Gustine City Council
May 19, 2026

AGENDA

CITY OF GUSTINE

CITY COUNCIL

SPECIAL MEETING

COUNCIL CHAMBERS, CITY HALL
352 5I STREET GUSTINE, CALIFORNIA
MAY 19, 2026 - 5:45 P.M.

The Council Chambers are open and in-person attendance is encouraged.

As a convenience, the City will be retaining the virtual component of public meetings for optional attendance with the use of an online meeting room.

Log-in and dial-in information is as follows:
https://meet.goto.com/89814431 7
or via telephone by dialing (872) 240-331 l, access code: 898-144-31 7 Feedback and noise will be muted by the meeting organizer.

Please note, in the event of a technical issue causing a disruption in the call-in option or internetbased option, the meeting will continue unless otherwise required by law, such as when a Council Member is attending the meeting virtually pursuant to certain provisions of the Brown Act.

CALL TO ORDER - PLEDGE OF ALLEGIANCE
Please take a moment to silence your cell phones.

ROLL CALL
Council Members: Melville -- Giles - Marsigli - Mayor Pro Tern Ford - Mayor Nagy

APPROVAL OF AGENDA
At this time, any member of the City Council or staff may advise of any updates to the order of, or changes to, the agenda as published.

Any requested changes or edits shall be offered in the form of a motion by any City Council member, requiring a second, and followed by a 3/5 vote of approval by the Council.

DECLARATIONS OF CONFLICT OF INTEREST
At this time, any member of the City Council may declare their conflict of interest or their abstention from any item listed on, or within, the agenda.

PUBLIC COMMENT
At this time, any person may comment on any item which is not on the agenda. PLEASE STATE YOUR NAME FOR THE RECORD. Action will not be taken on the topic unless deemed an urgency matter by a 3/5 vote of the City Council. Topics not considered an urgency matter may be referred to City staff and/or placed on a subsequent agenda for consideration, by a 3/5 vote of the City Council.

Members of the public, who have questions or comments regarding a specific agenda item, may comment on that item before consideration of that item, when recognized by the Mayor.

ADMINISTRATIVE AGENDA

1. WORKSHOP: Waster Master Plan Update

1. Receive Staff Report and Presentation

2. Receive Public Comment

3. Conduct Workshop

ADJOURNMENT
Note:

I. In compliance with the Americans with Disabilities Act, a disabled person requesting a disability-related modification or accommodation to participate in this meeting, must contact City Hall at (209) 854-6471 or (209) 854-2127 (fax]. Requests must be made as early as possible, preferably one-full business day before the start of the meeting.
(continued)

2. Any document provided to a majority of the City Council regarding any open session item on this agenda is available for public inspection during normal business hours at the front counter of City Haff located at 352 5m Street, Gustine, CA. Documents or writings received after the general distribution of the agenda are also available for inspection.

CERTIFICATION
I, Desirae Porras, Deputy City Clerk, do hereby declare under penalty of perjury that the foregoing agenda was posted at the Gustine City Hall, 352 5 Street, Gustine CA and made available for public review on this 13# day of May, 2026, at .Desirae Porras -

ITEM NO. 1

COUNCIL AGENDA ITEM
MAY 19, 2026
PREPARED BY: Melanie Correa, City Manager
SUBJECT: WORKSHOP: Water Master Plan Update
STRATEGIC PLAN GOALS: 5. Robust Infrastructure

BACKGROUND
The City contracted with Gouveia Engineering, Inc. to prepare an updated Water Master Plan to replace the 2002 plan and provide a comprehensive evaluation of the City's water supply, storage, and distribution system needs through buildout. The updated plan incorporates the City's 2025 Zoning Map, the 2024-2032 Housing Element, and current annexation areas. As noted in the Executive Summary, the City's water service area is projected to grow from 870 acres to 1 ,825 acres, with population increasing from 6,138 to 11,616 at buildout.

A Council workshop has been scheduled to review the findings, recommendations, and capital improvement· program.

ANALYSIS/DISCUSSION
The Water Master Plan identifies several key system needs:
• Existing System Deficiencies: The City requires two new groundwater wells, two

0.5 MG storage tanks with booster pump stations, and replacement of approximately 14,000 feet of aging mains and 3,900 feet of undersized 4-inch pipelines.
• Future System Requirements: To meet projected buildout demand-expected to more than double-the preferred alternative is continued reliance on groundwater, requiring three new 620-gpm wells, three 1 .0 MG tanks with booster stations, and 43,000 feet of 12-inch transmission mains. • Capital Improvement Program: Total recommended improvements are estimated at $96.4 million, with approximately $37.9 million attributable to existing users and $58.5 million to future development.

