake Calavera Reservoir Improvements reservoir
improvements NA NA NA $1,200,000 L.S. $420,000 $ 1,620,000 Replacement of outlet tower valves and piping;
Re-grade reservoir bottom
34 255 Oceanside Intertie Upgrade intertie
upgrade NA NA NA $75,000 L.S. $26,250 $ 101,250 Valve, pipeline and meter replacements for the
exisfing inter-He
36 NA Groundwater/seawater desalination study report/study NA NA NA NA NA $ 649,860 Investigate treatment/delivery of City owned
groundwater:seawater desalination feasibility
Subtotal Phase 1 Impiovemeiits. $ 9,738 OOP
PHASE II -EMERGENCY SUPPLY
4 375
Bryant Drive from Longfellow to El Camino
Real, soulh on El Camino Real to College
and northeast on College lo Badger Lane
New
Watermain NA 12-in. 4000' $116/linear ft. $41 $ 624,900
Connects isolated portions of 375 Zone &
provides for supply from Maerkle Res. for ex.
and future development.
5 490
Upsize exisfing 20" to 30" along El Camino
Real from Cougar Dr. to Faraday Ave
including Maerkle Control Valve
Watemiain
Replacement
& valve
20-in. 30-in. 1500'
$250 /linear ft.
$150,000 L.S.
$88
$52,500
$ 708,800
Larger diam. pipe reduces pressure loss
during emergency supply to 550 Zone from
Maeri^le Dam
6 490/
446
College Blvd from Carlsbad Village Drive
south to Cannon Road, 490=>446 PRS
New
Watermain
& PRS
NA 16-in. 6330'
$133/linear ft.
$100,000 L.S.
$47
$35,000
$ 1,273,600 Increase supply capacity to 446 Zone from
Maeri^le Res.
7 490
College Blvd trom future intersecfion with
Cannon south to future Tee leading to
Maerkle Reservoir
New
Watermain NA 16-in. 4000' $133/linear ft. $47 $ 719,500 Primary feed for Robertson Ranch (490=>255
PRV); Increase supply capacity from Maerkle
10 490
In College Ave, from Badger Lane north
aprrox. 1,200 ft, then east through future
development
New
Watermain NA 36-in. 5200' $220 /linear ft. $77 $ 1,544,400 Increase supply capacity from Maerkle Res
and provide a redundant supply pipeline
11 490 Connection from terminus of Project #10
to Maeri^le Reservoir
New
Watermain NA 36-in. 4100' $220 /linear ft. $77 $ 1,217,700
Increase supply from Maerkle Res.; Supply to
new 490 development east of El Camino and
Rancho Carisbad qolf course.
15 700 El Fuerte Street from Palomar Airport
Road south to Rancho Pancho
New
Watermain NA 24-in. 5200' $163 /linear ft. $57 $ 1,141,000 Connects 700N and 700S Zones; Supply for
future development
20 700 Northeast comer of El Camino Real and
Palomar Airport Road Pump Station NA Capacity =
2,500 gpm $900,000 L.S. $315,000 $ 1,215,000
Provide emergency supply to 700, 680, 580S,
and 510 Zones from Maerkle Res; Pump
Stafion sized to supply the projected ull AAD
of the zones supplied.
23 375 Cannon Road, 1,800 feet NE h^om
Faradav Road
New
Watermain NA 16-in. 2760' $133/linear ft. $47 $ 496,500 Provide for 375 supply from Maerkle Res;
Increased capacitv for future development
29(a) 490 Maeri<ie Pump Stafion Capacity
Improvements
Enlarge Pump
Station NA Additional capacity =
5,000 gpm $500,000 L.S. $175,000 $ 675,000 Req'd for emergency supply from Maeri<le
Dam. Increase PS capacity to existinq ADD
Su btotal Phase II Improvements: $ 9,1^16,000
WATER MASTER PLAN UPDATE March 2003
Table 2-9 (continued)
Label Zone Description/Location Project Type Existing
Diam.
New Pipeline
Length
Const Unit
Cost
35%
Contingency
Total EsL
Cost* , Comment
PHASE ill - FUTURE D =VEi OPMENT
1 255 From end of Marron Road east lo
Tamarack; 446=>255 PRV al Tamarack
New
Watermain
&PRS
NA 12-in. 6600' $116/linear ft.
$100,000 L.S.
$41
$35,000
$ 1,168,600 Supply new developments in LFMZ 25 &
provide additional supply to the 255 Zone
8 375 College Blvd from Cannon Road south to
Badger Lane
New
Watermain NA 12-in. 4130' $116/linear ft. $41 $ 645,200 Supply for new development and creates 375
Zone loop east of El Camino
9 375 In Cannon Rd., from Merwin Drive east to
intersection with future College Blvd.
New
Watermain NA 12-in. 4400' $116/linear ft. $41 $ 687,400 Supply for new development and creates 375
Zone loop east of El Camino
12 700 In future extension of Melrose Dr., from
PAR north to future Faraday Rd.
New
Watermain NA 16-in. 4000' $133/linear ft. $47 $ 719,500 Provides looped supply to new North 700 zone
business park in LFMZ 16 (1 of 3)
13 700 In northem El Fuerte St. extension, to
future Faraday Road
New
Watermain NA 16-in. 2200' $133/linear ft. $47 $ 395,700 Provides looped supply to new North 700 zone
business park in LFMZ 16 (2 of 3)
14 700 in future Faraday Rd. extension, between
El Fuerte St. and Melrose Dr.
New
Watermain NA 16-in. 3600' $133/linear ft. $47 $ 647,600 Provides looped supply lo LFMZ 16 (3 of 3)
and supply lo 550 Zone from 700=>550 PRV
25 375 Poinsetfia Road from El Camino Real west
to Skimmer Court (Poinsettia Lane)
New
Watermain NA 12-in. 1300' $116/linear ft. $41 $ 203,100
Parallel existing 8-inch to increase capacity in
the 375 Zone and supply from the 550 Zone
thru Villages of La Costa
27 375 Constmct new 375 Zone water reservoir
next to existing D-3 Reservoir
New Water
Storage
Reservoir
NA Capacity = 8.5 MG $0.60/ gal $0.21/gal $ 6,885,000 Provides additional daily storage within the
distribution system for ultimate demands
28 490 Construct buried storage reservoir next to
existing Maeri^le Reservoir
New Water
Storage
Reservoir
NA Capacity = 15MG $1.00/gal $0.35/ gal $ 11,475,000
Provides additional emergency storage to
meel 10-day storage criteria based on ultimate
demands
29(b) 490 Maeri^le Pump Station Capacity
Improvements
Enlarge Pump
Station NA Additional capacity =
5,000 gpm $500,000 L.S. $175,000 $ 675,000 Req'd for emergency supply from Maeri<le
Dam. Increase PS capacity to projected ADD
30 375 Gross Pressure Reducing Station
Improvements
490=>375
PRS Upgrade NA NA NA $75,000 L.S. $26,250 $ 101,250 Increase capacity of existing Gross PRS to
supply new development from 490 Zone
35 392 Instail 490=>392 PRS at Cannon Road
and College Blvd.
490=>392
PRS NA NA NA $100,000 L.S. $35,000 $ 135,000 Project will lake place when existing "C"
Reservoir is taken out of service
37 580 Calavera Pump Station Improvements,
College Blvd at Carisbad Village Dr. PS upgrades NA NA NA $300,000 L.S. $105,000 $ 405,000 Install standby generator & building,
hydropneumatic tank & add'l pump
Subtotal Phase III Improvements: $24,143,000
CIP TOTAL PHASES 1 -III $43,497,000
Opinion of probable construction cost is based on a Construction Cost Index (CCI) of 6578 for November 2002.
City of Cartsbad
WATER MASTER PLAN UPDATE
Dudek & Associates, Inc.
March 2003
CHAPTER 3
EXISTING SYSTEM DESCRIPTION
This chapter summarizes the existing CMWD distribution system as of December 2001. The facilities
comprising the water distribution system include San Diego County Water Authority (SDCWA) tumouts,
fransmission mains, disfribution pipelines, pressure reducing stations, storage reservoirs and pump
stations. Information regardfrig the existing water distribution system faciUties was derived from the
District's water atlas books, as-built construction drawings, previous reports and studies, and input from
City ofCarlsbad Engineering and Public Works staff. The existing water distribution system is illusfrated
on the color wall map provided as Exhibit 1 in Appendix A.
3.1 GENERAL
The CMWD service area includes the majority ofthe City boundary, with the exception ofthe southeast
comer of tiie City. Water distribution in the southeastem area is provided by the Olivenhain Municipal
Water Disfrict (OMWD). Carlsbad's water service area extends from the Buena Vista Lagoon and Creek
south to the Batiquitos Lagoon, and from the Pacific Coast to approximately 5 miles inland. The
approximately 32 square mile service area is characterized by gently rolling to highly dissected mesa-like
hills, commonly topped by remnants of marine terraces. Elevations range from sea level along the coast
to just under 600 feet along the eastem boundary. The mean temperature range for tiie District's service
area is typically between 55°F in January to approximately 70°F in August. The average annual
precipitation witiiin the service area ranges from II to 15 inches. Precipitation generally occurs between
the months of November and March.
