Rainbow MWD Water Master Plan 2006

Transcription

WATER MASTER PLAN UPDATE
FINAL REPORT
Prepared For:
3707 Old Highway 395
Fallbrook, CA 92028-2500
Prepared By:
605 Third Street
Encinitas, CA 92024
TEL (760) 942-5147
May 2006
RAINBOW MUNICIPAL WATER DISTRICT
2006 WATER MASTER PLAN
ACKNOWLEDGMENT
Dudek & Associates would like to express its sincere appreciation for the assistance and
cooperation provided by the management and staff of the Rainbow Municipal Water District
during the completion and preparation of this Master Plan Update. In particular, the efforts of
the following individuals are acknowledged and greatly appreciated:
RMWD Board of Directors
Lawrence J. Sundram........................................................................................Board President
Rua Petty ........................................................................................................................ Director
Jack Griffiths .................................................................................................................. Director
Russ Hatfield .................................................................................................................. Director
Bill Bopf........................................................................................................................... Director
RMWD Management and Staff
Chris Trees .......................................................................................................General Manager
Brian Lee .......................................................................................................... District Engineer
Chuck Sneed ..............................................................................................Operations Manager
Brendan Park...........................................................................................Operations Supervisor
Greg Moser...........................................................................................................Legal Counsel
Dawn Washburn ............................................................................................... Board Secretary
ACKNOWLEDGEMENT
i
TABLE OF CONTENTS
Chapter
Description
Page
ACKNOWLEDGMENTS................................................................................. i
TABLE OF CONTENTS .................................................................................ii
LIST OF TABLES.......................................................................................... iii
LIST OF FIGURES ....................................................................................... iv
LIST OF APPENDICES .................................................................................v
ANNOTATION .............................................................................................. vi
1
INTRODUCTION
1.1
BACKGROUND................................................................................ 1-1
1.2
SERVICE AREA OVERVIEW........................................................... 1-1
1.3
PREVIOUS MASTER PLANS .......................................................... 1-2
1.4
2006 UPDATE SCOPE AND PURPOSE.......................................... 1-3
2
EXECUTIVE SUMMARY
2.1
INTRODUCTION.............................................................................. 2-1
2.2
EXISTING SYSTEM DESCRIPTION................................................ 2-1
2.3
EXISTING WATER DEMANDS ........................................................ 2-2
2.4
EXISTING SYSTEM EVALUATION.................................................. 2-3
2.5
ULTIMATE DEMAND PROJECTIONS ............................................. 2-4
2.6
ULTIMATE SYSTEM ANALYSIS...................................................... 2-5
2.7
RECOMMENDED CAPITAL IMPROVEMENT PROGRAM .............. 2-6
3
EXISTING SYSTEM DESCRIPTION
GENERAL ........................................................................................ 3-1
3.1
3.2
WATER SUPPLY ............................................................................. 3-1
3.3
WATER DISTRIBUTION SYSTEM................................................... 3-2
3.4
DAILY OPERATIONS....................................................................... 3-7
3.5
EMERGENCY SUPPLY OPERATIONS ........................................... 3-8
3.6
WATER QUALITY ............................................................................ 3-9
4
EXISTING WATER DEMANDS
4.1
HISTORICAL WATER CONSUMPTION........................................... 4-1
4.2
EXISTING WATER CONSUMPTION ............................................... 4-3
4.3
DEMANDS PER PRESSURE ZONE................................................ 4-5
4.4
EXISTING SYSTEM PEAKING ........................................................ 4-6
4.5
EXISTING RESIDENTIAL UNIT DEMANDS .................................... 4-9
TABLE OF CONTENTS
ii
5
EXISTING SYSTEM EVALUATION
5.1
PLANNING CRITERIA ........................................................................5-1
5.2
HYDRAULIC MODEL DEVELOPMENT ..............................................5-5
5.3
HYDRAULIC SIMULATION RESULTS................................................5-8
5.4
FIRE FLOW ANALYSIS .....................................................................5-10
5.5
STORAGE ANALYSIS .......................................................................5-12
5.6
AQUEDUCT SHUTDOWN OPERATIONS .........................................5-14
6
ULTIMATE DEMAND PROJECTIONS AND ANALYSIS
PLANNED DEVELOPMENT................................................................6-1
6.1
6.2
ULTIMATE LAND USE........................................................................6-4
6.3
DEVELOPABLE VACANT LAND ........................................................6-5
6.4
HYDRAULIC MODEL DEVELOPMENT ..............................................6-6
6.5
ULTIMATE SYSTEM HYDRAULIC ANALYSIS ...................................6-8
6.6
ULTIMATE STORAGE CAPACITY ANALYSIS ...................................6-9
6.7
ULTIMATE PUMP STATION ANALYSIS............................................6-11
6.8
EMERGENCY SUPPLY ANALYSIS ...................................................6-12
6.9
ALTERNATIVE WATER SUPPLIES...................................................6-13
7
RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
7.1
7.2
7.3
TABLE OF CONTENTS
RECOMMENDED IMPROVEMENT PROJECTS ................................7-1
BASIS OF CONSTRUCTION COSTS .................................................7-2
PHASED CAPITAL IMPROVEMENT PROGRAM ...............................7-3
iii
LIST OF TABLES
Table 2-1
Table 2-2
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 3-5
Table 3-6
Table 4-1
Table 4-2
Table 4-3
Table 4-4
Table 4-5
Table 5-1
Table 5-2
Table 5-3
Table 6-1
Table 6-2
Table 6-3
Table 6-4
Table 6-5
Table 7-1
Summary of 2004/05 System Demands........................................................... 2-2
Projected Ultimate Demands by Pressure Zone............................................... 2-5
RMWD Aqueduct Connections ........................................................................ 3-2
Pressure Zone Summary ................................................................................. 3-3
Hydraulic Model Pipeline Summary ................................................................. 3-4
Existing Reservoir Summary............................................................................ 3-5
Pump Station Summary ................................................................................... 3-6
Pressure Reducing Station Summary .............................................................. 3-7
Water Billing Categories .................................................................................. 4-4
2004/05 Water Usage by Category .................................................................. 4-4
Average Day Demand by Pressure Zone......................................................... 4-5
Summary of 2004/05 System Demands........................................................... 4-6
Historical Maximum Day Water Purchases ...................................................... 4-8
Planning and Performance Criteria .................................................................. 5-1
Fire Flow Criteria ............................................................................................. 5-3
Required Storage Based on Existing Demands .............................................. 5-13
Projected Demands for Planned Development ................................................ 6-3
Projected Demands for Vacant Parcels ........................................................... 6-6
Projected Ultimate Demands by Pressure Zone............................................... 6-8
RMWD Storage Requirements Based On Ultimate Demands ......................... 6-10
Required Pump Station Capacities ................................................................. 6-11
RMWD Recommended Capital Improvement Program ................................... *7-3
* Follows this page number
TABLE OF CONTENTS
iv
LIST OF FIGURES
Figure 1-1
Figure 1-2
Figure 3-1
Figure 3-2
Figure 4-1
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 5-1
Figure 5-2
Figure 6-1
Figure 6-2
Figure 6-3
Figure 6-4
Figure 6-5
RMWD Vicinity Map ........................................................................................ *1-1
RMWD District Boundary ................................................................................ *1-1
Existing Water Distribution System ................................................................. *3-2
Existing System Hydraulic Schematic ............................................................. *3-2
RMWD Historical Water Demand Based on Sales ........................................... 4-1
Annual Water Purchases and Rainfall Totals ................................................... 4-2
Annual and Maximum Day Water Purchases .................................................. 4-3
2004/05 Water Usage by Billing Category........................................................ 4-4
RMWD Seasonal Demand Variations .............................................................. 4-7
Sample Residential Demand Areas .................................................................*4-9
Sample Water Demand investigation Area...................................................... 4-10
Residential Demand per Acre ......................................................................... 4-11
RMWD Fire Protection Districts ...................................................................... *5-3
Maximum Day Demand Peaking Factor Curve ................................................ 5-7
Residential Demand per Parcel ...................................................................... 6-1
Planned Development Projects....................................................................... *6-2
Ultimate Land Use for Developable Vacant Land............................................ *6-3
Remaining Developable Land ......................................................................... 6-4
Ultimate Pressure Zone Service Areas ........................................................... *6-7
* Follows this page number
LIST OF APPENDICES
Appendix A – Exhibits
Exhibit A1 – Existing Distribution System (pipelines color-coded by zone)
Exhibit A2 – Recommended CIP
Appendix B – Fire Flow Analysis
Exhibit B1 – Fire Flow Analysis Results
Appendix C - Existing and Ultimate System Model (on CD ROM)
ADDENDUMS
ADDENDUM 1 – Eastern Service Area Expansion Analysis
TABLE OF CONTENTS
v
ANNOTATION
The following abbreviations and acronyms were used in the preparation of this Master Plan:
ACP
AAD
ADD
AF
APN
CCI
cfs
CIP
CMLC
CWA
DBP
diam.
DIP
DOHS
EDU
EIR
FCV
fps
Ft
GIS
gpd
gpm
HCF
HGL
Hp
hr
HWL
lf
in
ISO
MCL
MDD
Met
MWD
MFDU
ANNOTATION
Asbestos concrete pipe
Average Annual Demand
Average day demand
Acre-feet
Assessor parcel number
Construction cost index
Cubic feet per second
Capital improvement program
Concrete mortar lined and coated
County Water Authority [San Diego]
Disinfection by-products
Diameter
Ductile iron pipe
Department of Health Services [California]
Equivalent dwelling unit
Environmental Impact Report
Flow control valve
Feet per second
Feet
Geographical Information System
Gallons per day
Gallons per minute
Hundred cubic feet
Hydraulic grade line
Horsepower
Hour
High water level
Linear feet
Inches
Insurance Services Office
Maximum contaminant level
Maximum day demand
Metropolitan Water District of Southern California
Multi-family dwelling unit
vi
MG
mgd
MRDL
msl
MWD
PF
PRS
PRV
psi
PSV
PVC
RMWD
SanGIS
SCADA
SDCWA
SFDU
sqft
TAP
TTHM
USGS
VFD
WRP
yr
ANNOTATION
Million gallons
Million gallons per day
Maximum residual disinfectant level
Mean sea level
Peaking factor
Pressure reducing station
Pressure reducing valve
Pounds per square inch
Pressure sustaining valve
Polyvinyl chloride
Rainbow Municipal Water District
San Diego County Geographic Information System
Supervisory control and data acquisition
San Diego County Water Authority
Single family dwelling unit
Square feet
Tri-Agency Pipeline
Total trihalomethanes
United States Geologic Survey
Variable frequency drive
Water Reclamation Plant
Year
vii
1.0 INTRODUCTION
This Water Master Plan Update for the Rainbow Municipal Water District (RMWD) 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 2001. Since the last Master Plan Update,
development within the District has been relatively slow and steady. The need to restructure the
past Capital Improvement Program and look at various other technical issues and expansion
possibilities has resulted in the need for an update to the Master Plan. This current Master Plan
presents an update of the District’s Water Master Plan for the planning period between 2005
and build-out of the District’s service area, which is anticipated to occur by 2025.
1.1
BACKGROUND
The Rainbow Municipal Water District (RMWD or District) is a local governmental agency that
provides water to an unincorporated area of northern inland San Diego County. The District was
established in 1953 under the Municipal Water District Act of 1911 (Section 7100 et. seq. of the
California Water Code). The District joined the San Diego County Water Authority and the
Metropolitan Water District of Southern California the same year to acquire the right to purchase
and distribute imported water throughout its service area.
1.2
SERVICE AREA OVERVIEW
The RMWD water service area covers approximately 80 square miles (51,200 acres) in North
San Diego County, as illustrated on the location map in Figure 1-1. The District serves the
unincorporated communities of Rainbow and Bonsall, as well as portions of Pala and Fallbrook,
in northern San Diego County. The District is responsible for providing water service to almost
7,300 metered accounts. Water supply is derived from the regional aqueduct systems owned
and operated by the Metropolitan Water District of Southern California (MWD or MET) and the
San Diego County Water Authority (SDCWA). Filtered water is supplied from two SDCWA
water aqueducts through eight connections. Water is stored in a total of 16 water tanks and
reservoirs, and is conveyed to twelve major pressure zones utilizing seven potable water pump
stations and over 30 pressure reducing stations. Over 300 miles of delivery and distribution
pipelines distribute potable water to a population of approximately 17,750. The RMWD service
area boundary and adjacent district boundaries are shown on Figure 1-2.
The terrain within the RMWD is predominantly rugged and mountainous, with some flatter areas
along river valleys. Service area elevations vary from just over 2,200 feet above mean sea level
(msl) at the northeastern portion of the District, to under 150 feet above msl in the southwestern
portion of the District. The lowest elevations are along the San Luis Rey River, which traverses
the southern portion of the District and flows west before turning to the south. The highest
pressure zone is at the northeast corner of the service area, and the eleven lower zones
generally decrease in pressure from east to west and north to south. The exception is the
Gopher Canyon Zone, which supplies water south of the San Luis Rey River to the southern
boundary, where elevations begin to rise.
The Rainbow District is largely agricultural, however significant growth in its residential customer
base is projected in the near future. The service area is predominantly developed groves, with
some residential areas interspersed in the more accessible valleys. The agricultural use
includes citrus, avocados, strawberries, tomatoes, corn, commercial nurseries, and livestock.
Much of the area still remains in its natural state of chaparral, oak, and coastal sage vegetation,
characteristic of Mediterranean west coast climatic regions. Temperatures vary from a low
mean daytime temperature of 69 degrees in the winter to a high mean daytime temperature of
86 degrees in the summer.
1.3
PREVIOUS MASTER PLANS
A summary of the previous Water Master Plans is provided in the sub-sections below.
1.3.1 1975 Water Master Plan
In 1975, a Water Master Plan was prepared by NBS/Lowry Engineers and Planners that
identified proposed Bureau loan and District funded projects. These projects were needed to
improve the District’s supply, storage and distribution system.
1.3.2 1986 Water Master Plan Update
The 1986 Water Master Plan Update was also prepared by NBS/Lowry Engineers and
Planners. The purpose of this update was to update the status of the Bureau of Reclamation
projects, update the District’s computer model of the water system, and to utilize the model to
determine recommended additional Bureau and District projects to correct deficiencies in the
existing system and provide for projected growth within the District.
A 1994 Master Plan was prepared by Albert A. Webb Associates. This plan determined that the
storage facilities within the District were undersized by approximately 17.8 MG to meet the year
2015 water demand.
The 2001 Water Master Plan Update was prepared by Dudek & Associates, Inc. This study
included a complete GIS map of the water system based on as-built construction drawings. A
hydraulic model was prepared based on this information. The master plan evaluated future
supply and demands within the existing service area and a CIP (Capital Improvement Plan) was
developed to identify projects that would enhance system operations.
1.4
2006 UPDATE SCOPE AND PURPOSE
Since the last Master Plan Update there have been a significant number of changes that have
occurred within the District. Development has generally been slow in the region, but changes in
operational characteristics, aging facilities, and the potential need for improvements in
efficiency, water quality, and monitoring of the water system have lead to the need for a Master
Plan update. The Rainbow Municipal Water District, in its Notice to Proceed dated August
2005, retained Dudek & Associates, Inc. to provide engineering services necessary to analyze
and evaluate existing and future requirements for 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. To
analyze the water distribution system, the District’s 2001 WaterCAD 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 RMWD at
build-out conditions.
2.0 EXECUTIVE SUMMARY
The 2006 Water Master Plan presents an update of the Rainbow Municipal Water District’s
(RMWD) Water Master Plan for the planning period between 2005 and build-out of the District’s
service area, which is anticipated to occur by 2025. The purpose of the Master Plan Update is
to identify deficiencies in the system, confirm transmission main sizing, and identify future
capital improvement projects based on updated ultimate demand projections. The scope of
work for this study includes tasks to document and analyze existing facilities, develop unit water
demands and peaking factors, project ultimate water demands, update the water system
hydraulic models, and recommend facility and operational improvements based on hydraulic
analyses results.
2.1
INTRODUCTION
The Rainbow Municipal Water District (RMWD or District) is a local governmental agency that
provides water to nearly 7,300 metered accounts, serving approximately 17,750 customers in
an unincorporated area of northern inland San Diego County. The water service area covers
approximately 80 square miles encompassing the communities of Rainbow and Bonsall, as well
as portions of Pala and Fallbrook. Water supply is obtained from the regional aqueduct systems
owned and operated by the Metropolitan Water District of Southern California (MWD or MET)
and the San Diego County Water Authority (SDCWA).
The Rainbow District is largely agricultural, however significant growth in its residential customer
base is projected in the future. Since the last Master Plan Update in 2001 there have been a
significant number of changes that have occurred within the District. Development has
generally been slow in the region, but changes in operational characteristics, aging facilities,
and the potential need for improvements in efficiency, water quality, and monitoring of the water
system have lead to the need for a Master Plan update.
2.2
EXISTING SYSTEM DESCRIPTION
Filtered water is supplied to the RMWD through eight turnout connections off two separate
SDCWA water aqueducts. The existing water distribution system consists of 12 major pressure
zones. The Beck, North, Gopher Canyon and Canonita zones are supplied directly from aqueduct
connections and the remaining zones are supplied through pressure reducing stations or
booster pump stations. Each major pressure zone has at least one tank or reservoir to regulate
pressures and provide operational, emergency and fire flow storage.
Operation of the RMWD water distribution system is very complex and relies on manual
changes to the system, which are subject to personal judgment rather than automation. The
water distribution system is flexible in that supply from the eight 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.
There are a total of 16 operational reservoirs and enclosed storage tanks within the RMWD
distribution system. All storage tanks are circular above-ground steel tanks ranging in size from
0.4 million gallons (MG) to 6.0 MG. There are four larger open reservoirs constructed of
reinforced concrete or asphalt which range in size from 7.8 MG to 203.7 MG. The reservoirs
provide additional reserve storage capacity for annual planned shutdowns or emergency
shutdowns of the aqueduct supply system. Over the next several years floating covers will be
installed on all the open reservoirs.
The existing distribution system has over 300 miles of pipelines 6-inches in diameter and larger.
There are seven booster pump stations in the RMWD distribution system which pump water up
to higher zones with storage reservoirs. Pump operations are controlled based on tank water
levels and some pumps are operated only during the night, to take advantage of off-peak
electricity charges. Over 40 pressure reducing stations supply 23 small reduced pressure
zones without storage reservoirs that are supplied from the Morro, Gopher Canyon, Beck and
Canonita Zones.
2.3
EXISTING WATER DEMANDS
Within the District, water use is categorized as either agricultural or non-agricultural (domestic).
Water for agricultural use is purchased and sold at a discounted rate. The total average rate of
water supplied for 2004/05 based on RMWD billing records was 21.5 MGD. While approximately
9% of the RMWD meters are agricultural meters, the water usage from these meters is
approximately 37 percent of the total system demand. The 2004/2005 system demands based on
water purchase records are summarized in Table 2-1. It is noted that rainfall during the 2004/05
season was much higher than average, therefore annual water usage was lower than normal.
Table 2-1
SUMMARY OF 2004/05 SYSTEM DEMANDS
Average
Day
Minimum
Month
Maximum
Month
21.5 MGD
33.3 CFS
14,931 gpm
8.6 MGD
13.3 CFS
5,972 gpm
34.4 MGD
53.2 CFS
23,889 gpm
2.4
EXISTING SYSTEM EVALUATION
Planning criteria were first established for the design and evaluation of potable water facilities in
RMWD based on existing system performance characteristics, past criteria used by the District,
and current industry and area standards. Planning criteria include standards for demand
peaking factors, system pressures, distribution pipelines, storage reservoirs, and booster pump
stations.
To determine compliance with established planning criteria, an updated computer model of the
water distribution system was developed with the 2006 Master Plan. The hydraulic model is
made up of pipes, junction nodes, valves, tanks and pumps. Water demands were input to the
existing system model based on fiscal year 2004/05 water billing records that were increased by
16 percent to more accurately represent “average” existing demands from a normal rainfall
season. The required fire flow demand was also input at each node. An extended period
simulation with maximum day demands was run to assess reservoir performance (the ability to
supply peak flows and refill after draining) and pipeline velocities and pressures.
Results of the 24-hour simulation were reviewed and analyzed, and deficiencies were noted.