The workshop will provide Council with a detailed presentation of system conditions, modeling results, and recommended improvements.

COMMUNITY OUTREACH
No formal outreach has been conducted at this stage. Public engagement will occur as individual capital projects move forward.

FISCAL IMPACT
There is no immediate fiscal impact associated with receiving the Water Master Plan.

The plan will guide future rate studies, capital planning, and pursuit of State and Federal funding opportunities. As noted in the plan, Gustine's status as a Disadvantaged Community strengthens eligibility for external funding.

The fee for updating the master plan was accounted for in the adopted FY2025/2026 budget.

STRATEGIC PLAN GOALS
This item supports goal #5, Robust Infrastructure, objective #2 ensuring reliable water supply and distribution.

RECOMMENDATION
Staff recommends that the City Council receive the presentation and provide direction on the 2026 Water Master Plan. The plan will be brought forward at a future meeting for Council's formal adoption.

EXHIBIT(S)
A) Draft 2026 Water Master Plan (Gouveia Engineering, Inc.)

CITY OF GUSTINE

WATER MASTER PLAN

FINAL DRAFT REPORT
April 2026

PREPARED BY
GOUVEIA ENGINEERING, INC.

CONSUL TING ENGINEERS
456 SIXTH STREET
GUSTINE, CA 95322

Table of Contents
Executive Summary 6
City Growth 6
Water Demand 6
Improvements Needed for Existing Water System 7
Future Water System Recommendation - 7
Alternative 1: Expansion by New Wells Only 7
Alternative 2: Expansion by Surface Water 7
Recommended Capital Improvement Program 8

1.0 Introduction 9

1.1 Purpose 9

1.2 Scope of Services 9

1.3 Project Approach 9

1.4 Project Team 10

1.5 Definition of Key Terms 10

1.6 Report Organization 11

2.0 Study Area 13

2.1 Existing Water Service Area _ 13

2.2 Buildout Water Service Area 13

2.3 Historical Population 13

3.0 Existing Water System 16

3.1 Water Supply Facilities 16

3.2 Water Distribution System & Storage Facility 17
Water Pipelines 17
Water Storage Facility 18

4.0 Water Demand 19
2

4.1 Historical Water Production 19

4.2 Unaccounted-for Water 20

4.3 Existing Water Demand 21

4.4 Future Water Demand Projections 22
Undeveloped Land 22
Unit Water Demands 22
Historical and Projected Water Demands 23
Per Capita Water Demand 24
Buildout Population Based Water Demand Projection 24
Groundwater Basin 26
Comparison of Land Use and Population Based Demand Projections 25

5.0 Water Supply 26

5.1 Sustainable Groundwater Management Act 26
Groundwater Sustainability Agencies 26

5.2 Subsurface Geologic Conditions 27

5.3 Well Production 27

5.4 Groundwater Levels 28

5.5 Groundwater Quality 28

5.6 Water Supply Reliability 29

5.7 Future Water Supply 29

6.0 Water System Design and Operational Criteria 30

6.1 Fire Flow Requirements , , 31

6.2 Water Supply and Pumping Capacity 32
Maximum Day Demand Plus Fire Flow 33
Peak Hour Demand 33
Operational Storage 33
Fire Storage 34
3

Emergency Storage 34
Total Storage Capacity 35

6.3 Water Transmission and Distribution Pipeline Sizing 36 Modeling Software 38
Water Transmission Pipeline Sizing 36
Water Distribution Pipeline Sizing 37

7.0 Hydraulic Model Development 38

7.1 7 .2 Modeling Assumptions 38

7.3 Hydraulic Model Element Naming Scheme 39

7.4 Water System Facilities Creation in Computer Model... 41 Pipes 41
Junctions 41
Wells and Tanks 41

7.5 Water Demand Allocation in Computer Model... 41
Large Water User Demand Assignment Based on Metered Data 41 Remaining Demand Allocation 42

8.0 Existing Water System Evaluation 43

8. 1 Existing Water Demand 43

8.2 Existing Water Supply and Pumping Capacity Evaluation 43

8.3 Existing Water Storage Capacity Evaluation 44

8.4 Existing Water Distribution System Evaluation 45
Average Day Demand Analysis 45
Maximum Day Demand Analysis 45
Maximum Day Demand plus Fire Flow Analysis 45
Peak Hour Demand Analysis 46