3.2 WATER SUPPLY
The CMWD imports water through the SDCWA for their potable water needs. Water is supplied to the
CMWD through four separate SDCWA treated water tumouts. Two of tiie tumouts, CWA No. 1 and
CWA No. 2, are direct connections to the SDCWA Second Aqueduct. CWA No. 1 supphes only the
CMWD, and CWA No. 2 supphes the Vallecitos Water District (VWD) and tiie Olivenhain Municipal
Water District (OMWD) in addition to tiie CMWD. Water supply to the CMWD from CWA No. 2 is
delivered through a VWD transmission main. Connections No. 3 and No. 4 to the aqueduct system are on
the SDCWA owned and operated Tri-Agency Pipeline (TAP), which is also supphed from the SDCWA
Second Aqueduct. The TAP also serves the City of Oceanside and the Vista Irrigation District (VID).
The SDCWA aqueduct coimections are summarized in Table 3-1. Emergency sources of water are
discussed later in this chapter (Section 3.4).
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 3-1 March 2003
Table 3-1
SDCWA AQUEDUCT CONNECTIONS
San Diego
County Water
Authority
Connection
Supply
Source
Rated
Capacity*
Normal Delivery Rate Range
Supply Zone/
Reservoir
San Diego
County Water
Authority
Connection
Supply
Source
Rated
Capacity* Summer Winter Supply Zone/
Reservoir
San Diego
County Water
Authority
Connection
Supply
Source
(Cfs) (lUIGD) (cfs) (IVIGD) (cfs) (MGD)
Supply Zone/
Reservoir
CWA No. 1
(Palomar Airport
Road Connection)
Second SDCWA
Aqueduct 36 23 11-22 7-14 6-15 4-10 700N/ Sante Fe 1
Resen/oir
CWA No. 2 Second SDCWA
Aqueduct 13.3 9 3-10 2-6 2-4 1-3 700S/ La Costa
Hi Reservoir
TAP No. 3
(Maerkle
Connection)
Tri-Agency
Pipeline (TAP) 18 12 7-10 5-6 3-8 2-5 490/ Maerkle
Reservoir
TAP No. 4
(TAP Connection)
Tri-Agency
Pipeline (TAP) 13.5 9 4-10 3-6 2-5 1-3
580/ TAP
Reservoir (446
Zone)
TOTALS 81 52 25 -52 16-34 13 -32 8 -21
* Rated capacity for Conn. No. 1, 3 and 4 is the capacity of the SDCWA meter at the turnout, minus 10%. Rated
capacity for Conn. No. 2 is based on a contractual agreement with VWD, OMWD, and Carisbad. The maximum
flow that can be delivered may be less due to downstream pipeline capacity limitations.
CMWD Operations staff remotely set daily water delivery rates for tiie SDCWA tumouts. Water order
requests are made to tiie SDCWA 24-hours prior to dehvery. Presently tiie CMWD has an option to
adjust flow through any of the four connections twice a day. With the exception of tiie TAP No. 4
comiection, water is supplied dfrectly to zones with a reservofr to ensure that a constant flow rate can be
provided regardless of demands in the system. Flow from tiie TAP No. 4 connection is supplied to tiie
580 Zone, which has no storage reservoir. However, a sustaining valve from the 580 Zone to the 490
Zone allows the 490 Zone TAP Reservoir to provide buffering capabilities for this connection.
3.3 WATER DISTRIBUTION SYSTEM
The existing distribution system consists of 17 major pressure zones. Four of the zones are supplied
dfrectly from the SDCWA aqueduct connections (700N, 700S, 490, 580). The remaining zones are
suppUed through pressure reducing stations. The CMWD hydraulic profile schematic showing aqueduct
connections, pressures zones, storage facilities, pump stations and primary pressure reducing stations is
provided on Figure 3-1.
CMWD
WATER MASTER PLAN UPDATE 3-2
Dudek & Associates, Inc.
March 2003
E
CL
CO
5
X)
E
0
o '/)
m
CM O
0
ro T3 Q. D
I
Q-
X3 ro .Q (fi T: ro O Ul c
'i-0) 0)
c
'?
(i
800
700
600
500
400
300
200
100
SDCWA TAP
124
^0
SDCkV>4 SECOND AQUEDUCT
TAP
CONNECTION
•514
MAERKLE
RESERVOIR
PUMP STA.
MAERKLE
CONNECTION
PALOMAR
AIRPORT RD (PAR)
CONNECnON
^0-
SANTAFEII
RESERVOIR
9.0 MG
580
473
^446 6.0 MG
MAERKLE
RESERVOIR
10 MG
CALAVERA HILLSi-PUMP
<9
349 1
-32
1—4—
4«
091 '
-1^
—rl-
•351.5
-330
ELLERY
^SJUMG-
rL__:_—1-351.5 p
]NC
I
^^255 ^^^^^^
NC
— CO-
BUENA VISTA
PUMP STA.
302
ELM
1.5 MG
241
SKYLINE
1.5 MG
264
"E"RESER.
1.5 MG
255
•490 inxEjfRLPwar
195 MG Tr
430
490
MAERKLE
CONTROL VAULT
65
U-^ -O-
.73
72 106
?fl5
"I"! ^^-1
3i
•375
D3
RESERVOIR
8.5 MG
375
r 15-
550
-732
—700-
i
M COSTA HI
RESERVOIR
6.0 MG
TOON
NC
550
52
SECOND
AQUEDUCT
CONNECTION
THROUGH VWD
-727
-760
—I
700 S
356.5 NC
U
59
318
1.5 MG
318 •A
5t0
125
800
700
600
550
S
500
400
300
200
100
I I
LEGEND
EXISTING FACILITIES:
<1> SDCiyy4 FLOW CONTROL NORMALLY CLOSED VALVE
PRV OR PRV/PSV COMBINA TION PUMP STATION
M
PSV
L J-BASE STORA GE RESER VOIR
ELEV. M CHECKVALVE PRIMARYSUPPLY
M BUTTERFLY VALVE EMERGENCY OR BACK-UP SUPPL Y
0 PLUG VALVE
NOTE:
VAL VE ID NUMBERS CORRESPOND TO ID NUMBERS
IN THE CONTROL VALVE SUMMARY TABLES.
FIGURE 3-1
CARLSBAD MUNICIPAL WATER DISTRICT
EXISTING SYSTEM HYDRAULIC PROFILE
DUDEK & ASSOCIATES, INC.
3.3.1 Pressure Zones
The CMWD distribution system consists of 17 major pressure zones and several smaller reduced zones
witii private disfribution systems. Of tiie 17 major zones, nine are open zones with reservofrs. The
remainder are closed zones witii pressure regulating valves. Pressure zones witiiin tiie CMWD are
identified by a number that typically corresponds to tiie bottom elevation of the reservofr or, for zones
without storage, tiie hydraulic grade set by the primary pressure reducing station.
The pressure zone service areas are illusfrated on Figure 3-2, along with the existing distribution system
pipelines. The service area boundaries have been updated from the previous Master Plan based on input
from City operations staff. The zone boundaries were further modified based on existing elevations and
planned development for ultimate conditions. Therefore, some of tiie service areas identified on Figure 3-
2 do not have any existing distribution pipeUnes. It is noted that the existuig 700N and 700S Zones are
planned to be combined and operated as a single zone in the near future.
3.3.2 Distribution Pipelines
The existing distribution system has over 300 miles of pipelines 6-inches in diameter and larger. Most of
the pipelines are constmcted of asbestos cement pipe (ACP). Larger fransmission mains are constmcted
of CMLC steel and newer pipelines are primarily polyvinyl chloride (PVC). For tiiis Master Plan Update,
tiie existing system computer model developed as part of tiie previous Master Plan was reviewed and
updated to reflect current conditions. The 2001 model includes major delivery mains and looped
distribution pipelines. Onsite distribution pipelines tiirough commercial properties and smaller dead-end
pipelines are typically not included in the model. The pipelines color-coded by pressure zone in tiie
updated existing system model are shown on Exhibit 1 in Appendix A. Table 3-2 summarizes pipeUne
lengths by diameter included in the hydrauUc model.
Table 3-2
HYDRAULIC MODEL PIPELINE SUMMARY
PipeUne Diameter Total Pipdiiu-Pipeline Diameter lolal Pipeline
(inches) Length (miles) (inches) Length (miles)
6 24.8 24 27
8 105.9 27 1.8
10 45.1 30 3.3
12 51.8 33 0.6
14 11.8 36 3.2
16 23.8 37 1.3
18 3,6 42 0.4
20 2.3 48 0.4
21 3.0
CMWD
WATER MASTER PLAN UPDATE 3-3
Dudek & Associates, inc.