The main concern with the existing distribution system is the many areas with pressures higher
than 200 psi. This is primarily due to the steep and varying terrain, the preference of agricultural
customers for high delivery pressures, and low density development, which makes strict
adherence to design standards uneconomical. Several zone boundary changes and additional
reduced zones were recommended and confirmed with the hydraulic model to reduce the
highest system pressures. Other findings of the hydraulic analysis included high pipeline
velocities in a few small 6-inch pipelines and in transmission mains extending from the North
Reservoir under certain operating conditions. The high velocities generally did not result in
pressure problems due to high static pressures. The model also confirmed difficulties with
balancing reservoir levels in the North and Gopher Canyon Zones, and the filling of the Morro
Reservoir during peak demand periods.
A series of fire flow analyses were performed with a fire flow applied sequentially at every node
near an existing fire hydrant. Analysis results indicated that the available fire flows ranged from
approximately 250 gpm to over 30,000 gpm. Over 280 nodes were initially identified that could
not deliver the required fire flow of 1,500 gpm for residential areas. Most of the fireflow deficient
areas are located on 6-inch diameter or dead-end pipelines. Improvement projects based on a
series of hydraulic computer simulations are proposed to bring the existing water system up to
compliance with minimum fire flow requirements. Fire flows can always be increased by
upsizing individual pipelines, but efforts were taken to minimize the required improvements and
identify upstream projects that could benefit downstream areas at multiple locations.
The required storage volume based on design criteria was calculated and compared to the
capacity of the existing system reservoirs. There is an overall storage surplus of 173 MG
based on daily and reserve storage requirements. Considering only the daily storage
requirements per zone, however, there is a small storage deficit (less than 1 MG) in the
Vallecitos and Canonita Zones, and a deficit of approximately 4.7 MG in the Gopher Canyon
Zone.
Operation of the existing distribution system during an aqueduct shutdown was also analyzed.
System operation without supply from aqueduct connections is much more complicated than
during normal operating conditions. RMWD Staff requested that improvement projects be
identified in this Master Plan Update to eliminate the need to rent portable gas-driven pumps
and purchase water from outside agencies during an aqueduct shutdown. Analysis results were
used to identify several locations for proposed permanent pump stations.
2.5
ULTIMATE DEMAND PROJECTIONS
Ultimate water demands for the RMWD are made assuming buildout of all parcels within the
existing RMWD boundary. Demands were first projected for planned developments, which
include projects that range from those currently in construction to projects in the conceptual
development stage. Planning information was collected for 26 residential projects, ranging in
size from lot splits creating one additional residential parcel to projects spanning several large
parcels with up to 1,360 future residential units. Future water demands are projected based on
the average lot size within the project and unit water demand factors developed from the
analysis of existing residential water use. Non-residential planned projects with significant water
demands include the Fallbrook High School and four future park sites included in the 2005 San
Luis Rey River Park Master Plan. The projected net increase in water demands for the 31
planned development projects is approximately 3.3 MGD (3,700 afy). This represents an
increase in demand of approximately 13% over existing RMWD demands. It is noted that the
agricultural demand that will be replaced by the planned development is estimated at only 0.16
MGD.
After construction of the planned development projects, the proportion of developable land
remaining in the District is estimated at 18 percent of the total land area, or approximately 9,300
acres. For this remaining developable land water projections are based on the SANDAG 2020
land use map. The main SANDAG land use classifications are residential, commercial and
industrial, government, and open space. Residential land use is classified as either rural (lot
size 1-20 acres), single family, or multi-family residential, and approximately 66 percent of the
developable land is classified with a rural residential land use. Demands for the remaining
vacant land are projected to be 4.9 MGD, and the total water demands for the ultimate system
are projected to be 33.6 MGD, as shown in table 2-3. It is noted that existing demands in this
table are increased by 16 percent from 2004-05 demands to account for the lowered water use
resulting from the much higher than normal rainfall.
Table 2-3
PROJECTED ULTIMATE DEMANDS BY PRESSURE ZONE
Major Pressure Zone*
Name
HGL
Magee
Rainbow Heights
Gomez
U-1
Vallecitos
Northside
North
Canonita
Beck
Gopher Canyon
Morro Reservoir
Morro Tank
Totals
2160
1,967
1,710
1579
1338
1282
1,212
1,019
897
1,011
825
865
Existing
AAD
(MGD)
0.03
0.52
1.17
0.25
0.23
1.56
2.44
2.92
2.70
7.50
5.15
0.69
25.2
Projected
Ult AAD
(MGD)
0.57
1.25
1.47
0.56
0.28
1.64
2.69
2.89
5.12
8.34
7.96
0.77
33.6
Projected
Percent
Increase
1797%
140%
26%
130%
18%
5%
10%
-1%
90%
11%
55%
11%
33%
* Ultimate pressure zones incorporate proposed zone boundary changes
2.6
ULTIMATE SYSTEM ANALYSIS
Future demands in the ultimate system will be supplied from an expansion of the existing
distribution system pressure zones. It is anticipated that no new major pressure zones will be
required, although there may be additional smaller reduced pressure areas within several of the
major pressure zones. Hydraulic analysis of the ultimate system was performed to size and
verify proposed future facilities. An ultimate system H2OMAP model was developed from the
existing system model incorporating layout plans for planned developments and current capital
improvement program (CIP) projects. The ultimate system model was then analyzed under
both maximum day demand and emergency supply scenarios. Water supply from CWA
Connection No. 12, which is currently not connected to the distribution system, will be required
to maintain water levels in the Moro Reservoir as system demands increase. Analysis results
indicate that the additional flows to meet ultimate demands in other zones can be provided
adequately from the existing CWA Connections.
An analysis of system storage indicates that there will be an overall storage surplus of 98 MG in
the ultimate system based on total storage requirements. Considering only the daily storage
requirements per zone, however, there will be storage deficiencies in the Gopher Canyon,
Vallecitos, and Canonita Zones. The Gopher Canyon and Vallecitos Zones also exhibited
storage deficiencies based on 2004/05 demands, but they were not as large. New storage tank
locations were identified and verified based on analysis results.
Based on the existing duty capacity of each pump station, pump station capacity improvements
will be required at the Morro Hills, Vallecitos, Northside and possibly the Magee Pump Stations.
The Morro Hills Pump Station requires a second pump for redundancy. It is also recommended
that two new pumps be installed at the Vallecitos Pump Station, which is currently not
operational (water is now pumped to a higher zone and supplied to the Vallecitos Zone through
a pressure reducing station).
The ultimate system model was analyzed under an emergency supply scenario, with average
day demands supplied from reservoir storage and proposed emergency pump stations. A series
of simulations were made to locate the required pump stations, verify the flow rate that could be
delivered, and determine the impact to system pressures. New emergency pump stations are
proposed to supplement storage in the northern zones from the Beck Reservoir, to replace the
portable gas-driven pump that supplies the Canonita Zone from Beck Reservoir, and to supply
the Gopher Canyon Zone from the Morro Zone.
2.7
RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
Water system capacity and operational improvements are recommended to improve system
reliability, increase the available fire flow, regulate system pressures, meet pumping and
storage capacity requirements, and supply the entire distribution system from storage during a
shutdown of the CWA Aqueduct system. Recommend projects are organized into a phased
Capital Improvement Program (CIP). Phase I projects include Improvements to correct
deficiencies, improve system operations, or increase reliability of the existing water distribution
system. The majority of the facility improvements are pipeline projects recommended to
improve fire flows and meet redundancy criteria. Phase II projects are improvements
recommended for the ultimate water system, and include construction of additional pipelines,
pressure reducing stations, and operational and emergency storage facilities. It is noted that
rehabilitation and replacement projects based on the age and condition of facilities are not
included in the Master Plan CIP.
An opinion of probable construction costs was determined for the CIP projects based on the
most recent bidding information for similar types of projects. The total construction cost of
Phase I projects are estimated at $23,008,000 and the cost of Phase II projects is projected to
be $23,692,000. The construction costs do not include engineering, administration, inspection,
legal, or environmental costs. To estimate the total project cost, it is recommended that the
probable construction costs be multiplied by 145 percent.
3.0 EXISTING SYSTEM DESCRIPTION
This chapter summarizes the existing RMWD distribution system. The facilities comprising the
water distribution system include San Diego County Water Authority (SDCWA) aqueduct turnouts,
transmission mains, distribution pipelines, storage reservoirs, pressure reducing stations, and
pump stations. Information regarding the existing water distribution system facilities was derived
from the District’s water atlas books, as-built construction drawings, previous reports and studies,
and input from Rainbow District staff. The existing water distribution system is illustrated in
Figure 3-1.
3.1
GENERAL
The District’s 51,200-acre service area is located in northern San Diego County, approximately 40
miles north of the City of San Diego and 17 miles east of the Pacific Ocean. The northern
boundary of the District is coincident within the San Diego/Riverside County border. While
officially within unincorporated San Diego County, the District contains several recognized
communities. These include Rainbow and portions of Fallbrook, Bonsall, and Valley Center.
Portions of the District are also within the designated Pala/Pauma Sub-regional Area.
3.2
WATER SUPPLY
Water is supplied to the District through a series of aqueduct connections (turnouts) located
along the Metropolitan Water District of Southern California (MWD or MET) and San Diego
County Water Authority (SDCWA) aqueduct systems. Two separate aqueduct systems with
multiple pipelines traverse the District in a generally north to south alignment. Water in the
filtered pipelines is treated to potable standards at the Lake Skinner filtration plant. The water is
generally a blend of Colorado River and State Water Project water supplies. In the past, the
District maintained raw water connections to these aqueducts that could provide unfiltered (raw)
water for agricultural use. Due to increased regulatory requirements and the complexity of
operating separated systems, the unfiltered water supply has been discontinued.
All treated water aqueduct connections are shown on Figure 3-1. Table 3-1 describes the
District’s existing turnouts associated with the MWD and SDCWA aqueduct systems. Water is
currently delivered from four MWD connections and four SDCWA connections, and there is a
fifth SDCWA connection that does not yet have a pipeline connection to the District. It is noted
that water purchased from the SDCWA includes a transportation charge in addition to the
commodity rate, which is the same for both the MWD and SDCWA. RMWD operators are
allowed to make up to two flow changes per day. Additionally, flows can be transferred between
connections that are located on the same aqueduct pipeline.
Table 3-1
RMWD AQUEDUCT CONNECTIONS
Connection Capacity (cfs)
Conn.
Connection
RMWD Supply Zone
Elevation
HGL
Max
Max
Min
(ft)
Max/Min (ft)
Rating Supplied Allowed
Filtered Water Connections on CWA Aqueduct No. 1 (Barrels No. 1 & 2):
RB 1
MWD
22
20
2.5
1131
1272/1268
North (North Reservoir)
RB 10
MWD
22
8
2.5
1027
1251/1247
North (Rice Canyon Tank)
Filtered Water Connections on CWA Aqueduct No. 2 (Barrel No. 4):
RB 3
CWA
22
20
2.5
879
1110/1077
Gopher Canyon (Turner Tank)
RB 6
CWA
22
20
2.5
876
1151/1077 Gopher Canyon (to Morro thru valve)
RB 7
CWA
40
36
4
909
1232/1077 Canonita (to Beck & Morro thru valve)
RB 8
MWD
25
23
3
720
1253/1066
Canonita to Beck thru valve)
RB 9
MWD
20
9
2
835
1297/1215
North (Rice Canyon Tank)
RB 11
CWA
30
27
3
953
1080/1040
Gopher Canyon (Gopher Tank)
RB 12
CWA
20
----Morro
Raw Water Connections on CWA Aqueduct No. 2 (Barrel No. 3):
RB 4
CWA
22
-RB 5
CWA
22
21
2.5
905
1204/1079
-Turnout Wholesale
Number Agency
Connection
Status
Active
Active
Active
Active
Active
Active
Active
Active
for future use
Closed
Closed
At this time, the District (and most of Southern California) is wholly dependent on imported
water for service of its entire water demand. Through the advent of water-banking legislation,
there have been alternative sources discussed within the last few years that could provide nonMWD or non-SDCWA water supplies. However, this water would still be delivered through the
existing MWD and/or SDCWA facilities, and as such offers no specific advantages to the District
with respect to future infrastructure needs. Certainly, increasing the sources of cost-effective
and reliable water supply is viewed as an improvement to any water delivery system, and these
alternative supplies should be thoroughly investigated and developed.
3.3
WATER DISTRIBUTION SYSTEM
The existing distribution system consists of 12 major pressure zones. Four of the zones are
supplied directly from the SDCWA aqueduct connections. The remaining zones are supplied
through pressure reducing stations or booster pump stations. The RMWD hydraulic profile
schematic showing aqueduct connections, pressure zones, storage facilities, pump stations and
primary pressure reducing stations is provided in Figure 3-2.
3.3.1 Major Pressure Zones
There are twelve major pressure zones within the RMWD system. Each pressure zone has at
least one reservoir or tank. All of the reservoirs are currently uncovered basins. Pressure zones
within the RMWD are identified by a number that corresponds to the hydraulic grade set by the
high water level of the tank or reservoir. The hydraulic grade line, elevation variations, range of
static pressures, and water supplies are summarized in Table 3-2. Elevations and static
P.S. #7
Ö
!
=
P. S. #3
#1
#2
UU
T
T
CONN #1
Ö
! P. S. #1
#=
T
U
HEIGHTS
TANK #2
K
J
P. S. #2
=
Ö
!
K
J
MAGEE
TANK
T RAINBOW
U
Ö
!
=
#
NORTHSIDE
RESERVOIR
VALLECITOS
TANK
T
U
U-1 TANKS
NORTH
RESERVOIR
CONN #9
!
Ö
=
P. S. #4
GOMEZ
T CREEK
U
TANK
LEGEND
CANONITA
TANK
CONN #8
#
RICE CANYON
TANK
T
U
BECK
RESERVOIR
K
J
# CONN #7
CONN #10
#
=
Ö
!
T
U
DISTRICT BOUNDARY
PARCELS
P. S. #6
#
SDCWA AQUEDUCT CONNECTION
K
J
RESERVOIR
T
U
STORAGE TANK
Ö
!
=
PUMP STATION
WATER DISTRIBUTION SYSTEM
MAJOR PRESSURE ZONES
BECK
CANONITA
GOMEZ
GOPHER CANYON
MAGEE
HUTTON
TANK
P. S. #5
MORRO TANK
NORTHSIDE
Ö
=
!
MORRO
TANK
MORRO
RESERVOIR
T
U
MORRO
T
U
CONN #6
K
J
#
RAINBOW HEIGHTS
NORTH
U-1
VALLECITOS
CONN #3
#UT TURNER
(SOUTH)
TANK
³
1"=8000'
CONN #11
#UT GOPHER
CANYON TANK
FIGURE 3-1
EXISTING WATER DISTRIBUTION SYSTEM
04-2006 RMWD_WA31_ExistWatSystem.mxd
pressures are provided for locations in the distribution system with water meters. It is noted that
the Morro, Gopher Canyon, Beck and Canonita Zones supply several small reduced pressure
zones through pressure reducing stations. The maximum pressures in the distribution system
may therefore be lower than the pressures shown in Table 3-2 for these zones. Also, it is noted
that private pumps are being operated to boost pressures at several service meters located near
storage tanks.
Table 3-2
PRESSURE ZONE SUMMARY
Zone
HGL
Elevation
Min.
Max.
Magee
2,160
1,530
2,080
35
273
Rainbow
Heights
1,972
1,160
1,915
25
352
Gomez
1,710
640
1,510
87
464
U-1
1,579
1,130
1,520
26
195
Vallecitos
1,338
1,080
1,290
21
112
Northside
1,282
600
1,190
40
296
North
1,212
350
1,120
40
374
Canonita
1,019
230
840
78
342
Beck
897
240
840
25
285
1,011
230
970
18
339
825
140
750
33
297
865
500
710
67
158
Gopher
Canyon
Morro
Morro Tank
Static Pressure
Min.
Max.
Water Supply
Main
Supplement
Rainbow Heights
None
via Booster PS #7
North Zone via
Magee
Booster PS # 1
North Zone via
Rainbow Heights
Booster PS # 6
North Zone via
None
Booster PS # 2
North Zone via
Rainbow Heights
Booster PS # 3
North Zone thru
None
Booster PS #4
Connections 1, 9,
Rainbow Heights &
and 10
Northside
Northside & Beck via
Connections
7 and 8
emergency pumps
Connection 7 via
Canonita System
Canonita
Connections 3, 6 Morro via emergency
and 11
pumps
Beck Zone
Gopher Canyon
Morro Zone thru
Beck via Morro Zone
Booster PS #5
3.3.2 Distribution Pipelines
The existing distribution system has over 300 miles of pipelines 6-inches in diameter and larger.
Most of the smaller diameter pipelines are constructed of asbestos cement pipe (ACP) or steel,
although ductile iron pipes are used in high pressure areas. Larger transmission mains are
constructed of CMLC steel and newer pipelines are ductile iron pipe (DIP). The pipelines colorcoded by pressure zone in the updated existing system model are shown on Exhibit A1 in
Appendix A. Table 3-3 summarizes pipeline lengths by diameter.
Table 3-3
HYDRAULIC MODEL PIPELINE SUMMARY
Pipeline Diameter
Pipeline Diameter
Total Pipeline
(inches)
(inches)
Length (miles)
4
4.6
20
6
64.8
22
8
116.5
24
10
18.7
27
12
39.3
30
14
20.1
36
16
23.7
42
18
11.5
Total length of Pipe = 318 miles
Total Pipeline
Length (miles)
10.4
1.0
5.8
0.3
0.6
0.6
0.4
3.3.3 Water Storage Facilities
Each major pressure zone has at least one tank or reservoir to regulate pressures and provide
operational, emergency and fire flow storage. There are a total of 16 operational reservoirs and
enclosed storage tanks within the RMWD distribution system. All storage tanks are circular
above-ground steel tanks ranging in size from 0.4 million gallons (MG) to 6.0 MG and there are
four larger open reservoirs constructed of reinforced concrete or asphalt which range in size
from 7.8 MG to 203.7 MG. The reservoirs provide additional reserve storage capacity for
planned or emergency shutdowns of the aqueduct supply system. In addition to the operational
storage facilities, there is also one reservoir (8.8 MG Pala Mesa Reservoir) and one tank (0.9
MG Rainbow Heights Tank No. 1) that are currently not in service. Table 3-4 provides a
summary of the storage facilities.
The distribution system reservoirs have been designed to be extremely flexible in their ability to
transfer water throughout the District. Reservoir water levels are recorded by the RMWD
SCADA (supervisory control and data acquisition) system. RMWD Operations Staff closely
monitor the water level and quality in each storage reservoir and operate the water system to
cycle water through the reservoirs for improved turnover rates.
The four open reservoirs have on-site chlorine generation and injection facilities to maintain
proper chlorine residuals leaving the reservoirs. Department of Health Services (DHS)
standards, however, now require covers on all treated water reservoirs. RMWD evaluated
options for water treatment and reservoir covers, and determined that floating covers would be
the most cost effective alternative for compliance with DHS standards. A floating cover for
Morro Reservoir is currently being designed and will be installed in 2007. Floating covers will be
installed on the remaining three reservoirs within the next four years.
Table 3-4
EXISTING RESERVOIR SUMMARY
Pressure Zone
Reservoir
Capacity
Magee Tank
Magee
Rainbow
Rainbow Hts Tank No. 2
Heights
Rainbow Hts Tank No. 1*
Gomez Tank
Gomez
U-1 Tank No. 1
U-1
U-1 Tank No. 2
Vallecitos Tank
Vallecitos
Northside Res
Northside
North Res
North
Rice Tank
Canonita Tank
Canonita
Beck Reservoir
Beck
Pala Mesa Reservoir*
Gopher Canyon
Gopher Canyon
Hutton Tank
South (Turner) Tank
Morro Reservoir
Morro
Morro Tank
Morro Tank
TOTAL
3.0 MG
4.0 MG
0.9 MG
3.5 MG
0.55 MG
1.5 MG
0.4 MG
22.8 MG
7.8 MG
4.0 MG
6.0 MG
203.7 MG
8.8 MG
4.0 MG
4.0 MG
4.0 MG
151.5 MG
4.0 MG
434 MG
Storage Facility
High Water
Level
(ft.)
2,160
1,967
1,972
1,710
1,579
1,579
1,338
1,282
1,212
1,206
1,019
897
898
1,011
1,011
1,011
825
865
Bottom
Elevation
(ft.)
2,120
1,927
1,940
1,672
1,545
1,533
1,316
1,240
1,192
1,167
980
846
878
971
971
971
778
824
Diameter
(ft.)