8.5 Existing Water System Recommendations 46
Water Storage and Pumping Capacity Improvements 46
4

Recommended Water Distribution System Improvements 47

9.0 Future Water System Analysis 48

9.1 Future Water Demand 48

9.2 Future Water Supply and Pumping Capacity Evaluation 48

9.3 Future Water Storage Capacity Evaluation 49

9.4 Future Water Distribution System Analysis 49
Buildout Water Distribution System 49
Alternative 1: Expansion by New Wells Only 50
Alternative 2: Expansion by Water Treatment Plant, Storage Tanks and Booster Pump Stations ..................................................................................................................................................... so

10.0 Recommended Capital Improvement Program 51

10.1 Total Capital Costs 53

10.2 Groundwater Wells 53

10.3 Water Storage Tanks and Booster Pump Stations 53

10.4 Water Pipelines 53

10.5 Other Costs 53

10.6 Implementation Strategy , , 54

11.0 References , 55
5

Executive Summary
The City of Gustine (City), located in Central California as shown in Figure ES-1, contracted with GOUVEIA Engineering, Inc. (GOUVEIA) to prepare this Water Master Plan. This is an update to the 2002 Water Master Plan prepared by Stoddard & Associates Civil Engineers (City of Gustine, 2002a). It is based on the City's 2025 Zoning Map, 2024-2032 Merced County Multi-Jurisdictional Housing Element Update, and the City's annexation plans. This master plan is designed to help the City plan and expand its water system to meet the potable water needs of its growing population through buildout.

City Growth
The buildout land use on which this Master Plan is based is shown in Figure ES-2. The City's water service area currently occupies approximately 870 acres and is projected to grow to approximately 1,825 acres by buildout of the residential portion, representing more than a doubling of the existing water service area. This service area population is projected to grow by approximately 90 percent from 6,138 in 2024 to 11,616 by buildout as shown in Table ES-1.

Table ES-1. Existing and Projected Service Area Population Existing (2024) Buildout
Population 6,138 11,616
Planning Horizon
Demand Type 2002 WMP 2024 (Existing) Buildout
Annual Production, afy 1,371 1,148 2,392
Average Day Demand (ADD), gpm! 1,000 1,133 2,366
Average Day Demand, mgd 1.44 1.63 3.41
Maximum Day Demand (MDD), mgd 2.88 2.45 5.11
Peak Hour Demand (PHD), gpm" 4,000 2,550 5,324
The City's growth will place additional demand on the existing water system which will need to be expanded to adequately serve existing and new customers.

Water Demand
The existing and projected water demand of the City is summarized in Table ES-2. The water demand is anticipated to double from 2024 to buildout. This increased water demand will require additional water supplies and facilities which are addressed in this Master Plan.

Table ES-2. Historical and Projected Water Demand
(ADD calculated as average daily water use in maximum month and not as an average of annual water use. (bMDD calculated as 1.5 times ADD in current Water Master Plan but as 2 times ADD in 2002 Water Master Plan. !<lPHD calculated as 1.5 times MDD in current Water Master Plan but as 2 times MDD in 2002 Water Master Plan. 6

Improvements Needed for Existing Water System
An evaluation of the existing water system shows that the following improvements are needed to serve existing customers reliably:

1. Construct two new groundwater wells to supply 850 gpm each.

2. Construct two 0.5 MG at grade tanks plus 0.85 MGD (700-gpm) booster pump stations.

3. Replace 14,000 feet of aging and leaky water mains along SR 33 and 140 corridors. This includes the replacement of valves and fire hydrants.

4. Replace 3,900 feet of the 4-inch pipelines with 8-inch pipelines:
a. 2,200 feet of pipelines on Wallis Avenue from West Avenue to Railroad Avenue. b. 350 feet of pipelines on Ash Avenue.
c. 450 feet of pipelines on Carnation Avenue.
d. 900 feet in two alleys between Grove A venue and Railroad A venue Street.

5. Replace miscellaneous pipelines, hydrants, and valves.

Future Water System Recommendation
Two main alternatives for providing additional water supplies to meet the City's projected water demands were considered. These included:

Alternative 1: Expansion by New Wells Only
Alternative 1 assumes that the City continues to rely solely on groundwater to meet its water demand by drilling new wells only. Alternative 1 requires the following facilities by buildout:
• Three 620-gpm groundwater wells.
• Three 1.0 MG at grade tank plus 1.7 MGD (1,400-gpm) booster pump station (one at each new well site).
• 43,000 feet of 12-inch pipelines.