March 2003
OCEANSIDE
LEGEND
WATER SERVICE AREA BOUNDARY
EXISTING DISTRIBUTION SYSTEM
PRESSURE ZONE BOUNDARIES
• 198 • 349 • 510
• 255 • 375 dl 550
• 285 • 430 • 580N
• 318 • 446 • 580S
• 330 • 490 • 680
• 700N
m 700S
FIGURE 3-2
CARLSBAD MUNICIPAL WATER DISTRICT
PRESSURE ZONE SERVICE AREAS
DUDEK !&.-\S5<X."l.\TE.s. INC.j
02-2003 Cartsbadwa32.mxd
3.3.3 Water Storage Facilities
Maerkle Dam is the major treated water storage facility for tiie CMWD, witii a capacity of approximately
600 acre-feet (195.5 MG). This reservoir serves as an operational water supply and is also used ia
meeting tiie City's requfrement to provide a minimum of ten days of emergency drinking water storage.
Currently tiie high pressure zones in the soutiieast portion ofthe service area (700, 680, 580S and 510)
caimot be suppUed witii emergency water from the dam. In 1998, CMWD instaUed a floating cover and
an asphalt liner to Maerkle Dam to meet tiie State Department of Healtii Services standard requiring that
reservofrs be lined and covered to prevent possible contamination. This standard comphes with the
Envfronmental Protection Agency's Surface Water Treatment Rule. Under normal operations, water is
suppUed to Maerkle Dam from tiie SDCWA TAP No. 3 connection and then pumped into the adjacent
Maerkle Reservoir. Frotn Maerkle Reservoir water is suppUed by gravity to the distribution system.
Water storage for fire flow and daily water operations is provided by eleven reservoirs (enclosed storage
tanks) within the distribution system. Additionally, tiiere is one reservoir that is currentiy not in use (2.5
MG Santa Fe I). The existing operational storage capacity is 51.5 MG, excluding Maerkle Dam.
Table 3-3 provides a summary ofthe storage faciUties, including a smaU reservoir used as a forebay for
tiie Buena Vista Pump Station. AU water storage is above ground except for tiie Maerkle Dam and
Maerkle Reservoir. The disfribution system reservoirs have been designed to be exfremely fiexible in
thefr ability to ttansfer water throughout the District. AU reservoirs are constmcted of steel except for the
Santa Fe I, Santa Fe II, La Costa Hi and TAP reservoirs, all of which are circular pre-sfressed concrete,
and the buried 10 MG Maerkle reservoir, which is rectangular and constmcted of reinforced concrete.
Reservofr water levels are recorded by tiie CMWD SCADA (supervisory confrol and data acquisition)
system.
The major pressure zones have at least one reservoir to regulate pressures and provide operational and ffre
flow storage, with the exception ofthe 580 Zone. The 580 Zone is suppUed dfrectly from the TAP No. 4
aqueduct coimection. To regulate pressures in the 580 Zone, a pressure sustaining valve assembly is
utilized which passes flow to tiie 446 Zone TAP Reservofr. In the event of a loss of water supply, a
booster pump station can deliver 1,500 gaUons per minute (the required residential fire flow) from the 446
Zone back to the 580 Zone.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 3-4 March 2003
Table 3-3
EXISTING RESERVOIR SUMMARY
Reservoir Supply Tank Type
Bottom
Elev.
(ft)
Hi-water
Level
Tank
Height
(ttl
Tank
Dia.
Storage
Capacity
(MG)
Reservoir Supply
Name Zone Tank Type
Bottom
Elev.
(ft) (ft)
Tank
Height
(ttl (ft)
Storage
Capacity
(MG) Supply Source Normal Fill Operation
Santa Fe II 700 Circular pre-
strpssfiri mnr.rfitfi 700.0 732.0 32.0 219 9.0 SDCWA Conn. #1 Direct from SDCWA #1
La Costa Hi 700 Circular pre-
.'5trfi.«!Sfiri mnnrfitfi 700.0 727.0 27.0 194 6.0 SDCWA Conn. #2 Direct from SDCWA #2
Santa Fe P' 700 Circular 660.0 685.5 27.5 125 2.5 SDCWA Conn. #1 Disconnected from
.system in 1987
Maerkle
Reservoir 490
reinforced concrete
baffled reservoir
w/nhloramination
491.3 514.0 22.8
267x
215
(rect.)
10.0 Maerkle Dam or
TAP #3
Pumped from Maerkle
Dam and/or direct from
TAP #3
Maerkle Dam 490
(pumped)
lined dam with
floating cover 442.5 500.0 61.0 -195.0 TAP #3 Direct from TAP #3
TAP 446 Circular pre-
stressed concrete 446.0 473.0 27.0 194 6.0 TAP #4 Through 580 Zone from
SRn=>44R TAP #4 PSV
Cannon "C'^' 392 circular steel 392.0 423.0 31.0 75 1.0 Maerkle Reservoir periodic fill with manual
valve'^>
D-3 375 circular steel 375.0 430.0 55.0 175 8.5 Santa Fe II Res.
via 550 Zone
550=>375 PRV &
throttled 12" plug valve
Ellery 330 circular steel 330.0 352.5 22.5 194 5.0 Maerkle Reservoii Ellery Reservoir PSV
4C)n=>:^3n
La Costa Lo 318 circular steel 318.0 356.5 38.5 81 1.5 La Costa Hi/ D3 /
Santa Fe 11 Res.
remote PRVs in 318
Zone
Buena Vista
Fore bav
330
(pumped' circular steel 223 243 20.0 9 0.01 Skyline Reservoir Used in emergency only
Skyline 255 circular steel 241.0 263.5 22.5 106 1.5 Maerkle/TAP
Reservoirs
remote PRVs; tank has
12" altitiidfi valve
"E" 255 circular steel 264.0 302.5 38.5 81 1.5 D3 Reservoir
throttled 8" plug valve;
B'Fly valve downstream
controls tank level.
Elm 255 circular steel 255.0 277.5 22.5 106 1.5 Maerkle/Ellery
Reservoirs
remote PRVs; tank has
12" a'titude valve
RESERVOIR CAPACITY TOTAL: 249.0 MG
(1) Santa Fe 1 Reservoir is proposed to be used in the recyded water
(2) Cannon "C" tank is being eliminated from the potable water system.
system in the future,
and will be used in the Phase 11 Recyded Water System beginning 2004.
3.3.4 Pump Stations
There are four booster pump stations in tiie CMWD distribution system. Three are used for emergency
purposes and the fourth, tiie Maerkle Reservoir Pump Station, suppUes water from Maerkle Dam mto
Maerkle Reservoir. Under normal operations, this pump station is operated to circulate water in Maerkle
Dam. In addition, the CMWD owns a frailer-mounted pump tiiat can be used in emergency conditions.
The location of each pump station is shown on Exhibit 1 in Appendix A and a summary of each
pemianent pump station is provided in Table 3-4.
CMWD
WATER MASTER PLAN UPDATE 3-5
Dudek & Associates, Inc.
March 2003
Table 3-4
PUMP STATION SUMMARY
Pump
Station
Suction Zone =>
Discliarge Zone
Station
Capacity
(gpm)
lUotor
Size/Type
Back-Up
Power Comment
Maerkle
Reservoir
Maerkle Dam =>
Maerkle Reservoir 7000 3-150
HpA/FD
450 KW
Generator
2 - 7 5 Hp solution pumps &
1-1% Hp mixing pump are in
building
Ellery 330 => 446 1200
1000
1-50 Hp
1-40HpA/FD None
Pump may operate during
peak demand periods In
response to a pressure drop.
Calavera
Hills 446 => 580 1500 2 - 75 Hp None Emergency use only
(580 Zone has no storage)
Buena Vista 255 => 330 1700 2-150 Hp None Emergency use only.
10,000 gal forebay
The 580 Pressure Zone is provided with emergency booster pumping from the Calavera Hills Pump
Station located near tiie TAP Reservofr. The station has a capacity of 1,500 gpm to provide the requfred
fire flow for tiie residential area. The electiical confrols at the EUery Pump Station are in need of
replacement, which is scheduled to occur within the next year.
3.3.5 Pressure Regulating Stations
The CMWD utilizes pressure regulating stations to supply water to lower pressure zones from higher
zones. The pressure regulating stations typically include combination pressure reducing and pressure
sustaining valves (PRV/PSV). A combination PRV/PSV operates by reducing tiie downsfream pressure
for as long as the upstream pressure does not drop below a set point, fri the event that the upsfream
pressure drops to the set point, the combination valve wiU switch to a pressure sustaining mode,
effectively sacrificing the lower pressure zone setting to maintain the minimum upstream pressure.