115
131
70
122
53
75
57
--131
164
--133
133
133
-135
* Currently out of service
3.3.4
Pump Stations
There are seven booster pump stations in the RMWD distribution system which pump water up
to higher zones with storage reservoirs. Pump operations are controlled based on tank water
levels and some pumps are operated only during the night, to take advantage of off-peak
electricity charges. Pump operating status is included in SCADA system. The location of each
pump station is shown on Figure 3-1 and a summary of each permanent pump station is
provided in Table 3-5. RMWD also owns a trailer-mounted pump that can be used in
emergency conditions. In addition, the District can rent trailer mounted pumps for planned
facility shutdowns or emergencies.
Table 3-5
PUMP STATION SUMMARY
Tested Operating
No. of
(1)
Pumps
Point
2 - 250 Hp 967 gpm @ 748'
North (CWA Conn.1)
5463 Eight Street
1- 300 Hp 952 gpm @ 752'
=> Rainbow Heights
1- 290 HP 814 gpm @ 752'
503 gpm @ 345'
North (North Res.)
1040 Rainbow Glen Rd
3- 75 Hp
580 gpm @ 345'
=> U-1
532 gpm @ 346'
760 gpm @ 270'
North (CWA Conn1)
2718 Rainbow Valley Blvd. 2- 75 Hp
=> Vallecitos
750 gpm @ 270'
1 - 150 Hp 4,044 gpm @ 97'
North (CWA Conn.1)
933 Rainbow Valley Blvd
=> Northside
1 - 75 Hp
2,252 gpm @ 65'
Suction/Discharge
Zone
Name
BPS #1
Rainbow
Heights
BPS # 2
U-1
BPS #3
Vallecitos
BPS # 4
Northside
BPS # 5
Morro => Morro Tank
Morro Hills
BPS #6
North (Rice) => Gomez
Gomez (Huntley)
BPS #7
Magee
Rainbow Heights
=> Magee
Location
421 Morro Hills Rd
9215 Huntley Rd
39190 Magee Rd
1 - 150 Hp 3,455 gpm @ 118'
2111-
Duty
Capacity(2)
2,600 gpm
1,000 gpm
800 gpm
1,900 gpm
0 gpm
300 Hp 1,566 gpm @ 541'
2,800 gpm
250 Hp 1,306 gpm @ 551'
50 Hp
717 gpm @ 229'
700 gpm
100 Hp 681 gpm @ 226'
(1) Tested operating point obtained from the 10/2005 pumping system analysis performed by Pump Check
(2) Duty capacity is the total station capacity with the largest pump out -of-service; Duty capacity was determined from
computer simulations with the storage tanks half full and maximum day demands on the system.
3.3.5
Pressure Regulating Stations
The RMWD utilizes over 40 pressure regulating stations to supply water to lower pressure
zones from higher zones. These stations are comprised of one or more hydraulically actuated
pressure reducing valves (PRVs), which are globe valves that are set to maintain a downstream
pressure. If the downstream pressure should rise above the PRV pressure setting, the valve
will close.
Most of the pressure reducing stations are used to supply the 23 small reduced pressure zones
without storage reservoirs that are supplied from the Morro, Gopher Canyon, Beck and
Canonita Zones. These stations typically have a main valve with a smaller by-pass valve.
Additionally, several stations separate major pressure zones and are set to supply flow only in
response to a large pressure drop, such as fire flow. A few pressure reducing stations are
manually opened only to fill downstream reservoirs from upper zones. These may also include
a pressure sustaining control to limit the pressure drop in the upstream (high) zone. A summary
of the pressure reducing stations grouped by the upstream supply zone is provided in Table 3-6.
Included in the table are the number and size of the valves and the current valve settings, as
provided by RMWD Operations Staff.
Table 3-6
PRESSURE REDUCING STATION SUMMARY
PRS
No.
Pressure Zones
Upstream => Downstream
2
Rainbow Hts
1
Northside
4
Northside
3
North
12
Canonita
13
Canonita
11
Canonita
16
Canonita
9
Canonita
10
8
Canonita
19
Canonita
39
Gopher Canyon
40
Gopher Canyon
36
23
Gopher Canyon
27
Gopher Canyon
35
37
Gopher Canyon
44
Gopher Canyon
41
Gopher Canyon
18
Beck
20
Beck
21
17
Beck
14
Beck
15
Beck
22
Morro Tank
34
Morro
32
Morro
25
Morro
33
Morro
43
Morro
42
Hutton
38 Tres Amigos East
24
Moosa Crest
45
=> North/Vallecitos
=> North
=> Canonita
=> Canonita
=> Beck
=> Beck
=> Pala Mesa CC # 1
=> Pala Mesa Fairways
Facility Name
Vallecitos PS
Booster Station #4
Los Alisos
Canonita
Stewart
Laketree (By-pass)
Pala Mesa Condos
Daisy Lane
Pala Lake North
=> Pala Mesa CC #2
Pala Lake South
=> Pala Mesa Greens
Pala Mesa Greens
=> Monserate Hill
Fire Road
=> Morro
Dentro de Lomas*
Via Mariposa East
=> Via Mariposa
Via Mariposa West
=> Bonsall
Bonsall
Sunset
=> Esponsito
Cotton Tail*
=> Tres Amigos East
Tres Amigos "E"
=> Moosa Crest
Moosa Crest
=> Hutton
Hutton
=> Moro
San Luis Rey Heights
Rancho Monserate "W"
=> Rancho Monserate
Rancho Monserate "E"
=> U-4
U-4
=> Laketree
Laketree
=> Oakcliff
Oakcliff
=> Morro
Morro Booster Station
=> Club Vista
Lake Vista Drive
=> SLR Downs
SLR Downs Track
=> Via Casitas
Via Casitas
=> Villas Fore
Villas Fore
=> Holly Lane
Holly Lane
=> Trendal
Trendal
=> Tres Amigos West
Tres Amigos "W"
SLR Ranch E
=> San Luis Rey Ranch
SLR Ranch W
Valve
Size
4" & 3/4"
6"
6" & 2"
8" & 3"
10"
8"
6" & 2"
6" & 2"
6" & 2"
6" & 2"
8" & 2"
6"
8" & 2"
4" & 2"
4"
8" & 2"
6"
6"
6" & 1"
8" & 4"
4"
10"
10" & 2"
10" & 2"
10" & 3"
6" & 4"
6" & 2"
6"
8" & 2"
6" & 3"
6" & 2"
6" & 2"
4" & 3"
4"
6"
8" & 2"
8" & 2"
Press.
Setting
(psi)
45
50
80
150
85
85
75
75
100
120
120
55
260
95
95
120
95
110
85
110
80
85
110
110
70
110
120
120
100
125
110
125
70
85
95
70
51
Comments
normally closed; backup supply to Vallecitos
normally closed; backfeed fr/pumped zone
emergency supply to Canonita
comb. PRV/PSV; normally closed
Normally closed;can be used to fill Beck Res.
Normally closed; back-up supply to Beck
sole supply to reduced pressure zone
primary supply to reduced zone
secondary supply to reduced zone
out-of service until line under I-15 is repaired
comb. PRV/PSV; setting too low to fill res.
normally closed; backfeed fr/pumped zone
* reducing station is currently out of service
3.4
DAILY OPERATIONS
Operation of the RMWD water distribution system is very complex and relies on manual
changes to the system, which are subject to personal judgment rather than automation. The
water distribution system is flexible in that supply from the eight 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.
Reservoir water levels are connected to the RMWD SCADA system so that the water operators
can monitor the system throughout the day at the water operations center.
Filling of the Beck and Morro Reservoirs is accomplished through manual valve operations. The
Morro Reservoir can take up to 2 weeks or more to fill during summer months. Tank water
levels in several zones are also operated in a fill/drain scenario with water levels set low to
improve the turnover rate and water quality. Water Operations staff has stated that several
operational changes and manual adjustments are typically made each day during peak demand
periods. Manual operational changes that may be made under normal supply operations
include:
•
A butterfly valve may be throttled to supply water from SDCWA Connection No.
7/Canonita Zone to the Beck Zone. This is the primary supply to the Beck Reservoir.
•
Operators may manually open or throttle a ball valve at Highway 76 and Gird Road to
supply water to the Morro Zone from the Beck Zone. This valve is opened periodically to
fill the Morro Reservoir and is usually opened in conjunction with supply into the Beck
Zone as described above.
•
A normally closed plug valve at Redondo can be throttled to supply the Morro Zone from
the Gopher Canyon Zone. This valve is typically used as a supplemental supply to fill
Morro Reservoir during summer months. When this valve is opened, additional water is
ordered from SDCWA Connection No. 6.
•
There is occasionally a loss of chlorine residual in the Magee Tank. When this occurs,
the operators open the bypass valve at Booster Pump Station 7. The water then blends
with the water in the Rainbow Heights zone. Chorine tablets are used to boost the
chlorine residual in the tank.
In addition to these normal supply operations, system operators have several documented
procedures for alternative supplies to zones in the event that pump stations fail, tanks need to
be removed from service, or when water quality problems arise in tanks or reservoirs. As an
example, the Vallecitos Zone can be supplied from the Rainbow Heights Zone through a North
Zone pipeline by opening and closing several isolation valves.
3.5
EMERGENCY SUPPLY OPERATIONS
Annual planned shutdowns of the SDCWA aqueduct are normally scheduled for up to 10 days
during the winter. Most years involve a shutdown of only one of the two aqueduct systems
(Barrel 2 or Barrel 4), but occasionally both aqueducts are out of service, requiring the
distribution system to operate completely from water stored in tanks and reservoirs.
During planned shutdowns of the SDCWA Second Aqueduct, zones normally supplied from
Connections 3, 6, 7, 8, and 11 are supplied from the Beck and Morro Reservoirs, which have
the most excess storage capacity. Portable gas powered pumps are utilized to pump water
from the Morro Zone to the Gopher Canyon Zone and from the Beck Zone to the Canonita
Zone. Supply to the Gopher Canyon Zone is also supplemented from the City of Oceanside’s
Weese Filtration Plant via a portable pump. The North Zone and all zones that are pumped
from the North Zone are normally supplied from Connections 1 and 10 on the First Aqueduct
and Connection 9 on the Second Aqueduct. During a shutdown of both aqueducts, these zones
rely on water from in-zone tank storage, the North and Northside Reservoirs, and additional
supply from the Fallbrook Public Utility District’s (FPUD) Red Mountain Reservoir, which is
pumped into the North Reservoir. Water in the Northside Reservoir can be supplied down to the
North and Canonita Zones through bypass valves and pressure reducing stations.
3.6
WATER QUALITY
The storage reservoirs provide storage capacity for daily operational needs and supply the
distribution system when imported water is not available from the SDCWA (due to aqueduct and
treatment plant shutdowns). The largest reservoirs, Beck, Morro, North and Northside
Reservoirs are all open reservoirs. The quantity of potable water being held in the large
reservoirs and the fact that they are not covered is affecting the District’s ability to maintain
water quality. Further complicating the issue is the fact that the water enters and leaves the
reservoirs through a single inlet/outlet pipe. This reduces water circulation and “turn-over” in the
reservoirs, since the water farthest from the inlet/outlet does not readily mix with the fresher
water coming into the reservoir.
The treated water purchased from the SDCWA uses chloramines as the secondary or residual
disinfectant. Chloramines reside in a system much longer than free chlorine, but due to the long
residence time in the reservoirs and exposure to UV light, the District struggles to maintain a
residual in the open reservoirs. Because there is often no chloramine residual in the water
leaving the reservoirs, RMWD practices breakpoint chlorination to remove the ammonia and
produce a free chlorine residual in the reservoir effluent water. The water is chlorinated by
using MIOX, a proprietary mixed oxidant and sodium hypochlorite solution that is generated onsite.
The District has recently received a citation from the Department of Health Services for the open
water reservoirs. This citation will require that the District cover all reservoirs by 2009.
4.0 EXISTING 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. Unit
demand factors are developed based on existing demands for use in future demand projections.
4.1 HISTORICAL WATER CONSUMPTION
Within the District, water use is categorized as either agricultural or non-agricultural (domestic).
Water for agricultural use is purchased and sold at a discounted rate. The sum of these two
demand categories represents the total water demand for the system. Using demand data
derived from District water sales, the average day demand (ADD) for the past 20-years is shown
on Figure 4-1.
Figure 4-1
HISTORICAL CALENDAR YEAR WATER SALES
40
Annual Water Use (1000 Acre-ft)
35
30
25
20
15
10
Total Sales
Agricultural Rate
Domestic Rate
5
0
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
The water demand for any particular year is affected by the annual rainfall, which averages
approximately 16 inches per year but can vary significantly from year to year. Larger water use
trends can also be observed from the historical water data. Demand records indicate a
decrease in agricultural water demand beginning in approximately 1988. During a period of
seven years following 1988, the agricultural demand within the District reduced by
approximately 40 percent. This decrease is considered to be attributed to several socioeconomic factors including marketability of grove produce and weather patterns making
watering of groves too expensive to maintain. These factors led to the reduction or “stumping”
of groves and a general decrease in farming activities within the District’s service area.
A further decrease in agricultural water demand was experienced in approximately 1995-1996.
This decrease was attributable to avocado prices of less than $0.17 per pound and the
increasing incidence of “root-rot”. Recent records indicate a substantial increase in agricultural
water demand; this is typically attributed to ending of the previously discussed drought and the
return of favorable avocado prices, thereby allowing suspended agricultural activities to resume.
In any case, agricultural water demand is not anticipated to return to its pre-1995 levels because
of the loss of grove lands experienced during the last drought period. Correspondingly,
historical domestic water demand exhibits a similar decrease during the drought period between
approximately 1987 and 1995. As the drought period ends, domestic water demands
experience a slight increase.
Total water consumption data was also obtained for the water purchased from SDCWA. The
consumption data was obtained from RMWD production reports and is based on the water
supplied by the SDCWA. Figure 4-2 illustrates the annual water purchases over the past 10 years
together with the average annual rainfall (based on CIMIS data for the Temecula station). A
trendline is also plotted on the graph, indicating a steady demand increase. Existing system
analysis was based on elevating 04/05 annual demands to approximated by the trendline, as
discussed in 5.2.2. It is noted that the variance in demand related to rainfall is projected to
decrease as agricultural demands are replaced by domestic demands.
Figure 4-2
ANNUAL WATER PURCHASES AND RAINFALL TOTALS
40,000
100
Annual Rainfall
90
Annal Water Purchase
Annual Water Purchase (AFY)
Purchase Trendline (log)
80
30,000
70
60
25,000
50
20,000
40
30
15,000
20
10,000
10
5,000
0
1994-95 1995-96 1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05
Fiscal Year
Average Annual Rainfall (inches)
35,000
Figure 4-3 illustrates both the average and maximum day delivery rates for the past five years.
The maximum/average ratio is also provided for each year. This ratio, which is referred to as the
maximum day peaking factor, is used to size distribution system facilities.
Figure 4-3
AVERAGE AND MAXIMUM DAY WATER PURCHASES
70
(2.17)
60
(2.13)
(2.23)
System Demand (mgd)
(2.84)
(1.72)
50
40
30
20
10
0
2000
Average Day Demand
4.2
2001
2002
Max Day Demand
2003
2004
(x.x) Max Day/ADD Peaking Factor
EXISTING WATER CONSUMPTION
Monthly water billing records from July 2004 through June 2005 (FY 2004/05) were obtained and
analyzed to establish the existing water demands and distribute water demands in the distribution
system hydraulic model. The billing accounts were averaged over the 12-month period to
determine the average day demand (ADD).
The RMWD identifies four categories of water users for billing purposes, which are identified in
Table 4-1. The number of customers and the total demand per account type in 2004/05 are
shown in Table 4-2. The total average rate of water supplied for 2004/05 based on RMWD billing
records was 21.5 MGD. Figure 4-4 illustrates the percentage of each water billing category based
on the total system ADD. It is noted that while the approximately 9% of the RMWD meters are
agricultural meters, the water usage from these meters is approximately 37 percent of the total
system demand.
Table 4-1
RMWD WATER BILLING CATEGORIES
CATEGORY
BILLING RECORD METER TYPE
Agriculture
Agricultural account with a MWD discount
Domestic and agricultural account on one meter, choose to participate in
Agricultural/Domestic
MWD discount program
Domestic account. These accounts may include agricultural use, but they
Domestic
do not receive the MWD discount
Construction
Temporary construction account
Table 4-2
WATER USAGE BY CATEGORY
FY 2004-05
No. of
Active
Accounts
% of Total
Accounts
Avg. Day
Demand
(GPD)
% of
Total
Demand
ADD per
Account
(GPD)
Average
Demand per
Acre (GPD)
632
9.2%
7,944,010
36.9%
12,570
2,863
Agricultural/Domestic
1,558
22.6%
7,341,122
34.1%
4,712
1,201
Domestic
4,655
67.6%
6,215,157
28.9%
1,335
1,252
37
0.5%
10,816
0.05%
292
N/A
CATEGORY
Agriculture
Construction
Total
6,882
21,511,105
Figure 4-4
2004-05 WATER USAGE BY BILLING CATEGORY
Agricultural/
Domestic
34%
Construction
0%
Domestic
29%
Agriculture
37%
4.3
DEMANDS PER PRESSURE ZONE
RMWD water billing data for the fiscal year 2004-2005 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; account information, water use
information, pressure zone boundaries, water meter locations, and the parcel base map were
combined to assign each billing record a unique coordinate location.
Both the parcel base map and existing meter locations were used to locate the billing records.
First, the Application Numbers from the billing information were matched to the Application
Numbers in the existing meter locations layer. Records were assigned a unique X and Y
coordinate location based on their associated meter location. A small number of records
remained unmatched. For those remaining records that did not match, APN values from the
billing information were matched to APN values in the parcel layer. The matching billing records
were assigned coordinate locations based on the associated parcel centroid. A small
percentage of billing accounts (approximately 3%) did not match either an APN or an
Application Number. The data that could not be located accounted for only 0.3% of the total
water use demand.
Pressure zone boundaries were updated to reflect recent construction. The pressure zone map
layer was used to assign billing accounts to their respective pressure zones. The desired
pressure zone was selected, and coordinate locations that were contained within its boundaries
were assigned the appropriate pressure zone value. The existing demand per pressure zone is
provided in Table 4-3.
Table 4-3
AVERAGE DAY DEMAND BY PRESSURE ZONE - FY 2004/05
Major Pressure Zone
Name
HGL
Magee
Rainbow Heights
Valecitos
Gomez
North
U-1
Northside
Canonita
Beck
Gopher Canyon
Morro Reservoir
Morro Tank
Totals
2160
1,967
1338
1,710
1,212
1579
1282
1,019
897
1,011
825
865
Demand Per Account Type (MGD)
Agriculture Domestic w/Ag
-0.138
0.117
0.591
1.207
0.035
0.414
0.843
0.516
2.827
1.186
0.064
7.94
0.004
0.200
0.054
0.338
0.609
0.103
0.637
1.081
0.708
2.216
1.072
0.319
7.34
Domestic
0.02
0.08
0.03
0.06
0.28
0.07
0.31
0.57
1.27
1.36
1.92
0.25
6.22
Total
Demand
(MGD)
0.03
0.42
0.20
0.99
2.10
0.21
1.36
2.49
2.49
6.40
4.18
0.63
21.5
4.4
EXISTING SYSTEM PEAKING
Water demands are typically presented in terms of the average daily water consumption, which is
an average over the entire year. Actual water use, however, follows a widely varying pattern 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 2004/2005 system demands based on water purchase records are
summarized in Table 4-4 and described in detail in the following sub-sections.
Table 4-4
SUMMARY OF 2004/05 SYSTEM DEMANDS
Average
Day
Minimum
Month
Maximum
Month
21.5 MGD
33.3 CFS
14,931 gpm
8.6 MGD
13.3 CFS
5,972 gpm
34.4 MGD
53.2 CFS
23,889 gpm
It is noted that the MDD and peak hour demand cannot be determined directly for the RMWD
distribution system. The method of estimating these peaking factors is addressed in the sections
below.
4.4.1
Seasonal Demand Variations
RMWD water billing and CWA water purchase records were utilized to determine the seasonal
variation in water demands. The monthly peaking based on water purchase records for the past
five years is illustrated on Figure 4-5. The data is presented in terms of the monthly peaking
factor, which is the monthly purchase amount divided by one-twelfth of the total demand, or the
average monthly demand for that year. Also included on this chart is a trendline of the data.
From this chart it is apparent that the maximum month demand is approximately 1.5 times the
average month demand, and the maximum water usage typically occurs in August. The minimum
month demand is approximately 0.5 times the average month demand, and the minimum water
usage typically occurs in February or March.