Alternative 2: Expansion by Surface Water
Alternative 2 is based on conjunctive water use by adding treated surface water to the existing groundwater to meet future water demand. This requires that the City purchase surface water, construct a 20-inch water transmission main, 8 MGD water treatment plant and a 4 MG water storage tank totaling about $32.5 million according to the 2002 Water Master Plan. Accounting for inflation, this surface water treatment option would cost about $60 million in 2025 dollars. 7

Even though conjunctive use which adds surface water will provide the City with the most flexible water supply sources, the capital cost together with the challenges of acquiring surface water pose significant challenges. Consequently, it is recommended that the City focus on expanding its water supply at this time using groundwater wells. Therefore, alternative 1 is preferred.

Recommended Capital Improvement Program
The recommended capital improvement program to meet the City's water system obligations by buildout is shown in Figure ES-3. The total cost is approximately $96.4 million as shown in Table ES-3. About $37.9 million is needed for improvements to the existing water system and the remaining $58.5 million is needed for future development.

Table ES-3. Recommended Water System Capital Improvement Program Category Capital Improvement Estimated Cost, x$1,000
Existing Users Improvements to Existing System 37,901
Future Users Future Facilities 58,493
Total 96,393
8

1.0 Introduction

1.1 Purpose
This report documents the updated Water Master Plan (Master Plan) of the City of Gustine (City) The City is located in Merced County in Central California as shown in Figure 1-1. The purpose of this Master Plan is to help the City plan and expand its water system to meet the potable water needs of its growing population through buildout of the Sphere of Influence minus the large commercial/agricultural land uses on the outskirts.

This Master Plan is an update to the 2002 Water Master Plan prepared by Stoddard & Associates Civil Engineers. It is based on the City's 2025 Zoning Map and 2024-2032 Merced County Multi-Jurisdictional Housing Element Update, and the City's annexation plans. The City's growth is being driven primarily by infill and planned development in the north, east, west, and south of the City.

This chapter presents the purpose, scope, project approach, key definitions, and report organization.

1.2 Scope of Services
Gouveia Engineering Inc. (Gouveia), was contracted by the City to prepare this Master Plan.

The scope of services can be summarized as follows:

I.

II.

III.

IV.

V.

VI.

VII.

VIII.

IX.

X.

1.3 Executive Summary
Introduction
Study Area and Water Demand
Existing Water System
Water Supply Alternative and Modeling
Recommended Water System Improvements
Project Implementation
Tables
Figures
Appendices
Project Approach
Previous reports and technical memoranda prepared for the City were used for background information. This included the City's 2002 Water System Master Plan and other water system studies. These reports were supplemented by field data collection including a survey of fire hydrant and valve locations. Data was also collected on the City's historical water production, operations, and a topographic survey of selected locations across the City. 9

Discussions were held with City staff to solicit input through progress meetings and telephone conversations. The City's staff, shown in Table 1-1, were instrumental in successfully completing this Master Plan, for which we are grateful.

Table 1-1. City Proiect Officers
Position Name Email Telephone
City Manager Melanie Correa Mcorrea @cityofgustine.com 209-854-64 71 Account Clerk Fabiola Caballero [email protected] 209-854-64 71 Finance Director Jennifer Morrison [email protected] 209-854-6471

1.4 Project Team
The main Gouveia project staff are shown in Table 1-2.

Table 1-2. Gouveia Project Officers
Position Name Email Telephone
Project Manager Danny Reed [email protected] 209-854-3300 Principal-In-Charge Mario Gouveia [email protected] 209-854-3300

1.5 Definition of Key Terms
The key terms used in this Master Plan are defined as follows:
• Average Day Demand: The average volume of water used daily by customers calculated as the maximum month water use divided by the number of days in the maximum month. • Distribution Pipelines: Generally, pipelines less than 12 inches in diameter and used to distribute water to customers within the service area.
• Diurnal: A term used to describe the time variability of water demands over a given day. • Fire Flow: The flow rate of a water supply, measured at 20 pounds per square inch (psi) residual pressure that should be available for firefighting. • Maximum Day Demand: The maximum volume of water used in one day during a given year. Based on measured water use data for the City of Gustine, this term is defined as 1.5 times the Average Day Demand.
• Peak Hour Demand: The maximum volume of water used during a single, one-hour period during a given year. This term is defined as 2.25 times the Average Day Demand of the City.
10

• Tank: A watertight structure, usually made of concrete, steel, or some other material, used to hold water. Other names for tanks include storage tank and reservoir. • Transmission Pipelines: Generally, pipelines equal to or greater than 12 inches in diameter, and used to convey water from sources of supply (water treatment plant or well) to storage tanks.
• Water Demand: The volume of water used by customers to satisfy their needs. • Water Supply: Water supplied to customers from sources such as groundwater and/or surface water.