Under normal operations, a combination PRV/PSV operates in a pressure reducing mode.
The water distribution system operates with over 50 pressure regulating stations, and each station has one
or more valves. Several stations operate in pure sustaining mode and several in pure reducing mode, but
the majority ofthe stations have at least one combination PRV/PSV. There are also a few stations with
plug valves. A summary of the main stations is provided ui Table 3-5. Included in the table are the
number, type and size ofthe valves and the current valve settings, as provided by CMWD operation staff.
CMWD
WATER MASTER PLAN UPDATE 3-6
Dudek & Associates, Inc.
March 2003
Table 3-5
CONTROL VALVE SUMMARY
Supply
Zone Station Name
Pressure Zone Elev
(feet)
Valve
Type
Valve
Size
(in.)
Valve setting'
Comments Supply
Zone Station Name Station
No. Up j Down Elev
(feet)
Valve
Type
Valve
Size
(in.)
doYvAetream
qrade
upstream
qrade
Comments
680
Alga Road PRV #1 1 7003 => 680 438 PRV 8 95 657 Only supply to zone Alga Road PRV #1 1 7003 => 680 438 PRV 12 90 646 Only supply to zone
SSO
TAP #4 Cannon 124 CWA => 580 403 PSV 12 230 — 934 Note: Hydraulic grade in 580 Zone is set
bv the Elm TAP PSV f580=>490>
5805
La Golondria 55 680 => 580S 356 PRV 2^6 90 564 Primary; 6" PRV set at 72psi La Golondria 55 680 => 580S 356 Pf>V 6 IPO 587 Primary; 6" PRV set at 72psi
Colibri PRV 20 680 => 5803 397 PRV 6 62 540 Secondary
550 , . _.
North Point D 88 700N => 550 283 PRV 6/8 105 525 Backup North Point D 88 700N => 550 283 PSV 6/8 1fiS 664 Backup
South Point D 87 700N => 550 283 PRV 12/16 115 548 Main station South Point D 87 700N => 550 283 PSV 12/16 165 664 Main station
550E
Rancho Poncho 156 7003 => SSOE 192 PRV m 130 492 Rancho Poncho 156 7003 => SSOE 192 PSV fi/R ?00 653
Melrose 143 700N => 550E 322 PRV 6/10 80 507
810
Unicomio 125 680 => 510 346 PRV 6 40 438 Backup
El Fuerte and Bolero 34 680 => 510 400 PRV 6/10 45 504 Primary Feed El Fuerte and Bolero 34 680 => 510 400 PSV 10 100 631 Primary Feed
Alga Road Station #2 2 680 => 510 383 PRV 8/10 50 498 Backup Alga Road Station #2 2 680 => 510 383 PSV 8/10 105 625 Backup
490
Maerkle Control Vaull 65 550 =>490 305 PLUG 20 Throttled to -0-5 cfs; adiusted priodicallv
Elm TAP 41 580 =>490 PSV 8 0 normally closed (manual operation)
44B
TAP #4/Hi-Low Vault 122 580 => 446 440 PSV 10/10 50 556 SUDDIV to TAP Res.; Sets 580 Zone qradi
Olympia 77 580 => 446 285 PRV 6/12 64 433 Backup Olympia 77 580 => 446 285 PSV B/12 fM 479 Backup
Rising Glen 91 490 => 446 127 PRV 2/8 140 450 Usually dosed; 2 & 8" PRV have the
same settina Rising Glen 91 490 => 446 127 PSV 2/8 ISO 474
Usually dosed; 2 & 8" PRV have the
same settina
Laquna Riviera 56 490 => 446 46 PRV 6 165 427
Chestnut 17 490 => 446 270 PRV 4/8 65 466 May run Chestnut 17 490 => 446 270 PSV 8 95 489 May run
6-line valve vault 4 490 => 446 PLUG 14 normallv not active
College East 21 550 => 430 206 PRV 6/8 98 432 Always runs College East 21 550 => 430 206 PSV 6/8 120 483 Always runs
Halley 46 550 => 430 205 PRV 6/8 98 431 Always runs Halley 46 550 => 430 205 PSV 6/8 100 436 Always runs
375
D Reservoir 28 550 => 375 370 PRV 8/12 24 425 Fills Reservoir, Downstream 12" plug
valve limits flow rate (28-32% ooen) D Reservoir 28 550 => 375 370 PSV fl/12 4,'> 474
Fills Reservoir, Downstream 12" plug
valve limits flow rate (28-32% ooen)
College West 22 550 => 375 234 PRV 6/12 65 384 Primary College West 22 550 => 375 234 PSV 6/12 100 465 Primary
Palomar Oaks 82 550 => 375 194 PRV 6/10 60 379 Always runs; 10" PRV set at 65 psi Palomar Oaks 82 550 => 375 194 PSV 6/10 115 460 Always runs; 10" PRV set at 65 psi
Grosse 43 490 => 375 95 PRV 6 130 395 SuDDlies isolated oortion of zone
Lower Faradav 170 430 => 375 120 PRV 4/6 105 363
Jackspar 48 430 => 375 105 PRV 4/6 100 336 Supplies Isolated portion of zone Jackspar 48 430 => 375 105 PSV 120 — 382 Supplies Isolated portion of zone
CMWD
WATER MASTER PLAN UPDATE 3-7
Dudek & Associates, Inc.
March 2003
Table 3-5 (Continued)
CONTROL VALVE SUMMARY
Supply
Zone Station Name
Pressure Zone Elev
(feet)
Valve
Type
Valve
Size
(ml
Valve setting*
Comments Supply
Zone Station Name No. Up j Down
stream 1 siream
Elev
(feet)
Valve
Type
Valve
Size
(ml (psl> dowirsiream
qrade
upstream
grade
Comments
349
Tamarack Point 105 446 => 349 170 PRV 2/8 60 308 Tamarack Point 105 446 => 349 170 PSV e 85 366
330
Ellery Reservoir 37 490 => 330 326 PSV 14 72-80 492-511 Supplv to reservoir; adiusted periodically
Donna and Basswood 25 446 => 330 245 PRV 8 35 326 Fire Flow onlv
Clearview 19 446 => 330 248 PRV 6 35 329 Fire Flow only Clearview 19 446 => 330 248 PSV 6 50 364 Fire Flow only
31B
Ayres PRV 3 550 => 318 196 PRV 6/12 60 334 Control by Telemetry; Big AM feed Ayres PRV 3 550 => 318 196 PSV 12 120 473 Control by Telemetry; Big AM feed
La Costa Low 52 510 => 318 310 PSV 12 100 541 Supply to La Costa Lo Res.; Norm closed
Lower El Fuerte 33 510 => 318 210 PRV 9 62 353 Primarv Feed for 318 Zone
Bolero 6 510 => 318 193 PRV 8 68 350 Backup to No. 33 Bolero 6 510 => 318 193 PSV 8 120 470 Backup to No. 33
Poinsettia 85 375 => 318 124 PRV 4/8 80 309 8" PRV set at 65 psr Poinsettia 85 375 => 318 124 PSV !H 341 8" PRV set at 65 psr
Las Ondas 59 375 => 318 142 PRV 4 78 322 Small valve usually runs Las Ondas 59 375 => 318 142 PRV 8 50 257 Small valve usually runs
Blackrail 5 375 =>318 50 PRV 6/12 116 318 Backup; can be major feed Blackrail 5 375 =>318 50 PSV 6/12 138 369 Backup; can be major feed
2«5
Tanglewood 106 490 => 285 126 PRV 4/10 80 311 Tanglewood 106 490 => 285 126 PSV 10 170 519
Manon /Avenida de Anita 72 255 => 285 check 10 Emeraencv/ Back-uo onlv
2S5
May Co. PRV 73 490 => 255 79 PRV 6/8 81 266 Primary feed May Co. PRV 73 490 => 255 79 PSV 6/8 135 391 Primary feed
Kelly PRV 49 446 => 255 46 PRV 4/6 90 254 4" runs during high demands Kelly PRV 49 446 => 255 46 PSV 4/6 150 393 4" runs during high demands
Sierra Morena 95 446 => 255 105 PRV 8 56 234 Fire flow only; assumed elevation Sierra Morena 95 446 => 255 105 PSV 13f> 417 Fire flow only; assumed elevation
Skyline East 96 446 => 255 105 PRV 2 60 243 Supply to Skyline Res.; Normally closed Skyline East 96 446 => 255 105 PSV 8 90 313 Supply to Skyline Res.; Normally closed
•E" Vault 32 37S => 255 251 PLUG 8 adjusted to < 1/4 open Supply to "E" Res.; Bfly valve on res.
outlet limits flow from tank
Palomar West 83 375 => 255 78 PRV 6/8 73 246 Secondary feed; Usually runs Palomar West 83 375 => 255 78 PSV 6/8 115 344 Secondary feed; Usually runs
Cannon 15 375 => 255 125 PRV 478 45 229 — Backup
Pine 84 330 => 255 138 PRV 3/8 45 242 Larger valve fire flow only Pine 84 330 => 255 138 PSV 3/B 75 — 311 Larger valve fire flow only
Elm Res PSV 40 330 => 255 240 PSV 10 45
—
344 SuDolv to Elm Res; Normallv closed
Buena Vista 7 330 => 255 178 PRV 6/12 30 247 — adjusted periiodically to run water thru 6"
Encinas 42 318 => 255 42 PRV 8 85 238 Back-up/fire flow Encinas 42 318 => 255 42 PSV 8 100 273 Back-up/fire flow
Hilton 111 318 =>255 46.5 PRV 4 85 243
IM fonvate svstam\
Terramar #1 107 490 => 374 50 PRV 8 90 258 Supplies mobile homes; There are 2
PRVs inseries Rancho Carisbad 89 374 => 198 50 PRV 6 60 188
Supplies mobile homes; There are 2
PRVs inseries
' For stations with mulipte reducing valves, setting proivded is tiased on the smaller valve. The setting for the larger valve is typically 5 to 10 pst lower, unless
noted otherwise. For PRV/PSV combination valves, sustaining setting is typcially 18-20 pounds lower than the normal upstream operating pressure.