Figure 4-5
RMWD SEASONAL DEMAND VARIATIONS IN WATER SALES
1.8
Monthly Peaking Factor
(Monthly Demand/Montlhly Average)
1.6
1.5
1.4
1.2
1.0
0.8
0.6
0.4
0.5
0.2
0.0
Jan
Feb
2004
Mar
Apr
2003
May
2002
Jun
Jul
2001
Aug
2000
Sep
Oct
Nov
Dec
Trendline
4.4.2 Maximum Day Demand
Maximum day demands are used to size pump station and storage facilities. The MDD
represents the maximum water 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 RMWD, the single day with the maximum water consumption normally occurs
during a dry, windy day between July and September.
To quantify the actual MDD, water must be metered both coming into the system from aqueduct
connections, and in/out from all water storage facilities. Since historical flow meter data is
unavailable, the maximum water demand during the year for RMWD can only be approximated
from water delivery records. The District operates their largest reservoirs in a fill/draw manner,
where extra water is ordered to fill the reservoirs and then the reservoirs are allowed to drain
over a period of several days. System operations were investigated for the three highest water
delivery days in 2004, and it was determined that either the Beck or Morro Reservoirs were
being filled on all three days. The actual water consumption on a daily basis is therefore not
necessarily equal to the water delivered.
For the purpose of determining the maximum day demand, water purchases during the summer
months were averaged over 5 days. This averaging eliminates the extreme peaks and dips in
water purchased due to the filling of reservoirs. 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
three years. It also shows the effect of the adjusted 5-day averaged peaking factor. The
maximum delivery day 5-day average peaking factor over the past three years averages 1.9. This
is considered to be a good approximation of the maximum day demand for the water system.
Table 4-5
HISTORICAL MAXIMUM DAY WATER PURCHASES
WATER
AAD TO MAX
MAXIMUM
MAX DELIVERY
AAD TO MAX
DELIVERY DAY 5-DAY AVERAGE 5-DAY PEAKING
YEAR DELIVERY DELIVERED
DAY
(MG)
PEAKING FACTOR
(MG)
FACTOR
2004
2003
2002
8-Aug
3-Sep
3-Sep
64.2
64.2
55.4
2.8
2.2
2.1
48.0
49.3
47.2
2.1
1.7
1.8
4.4.3 Peak Hour Demand
Peak hour demands are used to size transmission and distribution pipelines. 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 morning hours. Hourly system
demands can sometimes be generated from CWA delivery rates and flow rates out of tanks and
reservoirs. This can not be done for the Rainbow system because the reservoirs do not have
flow meters. The SCADA system sends an indication of the reservoir height, but the open
reservoirs have a very large surface area and the precision of the SCADA system does not
allow for hourly flow calculations into and out of the reservoir. The peak hour demand must
therefore be estimated.
City of San Diego published peaking factor data for inland north areas and flow data recently
recorded and analyzed for the City of Escondido were used to estimate the peak hour peaking
factor for RMWD. Based on these sources, a peak hour factor of 3.0 times the ADD appears
appropriate when applied to the entire distribution system. It is noted that smaller portions of
the system, especially those with primarily agricultural demands, may experience higher
localized peaking. It is also noted that as the service area builds out, the system-wide peaking
will decrease.
4.5
EXISTING RESIDENTIAL UNIT DEMANDS
Ultimate water projections are made in this Master Plan Update based on known planned
development projects and 2020 San Diego County land use data. Demand generation factors
based on existing demands are used to project ultimate water demands. Future development
within RMWD is expected to be mostly single-family and rural residential development. This
master planning effort includes an extensive investigation of the existing water use per singlefamily residence to develop unit water demands for various lot sizes.
The water demand for single-family residences is comprised of an indoor water use component
and an irrigation component. For the RMWD, the outdoor water use is highly dependent on lot
size and the physical terrain. Water demands for ten different residential areas were evaluated
separately to determine the average water demand per dwelling unit and per acre. Figure 4-6
illustrates the locations of the sample areas, which were selected from a review of aerial
photographs and are generally more recent development projects that can be considered typical
of future development. The areas selected all had approximately uniform lot sizes and are
located west of Interstate 15, where most of the recent development has occurred.
Water billing data from an average of 30 to 40 meters was compiled for each of the ten
residential areas investigated. Each “Domestic” or “Agriculture with Domestic” meter account
included in the investigation included a full year of billing data. Lot sizes were verified for all
accounts, and ranged from an average of 0.13 acres to 3.1 acres. Figure 4-7 illustrates the
information obtained for one sample area comprised of 29 residences along Brook Hills Road,
Katie Court, and Wendi Court in a planned residential community. The average lot size in this
sample area is 2.1 acres, the average demand per residential parcel is approximately 2,800
gallons per day (gpd), and the average demand per acre is approximately 1,350 gpd.
A summary of the residential water use based on the investigation is provided in Figures 4-8.
The chart shows the relationship of water demand used per acre for various lot sizes from 0.5 to
3 acres in size. For residential lots the demand per acre decreases as the parcel size
increases, which is a typical trend observed for residential areas. For the RMWD, the water use
per acre begins to settle at approximately 1,000 gallons per day per acre for larger lots. The
conclusion of this investigation will be used for projecting ultimate water demands for vacant
areas that have a future single-family and rural residential land use.
Figure 4-7
SAMPLE WATER DEMAND INVESTIGATION AREA
Water Use per Parcel
2004 Annual Demand (GPD)
7000
6000
5000
4000
3000
2000
1000
0
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
Figure 4-8
RESIDENTIAL DEMAND PER ACRE BASED ON LOT SIZE
Average Day Demand per Acre
(gpd/Ac)
4,000
3,500
Avg. water use from RMWD
sample area
Tredline based on data points
3,000
2,500
2,000
1,500
1,000
500
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Lot Size (acres)
3.5
4.0
4.5
5.0
5.0 EXISTING SYSTEM EVALUATION
The level of service that is provided to a community is the result of the implementation of
improvements that are designed in accordance with accepted criteria. This chapter describes
the planning criteria, analysis methodology, hydraulic computer model and results of the
hydraulic system analyses used in the evaluation of the water distribution system relative to
2005 conditions. The hydraulic analysis employs the use of the H2OMAP® hydraulic modeling
software. System deficiencies are identified and summarized, and recommended projects to
mitigate or eliminate the deficiencies are presented in Chapter 7, Recommended Capital
Improvement Projects.
5.1
PLANNING CRITERIA
The planning criteria for the design and evaluation of potable water facilities in RMWD are
based on existing system performance characteristics, past criteria used by the District, and
current industry and area standards. Planning criteria include standards for demand peaking
factors, system pressures, distribution pipelines, storage reservoirs, and booster pump stations.
A summary of criteria that impact the design and performance of water facilities is provided in
Table 5-1. These criteria, which are discussed in detail in the remainder of this report section,
are the basis for evaluating water system performance and determining facilities required to
serve future development.
Table 5-1
RMWD PLANNING AND PERFORMANCE CRITERIA SUMMARY
WATER DEMAND
PEAKING
FACTORS
1.6 x ADD – Maximum Month Demand
1.9 x ADD – Maximum Day Demand
3.0 x ADD – Peak Hour Domestic Demand
SYSTEM
PRESSURES
Static Pressures (based on the reservoir HWL):
60 psi – minimum desired
150 psi – maximum desired
Dynamic Pressures (with reservoir levels half full):
40 psi – minimum desired pressure during peak hour demands
20 psi – minimum allowable pressure for fire flows
PIPELINES
8 fps – maximum desirable velocity at peak hour flow
5 ft. per 1000 ft of pipe – maximum desirable head loss at peak flow
DAILY STORAGE
RESERVE
STORAGE
PUMP STATIONS
Operational – 15% of Maximum Day Demand
Emergency – 100% of the Maximum May Demand
Fire Flow – Maximum fire flow for the required duration
10 days of storage based on the ADD for planned shutdowns of the CWA
aqueducts
Capacity equivalent to the MDD with the largest pumping unit out-of-service.
5.1.1 Demand Peaking Factors
The demand peaking factors are based on an analysis of current and historical RMWD peak
flows, as described in detail in the previous chapter (Section 3.4- Existing System Peaking).
The minimum and maximum month peaking factors of 0.4 and 1.6, respectively, are
documented for the first time in this report. The maximum day peaking factor used in the
analysis of the existing and ultimate system is 1.9, and a peak hour factor of 3.0 is applied to
domestic demands. It is noted that these peaking factors are applicable for the analysis of the
system as a whole, based on existing land use, and are considered conservative for the ultimate
system, since peaking factors will generally decrease with increasing demands. Higher peaking
factors should be used when evaluating small portions of the distribution system with a single
land use type.
5.1.2 System Pressures
The range of water pressures experienced at any location is a function of the hydraulic grade
and the service elevation. Within a specific pressure zone, the hydraulic grade is affected by
the reservoir or tank water level and/or pressure reducing valve settings, friction losses in the
distribution system, and the flow delivered through aqueduct connections, if applicable. The
maximum static pressure within a pressure zone is based on the high-water level of the
reservoir or highest pressure reducing valve setting and the elevation at any specific point in the
zone. The maximum desired pressure is 150 psi and the maximum pressure should be no
greater than 200 psi. It is noted that, due to the hilly terrain and dominance of agricultural
customers, there are currently many areas of the RMWD distribution system where pressures
exceed 200 psi.
The minimum static pressure is used as a general guideline for initial design efforts, as the
operating or dynamic pressures will generally be lower. The minimum allowable pressure is 40
psi under peak hour flow conditions and 20 psi at a fire flow location during a fire occurring
under maximum day demand conditions. Under certain circumstances, RMWD will approve the
installation of private pumps for areas that receive less than the minimum 40 psi operating
pressure. The minimum pressure in the distribution system for these areas must be 20 psi
based on the Fire Department guidelines and the ability to provide adequate pressures for fire
flows.
5.1.3
Pipelines
Criteria for pipeline sizing are based on keeping velocities low to minimize wear on valves and
scouring of interior coatings, and limit head loss in the distribution system. Water distribution
mains should be designed to supply peak flows at velocities below eight feet per second, and
the corresponding head loss should not exceed five feet per 1000 feet. These criteria may be
exceeded during fire flow situations or in areas where there is a large safety factor in meeting
pressure criteria. Generally, transmission mains are designed based on peak flows and
reservoir filling conditions, while distribution piping is sized for fire flows. For zones with long
transmission mains, the pipeline friction loss will typically need to be less than 3 to 5 feet per
1000 feet to maintain adequate pressures and minimize pressure swings. Looping is highly
desirable in a distribution system and long, dead-ended pipelines should be avoided where
possible due to reliability and water quality concerns.
5.1.4
Fire Flow Requirements
Water must be available not only for domestic and agricultural use, but also for emergency fire
fighting situations. This type of water use is called a fire flow, and the fire flow must be
sustainable for a specific duration at a minimum pressure of 20 psi at the hydrant. General
standards establishing the amount of water for fire protection purposes are set by the Insurance
Services Office (ISO), and these general standards are applied by local jurisdictions. RMWD is
served by several fire protection agencies. The majority of the service area is within the North
County Fire Protection District (FPD), while the northeast area is covered by the County of San
Diego, the southern part is in within the Vista Fire Protection District (FPD), the southeast
portion of the District is serviced by the Deer Springs FPD, and the Southwest is covered by
Oceanside. Figure 5-1 illustrates the service area for each agency.
Considerations such as type of occupancy, type of construction and construction materials,
distance from other structures, and other factors are considered when assigning fire flow
requirements. In lieu of calculating specific fire flows for individual structures, minimum fire
flows for general building categories were reviewed with the North County FPD and used in the
fire flow analysis for this Master Plan Update. The required fire flows are listed in Table 5-2. A
minimum fire flow of 1,500 gpm is required for single-family and duplex residential units. A
2,500 gpm fire flow applies to residential multi-family buildings consisting of four or more
residential dwelling units, schools, and commercial, industrial, office and institutional buildings.
It is noted that for any new buildings constructed within the District, the applicable fire projection
agency will specify the minimum required fire flow. Higher fire flows than those shown in Table
4-2 may be required under certain circumstances, such as developments adjacent to open
space areas susceptible to wild fires or buildings with floor areas in excess of 300,000 square
feet. Fire sprinklers may also be required.
Table 5-2
FIRE FLOW CRITERIA
Land Use
Residential - single family
Residential – multi-family
Commercial, Industrial & Office
Schools
Minimum Required
Fire Flow @ 20 psi
1,500 gpm
2,500 gpm
2,500 gpm
2,500 gpm
Required
Duration
2 hrs
2 hrs
2 hrs
2 hrs
Required
Storage
0.18 MG
0.30 MG
0.30 MG
0.30 MG
5.1.5 Storage Criteria
Water storage is used to supply peak hourly fluctuations, make up the difference between the
amount of water ordered and consumed, provide fire flows, and supply the service area in the
event of an emergency situation or planned shutdown of the SDCWA aqueducts. Storage tanks
or reservoirs should be provided separately in each zone or, if necessary, in a higher pressure
zone. The amount of storage that should be located within each zone is based on the “daily”
storage requirements. Emergency reserve storage is required for long-term supply disruptions,
and is typically located in one or more large reservoirs.
Operational Storage
Operational storage is defined as the storage required under normal operating conditions to
balance the difference between water supply and daily variations in demand. Water is supplied
to the RMWD distribution system from the SDCWA at a constant supply rate, which is the
projected water use for the following 24-hour period. Peak hour demands in excess of the 24hour average demand must be satisfied by drawing on water stored in the RMWD water storage
tanks and reservoirs. Providing operational storage within each zone also allows transmission
mains to be sized for maximum day demands, rather than higher peak hour flows.
The required operational storage is usually defined as the volume of water required during peak
demand periods above the maximum day average flow rate. An operational storage
requirement equal to 15 percent of the MDD is typical, and was used for the RMWD analysis. It
is noted, however, that while the operational storage requirement as defined pertains to the
water system as a whole, it may not be applicable for some of the pumped zones. The RMWD
pumped zones typically have pumps with significantly higher flow capacities than the zone
demand requirements (see section 4.1.5). Additional storage is also required to operate pumps
only during off-peak energy periods at night. For the pumped zones, the storage that is required
for daily operations would be more accurately based on the storage required for current
pumping operations. As the zone demands increase, however, the pumps will operate for
longer periods, and the required storage will more closely approximate the 15 percent of MDD
requirement.
Emergency Storage
Emergency storage provides water during incidents such as pipeline failures, pumping or
equipment failures, and electrical power failures. These in-District emergencies would typically
be repaired or mitigated in a short period of time. An emergency storage requirement of 100
percent of the maximum day demand has been allocated for these purposes.
Fire Flow Storage
Each reservoir serving the RMWD must contain an available supply of water to be used in the
event of a fire within its service area. Fire flow storage is equal to the volume of water required
for the largest fire flow requirement within the reservoir service area, as determined by the land
use (see Table 4-2). For zones with multiple storage reservoirs, the required fire flow storage
may be divided between the reservoirs. In addition, when one reservoir supplies a very large
service area or more than one major pressure zone, the fire flow storage for that reservoir may
be increased based on the probability of simultaneous fires within the service area.
Reserve Storage
In the event of a loss of supply from the SDCWA or MWD, RMWD would be primarily dependent
on stored water to meet supply requirements. The SDCWA performs annual maintenance and
repairs on the treated water aqueduct supply system each winter, requiring a shutdown of their
supply connections. The wholesale agencies recommend that each of its member agencies
have 10 days of storage to meet demand requirements until supply facilities are repaired or
returned to service. The storage allocated for this purpose is termed reserve storage. Reserve
storage is in addition to the daily storage requirements. For the RMWD, reserve storage is
located primarily in the Morro, Northside, and Beck Reservoirs. Temporary pumps are required
to supply water to certain zones, depending on which CWA aqueduct pipeline is out of service
or water use trends during the shut-down period.
5.1.6 Pump Station Criteria
Pump Stations should include one redundant pump and are sized based on the maximum day
demand with the largest pumping unit out of service. As stated above, reservoir storage
provides for flow differences between maximum day demand and fire-flow or peak hour flows. It
is noted that additional pumping capacity is required for pump stations to operate only during
off-peak energy periods.
5.2
HYDRAULIC MODEL DEVELOPMENT
Analysis of the water distribution system is performed using the H2OMAP® modeling, analysis
and design software developed by MWH Soft, Inc. H2OMAP provides a Graphical Information
System (GIS) interface for building and editing model facilities, and a hydraulic analysis engine
to perform extended period simulations. A skeletonized water hydraulic computer model was
developed for RMWD in 2001 as part of the 2001 Water Master Plan Update. For this current
Master Plan Update, the 2001 model has been updated and small diameter pipelines have been
added based on the water system GIS. The 2005 existing system hydraulic model with
pipelines colored coded by pressure zone is illustrated on Exhibit A-1 in Appendix A.
5.2.1
Physical Data Input
The hydraulic model is made up of pipes, junction nodes, valves, tanks and pumps. Pipeline
inputs consist of the alignment, length, diameter, pipeline material, and a roughness coefficient.
The function of the roughness coefficient, which is also known as the Hazen Williams “C”
coefficient, is to estimate system friction losses. A “C” coefficient of 130 has been assigned to
newer and PVC pipelines while older steel and VCP pipelines have a “C” coefficient of 120.
Node inputs consist of the demand, a fire flow requirement, and the elevation. Topographic
data is derived from National Oceanic and Atmospheric Administration (NOAA) Coastal
Services Center data collection of elevation point data derived from Interferometric Synthetic
Aperture Radar (IfSAR). Contour data was derived from a 10 feet grid of elevation points, with
horizontal accuracy of 14 feet and vertical accuracy of 7 feet at a 95% confidence level.
Proper modeling of valves in the RMWD hydraulic model is essential for an accurate
representation of the distribution system. For this Master Plan Update, the location of isolation
valves that separate pressure zones were reviewed and re-located based on input from RMWD
Operations Staff. Flow input from the SDCWA connections is modeled with flow control valves.
All active pressure regulating stations are modeled using dimensional data and pressure
settings from the Water Atlas Books. The settings were reviewed with Operations Staff and, in
some cases, adjusted based on their input. For pressure reducing stations with multiple valves,
only the largest valve size is typically modeled. The pressure reducing valves are assigned a
minor loss coefficient (“K” factor = 10) to calculate friction losses in the event that a valve cannot
maintain the downstream setting and operates in a fully open position.
Storage reservoir and tank dimensional data is input to the model to be able to perform
extended period simulations. Individual pumps at the booster pump stations are modeled based
on the original pump curves, with the curves de-rated based on recent flow test data. Pump
controls in the model are based on reservoir level set points input to the SCADA system.
5.2.2
Demand Input
Water demands are input to the model at junction nodes. For this Master Plan Update, new
demands were input to the existing system model based on fiscal year 2004/05 water billing
records. Because rainfall during the 2004/05 season was much higher than average, annual
water usage was lower than normal. All demands were therefore increased by 16 percent
to more accurately represent “average” existing demands (refer to the trendline in Figure 42). For the existing system model, the ADD is therefore 25.2 MGD (39 CFS).
The process of importing the billing data was performed using GIS techniques. To input meter
account data into the model, a copy of the model nodes was initially exported from the hydraulic
model and input into the GIS software. A routine was then enacted to link the adjusted 2004/05
billing data, spatially located to the RMWD parcel base, to the nearest model node. The
demand at each model node is therefore a sum of the water billing data from various account
types on the surrounding parcels. Prior to exporting the nodes, the model was reviewed and a
number of nodes were assigned as “no-demand” nodes. This additional step was necessary for
locations where a transmission main for one pressure zone extends through a service area for a
different pressure zone. In this case, the accounts on the surrounding parcels are assigned to
the distribution pipelines in the correct service zone, and not the transmission main, which
serves no demands.
The required fire flow demand was also input at each node. A flow rate of 1,500 gpm was
initially input at all nodes. The existing land use map was then reviewed to determine locations
with larger required fire flows (commercial, multi-family, government). Fire flows were
subsequently increased in the model at these corresponding locations.
To perform extended period simulations, a 24-hour peaking curve was developed and input to
the existing system model. The 24-hour maximum day peaking curve with an average flow of
1.9 times the ADD and a peak hour flow of 3.0 times the ADD is shown in Figure 5-2. This
curve is based on hourly flow patterns measured for Escondido and was adjusted to match
RMWD peaking factors as derived in section 4.4 of this report. The curve is considered to be an
approximation of water use for the overall District. It is noted, however, that large agricultural
water users may impact the peak flows within specific zones. Based on this representative
curve and an existing system ADD of 25.2 MGD, the maximum day 24-hour demand analyzed
is 47.9 MGD (74 CFS), and the peak hour demand is 75.6 MGD (52,500 gpm).