CMWD
WATER MASTER PLAN UPDATE 3-8
Dudek & Associates, Inc.
March 2003
3.4 INTER-TIE CONNECTIONS WITH OTHER AGENCIES
The CMWD has several inter-tie connections witii tiie Oceanside Water District (OWD), Olivenhain
Municipal Water District (OMWD), tiie Vista Irrigation Disfrict (VID), and tiie Vallecitos Water District
(VWD), as summarized in Table 3-6. AU but one of tiiese inter-ties, tiie connection witii the VWD tiiat
suppUes water from tiie SDCWA No. 2 connection, are for use in the event of a planned aqueduct shut
down or in the event of an emergency. There are a wide variety of physical inter-tie configurations,
ranging from pressure conttol faciUties with flow meters to a simple isolation valve, which could be
opened manually to supply an isolated area ofthe distribution system. It is noted that many ofthe inter-
tie connections with only closed valves are potential two-way connections that have never been used.
Table 3-6
OTHER AGENCY INTER-TIES
Agency Location Capacity Purpose Other Agency
Zone
Carlsbad
2one Flow Control
Oceanside El Camino Real /
Hvw78 5 cfs Supply during aqueduct
shut down / Emergencv
Henie Hills
HWL =409' 255 12" pipeline with plug
valve and meter
Oceanside College Blvd /
City limits -Supply during aqueduct
shut down / Emergency
San Francisco
Peak-481' 446 PRV for flow to
Carlsbad & meter
OMWD La Costa Ave / El
Camino Real 5 cfs Fire flow conn, to OMWD
/ Emergency 437 318 12" pipeline with 10"
PRV set to 40 Dsl
OMWD Calle Madero -Emergency Connection 437 318 Closed valve on 8"
pipeline
OMWD Nueva Castilla -Emergency Connection 437 318 Closed valve on 12"
pipeline
OMWD La Costa Ave /
Romeria -Emergency Connection 437 318 Closed valve on 8"
pipeline
VID Palomar Airport Rd /
Business Park Dr 3.3 cfs Supply to CMWD during
aoueduct shut down 690 700 Temp, pump installed
with meter
VWD El Fuerte / Corintia -Emergency Connection 686 700 Closed valve on 12"
pipeline
VWD Melrose / Alga -Emergency Connection 815 700 Closed valve on 12"
pipeline
VWD San Marcos Blvd /
RSF Road Emergency Connection 855 700 Closed valve
VWD East of El Fuerte /
Alga Rd. 13.3 cfs Supply to CMWD from
SDCWA Conn. No. 2 815 700 27" pipeline with flow
control valve & meter
3.5 DAILY OPERATIONS
The CMWD water distribution system is flexible in tiiat supply from tiie four aqueduct connections can
be routed to different parts of the distribution system by making changes to several key valve settings.
This allows system operators to balance reservofr levels and correct for discrepancies in tiie amoimt of
water ordered versus the amount that is deUvered through service coimections. Reservofr water levels and
several confrol valves are coimected to the CMWD SCADA system so that some operational changes can
CMWD
WATER MASTER PLAN UPDATE 3-9
Dudek & Associates, Inc.
March 2003
be made remotely from the water operations center. Water Operations staff has stated tiiat several
operational changes and adjustments are typically made each day during peak demand periods. Changes
that may be made under normal supply operations include:
• The Maerkle confrol valve stiiicture consists of a 20-inch plug valve tiiat separates the 490 Zone
from the 550 Zone. Flow through tiiis valve is metered and the valve may be closed or tiirottled to
allow excess supply from tiie 700 Zones via tiie 550 Zone into the 490 Zone. Under emergency
supply scenarios tiie valve can be opened to supply the 550 Zone from Maerkle Dam.
• The 375 Zone D3 Reservofr can be suppUed from the 550 Zone via a pressure reducing station
located adjacent to the reservofr. Downsfream of tiiis station is a 12-inch plug valve, which is
typically throttled from 28 to 32 percent open to regulate reservoir water levels. Water supply to
tiie D3 Reservoir can decrease significantly when supplemental potable water is suppUed from the
550 Zone to the adjacent recycled water tanks.
• Supply to tiie 330 Zone EUery Reservofr from tiie 490 Zone is controlled by a pressure sustaining
valve. The setting of tiiis valve is adjusted periodically, and typically ranges between 72 and 80
pounds per square inch (psi).
• The Aryes PRV suppUes the 318 Zone from tiie 550 Zone. The valve setting can be changed by
telemetry and is adjusted to regulate water levels in the 318 Zone La Costa Lo Reservofr.
• The Cannon C Reservofr estabUshes a 392 Zone tiiat currentiy serves several agricultural
customers. Supply to tiiis reservofr is from the 490 Zone from a manual valve tiiat is periodicaUy
opened to fill the reservofr. It is noted tiiat tiie C Reservoir is planned to be removed from tiie
potable water system in 2004 and wiU be used in the recycled water system.
• The 255 Zone E Reservoir is at a significantly higher elevation than tiie otiier two reservoirs in tiie
255 Zone. Because of this, the E Reservoir cannot "float" on the system and is considered an
emergency storage reservofr only. Supply to tiie E Reservoir from tiie 375 Zone is conttolled by a
plug valve, which is typically set at less than 25 percent open. A butterfly valve on the outiet
piping is throttled to conttol the reservofr supply rate.
With tiie exception of tiie confrols described above, supply to most storage reservofrs in the distribution
system is from pressure reducing stations remotely located from tiie tank at the edges of tiie service zone.
Most reservofrs also have a dfrect supply to the tank, which is typically controlled by a valve setting to
operate closed. These valve settings can be opened manually as needed to provide additional supply to
the reservoirs. It is also noted that most reservoirs in the system do not have altitude valves.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 3-10 March 2003
3.6 EMERGENCY SUPPLY OPERATIONS
During planned shutdowns of tiie SDCWA aqueduct, which are normally scheduled for up to 10 days
during the winter, most of the CMWD is suppUed from Maerkle Dam through the 490 Zone Maerkle
Reservofr. Supply to tiie 550 Zone is accompUshed by closing off tiie normal supply from tiie 700 Zone
(closing valves at pressure reducing stations) and opening the by-pass valve in tiie "Maerkle Confrol"
vault. This allows tiie 490 Zone to supply tiie 550 Zone and effectively operate as a single pressure zone.
Under normal operations existing pressures in tiie 550 service area are generally over 90 psi. Under
emergency supply conditions pressures drop by approximately 25 to 35 psi, but are stiU high enough to
meet minimum pressure criteria.
During an aqueduct shutdown the 700, 680, 580N and 510 Zones are currently suppUed from the 700
Zone reservoirs (Santa Fe n and La Costa Hi) and an inter-tie witii tiie VID. The VID shares ownership
of a water freatment plant with the City of Escondido, and is tiierefore not completely dependent on
supply from tiie freated water aqueduct. To boost VID system pressures and supply tiie 700 Zone, a
rented water pump is instaUed at tiie inter-tie and operated at a capacity of approximately 1,500 gpm. To
minimize the impact on the VID distribution system, the pump is not operated during the moming peak
demand period. Supply to Carlsbad from the VID inter-tie is metered.
3.7 WELL WATER AND SURFACE WATER SUPPLIES
The CMWD has groundwater rights in tiie San Luis Rey Basin of 750 acre-feet per year, which is Usted in
State Water Resources Account No. 37-004C. CMWD owns nine groundwater wells located in
Oceanside that have not been used for over tiifrty years. The location ofthe weUs are shown in Figure 3-
3. These wells do not currently contribute to the potable water distribution system. In 2003, CMWD wiU
be removing aU nine weUs in accordance witii CaUfomia State Health Department requirements.
Groundwater wells were also constructed in the vicinity of Carlsbad Ranch Mobile Home Park. Some of
these wells are stiU used to supply water to the private golf course in the area. Additional Information on
the groundwater weUs is provided in the Water Resource Master Plan, Volume II of tiie 1997 Master Plan
Update.
CMWD also has capacity rights to surface water in two locations. The first includes 750 acre-feet per
year tributary to Lake Calavera. In tiie 1950's there was a water tteatment plant downstteam of the Dam
for Lake Calavera. Surface water coUected in the reservofr was tteated and then suppUed in a
ttansmission main to tiie Terramar Area of Carlsbad. The second area of surface water includes capacity
rights to 500 acre-feet per year ttibutary to Maerkle Dam.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 3-11 March 2003
Legend
WELL LOCATIONS
FIGURE 3-3
CARLSBAD MUNICIPAL WATER DISTRICT
SAN LUIS REY GROUNDWATER WELLS
& ASSOCIATES, INC.
03-2003 Cat1sbadwa33.mxd
3.8 Water Quality
Maerkle Dam provides storage capacity for daily operational needs and suppUes the distribution system
when imported water is not available from the SDCWA (due to aqueduct and freatinent plant shutdowns).
The dam is also used to maintain sufficient local storage to meet tiie City's "Growtii Management
Requfrement", which states that the CMWD is to maintain 10 days of storage for the distribution system.
These storage requfrements, however, are affecting CMWD's abiUty to maintain water quality in Maerkle
Dam.
The freated water purchased from the SDCWA uses chloramines as the secondary or residual disinfectant.
The water therefore contains low concentrations of ammonia, which serves as a potential source of
reduced nifrogen. Due to the presence of ammonia combined with the long residence time in Maerkle
Dam, additional tteatment of the water is required to avoid water quality compUcations due to
nittification. Nitrification is the resuU of biological conversion of ammonia to nitrite, which represents
an oxidant demand. Historically, CMWD practiced breakpoint chlorination to remove tiie ammonia and
produce a free chlorine residual in the reservoir influent water. However, this practice fonned high
concenttations of disinfection byproducts (DBPs) and may have adverse consequences for water system
operation and compliance with the newly effective Stage 1 Disinfectants and Disinfection Byproducts
(D/DBP) Rule and tiie soon to be proposed Stage 2 D/DBP Rule.
To address both the elevated DBP formation and tiie potential for nitrification, CMWD requested an
amendment to its "Domestic Water Supply Pemiit" to test tiie use of chlorine dioxide for conttol of DBP
fonnation and nitrification. An amendment was issued on June 5, 2002 by tiie CaUfomia Department of
Healtii Services (DOHS) under pennit amendment 05-14-02PA-002. On June 19, 2002, CMWD
discontinued its current practice of breakpoint chlorination and began testing the use of chlorine dioxide
to reduce organohaUde DBP formation and produce a new byproduct, chlorite, to conttol nittification.
Monitoring results for chlorine dioxide in the unblended Maerkle Dam effluent feed show very steady,
predictable, and satisfactory results. The chlorite dioxide residual in the reservofr efEluent is well below
0.64 mg/L (80 % of Maximum Residual Disinfectant Level) and tiie daily chlorite level in the reservoir
effluent was weU below 0.80 mg/L (80% of tiie Maximum Contaminant Level). The weekly nifrite level
in the reservofr effluent has stayed below 0.010 mg/L with a stable chloramine residual being observed
(-1.0 mg/L), even after several months of detention in the reservoir.
Witii tiie cessation of breakpoint chlorination, TTHM concenfrations in the Maerkle Dam effluent are
rapidly decreasing, and disfribution system concenfrations also appear to be decreasing. TTHM in the
Maerkle Dam effluent have now approached the influent concenttations found in the tteated water supply
from the SDCWA. For these reasons, CMWD plans to continue the use of chlorine dioxide.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 3-12 March 2003
CHAPTER 4
EXISTING WATER DEMANDS
As population expands and the northem coastal areas of San Diego County continue to develop, the City
of Carlsbad has experienced graduaUy increasing water demands. This chapter documents existing
potable water demands within the water service area. Historical water demands are summarized and
water system peaking is analyzed and described. Peaking curves for two high demand days are developed
based on recent flow data. Finally, unit demands are developed for residential and commercial/industrial
areas.
4.1 HISTORICAL WATER CONSUMPTION
Historical water consumption for the CMWD potable water system over the past eleven years is
graphically illusfrated on Figure 4-1. The consumption data was obtained from CMWD production
reports, and is based on the water supplied from the SDCWA plus any net gain or loss in the volume of
water in Maerkle Dam. Both the average annual and maximum day deUvery rates are shown as well as
the maximum/average ratio for each year. This ratio, which is referred to as the maximum day peaking
factor, is used to size distribution system faciUties.
There has been a gradual increase in the average annual water consumption rate from 12.6 MGD in 1991
to 16.8 MGD in 2001. This is approxunately a 30 percent increase, or an average annual increase in the
water demand of approximately 3.0 percent. In 2002 the average consumption rate increased to 19.7,
primarily due to high winter demands resulting from a lack of rainfaU. The maximum 24-hour flow rate
deUvered over the past eleven years is more varied, ranging from 31 MGD in 1992 down to 20 MGD in
1996 and back up to 27.3 MGD in 2002. Witii tiie exception of 1991 and 1992, the maximum day
peaking factor has ranged between approximately 1.4 and 1.7 for the past decade.
The historical water usage reflects the decrease in potable water irrigation demands due to the start-up of
the CMWD Recycled Water System. The CMWD began delivery of recycled water in the faU of 1991.
Constmction of the Phase I Recycled Water System is now complete, and deliveries from this system
have steadily increased to approximately 1.9 MGD in fiscal year 200-2001. The recycled water deliveries
include approximately 0.36 MGD of supplemental potable water supplied to the recycled water system at
the "D" Tanks. It is noted that a portion of the existing irrigation demands ciurently served from the
potable water system have been identified as future recycled water system customers when the Phase n
Recycled Water System is constracted.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 4-1 March 2003
Figure 4-1
CMWD HISTORICAL DEMAND BASED ON SDCWA PURCHASES
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
lAverage Day Demand iMax Day Demand (x.x) Max Day/ADD Peaking Factor
4.2 EXISTING WATER CONSUMPTION
CMWD monthly water billing records for 2001 were obtained and analyzed to establish the existing water
demands and distribute water demands in the distribution system hydraulic model. Raw data ofthe 2001
monthly billing records used to create the summary is available at the CMWD. The billing accounts were
averaged over the 12-month period to determine the average day demand (ADD). For accounts with less
than 12-months of service, the water usage was averaged over the number of months in service.
The CMWD identifies 12 categories of water users for billing purposes. For this Master Plan Update,
several categories were combined and a summary of the resulting six demand categories is presented in
Table 4-1. The number of customers and the total demand per account type in 2001 are shown in Table
4-2. The total average rate of water supplied for 2001 based on CMWD billing records is 16.2 MGD.
The total amount of water billed in 2001 does not exactly match the volume of water entering the
distribution system. The difference between the SDCWA water purchased (and the gain/loss of stored
water in Maerkle Dam), and the amount that is billed to CMWD customers is "unaccounted for" water.
In most water distribution systems, the bulk of "unaccounted for" water is due to system leakage, meter
inaccuracies, and unmetered water consumption from fire fighting, street cleaning, and construction uses.
For the CMWD, the unaccounted for water in 2001 is calculated to be 221 MG, or an equivalent flow rate
CMWD
WATER MASTER PLAN UPDATE 4-2
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March 2003
of 0.61 MGD. This is 3.6 percent ofthe total amount entering the disttibution system. Water loss in the
CMWD over the past ten years has typically been between two and five percent.
Table 4-1
WATER DEMAND CATEGORIES
CATEGORY BILLING RECORD METER TYPE
Single-Family Single Family and Duplex accounts
Multi-Family Multiple and Multiple PDU
Commercial/industrial Commercial (Commercial/Industrial) and Institutional
Agriculture Includes Ag, Ag Rebate and Ag w/House account types
Irrigation Irrigation
Temporary Potable Temporary Potable and Fire Protection
Table 4-2
2001 WATER DEMAND BY CATEGORY
Category No. of
Accounts
%of
Total
Aim
PGD)
%-of •
totai
ADD per
Account
(GPD)
Single-Family 18,683 85.6% 7.22 44.7% 386
Multi-Family 662 3.0% 1.57 9.7% 2,371
Commerical/I ndustrial 1,185 5.4% 2.75 17.0% 2,321
Agriculture 42 0.2% 0.84 5.2% 19,999
Irrigation 681 3.1% 3.65 22.6% 5,359
Temp Potable 585 2.7% 0.13 0.8% 222
Totals: 21,838 100% 16.2 100%
The percentage ofthe total system demand for each water use category based on the ADD is illustrated on
Figure 4-2. As can be seen from the chart, residential water use accounts for 54 percent ofthe total water
demand. Commercial/Industrial/Institutional water use and irrigation demands make up 17 and 23
percent, respectively, of the total water demand. It is noted that the inigation demands do not include
users suppUed from the CMWD Recycled Water System, as recycled water users are identified with
separate recycled water account types. However, supplemental potable water is suppUed to the recycled
water system during peak demand periods at tiie D Tanks. The supplemental potable water is delivered
through an irrigation meter, and tiiis demand is therefore included in the irrigation demands. Agricultural
water demands cunentiy account for approximately five percent of the total water use.