Figure 5-2
MAXIMUM DAY DEMAND PEAKING FACTOR CURVE
3.2
3.0
2.8
Hourly Peaking Factor (AAD ratio)
2.6
2.4
Max Day Demand =
1.9 x Avg Annual Demand
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Midnight
3:00 AM
6:00 AM
9:00 AM
Noon
3:00 PM
6:00 PM
9:00 PM
Midnight
5.2.3
Boundary Conditions
Boundary conditions were set up to an extended period simulation with maximum day demands.
To determine the water supply to the model from the aqueduct connections, daily flow purchase
data from July 2005 was averaged for each of the eight CWA and MWD connections. Each
connection was then modeled with a flow control valve to maintain the average July flowrate for
the 24-hour simulation. Reservoir water levels were initially set at half full, with the exception of
the Magee and Rainbow Heights Reservoir, which were set lower. Pumps station controls
based on reservoir levels were activated and valves which are operated manually to fill the Beck
and Morro Reservoirs were closed. After a series of initial trials, the flow supplied from CWA
Connection 7 was reduced by approximately 50 percent to prevent overfilling of the Canonita
Reservoir, since higher flows from this connection are ordered to fill the Beck Reservoir. Flow
rates from various aqueduct connections were subsequently modified to analyze filling of the
Morro and Beck Reservoirs.
5.3
HYDRAULIC SIMULATION RESULTS
The analysis engine of the H2OMap hydraulic modeling software solves the hydraulic model by
using the “Gradient Algorithm Hybrid Method” developed by EPANET. EPANET is a hydraulic
and water quality analysis program developed by the Water Supply and Water Resources
Division of the U.S. Environmental Protection Agency'
s National Risk Management Research
Laboratory. The analysis method solves a system of linear equations in an iterative process
using matrix techniques. H2OMap performs extended period simulations (EPS) to route water
flows through the system using diurnal demand curves. The result of this analysis technique is
a balancing of reservoir flows and a more accurate system response to changing demands
within the subject distribution system.
An extended period simulation with maximum day demands was run to assess reservoir
performance (the ability to supply peak flows and refill after draining) and pipeline velocities and
pressures. Results of the 24-hour simulation were reviewed and analyzed. Model pressures
were sorted to determine both high and low pressure areas. During the peak hour demand
(hour eight of the simulation) pressures and pipeline velocities were plotted. Steady-state
simulations were also made to analyze impacts to the distribution system with the maximum
number of pumps operating at each station under tank filling conditions. Lastly, additional
series of extended period simulations were made to evaluate how reservoir water levels balance
in zones with multiple reservoirs (Gopher Canyon and North Zones). The following general
observations were noted:
•
There are many areas in the distribution system with pressures higher than 200 psi.
This is primarily due to the steep and varying terrain, the preference of agricultural
customers for high delivery pressures, and low density development, which makes strict
adherence to design standards uneconomical. It is possible to reduce pressures in
several areas by expanding or creating reduced pressure zones supplied by pressure
reducing stations. In general, however, pressures cannot be reduced to most areas
without significant zone reconfigurations involving the construction of new storage tanks
and transmission mains.
•
System operators maintain reservoir and tank water levels and operate pumps largely in
response to water quality concerns. Pumps are generally oversized based on the
demand served (pump capacity is greater than the maximum day zone demand), and
operators may run several pumps at a station to quickly fill tanks or reservoirs. High
velocities in the main delivery pipeline from the North Reservoir and resulting low
pressure areas were observed in the model when all pump stations were run
simultaneously at their maximum pumping capacities. This may not be a realistic
operating scenario, however. Operators should be aware of potential pumping impacts
on pressures in the North Zone.
•
The two North Zone Reservoirs do not communicate hydraulically due to the small
diameter pipelines connecting the reservoirs. Operators balance the reservoir levels
independently by the flow rates ordered at the nearest CWA connections. This
operating condition may be preferable, however, since the high water levels of the two
reservoirs differ by six feet. During aqueduct shutdown periods, pipelines are closed in
the North Zone to create separate service areas for each reservoir. This allows the
North Reservoir to be filled without overflowing the Rice Tank. Without flow from the
CWA connections, the model indicates that the Rice Tank drains more slowly than the
North Reservoir, despite its smaller size.
•
Water levels in the three Gopher Canyon Zone tanks are controlled largely by the flow
rates ordered at the closest CWA connection to each tank. With no flow entering the
zone from the aqueducts, the model indicates that the tanks have differing drain rates,
with the northernmost Hutton Tank being the slowest to drain and the Turner Tank
(South Tank) draining the fastest. The tank water levels during aqueduct shutdown
periods are largely affected by the location and operation of the temporary pumps. A
review of pipeline velocities indicated no specific pipeline restrictions or high velocity
sections of pipelines connecting the tanks. Analysis results indicate that there would be
no significant improvement in the balancing of tank water levels without significantly
upsizing the entire length of north/south pipelines connecting the tanks.
•
The Morro Zone has excess storage capacity and the Gopher Canyon Zone is deficient
in storage based on daily storage criteria and existing demands. The hydraulic grade of
the Gopher Canyon Zone is 186 feet higher than the Morro Zone. A significant portion of
the Gopher Canyon service area bordering the Morro Zone and along east/west valleys
is subjected to extremely high pressures, and could be better served at Morro Zone
pressures despite the approximately 80 psi pressure differential. The model was run
with proposed zone changes to extend the Morro Zone east of the San Luis Rey River
and serve portions of the existing Gopher Canyon Zone. Results indicated adequate
pressures and acceptable pressure swings in the expanded Morro Zone. This zone
reconfiguration would also allow for future Morro service to more planned developments.
5.4
•
Filling of the Morro Reservoir is a manual operation, largely controlled based on water
quality considerations. Operators typically let the Morro Reservoir drain down, and then
fill the reservoir from the Beck Zone. During peak demand periods flow is supplied from
the Gopher Canyon Zone as well. The model indicates a reduction in flow rate supplied
from the Beck Zone during peak demand periods due to pipeline friction losses in the
Beck Zone.
•
High pipeline velocities were observed in a few small 6-inch pipelines, and in
transmission mains extending from the North Reservoir under certain operating
conditions. High pipeline velocities were also observed with high flows from several
aqueduct connections, although in most cases the flows modeled did not match
demands in the system. The high velocities generally did not result in pressure
problems due to high static pressures.
FIRE FLOW ANALYSIS
Water reserved for emergency conditions, including fire suppression, is stored in each of the
District’s sixteen reservoirs and storage tanks located throughout the distribution system. The
distribution system facilities, including pipelines, pressure reducing stations, and booster pump
stations, must be adequately sized to deliver the required fire flows to hydrants. A fire flow
analysis determines the ability of a water system to provide the required fire flow rate at a
minimum pressure of 20 psi from storage facilities.
A fire flow analysis is typically performed in conjunction with maximum day water demands on
the system. Model controls and initial settings were revised for the fire flow simulations. Input
flows from the aqueduct connections were turned off, all pumps at booster pumps stations were
controlled to be off, and reservoir water elevations were set at either half full or, if normally
operated lower, the typical low operating level. These settings result in worst case but realistic
pressure conditions in most of the distribution system, and will verify the ability of storage
reservoirs to provide a fireflow in conjunction with a loss of power to system pumps.
A steady-state demand simulation with maximum day demands was first performed under the
modeling conditions described above. A series of fire flow analyses were then performed with a
fire flow applied sequentially at every node with a fire flow demand. Fire flow analysis results
provided from the simulation at each node include the “static” pressure (pressure with maximum
day demands and no fire flow), residual pressure with the required fire flow, and the available
fire flow at a residual pressure of 20 psi. If the distribution system cannot provide the required
fire flow at 20 psi, H2OMap calculates the resulting (residual) pressure, even if this pressure is
negative. The available fire flow at a residual pressure of 20 psi provides a more
comprehensible and realistic result.
Analysis results indicated that the available fire flows ranged from approximately 250 gpm to
over 30,000 gpm. Over 280 nodes were initially identified that could not deliver the required fire
flow. These node locations were each evaluated and compared to the location of fire hydrants
based on the RMWD atlas maps. At many locations, modifications were made to the model to
remove a fire flow from pipelines that do not serve hydrants or relocate nodes to match hydrant
locations. Analysis results from the fire flow simulations are provided in Appendix B and the
nodes that cannot deliver the minimum required fireflow are illustrated on Exhibit B-1. In
general, 4-inch diameter pipelines and pressure reducing valves cannot deliver a 1,500 gpm fire
flow. Additionally, dead-end 6-inch diameter pipelines can generally provide a 1,500 gpm fire
flow only if the length of the pipeline is very short and the static pressures are high. Since the
RMWD has very few 4-inch diameter pipelines, most of the fireflow deficient areas are located
on 6-inch diameter or dead-end pipelines.
It is noted that the available fire flow rate from H2OMap simulation results should be interpreted
only as an approximation. The actual flow rate available from any given fire hydrant with a 20
psi residual pressure is dependent on the exact location, elevation, and type of fire hydrant, and
also the physical condition (and resulting friction loss) of the upstream pipelines. The
operational status of aqueduct connections, pumps and reservoirs levels will also affect the
actual flow that can be provided. The results from the fire flow analysis should be considered as
a tool to help prioritize pipeline replacement projects. It is also noted that the available fire flows
are only calculated at discreet node locations along pipelines, which may or may not correspond
to actual hydrant locations. Nodes were added to the model at several locations to analyze flow
from specific hydrants.
Improvement projects are proposed to bring the existing water system up to compliance with
minimum fire flow requirements based on existing development. The identification of facility
improvements to correct fire flow deficiencies was made based on a series of hydraulic
computer simulations. Potential improvement projects were added to the computer model, and
fire flow simulations were re-run to verify the resulting fire flows. Fire flows can always be
increased by upsizing individual pipelines, but efforts were taken to minimize the required
improvements and identify upstream projects that could benefit downstream areas at multiple
locations. This often resulted in the identification of projects to loop pipelines instead of
replacing pipelines. Looping is very desirable in a distribution system because it utilizes existing
pipeline capacity and provides redundancy. It is noted, however, that field inspections were not
performed to assess the constructability of proposed pipeline alignments and the condition of
existing pipelines was not taken into consideration. The criteria that were developed for the
identification of fire flow improvement projects are as follows:
5.5
•
Improvement projects were not identified if available fire flows from the model were
within ten percent of the required flows, as this is considered within the margin of error
for this analysis.
•
It is assumed that the minimum diameter for future pipelines is 8-inches, which is the
size of most of the proposed new pipelines.
•
No improvements were identified for dead-end pipelines if the available residential fire
flows were a minimum of 1,000 gpm. This reduced fire flow criteria was established
since many dead-end pipelines serve very few meters, and the residences may already
have approved sprinkler systems installed.
•
Replacement projects are not specifically identified for 4-inch pipelines, since the District
plans on replacing all these pipelines. Six-inch diameter pipelines are recommended to
be replaced with larger diameter pipelines only if the line serves a fire hydrant and
minimum fire flows cannot be provided.
•
New pipelines have been identified to create loops with existing pipelines wherever
possible. The proposed new pipeline alignments were selected to be within existing
roadways or between property lines. If field conditions prevent the construction of
pipelines in the proposed alignments, existing pipelines can generally be upsized to
provide the required fire flows instead of constructing looped pipelines in new
alignments.
STORAGE ANALYSIS
The required storage volume based on the criteria defined in Table 5-1 and adjusted 2004/05
demands was calculated and compared to the capacity of the existing system reservoirs.
Calculations to determine the required daily and reserve storage volumes are shown in Table 53. Based on these calculations, there is an overall storage surplus of 173 MG based on daily
and reserve storage requirements. Considering only the daily storage requirements per zone,
however, there is slight storage deficit (less than 1 MG) in the Vallecitos and Canonita Zones,
and a deficit of approximately 4.7 MG in the Gopher Canyon Zone. It is noted that the surplus
reserve storage in the Beck and Morro Zones needs to be pumped through temporary booster
stations to make up for storage deficits in most of the other zones.
Table 5-3
RMWD STORAGE REQUIREMENTS BASED ON EXISTING DEMANDS
Storage Facility
Reservoir
Capacity
Magee Tank
Rainbow Hts Tank
Gomez Tank
U-1 Tank No. 1
U-1 Tank No. 2
Vallecitos Tank
Northside Res
North Res
Rice Tank
3.0 MG
4.0 MG
3.5 MG
0.5 MG
1.5 MG
0.4 MG
22.8 MG
7.8 MG
4.0 MG
Canonita Tank
6.0 MG
Elevation
(feet)
HWL Bott.
2,160 2,120
1,967 1,927
1,710 1,672
1,579 1,545
1,579 1,533
1,338 1,316
1,282 1,240
1,212 1,192
1,206 1,167
1,019
980
Beck Reservoir
203.7 MG
897
846
Hutton Tank
4.0 MG
1,011
971
Turner (South)
Tank
4.0 MG
1,011
971
Gopher Canyon
4.0 MG
1,011
971
Morro Reservoir
Morro Tank
TOTALS
151.5 MG
825
778
4.0 MG
865
824
425 MG
Service Zones
Magee
Rainbow Heights
Gomez
Existing Demand*
Daily Storage Requirements
Operational
Emergency
AAD
MDD
Fire
(MGD)
(MGD) (.15 x MDD)
Flow
(1 x MDD)
0.03
0.06
0.01 MG
0.18 MG
0.06 MG
0.52
0.99
0.15 MG
0.18 MG
0.99 MG
1.17
2.22
0.33 MG
0.18 MG
2.22 MG
0.2 MG
1.3 MG
2.7 MG
Surplus/
Deficit by
Zone
2.8 MG
2.7 MG
0.8 MG
Total
U-1
0.25
0.47
0.07 MG
0.18 MG
0.47 MG
0.7 MG
1.3 MG
Vallecitos
Northside
0.23
1.56
0.44
2.96
0.07 MG
0.44 MG
0.30 MG
0.18 MG
0.44 MG
2.96 MG
0.8 MG
3.6 MG
-0.4 MG
19.2 MG
North
2.44
4.64
0.70 MG
0.30 MG
4.64 MG
5.6 MG
6.2 MG
0.83 MG
0.30 MG
5.6 MG
6.7 MG
-0.7 MG
Canonita
Pala Mesa CC 1
Pala Mesa Fairways
Pala Mesa CC 2
Pala Mesa Greens
Monserate Hill
Beck
Rancho Monserate
U-4
Lake Tree
Oakcliff
Gopher Canyon
Hutton
Bonsall
Moosa Crest
Esponsito
Via Mariposa
Tres Amigos East
Tres Amigos West
San Luis Rey Ranch
Trendal
Morro
Club Vista
SLR Downs
Via Casitas
Villas Fore
Holly Lane
Morro Tank
2.41
4.58
0.004
0.01
0.05
0.09
0.05
0.09
0.02
0.03
0.40
0.75
2.26
4.30
0.29
0.56
0.06
0.11
0.05
0.09
0.04
0.08
6.16
11.70
0.14
0.27
0.05
0.10
0.42
0.80
0.18
0.34
0.10
0.19
0.10
0.19
0.07
0.14
0.23
0.43
0.04
0.07
4.79
9.10
0.09
0.17
0.20
0.38
0.04
0.08
0.01
0.03
0.02
0.03
0.69
1.32
25.2 MGD 47.8 MGD
* Based on 2004-05 billing data with water demands increased by 16% to reflect an average year.
Reserve Storage
10-day
Surplus/
AAD
Deficit
62.0 MG -29.5 MG
56.3 MG 140.5 MG
0.77 MG
0.30 MG
5.1 MG
6.2 MG
197.5 MG
2.14 MG
0.30 MG
14.2 MG
16.7 MG
-4.7 MG
1.47 MG
0.30 MG
9.8 MG
0.20 MG
0.18 MG
1.32 MG
1.7 MG
2.3 MG
7.2 MG
2.9 MG
47.8 MG
57.9 MG
367 MG
133.3 MG
1.9 MG
252 MG
113 MG
11.5 MG 140.0 MG
5.6
AQUEDUCT SHUTDOWN OPERATIONS
The SDCWA performs annual maintenance on their aqueducts, requiring the shutdown of one
or both of the aqueduct systems for a period of between one and two weeks. For most
shutdown periods there is no definite date for the resumption of water deliveries, as deliveries
are resumed when the maintenance or repair work is completed. During the shutdown period
the RMWD system operates primarily from water stored in RMWD reservoirs, but the largest
reservoirs can only supply a portion of the distribution system by gravity. Operation of the
system during the aqueduct shutdown requires advanced planning, training of operators,
coordination and agreements with other agencies, and the rental of several emergency pumps.
High water usage due to unseasonably warm and dry weather during the aqueduct shutdown
period can severely strain the limits of operation and deplete storage volumes in several zones.
Prior to the shutdown, customers are asked to voluntarily cut back on water usage and the
District’s largest customers are contacted directly by phone. During the shutdown, agricultural
use only meters may be turned off by operations staff if it appears that the storage is being
depleted too quickly. Emergency calls may also be made to high volume customers to
persuade them to curtail water usage.
System operation without supply from aqueduct connections is much more complicated than
during normal operating conditions. During a shutdown of the CWA Second Aqueduct, the
Morro Reservoir supplies the Morro and Morro Tank Zones, and also the Gopher Canyon Zone
through temporary pumps. During periods of high demand, the temporary pumps must operate
continuously to supply Gopher Canyon demands. Additional supply to the Gopher Canyon
Zone may also be required from the City of Oceanside. The City of Oceanside’s Robert A.
Weese Filtration Plant is located directly southeast of the Gopher Canyon Tank. During a
shutdown of the treated water aqueducts the raw water supply to the filtration plant is not
affected, and treated water can be supplied to RMWD from Weese. A permanent facility to
accommodate emergency pumps (discharge and suction piping with flanged connections) is
located adjacent to the Gopher Canyon Tank. It is noted that the supply of surplus water from
Oceanside is limited, as Oceanside also supplies the Vallecitos Water District and Vista
Irrigation District during aqueduct shutdowns.
The Beck Reservoir supplies the Beck and Canonita Zones during an aqueduct shutdown. A
temporary pump installed near the Beck Reservoir site is used to supply water to the Canonita
Zone. Noise and pollution from the temporary pump is an issue. Although there is surplus
water in the Beck Reservoir, there are no pipeline connections to the Gopher Canyon Zone or to
the northern zones during a shutdown.
The North Zone and the six northern zones supplied from booster pump stations do not have
sufficient storage during a shutdown. Operators fill both the North and Northside Reservoirs
and all the boosted zone storage tanks prior to a shutdown, but the existing reserve storage
capacity is only equivalent to approximately five days of average demand. The northern zones
therefore rely on supplemental water supplied from Fallbrook Public Utility District'
s (FPUD) Red
Mountain Reservoir. Red Mountain Reservoir is approximately twice the size of the Beck
Reservoir, and the excess capacity has historically been available to RMWD during aqueduct
shutdown periods. Water is pumped from the FPUD system to the North Zone Reservoir
through a portable pump. It is noted that FPUD is considering construction of a new pipeline to
connect Red Mountain Reservoir to their De Luz service area. If this pipeline is constructed,
there will be less surplus water available to RMWD during shutdown periods.
RMWD Staff requested that improvement projects be identified in this Master Plan Update to
eliminate the need to rent portable gas-driven pumps and purchase water from outside agencies
during an aqueduct shutdown. New permanent pump stations will be required at several
locations. Analysis of emergency scenarios with the proposed new emergency pump stations
was performed with the ultimate system model, and is discussed in Chapter 6.
6.0 ULTIMATE DEMAND PROJECTIONS AND ANALYSIS
Ultimate water demands for the RMWD are made assuming buildout of all parcels within the
existing RMWD boundary. Demand projections were performed in two phases. The first or
planned development phase considers future projects with available planning information. For
residential projects, the planning information includes the number of planned residential units.
The ultimate phase considers the buildout of all remaining vacant land, and projects water
demands based on the future land use as projected by the San Diego Association of
Governments (SANDAG).
6.1
PLANNED DEVELOPMENT
Information on planned development projects was obtained from a search of District files and
meetings with District Staff. Planning information was collected for 26 residential projects,
ranging in size from lot splits creating one additional residential parcel to projects spanning
several large parcels with up to 1,360 future residential units. Some development projects are
currently under construction, while others are in the conceptual planning stage. All the planned
developments include an estimate of the number of future residential units. Future water
demands are projected based on the average lot size within the project and unit water demand
factors developed from the analysis of existing residential water use, as discussed in Section
4.5 and summarized in Figure 6-1.
Figure 6-1
RESIDENTIAL DEMAND PER PARCEL
Average Day Demand per Parcel
(gpd)
4,000
3,500
3,000
2,500
2,000
Avg. water use from RMWD
sample area
Trendline based on data points
1,500
1,000
500
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Parcel Size (acre)
3.5
4.0
4.5
5.0
In addition to planned residential projects, the planned development includes Fallbrook High
School and four future park sites included in the 2005 San Luis Rey River Park Master Plan.
The San Luis Rey River Park Master Plan establishes the framework for the development of a
river park within the 8-mile corridor of the San Luis Rey River, between Interstate 15 and the
Old Bonsall Bridge. Water demand projections are made for landscaped areas and playing
fields defined as Tier A developed park sites.
For each planned development project, water billing records and aerial topography maps were
researched to identify existing water demands on the planned development parcels. Existing
water demands are identified so that a net increase in water demands from future development
can be calculated. Existing agricultural water use was identified for six of the development
projects based on 2004-05 billing data. The remaining planned development projects will be
constructed on parcels that are currently vacant or have no existing water usage. It is noted
that some of these parcels may have previously been used for agriculture and the meters were
recently turned of, or they may be irrigated with well water.
Table 6-1 summarizes the planned development projects and projected water demands and
Figure 6-2 illustrates the location of each project. The projected net increase in water demands
for the 31 planned development projects is approximately 3.3 MGD (3,700 afy). This represents
an increase in demand of approximately 13% over existing RMWD demands. It is noted that
the agricultural demand that will be replaced by the planned development is estimated at only
0.16 MGD. It is also noted that none of the proposed development projects are located in the
northern section of the service area, where there is no wastewater system and rocky soils and
steep topography restrict the installation of septic systems.
Table 6-1
PROJECTED DEMANDS FOR PLANNED DEVELOPMENT
2005 Ag
Projected AAD
Map
Add'l Est. Avg.
Tentative Total
(1)
ID
Planned Lot Size per Unit
Project Name/Street
Total
Demand
Map No.
Acres
Units
(Acres)
No.
(gpd)
(gpd)
(gpd)
Proposed Residential Projects
1 Hill Land Company
TM 5387
1.85
12
0.14
400
4,800
-2 Pala Mesa Highlands
TM 5187-1
70
130
0.43
1,400
182,000
-3 Lake Rancho Viejo Phase II
-285
0.13
500
142,500
-4 The Groves
4694-1
288
85
3.05
3,000
255,000
-5 Monserate Hill
-24.61
3
8.20
6,000
18,000
22,750
6 Malabar Ranch/Brook Hills II TM 4908
96.70
34
2.20
2,600
88,400
-7 Pala Mesa Dr sewer ext.
-7.39
2
1.85
2,500
5,000
-8 Pala Mesa
TM 4729-1 29.54
13
2.00
2,600
33,800
35,578
9 Valley of the Kings
TM 17567 24.49
3
7.35
4,000
12,000
-10 Citrus Lane
TM 20440 13.46
5
2.42
2,700
13,500
-11 Kent
L-14416
10.00
1
10.00
6,000
6,000
-12 Vista de Palomar
PM 18599 14.07
4
2.81
2,900
11,600
4,002
13 Morris Ranch
TM 4240-1 209.5
89
2.35
2,700
240,300
-14 Leatherbury
-178.1
85
2.10
2,600
221,000
-15 Rancho Camargo
-61.4
14
4.39
3,500
49,000
-16 Rancho Viejo LLC
-15
46
0.14
400
18,400
-17 Patapoff
TM 20313,17 38.17
10
2.88
5,000
50,000
69,200
18 San Luis Rey Downs
-29.5
116
0.20
500
58,000
-19 Polo Club
-442.0
165
1.5
2,200
363,000
-20 Hidden Hills
-131.0
53
2.0
2,500
132,500
16,194
21 Hill Ranch
-127.0
38.0
2.7
2,800
106,400
12,251
(2)
-1,074,000
-22 Passerelle (Campus Park)
-500 1,360
0.12
23 DR Horton
-25.85
65
0.30
600
39,000
-24 TM 82
-8
78
0.10
300
23,400
-Lake
Vista
Estates-vacant
lots
25
-49
21
2.33
2,700
56,700
-26 Brisa Del Sol
-206
27
5.5
3,500
94,500
-3,298,800 159,975
Subtotal
2,395 2,717 EDUs
Proposed Non-Residential Projects
27 Fallbrook High School
-50
---100,000
-Proposed San Luis Rey River Park Sites (landscaped parks/fields)
28 Vessels East site
-16
-40,000
-2,500 gpd/Ac
29 SDCWA site
-7
-17,500
-2,500 gpd/Ac
30 Model Airplane site
-10
-25,000
-2,500 gpd/Ac
31 Gopher Canyon site
-1
-2,500 gpd/Ac
2,500
-Subtotal
23 acres
85,000
-TOTALS
2,468
3,483,800
159,975
PROJECTED NET DEMAND INCREASE FROM PLANNED DEVELOPMENTS = 3.32 MGD
(1) 2005 water demands from existing AC/AD meters currently serving the parcel.
(2) Demand projections for Passerelle, which include single family, multi-family, commercial & industrial developement,
are obtained from the October 2005 Water Study performed by Dexter Wilson Engineering, Inc.
6.2
ULTIMATE LAND USE
Information on the projected ultimate land use within the RMWD service area was obtained from
SANDAG, San Diego’s regional planning agency. The main land use classifications for the
SANDAG 2020 land use map are residential, commercial and industrial, government, and open
space. Residential land use is classified as either rural (lot size 1-20 acres), single family, or
multi-family residential. The 2020 land use map was initially reviewed and modified using GIS
techniques to transfer some areas to non-developable categories. These areas, which were
mostly classified as rural residential, are considered to be in flood plains or too steep for
development (areas with slopes of 20 percent or higher). Figure 6-3 illustrates the future land
use types with associated water demands on existing vacant parcels.
Figure 6-4 illustrates the proportion of developable land remaining in the District, which is
estimated at 18 percent of the total land area, or approximately 9,300 acres. Approximately
6,100 acres or 66 percent of the developable land is classified with a rural residential land use,
which is defined by lot sizes between one and twenty acres.
Figure 6-4
REMAINING DEVELOPABLE LAND
NonDevelopable
Land
(designated
open space,
steep slopes,
wetlands)
24%
Developed
Land
58%
Vacant
Developable
Land
18%
The existing agricultural areas that are projected to remain in the ultimate system are also
included in the ultimate land use shown on Figure 6-3. Not shown on this figure is the portion of
Gilligan Groves located in the City of Oceanside, which the District currently serves and is
assumed to be served in the ultimate system. It is noted that most of the existing agricultural
areas are projected to convert to residential land use. It is not known at this time whether the
conversion from agricultural to domestic use may increase or decrease overall water demands.
The difference in water use between agricultural and residential areas is very site specific.
Existing agricultural land use in RMWD includes intensive cultivation in green houses, row
crops, horse pasture, and extensive groves of primarily avocado and citrus trees. Some
agricultural users have ground water wells and irrigation/blending ponds, which supplement
their potable water purchases. Existing groves may also not always be clear cut for new
residential development, as some parcels have only been cleared around housing pads, leaving
trees in place as landscaping for privacy and aesthetics. The change in water consumption
associated with the conversion of agricultural land to a residential use was discussed at several
meetings with RMWD Staff. A decision was made to assume no change in overall water
demands for future residential development that will occur in existing agricultural areas.
6.3
DEVELOPABLE VACANT LAND
For this Master Plan update, ultimate demands are calculated from the sum of:
•
•
•
existing demands
projected demands for planned development
projected demands for buildout of remaining developable vacant areas
It is noted that ultimate demand projections do not assume any change in demand for
agricultural parcels that will convert to residential land use. This is considered to be a
somewhat conservative assumption for the projection of ultimate water demands.
To project water demands for developable vacant areas, water demand unit factors were
developed to correspond to SANDAG land use categories based on existing water usage (refer
to report section 4.5). The ultimate demand calculations and unit water demands per acre are
shown in Table 6-2. It is noted that two separate unit demands applicable to different
geographical areas were developed for the rural residential category. The northern rural
residential category is applied to parcels approximately north of Pala Mesa Drive on the east
side of Interstate 15 and north of Rainbow Glen Road on the west side of Interstate 15. A lower
water demand factor was deemed more appropriate for the northern service area based on the
lower water usage per single family residence in this area, the larger lot sizes, and the
predominantly rocky soils, which are not conducive to lush landscaping and the associated high
water demands.
Table 6-2
PROJECTED DEMAND FOR VACANT PARCELS
6.4
Land Use
Unit demand
Rural Residential - northern area
Rural Residential
Residential - single family
Residential – multi-family
Commercial, Industrial & Office
Steep Slopes > 20%
Open Space
Transportation
500 gpd/acre
1,000 gpd/acre
1,500 gpd/acre
3,500 gpd/acre
5,000 gpd/acre
0 gpd/acre
0 gpd/acre
0 gpd/acre
Total Area
(acres)
4,457
2,549
39
1.6
17
10,619
130
99
17,913 acres
Projected
Demand
2.23 MGD
2.55 MGD
0.06 MGD
0.01 MGD
0.09 MGD
0 MGD
0 MGD
0 MGD
4.93 MGD
HYDRAULIC MODEL DEVELOPMENT
The ultimate system H2OMAP model was developed from the existing system model, layout
plans for planned developments, and the incorporation of current capital improvement program
(CIP) projects (see Chapter 7). Delivery mains were added to the model, as required, to supply
expanded service areas. Supply pipelines and transmission mains extending through planned
development projects are proposed, but distribution pipelines within specific projects are not
identified.
6.4.1 Ultimate Pressure Zones
Future demands in the ultimate system will be supplied from an expansion of the existing
distribution system pressure zones. It is anticipated that no new major pressure zones will be
required, although there may be additional smaller reduced pressure areas within several of the
major pressure zones. Topographical data was reviewed to determine logical extent of existing
pressure zone boundaries to cover the entire RMWD service area. Several zone boundary
adjustments are proposed based on hydraulic analysis of the exiting system and the location of
future demands. These zone changes will reduce high system pressures and move demand to
the Morro and Beck Zones, which have surplus storage capacity. In summary, the major
proposed zone changes are:
•
Transfer several areas of the western portion of the Gopher Canyon Zone to the Morro
Zone. The zone changes will allow the Via Mariposa reduced zone, which is currently
supplied from the Gopher Canyon Zone, to be supplied through existing PRVs from the
Morro Zone
•
Convert the majority of the Esponsito Zone, which is currently supplied from the Gopher
Canyon Zone, to be supplied directly from the Morro Zone. A very small portion of the
Esponsito Zone will be supplied directly from the Gopher Canyon Zone, and the two existing
PRVs will no longer be required.
•
Convert the Monserate Hill Zone, which is supplied through a single PRV from the Canonita
Zone, to be supplied directly from the Beck Zone.
The zone changes were included in the ultimate system model and verified through the ultimate
system analysis. Projects that are required to incorporate the proposed zone changes are
included in the CIP presented in Chapter 7. Figure 6-5 illustrates the major pressure zone
service areas proposed for the ultimate system with the proposed zone boundary changes.
6.4.2 Physical Data Input
Future transmission facilities were added to the existing system model based on the 2002
RMWD CIP and layout plans for planned developments. Layout maps in various stages of
development were provided by District Staff for some of the larger planned developments. The
final sizing of distribution pipelines within planned developments will be determined from future
hydraulic analyses required as part of the development approval process.
The 2002 RMWD CIP was reviewed with District Staff. Facilities currently in design or under
construction were added to the model. The remaining CIP projects that affect system hydraulics
were reviewed and modified as appropriate based on updated planning information and results
from the existing system hydraulic analysis, and then added to the ultimate system model for
further analysis and verification. Major facilities added to the ultimate system model include a
new transmission main from CWA Connection No. 12 to the Morro Zone (W24), new reservoirs
in the Vallecitos Zone (T1) and Gopher Canyon Zone (T2), and the zone boundary changes
discussed in the preceding section. Three new reduced pressure zones were also added to the
ultimate system model to reduce system pressures.
6.4.3 Demand Input
Projected demands were input to the ultimate system model using a multi-step process.
Projected demands from planned development projected were first manually added to one or
more nodes on existing and/or proposed pipelines. GIS techniques were used to add demands
for vacant parcels to the model. Each vacant parcel was spatially intersected with ultimate
pressure zone boundaries to assign the parcel a pressure zone. The ultimate demand for each
parcel was then joined to the model node closest to the parcel centroid in the assigned pressure
zone. Table 6-3 lists the existing demands and projected ultimate demands by major pressure
zone. The projected demand for the ultimate system reflects the proposed pressure zone
service area revisions identified in Section 6.4.1. The ultimate average annual demand for
RMWD is projected to be 33.6 MGD, which is approximately 37,600 acre-feet per year. Total
demands are therefore projected to increase by about one-third at buildout conditions.
Table 6-3
PROJECTED ULTIMATE DEMANDS BY PRESSURE ZONE
Major Pressure Zone*
Name
HGL
Magee
Rainbow Heights
Gomez
U-1
Vallecitos
Northside
North
Canonita
Beck
Gopher Canyon
Morro Reservoir
Morro Tank
Totals
2160
1,967
1,710
1579
1338
1282
1,212
1,019
897
1,011
825
865
Existing
AAD
(MGD)
0.03
0.52
1.17
0.25
0.23
1.56
2.44
2.92
2.70
7.50
5.15
0.69
25.2
Projected
Ult AAD
(MGD)
0.57
1.25
1.47
0.56
0.28
1.64
2.69
2.89
5.12
8.34
7.96
0.77
33.6
Projected
Percent
Increase
1797%
140%
26%
130%
18%
5%
10%
-1%
90%
11%
55%
11%
33%
* Ultimate pressure zones incorporate proposed zone boundary changes
6.5
ULTIMATE SYSTEM HYDRAULIC ANALYSIS
Hydraulic analysis of the ultimate system was performed to size and verify proposed future
facilities. The 24-hour maximum day peaking curve developed for the existing system analysis
(refer to Figure 5-2) was applied to all demands in the ultimate system model. The ultimate
system model was then analyzed under both maximum day demand and emergency supply
scenarios. Several simulation iterations were required to properly adjust CWA Connection
inflows and pressure settings for new PRVs. Successive revisions to the ultimate system model
were developed as proposed facilities were added or modified based on analysis results.
Supply from CWA Connection No. 12 to the Morro Zone was analyzed under reservoir filling
scenarios. This new source of supply will be required to maintain water levels in the Moro
Reservoir as system demands increase. The rated capacity of this connection is 22 cfs,
however very large diameter pipe and long transmission mains would be required to deliver this
flow rate to the Morro Reservoir from the south end of the zone. New pipeline facilities were
instead designed to deliver a maximum flow rate equivalent to the approximate projected
maximum day demand increase in the Morro Zone. This design criteria reduces the amount of
new pipeline projects required, and assumes that the Morro reservoir will continue to be
operated in the existing drain/fill mode. Analysis results indicate that the additional flows to
meet ultimate demands in other zones can be provided adequately from the existing CWA
Connections.
6.6
ULTIMATE STORAGE CAPACITY ANALYSIS
The required daily and reserve (10-day aqueduct shutdown) storage volumes based on the
criteria defined in Table 5-1 and projected ultimate demands are calculated in Table 6-4. The
Paula Mesa Reservoir has been included as an ultimate storage facility, since the District
intends to bring this reservoir back into service. Based on the calculations shown in Table 6-4,
there is projected to be an overall storage surplus of 98 MG in the ultimate system based on
total storage requirements. Considering only the daily storage requirements per zone, however,
there will be storage deficiencies in the Gopher Canyon, Vallecitos, and Canonita Zones. These
zones also exhibited storage deficiencies based on 2004/05 demands, but they were not as
large in the Gopher Canyon and Vallecitos Zones. Under emergency supply conditions, surplus
storage in the Beck Reservoir will need to be pumped to the northern zones and supplied to the
Morro Zone to make up deficiencies in these areas (see section 6.8).
New storage tank locations were identified and verified based on analysis results, but detailed
site investigations were not performed. For the Vallecitos Zone, a new reservoir with a capacity
of approximately 0.5 MG will be required. Ultimate demands in the Vallecitos Zone are
projected to increase by only 20 percent over existing demands, however commercial
development is proposed near the I-15 interchange. The Vallecitos distribution system has no
looping, and the existing reservoir location cannot provide the required 2,500 gpm commercial
fire flow without significant upsizing of most of the transmission system. A new tank site is
therefore proposed nearer to the future commercial development for a second storage tank in
the Vallecitos Zone. A new tank could potentially be constructed just east of I-15, near the
RMWD northern border, and tank elevations will need to match the elevations of the existing
Vallecitos Tank. It is reported that the District may have an existing lease with BLM for a tank
site in this area. It is noted that a new Vallecitos pump station is required to replace the existing
pump station, which is currently not operational. If there is no suitable tank site at the required
elevation, a larger tank with a capacity of 0.9 MG could be constructed at a slightly lower or
higher elevation to increase storage capacity and replace the existing Vallecitos Tank. There is
some flexibility in setting the elevation for a new tank since new pumps are required to replace
the existing pumps. If the existing Vallecitos Tank is removed from service, however, portions
of the distribution system may need to be upsized to supply residential fire flows in the vicinity of
the existing tank.
TABLE 6-4
RMWD STORAGE REQUIREMENTS BASED ON ULTIMATE DEMANDS
Reservoir
Storage Facility
Capacity
Magee Tank
3.0 MG
Rainbow Hts Tank 4.0 MG
Elevation
(feet)
HWL Bott.
2,160 2,120
Ultimate Demand
Storage Requirements- Normal Operations
Operational
AAD
MDD
Fire
Emergency
Total
(MGD)
(MGD) (.15 x MDD)
(1 x MDD)
Flow(1)
0.57
1.09
0.16 MG
0.18 MG
1.09 MG
1.4 MG
Surplus/
10-Day
Deficit By SDCWA
Zone
Shutdown
1.6 MG
1,967 1,927
1.25
2.37
0.36 MG
0.18 MG
2.37 MG
2.9 MG
1.1 MG
Gomez Tank
U-1 Tank No. 1
U-1 Tank No. 2
Vallecitos Tank
Northside Res
North Res
Rice Tank
Canonita Tank
3.5 MG
0.5 MG
1.5 MG
0.4 MG
22.8 MG
7.8 MG
4.0 MG
6.0 MG
1,710
1,579
1,579
1,338
1,282
1,212
1,206
1,019
1,672
1,545
1,533
1,316
1,240
1,192
1,167
980
1.47
2.80
0.42 MG
0.18 MG
2.80 MG
3.4 MG
0.1 MG
0.56
1.07
0.16 MG
0.18 MG
1.07 MG
1.4 MG
0.6 MG
0.28
1.64
0.53
3.12
0.08 MG
0.47 MG
0.30 MG
0.18 MG
0.53 MG
3.12 MG
0.9 MG
3.8 MG
-0.5 MG
19.0 MG
2.69
5.10
0.77 MG
0.30 MG
5.10 MG
6.2 MG
5.6 MG
2.89
5.50
0.82 MG
0.30 MG
5.5 MG
6.6 MG
-0.6 MG
Beck Reservoir
203.7 MG
897
846
5.12
9.73
1.46 MG
0.30 MG
9.73 MG
11.5 MG 201.0 MG
8.34
15.85
2.4
0.30
15.8
7.96
0.77
15.13
1.46
2.27 MG
0.30 MG
15.1 MG
17.7 MG 133.8 MG
0.22 MG
0.18 MG
1.46 MG
1.9 MG
2.1 MG
9.6 MG
2.9 MG
63.8 MG
76.2 MG
357 MG
Paul Mesa Res.
8.8 MG
898
Hutton Tank
4.0 MG 1,011
Turner Tank
4.0 MG 1,011
Gopher Tank
4.0 MG 1,011
Morro Reservoir 151.5 MG 825
Morro Tank
TOTALS
4.0 MG
434 MG
865
878
971
971
973
778
824
18.5
Surplus/
Deficit
84.6 MG -37.1 MG
80.2 MG 138.3 MG
-6.5
170.8 MG -3.3 MG
33.6 MGD 63.8 MGD
336 MG
98 MG
A new 6.5 MG tank is proposed for the Gopher Canyon Zone. Based on the location of the
three existing tanks, ultimate system demands, and existing transmission mains, a fourth tank
would operate best at the site of the Turner (South) Tank. It appears that there is ample room
at the Turner Tank site for a new tank, which could be constructed at the location of the
abandoned South Reservoir. Compacted fill may be required to match bottom elevations,
however. The Canonita Zone is projected to have a storage deficiency of 0.6 MG at buildout. It
is noted that ultimate demands are projected to decrease slightly in the Canonita Zone due to
the proposed Monserate Hill Zone conversion to the Beck Zone. Given that the Canonita Zone
is projected to have only a 10 percent storage deficiency, a new tank was not included in the
ultimate system CIP. If second tank is deemed necessary in the future, it should be sited
adjacent to the existing tank to simplify operations and minimize the construction of new pipeline
facilities.