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WATER MASTER PLAN UPDATE 4-3
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March 2003
Figure 4-2
2001 WATER DEMAND BY CATEGORY
Single-Family
Residential
44%
Multi-Family
Residential
10%
Commercial/
Industrial
17%
Temporary
1%
Irrigation
23%
Agriculture
5%
4.3 DEMANDS PER PRESSURE ZONE
CMWD water billing data for 2001 was used to determine the existing demand served within each
pressure zone. The multi-step process used to generate this information involved the use of advanced GIS
techniques, a graphical representation of each pressure zone, and water meter accounts that were
assigned an Assessor Parcel Number (APN) by City staff
The City parcel base map was used to locate the water accounts. The APN value from the billing
information was matched to APN fields in the parcel GIS layer. City staff was not able to provide an
APN for all the billing accounts. For accounts without APNs but with a street address, the address was
used to approximate the account location by a process called geo-coding. A small percentage of billing
accounts lacked either an APN or an address. These accounts were mostly irrigation or agriculture
accounts. There were also accounts with both APNs and addresses that did not match up with the City
parcel base. These accounts were found to be mostly in new developments. The accounts that could not
be located using GIS techniques were sorted by demand. The 20 accounts with the highest demands were
manually located based on consultation with the CMWD billing department. Of the 16.2 MGD of total
system demand, 14.9 MGD or 92 percent of the demand was successfully located. The remaining 1.3
CMWD
WATER MASTER PLAN UPDATE 4-4
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March 2003
MGD of flow was distributed evenly over aU the meter accounts to account for unlocated demands and
match the total ADD for the system.
To assign meter account data to pressure zones, a pressure zone service area map was first created. The
pressure zone map provided digitally from the last Master Plan was updated to reflect recent constraction.
The pressure zone service areas were then reviewed and conected by City Operations staff. The existing
demand per pressure zone, provided in Table 4-3, was created from an intersection ofthe pressure zone
map and the modified billing accounts database.
Table 4-3
AVERAGE DAY DEMAND BY PRESSURE ZONE
Pressure
Zone
Tota) Demand per Account Type (gpm) Total Demand Pressure
Zone SF MF Comm/
Indust irrig Ag Temp/
Fire flow (gpm) (MGD)
198 0 27 1 0 24 0 52 0.08
255 788 461 803 271 243 9 2,576 3.71
285 79 7 11 11 0 1 110 0.16
318 965 300 366 450 0 3 2,083 3.00
330 606 64 37 41 32 15 796 1.15
349 46 0 0 8 0 0 54 0.08
375 683 74 218 129 212 12 1,326 1.91
430 50 25 11 26 0 3 115 0.17
446 935 36 12 106 55 0 1,143 1.65
490 1 0 12 5 0 0 17 0.02
510 139 0 1 0 0 1 140 0.20
550 351 79 395 760 90 40 1,716 2.47
580N 231 0 1 49 0 0 281 0.41
580S 46 0 0 0 0 0 46 0.07
680 286 0 0 0 0 0 286 0.41
700N 186 31 42 235 0 3 498 0.72
700S 3 0 0 27 0 1 31 0.04
Totals: 11,272 16.23
Note: SF- single family residential
MF - multi-family residential
CMWD
WATER MASTER PLAN UPDATE 4-5
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March 2003
4.4 EXISTING SYSTEM PEAKING
Water demands are typically presented in terms of the average annual water consumption. Actual water
use, however, follows a widely varying pattem in which flows are sometimes weU below or far greater
than "average". Flow variations are commonly expressed in terms of peaking factors, which are
multipUers to express the magnitude of variation from tiie average day demand (ADD). Peaking factors
are commonly used to express the system maximum and minimum month demand, the maximum day
demand (MDD), and the peak hour demand. The 2001 system demands are summarized in Table 4-4 and
described in detail in the following sub-sections.
Table 4-4
SUMMARY OF 2001 SYSTEM DEMANDS
Average D^y | 16.2 MGD 25.1 CFS
Minimum Month , 8.0 MGD 12.4 CFS
Maximum Month 23.0 MGD 35.6 CFS
Maximum Day 26.5 MGD 41.0 CFS
Peak Hour 46.6 MGD 72.1 CFS
4.4.1 Seasonal Demand Variations
CMWD water billing records were utilized to determine the seasonal variation in water demands.
The monthly peaking based on billing records for the past five years is illusfrated on Figure 4-3.
Also included on this chart is a trendline of the data. From this chart it is apparent that the
maximum montii demand is approximately 1.5 times the average day demand, and the maximum
water usage typically occurs in August or September. The minimum month demand is
approximately half of the average day demand, and the minimum water usage typically occurs in
February or March.
CMWD
WATER MASTER PLAN UPDATE 4-6
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Figure 4-3
CMWD SEASONAL DEMAND VARIATIONS
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1997 1998 1999 •2000 2001 •Trendline
4.4.2 Maximuin Day Demand
The MDD represents the maximum consumption during any one day of the year. The maximum day
peaking factor is expressed as a ratio of the maximum day demand divided by the ADD. The ratio
generally ranges from 1.2 for very large water systems to 3.0 or even higher for specific small systems.
For the CMWD, the single day with the maximum water consumption normally occurs during a dry,
windy day between July and September.
Table 4-5 lists the day with the maximum water delivery and the amount of water delivered based on
SDCWA purchase records over the past ten years. It is noted that the maximum water demand can only
be approximated from water delivery records. The actual water consumption on a daily basis may not
equal the water delivered, since the volume of water storage may not be the same at the start and the end
of the day. As an example, the maximum day demand listed in Table 4-4 is higher than the recorded
water purchase on July 27, 2001 based on the more detailed analysis in the following sub-section.
CMWD
WATER MASTER PLAN UPDATE 4-7
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March 2003
Table 4-5
HISTORICAL MAXIMUM DAY WATER PURCHASES
Year Maximum Delivery
Day Water Delivered
2001 Julv 27 25.99 MG
2000 August 13 25.19 MG
1999 Julv 15 26.55 MG
1998 August 19 22.49 MG
1997 September 3 21.86 MG
1996 Julv 27 19.90 MG
1995 June 21 20.99 MG
1994 Julv 19 21.96 MG
1993 Julv 20 21.38 MG
1992 September 3 31.48 MG
1991 Julv 10 24.10 MG
The peaking factors corresponding to the maximum day demands listed above were shown previously in
Figure 4-1 and ranged from approximately 1.5 to 1.7. Botii tiie 1990 and 1997 Master Plans are based on
a maximum day peaking factor of 1.65. This value is still representative of the peaking that has occurred
over the past several years. For existing and future analysis of the distribution system, the same
maximum day peaking factor of 1.65 wiU continue to be used.
4.4.3 Peak Hour Demand
The maximum flow rate delivered by the distribution system on any single hour during the year
corresponds to the peak hour water demand. The peak hour peaking factor is the peak hour water demand
divided by the ADD. Peak hour demands typically occur during the moming hours. To detennine the
peak hour demand in the CMWD system, two twenty-four hour periods with high water use were
evaluated. Twenty-four hour demand curves were generated for July 27, 2001 and August 3, 2001 based
on SDCWA delivery rates, the pumped supply rate from Maerkle Dam, and recorded reservoir levels.
From tiie reservofr levels and tank dimensional data, the hourly volrnne of water entering or exiting each
tank was calculated. The hourly system demand was then calculated based on the SDCWA deUvery rate
plus the total net flow rate into or out of the reservoirs (negative flow for tanks filling, positive flow for
tanks emptying).