6.7
ULTIMATE PUMP STATION ANALYSIS
The existing duty capacity of each pump station is compared to projected ultimate maximum
day demands in Table 6-5. Based on this table, pump station capacity improvements will be
required at the Morro Hills, Vallecitos, Northside and possibly the Magee Pump Stations. The
Morro Hills Pump Station requires a second pump for redundancy. It is recommended that two
new pumps with a capacity of approximately 2,000 gpm each replace the existing 3,500 gpm
pump. Smaller pumps are recommended to reduce high velocities in the discharge pipeline and
more closely match the projected maximum day demand of the zone. Smaller pumps will also
work better with the space constraints of the existing building.
Table 6-5
REQUIRED PUMP STATION CAPACITIES
Duty
No. of
Capacity*
Pumps
2 - 250 Hp
Rainbow
Heights
1- 300 Hp 2,600 gpm
BPS #1
1- 290 HP
Ex. MDD
(gpm)
Capacity
Increase Req'd
Ult MDD
(gpm)
Future Capacity
Increase Req'd
730 gpm
No
2,400 gpm
No
BPS #2 U-1
3- 75 Hp
1,000 gpm
330 gpm
No
750 gpm
No
BPS #3 Vallecitos
2- 75 Hp
800 gpm
310 gpm
No
370 gpm
No
BPS #4 Northside
1 - 150 Hp
1,900 gpm 2,060 gpm
1 - 75 Hp
Yes
2,170 gpm
Yes
BPS #5 Morro Hills
1 - 150 Hp
Yes
1,020 gpm
Yes
No
1,940 gpm
No
No
760 gpm
Yes
Name
BPS #6 Gomez (Huntley)
BPS #7 Magee
2111-
0 gpm
920 gpm
300 Hp
2,800 gpm 1,540 gpm
250 Hp
50 Hp
700 gpm
40 gpm
100 Hp
* Duty capacity is the total station capacity with the largest pump out -of-service; Duty capacity was determined from
computer simulations based on derated pump curves and the storage tanks half full.
The existing Vallecitos Booster Pump Station has not been operational for some time, and
needs to be rebuilt. The Vallecitos Zone is currently supplied from the Rainbow Heights Zone
through a PRV. It is recommended that two new pumps be installed at this station with a
capacity of approximately 500 gpm each to replace the existing 800 gpm pump. Smaller pumps
are recommended to minimize high velocities and pressure drops in the North Zone, and also to
more closely match projected ultimate demands. The Northside Booster Pump Station does not
have adequate capacity based on the projected ultimate MDD with the largest pump out of
service. It is recommended that the smaller pump at this station be replaced with a larger
capacity pump. Although the duty capacity of the Magee Booster Pump Station Pump is slightly
less than the projected MDD, full buildout of this zone is very questionable. Therefore no
improvements for this station are recommended at this time.
6.8
EMERGENCY SUPPLY ANALYSIS
The ultimate system model was analyzed under an emergency supply scenario, with average
day demands supplied from reservoir storage and proposed emergency pump stations. A series
of simulations were made to locate the required pump stations, verify the flow rate that could be
delivered, and determine the impact to system pressures.
A new emergency pump station is proposed to supplement storage in the northern zones from
the Beck Reservoir. The pump station would supply the Northside Zone from a 14-inch
diameter transmission main in the Beck Zone. The proposed location for the station is near the
intersection of Scooter Lane and Reche Road. An existing PRV at the Northside Pump Station
(Booster Station #4) would allow the flow pumped from Beck Reservoir to enter the North Zone,
where it could be pumped to any higher zone as needed. A short length of new suction pipeline
will be required to connect the Beck and Northside distribution systems. The ultimate model
was run with this station supplying a flow rate of nearly 3,000 gpm, which is approximately
equivalent to the storage supplied from a 40 MG reservoir over 10 days.
A new emergency pump station is proposed to replace the portable gas-driven pump that
supplies the Canonita Zone from Beck Reservoir. The required capacity of this pump station
based on the projected ADD in the Canonita Zone is approximately 3,000 gpm. It is noted that
the Fallbrook Utility District is considering construction of a future water treatment plant at its
Red Mountain Reservoir, which could potentially be an emergency supply source to the North
Canonita Zones.
An emergency supply rate of approximately 6,000 gpm will be required into the Gopher Canyon
Zone based on ultimate demands and assuming construction of a new Gopher Canyon Storage
tank. Three new emergency pump stations are proposed to deliver this flow rate from the Morro
Zone. An emergency pump station and transmission main along the east side of I-15 was
initially proposed to supply the Gopher Canyon Zone directly from the Beck Zone. This
proposed project was eliminated from further consideration after hydraulic analysis indicated
that water supplied at this location under emergency conditions would quickly fill the Hutton
Tank. With the Hutton Tank full, pressures would then rise over static pressures at the northern
end of the system before the supply from Beck could fill the southern two tanks, potentially
bursting pipelines which already experience very high system pressures.
6.9
ALTERNATIVE WATER SUPPLIES
Operation of the ultimate water system has been assumed with water supplied from the
existing SDCWA and MWD aqueduct connections. Alternative supplemental water
sources, however, may become available to the District in the future. These alternative
supplies may include groundwater and water supplied from a future treatment plant at
FPUD’s Red Mountain Reservoir. Recycled water, should it become available to the
District, is also considered to be an alternative water source for irrigation demands.
7.0 RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
Water system capacity and operational improvements are recommended to improve system
reliability, increase the available fire flow, regulate system pressures, meet pumping and
storage capacity requirements, and supply the entire distribution system from storage during a
shutdown of the CWA Aqueduct system. Recommend projects are organized into a phased
Capital Improvement Program (CIP). To aid the RMWD in budgeting for capital improvements,
this chapter provides estimated construction costs for pipelines, reservoirs, pump stations and
miscellaneous improvements.
7.1
RECOMMENDED IMPROVEMENT PROJECTS
The recommended Master Plan CIP includes capacity and performance related projects
proposed for build-out of the water distribution system, which is based on SANDAG projected
2020 land use. The projects comprising the recommended CIP are illustrated on Exhibit A2 in
Appendix A. The different project categories are briefly summarized below:
2002 Capital Improvement Projects: Water projects from the 2002 RMWD CIP are included in
the Master Plan CIP if they are recommended to improve system capacity and performance.
Projects to replace old and deteriorating facilities are not included. The 2002 Projects are
assigned the same label identifiers in the Master Plan CIP, and have the prefix “W”. It is
important to note that many of the 2002 projects have been modified based on analysis results.
Also, a few 2002 projects were specifically eliminated based on analysis results.
Fire Flow Improvements: Twenty-six projects are recommended to increase the available fire
flow capacity in the existing system, which are labeled with the prefix “FF”. The majority of the
recommended improvements are pipeline replacement projects, specifically the replacement of
older 6-inch diameter pipelines with 8-inch diameter pipelines. Projects which construct new
pipelines to loop the existing distribution system and increase the fire flow are also included.
Four projects propose the upsizing or construction of new pressure reducing stations to
increase fire flows. It is recommend that RMWD conduct hydrant flow tests at the proposed
project locations to confirm the modeling results before constructing the recommended fire flow
projects. Boundary conditions in the system should be matched as closely as possible to
modeled conditions. As discussed previously in Section 5.4, the available fire flow is dependent
on the exact location, elevation and type of fire hydrant, and also the physical condition (and
resulting friction loss) of the upstream pipelines.
Storage Tank and Pump Station Projects: Projects to meet storage capacity and pumping
design criteria are assigned label prefixes of “T” and “PS”, respectively. Two tank projects and
three pump station projects are included. It is assumed that storage tanks will be constructed of
steel, be aboveground, and have a nominal depth of 32 feet. Limited site preparation and
grading, yard piping, valving, fencing and landscaping are assumed. It is noted that projects to
improve water quality in storage reservoirs are not included in the Master Plan CIP, since a
water quality analysis was not a part of this Master Planning effort. Several projects to improve
water quality are included in the 2002 CIP and continue to be recommended.
Emergency Supply Improvements: Projects recommended to improve emergency supply
operations during a shutdown of the aqueduct system are labeled with the prefix “E”. These are
projects to construct permanent pump stations to be used primarily under emergency supply
conditions. Emergency pump stations are assumed to be stand-alone enclosed units that will
be operated manually, with no other controls or instrumentation. While the District has the
option of integrating additional features into these facilities, the CIP cost development is based
on a low cost facility.
Ultimate System Capacity Improvements: Several transmission main capacity improvements
are recommended in the ultimate distribution system to supply future demands. These projects
are designated with the prefix “U”. Many distribution pipelines 12-inches in diameter and
smaller required to serve future development projects will be developer-funded projects. In
some cases, both the developer and the RMWD may share pipeline project costs. It is noted
that the supply capacity of the existing CWA and MWD aqueduct connections is projected to be
adequate for ultimate demands.
Zone Reconfiguration Projects: Projects required to revise zone boundaries are not
specifically called out, since many zone reconfigurations involve the opening or closing of valves
or minor construction projects, such as reconnecting a service meter to an adjacent pipeline.
Many zone reconfigurations improve fire flow or increase capacities for future demands, and are
therefore labeled accordingly as “FF” or “U” projects.
7.2
BASIS OF CONSTRUCTION COSTS
An opinion of probable construction costs was determined for the CIP projects based on the
most recent bidding information for similar types of projects. The costs presented in this Master
Plan are probable construction costs, which do not include engineering, administration,
inspection, legal, or environmental costs. To estimate the total project cost, it is recommended
that the probable construction costs be multiplied by 145 percent. The resulting total cost is an
approximation of both hard and soft costs itemized above, and also includes a construction
contingency. It is noted that no costs are included for land or right-of-way acquisition for
transmission and distribution pipelines, or pump stations and storage tanks.
7.3
PHASED CAPITAL IMPROVEMENT PROGRAM
A phased CIP has been developed to plan for future water system improvements. The
proposed improvements illustrated on Exhibit A2 are itemized with an opinion of probable
construction cost and summarized by phase in Table 7-1. The project phases are defined as
follows:
Phase I – Existing: Improvements to correct deficiencies, improve system operations, or
increase reliability of the existing water distribution system. The majority of the facility
improvements are pipeline projects recommended to improve fire flows and meet redundancy
criteria. Most of the emergency supply projects are also considered Phase I Projects.
Phase II Ultimate:
Improvements recommended for the ultimate CIP phase include
construction of additional pipelines, pressure reducing stations, and operational and emergency
storage facilities.
These two CIP phases should provide the RMWD 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
as required to account for changes in development schedules, availability of land or rights-ofway for construction, funding limitations, and other considerations that cannot be predicted at
this time.
Table 7.1
RECOMMENDED RMWD CAPITAL IMPROVEMENT PROGRAM
Project
No.
Zone
Description
System Benefit
Size
Quantity
Construction Cost
Unit Cost
Total Cost
PHASE I EXISTING SYSTEM PROJECTS
Northside
New PL in easement between Afton Farms Ln &
Calle de Talar
New PL in Live Oak Park/Ranger Rd
Loop lines for redundancy, water quality & emergency pumped
supply from Morro
Loop lines for redundancy & increase FF from 950gpm to 1700gpm
W10A
Gomez
New PRSs at Jeremy Wy & Gomez Creek Rd
Create new reduced zone to reduce high pressures (>400 psi)
W10B
Beck
New PRSs along Gird Rd w/pipeline inter-tie from
Sarah Ann Dr to Knottwood Wy
Create new reduced zone to reduce high pressures (>250 psi)
W14A
Canonita
W16
Morro Tank
W17
Morro
New PL in Sumac Rd
Upsize 6" PL in Sleeping Indian Rd & private road,
N of Mills Rd to last hydrant
New 12" PL in Old River Rd, between Dentro de
Lomas & Little Gopher Canyon
Increase fire flow from 875 gpm to 1925 gpm and provide looping
Increase fire flow to northern zone service area, from 825 gpm to
1525 gpm at north end
Loop lines for redundancy, expansion of Morro service area &
increased fire flow; Construct W49 first
W26
North
Upsize 8" PL in Rice Canyon Rd & new PRS at
Huntley Rd
Improve Rice/North Tank operations & reduce pressures at south end
of zone (> 300 psi)
Upsize 4" & 6" PL in Courtney-Smith PL Ext. and
extend West in easement to Disney Lane
New 12" PL in Old River Rd between Dentro de
Lomas & Lake Vista Drive
Increase fire flow from 725 gpm to 3,000 gpm & provide system
looping for redundancy
8-in
1,775 ft $
Loop lines for redundancy; Construct after W49 & W17
12-in
8-in
W3
Gopher Canyon
W6
W27 Gopher Canyon
W31
Morro
W38
Esponsito
W49
Morro
FF1
Gopher Canyon
FF2
FF3
Gopher Canyon
Gopher Canyon
Gopher Canyon
New PL in W Lilac Rd & Wrightwood Wy to conn 8"
w/Esponsito=>
in Tailisin Wy w/Bonsall Main Line
Morro Zone
New PL in Eagle Perch Ln (area of GC Zone
GC=>Morro
proposed to convert to Morro Zone)
Upsize 4" & 6" in Sleeping Indian Rd
Morro Tank
Upsize 6" PL in Foxglove Ln
Beck
New 8" PL in private rd, btwn W. Lilac Rd and
Gopher Canyon
Bonsall West lateral
New PL section in Gird Rd
Beck
New 8" PL in Country Rd
Canonita
Upsize 6" PL in Via Del Cielo
Canonita
Upsize 4" PL in Lupine Ln
Canonita
Upsize 6" Popp & Griffith Line in easement
Canonita
New Rainbow Heights=>Gomez PRS @ Booster
Gomez
PS No.1
FF4
FF5
FF6
FF7
FF8
FF9
FF10
FF11
FF12
FF13
FF14
Upsize 6" PL in easement at Cottontail Ln
Replace ex. PL under river at Dentro de Lomas
(trenchless construction assumed)
Upsize 6" portion of Line A-20 ext. A off N. Twin
Oaks Valley Rd.
Upsize 6" portion of Line A-15 (Van Cleave ext)
Upsize 6" PL in Via Ararat Dr & extend North
8-in
8-in
6" PRS
4" PRS
6" PRS
4" PRS
8-in
8-in
8-in
10-in
12-in
1,425 ft $
4,950 ft
1
1
1
1
LS
1,550 ft
2,880 ft
475 ft
144/ft.
$
205,000
144/ft.
$55,000
$50,000
$55,000
$50,000
$20,000
$ 144/ft.
$ 144/ft.
$ 180/ft.
$
713,000
$
105,000
$
125,000
$
223,000
$
500,000
$
4,225 ft $
216/ft.
16-in 20,800 ft $ 288/ft.
8-in
900 ft $ 144/ft.
6" PRS
1
$55,000
$913,000
$
6,175,000
144/ft.
$
256,000
4,500 ft $
144/ft.
$
648,000
950 ft $
144/ft.
$
137,000
16-in
1,300 ft $
900/ft.
$
1,170,000
Increase fire flow from 750 gpm to 1050 gpm
8-in
1,225 ft $
144/ft.
$
176,400
Loop lines for redundancy & increase FF from 900 gpm to 1150 gpm
Provide GC loop to Increase FF from 750 gpm to 1150 gpm. Project
req'd with conversion of Esponsito Zone to Morro Zone, which will
simplify system & reduce demand in GC Zone
8-in
8-in
1,000 ft $
3,325 ft $
144/ft.
144/ft.
$
$
144,000
478,800
8-in
2,250 ft $
144/ft. $
324,000
8-in
400 ft $
144/ft.
$
58,000
8-in
8-in
2,750 ft $
1,425 ft $
144/ft.
144/ft.
$
$
396,000
205,000
Loop lines for redundancy & fire flow with Esponsito Zone conversion
8-in
1,250 ft $
144/ft.
$
180,000
Increase FF from 775 gpm to 1250 gpm and loop system
Increase fire flow 850 gpm to 1475 gpm and provide looping
8-in
8-in
8-in
8-in
8-in
880 ft
1,075 ft
2,000 ft
700 ft
1,650 ft
144/ft. $
144/ft. $
144/ft. $
144/ft. $
144/ft. $
127,000
155,000
288,000
101,000
238,000
Increase fire flow from 450 gpm to 1200 gpm & provide redundancy
6" PRS
Provide redundant supply & increase fire flow from 475 gpm to 4900
gpm; construct before FF4 & Esponsito zone conversion
Supply for expanded Morro Zone; provide for supply from GC Zone
(Morro out-of-service & res. fill) & future emerg. pump to GC Zone
7-4
1
$
$
$
$
$
$55,000
$
55,000
Table 7.1
Project
No.
Zone
Description
System Benefit
Size
FF15
Canonita
New PL in Dos Niño's Rd to Citrus Ln
Increase fire flow from 625 gpm to 825 gpm and provide looping.
Higher FF is limited by static head of zone
8-in
700 ft $
144/ft.
$
101,000
FF16
Northside
8-in
1,150 ft $
144/ft.
$
166,000
FF17
FF18
Canonita
Canonita
Rancho
Monserate
Morro
North
North
Increase fire flow 500 gpm to 750 gpm. Available fire flow is limited
by high elevation/low static pressure
Increase FF 925 gpm to 1325 gpm & replace PL in easement
Increase FF 700 gpm to 2075 gpm and loop system
8-in
8-in
1,500 ft $
875 ft $
144/ft.
144/ft.
$
$
216,000
126,000
8-in
1,000 ft $
144/ft.
$
144,000
8-in
8-in
12-in
1,300 ft $
2,400 ft $
825 ft $
144/ft.
144/ft.
216/ft.
$
$
$
187,000
346,000
178,000
8-in
1,550 ft $
144/ft.
$
223,000
$
310,400
$
209,000
$
55,000
FF19
FF20
FF21
FF22
Upsize 4"PL in easement extension from Via
Chaparral
New PL in Reche Rd & Vista Valle Cam.
New pipeline in Via Vista Rd
Upsize 6" in Via San Alberto
New PL in Rancho Bonito Rd
New 8" PL in Calle Del Arco
Upsize 8" PL in W 5th St., E of Metzner Line
New Pl from Booster PS#3 to Chica Rd & between
Vallecitos /
FF23
Vargas PL & Chica Rd; Chica Rd zone conversion
North
fr/North to Vallecitos
Upsize 6" PL in Aqueduct Rd, Upsize 4" PRS
FF24 Gopher Canyon
Valves at Hutton & Trendal PRSs, Install FHs
FF25
New PL in Sunset Grove Rd
Morro
FF26
Monserate Hill
New Beck=>Monserate Hill emergency PRS
PS1
Vallecitos
Replace existing non-operational pumps
PS2
PS3
Northside
Morro Tank
Replace & upsize small pump at BS # 4
Install 2nd pump at BS # 5
T1
Vallecitos
New .0.6 MG storage tank east of I-15 on Districtowned land & delivery pipeline
T2
Gopher Canyon
New 6.5 MG storage tank at Turner Tank site
Beck=>Northside Booster PS at Scooter Ln/ Reche
Rd & supply pipe in Reche Rd
E2
Beck=>Canonita booster PS at Citrus/Vern
Canonita
E3 Gopher Canyon
Morro=>GC PS at W. Lilac Rd
E4 Gopher Canyon
Morro=>GC PS at Via Mariposa
PHASE I EXISTING SYSTEM PROJECTS
E1
Northside
Increase fire flow from 325 gpm to 850 gpm and provide looping;
Increase static press from 40 psi to 100 psi at end of Chica Rd
Quantity
Construction Cost
Unit Cost
Total Cost
8-in
2,100 ft $ 144/ft.
Provide min. fire flow of 1325 gpm to residential area without
hydrants
6" PRV
2
$4,000
Increase fire flow from 775 gpm to 2625 gpm & proving looping
8-in
1,450 ft $ 144/ft.
Increase fire flow from 700 gpm to 1475 gpm (not required if
6" PRS
1
$55,000
proposed zone conversion project U19 is constructed)
500
Supply to Vallecitos with smaller pumps to minimize pressure drop in 2 pumps $4,500
gpm
North Zone
1 - 2,500 gpm
Provide full back-up pumping capacity
$8,500
1 - 500 gpm
Provide back-up pump for redundancy
$4,500
0.6
MG
1
$0.90/gal
Provide add'l storage based on existing (.4 MG) and ult (.1 MG)
demands. Construct 2nd tank near commercial area for FF .
Provide add'l storage based on existing (4.7 MG) and ultimate
(1.8 MG) demands for daily operations.
Emergency supply from Beck to Northern zones during CWA
shutdown
Emerg supply during aqueduct shutdown
7-5
16-in
6.5 MG
2,150 ft $
LS
2 -3000 gpm
16-in
550 ft
2 -3000 gpm
2 - 3000 gpm
2 - 2000 gpm
288/ft.
$0.75/gal
$250,000
$ 288/ft.
$250,000
$250,000
$220,000
Subtotal
$9,000
$
$
8,500
4,500
$
624,600
$
4,875,000
$
408,400
$
$
$
250,000
250,000
220,000
$23,008,000
Table 7.1
Project
No.
Zone
Description
System Benefit
Size
Quantity
Construction Cost
Unit Cost
Total Cost
PHASE II FUTURE SYSTEM PROJECTS
Upsize 12" Morro Res. transmission main extending
Reduce velocity/press swings in southern Morro area
south & then east from res.
Upsize 8" PL in Old River Rd, btwn Little Gopher Provide supply from CWA conn. #12 to Morro service area E of SLR
W29
Morro
Canyon & E. Vista Wy
River
New PL in E. Vista Wy from CWA Conn. 12 to
Provide direct supply to Morro Zone from Conn. 12 for future
W43
Morro
Mission Ave.
development
Provide redundant supply to Moosa Crest Zone, reduce high press
Open/close valves to convert portion of Gopher
Gopher Canyon
U1
(>250 psi) in GC Zone, & provide for Morro Zone expansion
Canyon Z. to Moosa Crest Z. and construct PRS
/Moosa Crest
New looped PL in Rainbow Glen Rd., Long Oak Ln
Supply & FF for future residential development to meet minimum
U2
U1
& extension to Lookout Mtn Rd
pressures
U3
New PL in Anderson Road
Loop lines for reliability & future dev.
Rainbow Hts
U4
New PL in Magee Rd & Rainbow Heights Wy
Magee
U5
PL extension in future Pala del Norte
Supply for future development
Gomez
Loop zone for redundant supply to existing & future development;
U6
New PL in Pala Rd from HWY-395 to Gird Rd.
Beck
Supply FF to future commercial development on Hwy 76
U7
New Beck=>U-4 PRS near Pal Mesa Dr.
Provide redundant source of supply to new dev. in reduced zone
Beck/U-4
New Pl in Little Gopher Canyon & Gopher Canyon
Provide Morro supply to planned dev., w/back-up supply from GC
U8
Morro
Rd with new PRS
Zone
New PL in Gopher Canyon Rd, btwn Twin Oaks
Provide increased capacity for future dev. & emergency supply from
U9 Gopher Canyon
Valley Rd and Los Bancos line
Morro Zone
U10 Gopher Canyon
New PL in Par Valley Dr.
Loop lines for redundancy & future dev.
U11
Upsize 12" PL in Mission Rd/SLR Bridge
Provide increased flow rate fr/Conn. 12 for new development
Morro
U13
Upsize 10" PL in easement east of Morro Res.
Reduce high velocity and press. swings during peak demands
Morro
U14
New PL in Via Ladera
Rainbow Hts
U15
Southern extension of PL in Magee Rd
Expand service area for future development
Magee
New PL in Ranger Rd, north of Reche Rd.; Zone
Reduce high pressures (>250 psi) in existing Northside Zone
U16
Canonita
conversion from Northside to Canonita
New supply PLs in Pala Rd & Pankey Rd, new
Provide dual supply & looped distribution system for future
U17 Beck/Canonita
PRSs (5) and looped distribution PLs
development; Costs shown for offsite improvements only
New looped PL thru planned dev, connecting with
Provide dual supply and loop thru planned development
U18
Beck
12" #U-4 Unit A Line & 18" PL in Gird Rd
Conn Ex PL in Monserate Hill Rd w/ Pala Rd PL
Beck /
Convert Monserate Hill Zone to Beck Zone to eliminate reduced zone
U19
(U6); Open 10" Rcho Diego Unit 1 PL; close Fire Rd
and reduce pressure drop in Canonita Zone
Monserate Hill
PRS & connect 1st 2 meters to Canonita Z.
New PL in Old River Rd & new PRS at Camino Del
Provide redundant supply to planned development
U20
Club Vista
Rey
W9
U21
Morro
Gopher Canyon
New PL in Camino Del Rey w/PRS
U22
New PL in Via Grenada thru planned dev.
Morro
E5 Gopher Canyon
Morro=>GC PS at Dentro del Lomas
PHASE II FUTURE SYSTEM PROJECTS
Supply to new development
Provide looped supply to new development
TOTAL CAPITAL IMPROVEMENT PROGRAM
7-6
16-in
6,250 ft $
288/ft.
$
1,800,000
16-in
3,850 ft $
288/ft.
$
1,109,000
18-in
16-in
8,100 ft $
350 ft $
324/ft.
288/ft.
$
2,725,000
$
55,000
6" PRS
1
$55,000
8-in
9,875 ft $
144/ft.
$
1,422,000
8-in
8-in
8-in
4,025 ft $
4,000 ft $
6,575 ft $
144/ft.
144/ft.
144/ft.
$
$
$
580,000
576,000
947,000
16-in
12,575 ft $
288/ft.
$
3,622,000
1
$55,000
$
9,675 ft $ 144/ln ft.
$
1
$50,000 ea
55,000
6" PRS
12-in
6" PRS
1,443,200
12-in
5,050 ft $
216/ft.
$
1,091,000
8-in
16-in
16-in
8-in
8-in
2,825 ft
3,525 ft
1,650 ft
1,900 ft
8,250 ft
$
$
$
$
$
144/ft.
288/ft.
288/ft.
144/ft.
144/ft.
$
$
$
$
$
407,000
1,015,000
475,000
274,000
1,188,000
8-in
1,050 ft $
144/ft.
$
151,000
16-in
PRSs
6,550 ft $ 288/ft.
$
3
$80,000 ea
2,126,000
12-in
4,225 ft $
216/ft.
$
913,000
8-in
50 ft $
144/ft.
$
7,000
8-in
1,050 ft
6" PRS
1
8-in
1,450 ft
6" PRS
1
12-in
4,750 ft
2 - 2000 gpm
$
144/ft.
$55,000
$ 144/ft.
$50,000 ea
$ 216/ft.
$220,000
Subtotal
$ 1,026,000
$
220,000
$ 23,692,000
TOTAL
$ 46,700,000
$206,000
$
259,000
Addendum 1
of the RMWD 2006 Water Master Plan
Water System Expansion Alternative Analysis
Analysis of the ultimate RMWD supply and distribution system in the 2006 Water Master Plan
Update is based on complete buildout of areas within the existing District boundary. This
alternative analysis investigates expansion of the RMWD service area to supply planned
development areas east of the current District boundary that are within the San Luis Rey
Municipal Water District (SLR).
1.0
BACKGROUND
RMWD borders the SLR along the center portion of the eastern boundary. SLR encompasses
an area of approximately 3,000 acres extending east from RMWD along the San Luis Rey River
Valley. There is also a SLR island area of approximately 320 acres located between Interstate
15 and the proposed Passerelle development (formerly Campus Park) and Rancho Lake Viejo
in the RMWD. SLR is a “passive” district and its customers use local groundwater supplies
primarily for agricultural purposes. SLR is currently not a member of the SDCWA and has no
existing water supply sources for residential or commercial water use.
There are several projected developments within the SLR boundary with proposed residential
and commercial/industrial land use. A Master Plan dated October 2005 prepared for SLR by a
consultant (SLR Master Plan) provides a conceptual plan for domestic water, wastewater and
recycled water service at build-out conditions. The SLR Master Plan proposes that domestic
water be supplied to the future development projects from two new treated water connections
on the MWD aqueducts, requiring that SLR become a member agency of the SDCWA. The
proposed SLR supply and distribution system includes several large storage tanks that would
contain approximately five average days of storage capacity. Inter-agency connections and/or a
potential groundwater project is recommended to supplement the stored water supply during an
emergency or aqueduct shutdown.
2.0
PROPOSED DEVELOPMENT AND PROJECTED DEMANDS
Proposed development projects within SLR include Meadowood, Campus Park West, Pala Rey
Ranch, City Home, and Fritz Holdings, are illustrated on Figure 1. It is noted that water service
to future development in Passerelle and Lake Rancho Viejo were also included in the SLR water
analysis, although these developments are within the RMWD.
Water demand projections for the proposed development projects are provided in the SLR
Master Plan based on current San Diego County General Plan information supplemented with
Addendum 1 –Water System Expansion
land use plans for Meadowood (Pardee Homes) and Campus Park West (Pappas). A summary
of the projected demands and land use is provided in Table 1. Development for Fritz Holdings
and Pala Rey Ranch is not anticipated until after 2010, and the SLR Master Plan included very
preliminary estimates of the number of dwelling units. It is noted that the demand projections
appear to be very conservative, as the actual number of units allowed may be less than the
estimates provided by developers.
Table 1
LAND USE AND WATER DEMAND PROJECTIONS
Project Name
Meadowood
Land use
Rural Residential, SF,
MF, School, Park
SF, MF, Com., Office
No. of Projected Projected ADD*
Res. Units
(gpd)
1,155
892,500
580
422,000
Mixed use
580
423,000
Fritz Holdings
Rural Residential
775
814,000
Paula Rey Ranch
Rural Residential
1,200
660,000
Landfill
Rural Residential, Ag,
Multiple Rural Use
NA
71,000
87
454,850
Campus Park West
City Home
Gregory Canyon Landfill
County of San Diego
TOTAL
4,377 Units
3.74 MGD
* Demand projections obtained from the 2005 SLR Master Plan for Water & Wastewater Services
3.0
PROPOSED RMWD WATER SUPPLY AND DISTRIBUTION SYSTEM
The proposed RMWD supply and distribution system for the eastern service area is illustrated
on Figure 1. The water supply is proposed primarily from the Beck Zone through an expansion
of the 690 Zone proposed for planned development in Passerelle. Two primary pressure
reducing stations are recommended to supply the 690 Zone. A third pressure reducing station
located along Rice Canyon Road is proposed to supply peak summer demands from the North
Zone. Storage tanks are proposed at a reservoir site identified in the SLR Master Plan to
provide operational, fire flow and emergency storage, and to reduce the required supply rate
through the pressure reducing stations. Surplus storage capacity in the Beck Reservoir will
provide the required 10-days of reserve storage.
The northwest portion of the expanded service area within Meadowood is at elevations too high
to be supplied from a 690 Zone, and would be supplied from an expansion of the proposed
Passerelle 800 Zone. The 800 Zone will initially be supplied from the Canonita Zone through a
single pressure reducing station. A second supply to this zone is recommended from a new
pressure reducing station along the existing pipeline in Pala Mesa Heights Drive, which is
supplied from the Rice Reservoir in the North Zone. An additional supply to the 690 Zone is
also proposed from the North Zone through a PRV located along Rice Canyon Road. Storage
for the 800 Zone would be supplied from surplus storage in the North Zone, and emergency
reserve storage would be supplied from Beck Reservoir through the Canonita Zone, via a
proposed emergency pump station (CIP project E1).
Table 2 summarizes the projected demand in each zone and storage requirements based on
criteria defined in the 2006 RMWD Master Plan. It is noted that the demands in Table 2 include
projections for both Passerelle and the eastern service area expansion. Storage for the 690
Zone is proposed to be constructed in two phases, and would be required after build-out of
Passerelle and before any significant construction in the expanded service area.
Table 2
PROJECTED ZONE DEMANDS AND STORAGE REQUIREMENTS
RMWD
Zone
Projected Demands
ADD
Max Day
(gpd)
(gpd)
Required Storage
10-Day
Daily*
Reserve
Recommended
Storage
Facility
690
4,711,350
8,951,565
10.6 MG
47 MG
2 new 5.5 MG tanks
800
100,000
190,000
0.40 MG
1.0 MG
Rice Tank
* Includes operational, fire flow and emergency storage
4.0
OFF-SITE IMPROVEMENTS
The supply of water to the expanded eastern service zone will require off-site pipeline
improvements. Transmission mains and pressure reducing stations must be sized to
deliver the peak hour flow to the 800 Zone and the maximum day demand to the 690
Zone, which corresponds to a flow rate of over 6,000 gpm. The following off-site
improvements, which are in addition to the ultimate system improvements
recommended to supply Passerelle (CIP U17), are anticipated:
•
Upsize or parallel existing pipelines between Beck reservoir and the 690 Zone PRVs
to supply the entire 690 Zone service area during an aqueduct shutdown. This will
require a flow rate of approximately 4,000 gpm, which could be transported in a new
18-inch diameter pipeline.
•
Upsize the existing 8-inch diameter pipeline in Rice Canyon Road, south of Huntley
Road, to a 16-inch diameter pipeline. This pipeline is proposed to supplement Beck
Zone deliveries to meet peak summer demands.
5.0
COST OF EXPANDING THE SYSTEM
The SLR Master Plan estimates the total cost of supplying the ultimate demands of
developments within their service area and the Passerelle project to be approximately
$53,000,000. This is the total estimated project cost of pipelines, reservoirs, pressure
reducing stations, and turnout supply connections (includes engineering, legal,
administration, and contingencies). The addition of a groundwater treatment project for
a backup water supply is estimated to cost an additional $38.5 to $51.3 million. A cost
to SLR not addressed in the SLR Master Plan is the fee to become a member agency of
the SDWCA, which is currently $2,929 per acre. Given the 3,000 Acre area of the
SLRWD, becoming a member agency will cost approximately $8,787,000.
There would be a significant reduction in project costs for RMWD to expand its service
area to serve these future demands. Specifically, new turnout connections would not be
required and significantly smaller storage tanks are recommended based on RMWD
design criteria. Surplus storage capacity in Beck is also available to meet the 10-day
storage requirement, eliminating the need for groundwater treatment project and excess
in-zone storage. The potential cost savings are itemized in Table 3. Total project costs
were taken directly from the 2005 SLR Master Plan, with the addition of the SDCWA
connection fee, which was not identified in the plan. Cost deductions were itemized
exclusions as listed based on the 2005 SLR Master Plan. Although there will be
differences in the alignments and diameters of distribution pipelines within the proposed
development projects, it is assumed that the cost of these pipelines will be essentially
the same for service from SLR or RMWD. Furthermore, it is assumed that the cost of
one of the SLR aqueduct connection supply pipelines will be approximately equivalent
to the costs of a larger transmission main from Beck Reservoir.
Table 3
SLR/RMWD PROJECT COST COMPARISON
Total Project Cost - SLR supply
Pipeline, Tanks, PRVs & Turnout Connections
Groundwater treatment - 2.0 MGD desalter
SDCWA connection fee ($2,929/ac)
$ 100,340,000
$ 53,031,000
$ 38,522,000
$
8,787,000
Cost deductions for RMWD supply
Turnout supply connections (2)
17.4 MG storage capacity
Aqueduct supply pipeline (1)
Groundwater treatment - 2.0 MGD desalter
SDCWA connection fee ($2,929/ac)
$ (68,390,600)
$ (2,100,000)
$ (15,660,000)
$ (3,321,600)
$ (38,522,000)
$ (8,787,000)
Total Project Cost - RMWD supply
$
31,949,400
* Cost and deduction values based primarily on amounts listed in the 2005 SLR Master Plan
6.0
ALTERNATIVE CAPITAL REVENUE AND EXPENSE COMPARISON
Three alternatives were identified for considering expansion water service to the eastern
services:
1.
2.
3.
No Increase in Service area (District Only)
Expanding Service to the Eastern Service Area
Expanding Service to the Eastern Service Area and construction of a District
Operated Water Treatment Plant at the Beck Reservoir
Capital Expenses:
Capital Expenses for Alternative 1 are based on the 2006 Water Master Plan Capital
Improvement Plan. Capital expenses include capacity and redundancy projects only
and do not include replacement projects identified in the 2002 CIP, as these expenses
are typically funded over time through service fees.
Capital Expenses for Alternative 2 include all costs from Alternative 1 plus the RMWD
supply cost as shown in Table 3 above.
Capital Expenses for Alternative 3 include all costs from Alternative 2, minus the cost of
installing a floating cover to the Beck Reservoir ($5.8M), and includes a projected
capital cost of $40 million dollars for construction of a water treatment plant to convert
raw water from the Beck Reservoir to treated water. There are numerous benefits, as
well as cost for installation of a water treatment plant at the Beck Reservoir. For this
analysis, only a rough cost is presented. Further investigation and a through costbenefit analysis of a water treatment plant alternative is recommended.
Capital Revenue:
Capital revenue for Alternative 1 is supplied through sales of water meters to future
customers within the District. Projected planned developments, as identified in the 2006
Water Master Plan were included assuming a 1-inch meter per household.
Approximately 2,700 additional connections are expected for planned developments
within the District. Therefore the additional capital revenue from projected
developments equals 2,700 multiplied by the current connection charge of $9,803 for a
1-inch meter, totaling $26.8 Million.
For areas in the District, neither currently served or part of a projected development, it is
difficult to estimate the revenue potential. Since connection cost escalates according to
meter size, we have estimated potential revenue by assigning meters to current vacant
parcels according their current parcel size. The following Table 4 lists the number of
parcels of varying size and calculates the projected revenue from meter sales according
to the potential number of parcels. The total projected revenue from both projected
developments ($26.8M) and connections to vacant parcels ($35.7M) is estimated at
$62.5 Million by ultimate build-out of the District service area.
Table 4
Parcel Size
< 1 Acre
1-3 Acre
3-10 Acre
> 10 Acre
Estimated
Connections
90
322
496
372
1280
Meter Size
(Inches)
1
1.5
2
3
Meter Cost
$
$
$
$
9,803
15,081
26,391
45,242
$
$
$
$
$
Revenue
(in Millions)
0.88
4.86
13.09
16.83
35.7
Capital Income from Alternatives 2 and 3 are equal to the sale of meters to future
customers within the Eastern Service Area. Water EDU’s were provided in the SLRWD
Master Plan, but there is not a direct relation between EDU’s and actual meters sold.
Therefore a reduction was made by estimating the actual number of meters based on
projected numbers of homes, schools and other land uses. A total of 4,337 homes are
projected to be sold plus an additional 160 meters for schools, landscaping meters and
other meters within the area. All meters were assumed to be 1-inch in size in an effort
to be conservative. Actual meter size for landscaping and other commercial uses will
likely be higher.
The Figure 2 summarizes the comparison of Capital Expenses, Capital Income and Net
Review of each alternative. Annual revenue and expenses are not included at this time.
Based on this comparison, Alternatives 1 and 2 result in a net capital surplus through
build-out of the system. Alternative 3, which assumed an estimated capital cost for a
water treatment plant results in a nearly balanced revenue and expense.
Additional Studies:
In the event of a potential expansion of the RMWD service area, several additional
studies may be considered which were beyond the scope of services for this Master
Plan Addendum. The following are a listing of several additional studies the District may
consider exploring in the future.
Groundwater Availability: Currently the RMWD sells 100% imported water to
customers within the District. Groundwater is a potential alternative water source,
particularly for the lower Gopher Canyon area along the San Luis Rey River where
there are already a number of existing private wells to support the agricultural
customers. In the eastern service area, groundwater wells support 100% of the existing
agricultural lands. Therefore the groundwater availability is already proven, and with
proper planning, a non-potable water distribution system within the eastern service area
and/or within the current RMWD may provide relief from dependence on imported
water.
Non-Potable Water: Included in the 2006 Wastewater Master Plan update is an
addendum addressing the potential for expanding the wastewater service to the
eastern service area. A District operated wastewater treatment plant is a option
considered in the expansion. If such an alternative is feasible for wastewater service, it
would provide a viable source of non-potable water to service agriculture customers or
near-by golf courses.
Groudwater Storage at Beck: Alternative 3 within this Addendum considers the
conversion of the Beck Reservoir to raw water with the addition of a water treatment
plant. If this alternative is selected, the Beck reservoir could also become a storage
reservoir for pumped groundwater.
Addendum 1
2006 Water Master Plan
$140
Figure 2 Projected Capital Revenue and Expense at Build-Out of System
Alt 3
District + ESA
+ WTP at Beck
Alt 2
District + ESA
$120
Dollar amount (in Millions)
$100
$80
Alt 1
District Only
$60
$40
$25.2
$13.1
$20
$0
1
2
3
-$9.00
-$20
Capital Expenses
Addendum 1
Capital Income
4/21/06
Net Revenue

Rainbow MWD Water Master Plan 2006

Transcription

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