CMWD
WATER MASTER PLAN UPDATE 4-8
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March 2003
FIGURE 4-4
RESERVOIR LEVELS AND DIURNAL DEMAND CURVE FOR JULY 27, 2001
9 11 13
Time (Hours)
Santa Fe
Elm
LaCosta High
Tap
La Costa Low
Ellery
D-3
Maerkle Tank
Skyline
60
50
Q
C2 40
c
03
0)
Q
in
C/)
10
Pk Hr demand • 7/27/01 hourly system demand
46.3 MGD 7/27/01 avg 24-hr demand
2.86 X ADD 2001 Avg Annual Demand
24.8 MGD
1.53 X ADD ^^...^^^ /
3.6
3.4
3.2
3.0
2.8
2.6
2.4 ^
2.2%
2.0 i2
1.8 g>
03
-140
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1:00 3:00 5:00 7:00 9:00 11:00 13:00 15:00
Time of Day
17:00 19:00 21:00 23:00
CMWD
Water Master Plan Update 4-9
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March 2003
FIGURE 4-5
RESERVOIR LEVELS AND DIURNAL DEMAND CURVE FOR AUGUST 3, 2001
9 11 13
Time (Hours)
15 17 19 21 23
' Santa Fe
Elm
LaCosta High
Tap
La Costa Low
Ellery
D-3
' Maerkle Tank
Skyline
60
50
10
Pk Hr demand
46.6 MGD
2.88 X ADD
'8/3/01 hourly system demand
•8/3/01 avg 24-hr demand
'2001 Avg Annual Demand
6
4
2
0
8
6
4 ^
2^
o£
8 ^
03 4 0) ^ Q_
2
0
8
6
4
2
0
1:00 3:00 5:00 7:00 9:00 11:00 13:00 15:00
Time of Day
17:00 19:00 21:00 23:00
CMWD
Water Master Plan Update 4-10
Dudek & Associates, Inc.
March 2003
The reservofr levels and resulting demand curves for both days are shown on Figures 4-4 and 4-5. The
peak hour demand on July 27"" was calculated to be 46.3 MGD and the peak hour demand on August 3"*
was 46.6 MGD. The corresponding peak hour peaking factors for these days are 2.86 and 2.88,
respectively. The previous Master Plan used a peak hour factor of 2.5. Based on this recent data, a peak
hour peaking factor of 2.9 is deemed more representative ofthe existing water system.
It is noted that demand curves for most water districts typically exhibit two peak demand periods, one
during the mid-moming hours and a second, usually lower peak in the evening hours. The CMWD
peaking curves for the days analyzed display a somewhat unusual pattem, exhibiting the typical large
moming peak but no evening peak. Also, the average 24-hour demand on August 3'^ was determined to
be higher than the demand on July 27* which was recorded as the maximum demand day based on the
SDCWA supply rate. On July 27* the water purchased was 1.2 percent greater than the system demand,
whereas on August 3"^ the water purchased was 5.0 percent less than tiie demand.
4.5 EXISTING UNIT DEMANDS
Ultimate water projections are made in this Master Plan Update based on information in the Carlsbad
2001 Growth Database. The Growth Database identifies the number of future single-family and multi-
family residential units and the square footage of fiiture non-residential buildings. Demand generation
factors based on existing conditions are detemiined in the following sub-sections to develop uiut water
demands for ultimate flow projections.
4.5.1 Single-Family Residential Demands
The water demand for single-family residences is comprised of an indoor water use component and an
irrigation component. From Table 4-2 the average demand based on 2001 billing data for single-family
dueling units is calculated at 386 gallons per day (gpd). Using the 2001 billing data, a bell-curve (normal
distribution) graph was prepared to evaluate the range of existing residential demands. Figure 4-6
illusfrates the number of existing residential customers with average demands in 50 gpd increments. As
can be seen from this bar chart, there is a wide disttibution of average demands in excess of the average
demand, which is due in part to the high variation in tiie irrigation demand component. A residential unit
water demand of 576 gallons per day per equivalent dwelling unit (gpd/EDU) was used in the previous
Master Plan for projecting water system demands.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 4-11 March 2003
Figure 4-6
DEMAND DISTRIBUTION FOR SINGLE FAMILY RESIDENTIAL ACCOUNTS
1800
1600
1400 — — — —
2001 SFDU AAD = 386 GPD
— — — —
—
—
—
—
—
—
—
—
n n —
Iln
0) cn c n: 01
-a
i 1200
1000
800
^ 600 o
400
200
N<^^ 'b^^ # ^ # <^ A^ # c,^^
Average Annual Demand (GPD/SFDU)
4.5.2 Multi-Family Residential Demands
Apartments and public dwelling units are billed are assigned multi-family billing accounts. There is
typically one meter for each separate building comprising an apartment complex. Newer developments
have separate irrigation meters for common areas. In older or very small complexes, there may be only a
single multi-family meter. Water records for 2001 were analyzed for two larger complexes to determine
the average unit demand per multi-family unit. The water demand of the associated irrigation meters and
clubhouse facilities (commercial meter) were included in the total demand, so that the unit demand
represents both domestic and irrigation water use.
The multi-family developments analyzed were a low-income housing project consisting of 344 units north
of Cassia Road, and a 585-unit apartment complex known as Tanglewood. The average water demands
per unit for these complexes based on 2001 billings records are 155 gpd and 228 gpd, respectively. The
previous Master Plan used a multi-family unit demand of 144 gpd/EDU for planning purposes. Based on
this updated analysis, a higher unit demand is justified.
CMWD
WATER MASTER PLAN UPDATE 4-12
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March 2003
4.5.3 Industrial/Commercial Demands
An investigation was conducted to determine a representative unit water demand per building area for
industrial business park developments. The sewer service area of the Faraday Upper Lift Station was
analyzed as part of the Sewer Master Plan Update, and this same service area was used to determine the
average unit water demand. The Faraday Upper Lift Station service area is known as the Faraday
Business Park, and consists primarily of office and Ught industrial uses, with a few commercial
establishments. There are no residential units in the service area.
Consistent witii the analysis performed for the sewer system, water records from July 2001 through
February 2002 were obtained from tiie CMWD accounting department staff and reviewed. The Faraday
Business Park is not yet fully developed, and there are numerous buildings within tiie study area that are
vacant or only minimally occupied. Water records from August 2001 were reviewed in detail, and only
parcels with water usage from commercial meter accounts were included in the analysis. The occupancy
of buildings with low water usage was verified by visual observation, and corresponding information on
the building area and parcel size was obtained from tiie City's Growth Database. Each parcel typically
has separate accounts for commercial, irrigation, and fire protection meters. Eighty-one parcels were
included in the analysis with 93 corresponding commercial water accounts (some parcels have more than
one water meter). Demands from irrigation meters for sfreetscaping, which have an address but no
associated APN, were also included in the analysis.
A summary of tiie Faraday Business Park demand data is provided in Table 4-6. In August 2001, the
total commercial demand was approxunately equal to the irrigation demand within the study area. Water
demands for the commercial accounts were highly variable, and the interior water use was generally less
than the on-site irrigation water use. However, the interior water use for CaUaway Golf at 2180
Rutherford Road significantiy increased the commercial account totals. Water delivered to the two active
commercial meters on this parcel amounted to 27 percent of the total water use in the study area for
August 2001. The variance in water usage from commercial and irrigation meters over the seven-month
period analyzed is shown on Figure 4-7.
The unit water demand for the Faraday service, area based on the building size, was detemiined to be
1,200 gpd per 10,000 square feet (sqft) of building area. The previous Master Plan used unit demand
factors based on the lot size, and the industrial unit demand was 2,160 gpd per acre. The unit demand
based on lot size for the Faraday area is calculated to be 1,529 gpd per acre.
CMWD Dudei< & Associates, Inc.
WATER MASTER PLAN UPDATE 4-13 March 2003
Table 4-6
SUMMARY OF FARADAY INDUSTRIAL PARK ANALYSIS
Total Water Consumption in August 2001 -19.840 HCF
Total from Commercial meters -9,863 HCF
Total from on-site Irrigation meters • 8,448 HCF
Total from streetscape Irrigation meters -1,529 HCF
Total Water Consumption in August 2001 • 14.8 MG
Total Area of Included Parcels • 313 acres
Total Building Area -3,990,514 sqft
Total Building Area " 92 acres
Average Building Coverage • 29% of parcel area
August 2001 Unit Water Consumption -3.72 gal/building sqft
Unit water demand -1,200 gpd/10,000 sqft
Unit water demand -0.83 gpm/10,000 sqft
Unit water demand • 1,529 gpd/acre
Note: HFC - hundred cubic feet
Figure 4-7
FARADAY BUSINESS PARK 2001-2002 MONTHLY WATER CONSUMPTION
c o
Q.
E
D
C o o
To
$
_><
c o
July August September October November Decern ber January
CMWD
WATER MASTER PLAN UPDATE 4-14
Dudek & Associates, Inc.
March 2003
In addition to the Faraday Business Park, water demands for restaurants were also investigated.
Commercial water accounts for five restaurants on Avenida Encinas were analyzed together with data on
the building size. The average unit water demand for the restaurants is estimated at 4.9 gpm per 10,000
square feet of building area. This is approximately six times higher than the calculated industrial unit
demand for the Faraday Business Park.
CMWD Dudek & Associates, Inc.
WATER MASTER PLAN UPDATE 4-15 March 2003