1.6 Report Organization
Following this introductory chapter, this Master Plan includes the following chapters:
• Chapter 2 - Study Area provides background information such as population and land use on the City's water service area.
• Chapter 3 - Existing Water System provides background information on the City's water system including water supply, storage, transmission, and distribution facilities. • Chapter 4 - Water Demand presents historical and projected water use which corresponds to the growth projections of the City's water service area. • Chapter 5 - Water Supply describes the existing and future sources of water supply to satisfy the City's water demand.
• Chapter 6- Water System Design and Operational Criteria present planning and design criteria used as a basis for assessing the adequacy of the existing water system and for proposing future water system facilities.
• Chapter 7 - Hydraulic Model Development describes the development of the City's 2025 computer hydraulic model which was used in simulating the water system operations.
• Chapter 8 - Existing Water System Evaluation presents the analysis of the existing water distribution system facilities in comparison to the City's design and operational criteria.
• Chapter 9 - Future Water System Analysis presents the future system pipelines and water system facilities needed to satisfy the City's design and operational criteria. 11

• Chapter 10 -- Recommended Capital Improvement Program details the proposed water system improvements and associated costs resulting from this master planning effort.
12

2.0 Study Area

2.1 Existing Water Service Area
The City of Gustine is about 29 miles west of the City of Merced and about 5 miles east of Interstate 5. State Highways 33 and 140 intersect at the City. The existing water service area is about 870 acres and shown on the existing land use map in Figure 2-1.

Gustine's General Plan provides policies and programs to guide the development in the City. The City last updated its General Plan in 2002; however, the Land Use Map was updated in 2012, and the Housing Element was updated in 2019. The City ensures that all goals and policies contained within the Housing Element are consistent with the goals and policies set forth in all other elements of its General Plan.

The City's land use has the following major groups:
• Residential
• Commercial
• Industrial
• Parks/Greenway/Open Space

2.2 Buildout Water Service Area
The land use in the City of Gustine's Sphere oflnfluence (SOI) is shown in Figure 2-2 and totals approximately 3,400 acres. The buildout area was calculated by subtracting the land use on the outskirts of the City designated as agricultural commercial and shown in red color in Figure 2-2.

Even though this land is designated as agricultural commercial, it is really agricultural land that tends to have its own water supply from private wells. Furthermore, this agricultural land was not planned for in the 2002 Water Master Plan. Therefore, it was not taken into account in this Master Plan.

The buildout water service area is comprised of the existing service area of 870 acres plus 955 acres of undeveloped land within the City's Sphere oflnfluence, totaling 1,825 acres. The buildout area is the total developable land as of now. This area may change in the future if the agricultural lands on the outskirts of the City are rezoned. Future Master Plans can account for any change in rezoning.

2.3 Historical Population
The historical population of the City of Gustine is shown in Table 2-1. The data is from the California Department of Finance (DOF).
13

The DOF estimates are from the E-4 Population Estimates for Cities, Counties, and the State, with 1990, 2010, and 2020 Census Benchmarks.

Table 2-1. City of Gustine's Population
Year Population Growth Rate, %
1998 4,377 5.85
1999 4,473 2.19
2000 4,862 8.70
2001 5,071 4.30
2002 5,237 3.27
2003 5,352 2.20
2004 5,416 1.20
2005 5,352 -1.18
2007 5,282 -1.31
2008 5,339 1.08
2009 5,412 1.37
2010 5,520 2.00
2011 5,601 1.47
2012 5,667 1.18
2013 5,767 1.76
2014 5,785 0.31
2015 5,851 1.14
2016 5,933 1.40
2017 5,991 0.98
2018 6,061 1.17
2019 6,070 0.15
2020 6,079 0.15
2021 6,103 0.39
2022 6,005 -1.61
2023 5,978 -0.45
2024 6,035 0.95
2025 6,021 -0.23
(Data from State of California Department of Finance.

The population of the City grew at an annual rate of 0.76 percent from 2002 (when the 2002 Water Master Plan was developed) to 2025. The City had its greatest annual population growth rate of 8.7 percent in 2000 and its greatest decline of 1.6 percent in 2022. This can be explained as follows.

The United States (US) economy in the year 2000 was at the tail end of the longest economic expansion in history, characterized by robust growth, low inflation, and a federal budget surplus.

However, in 2020 the economy experienced the worst contraction since World War II, shrinking by 3.5% annually due to the COVID-19 pandemic. This led to widespread lockdowns, massive 14

job losses, and business closures. The effect on the City of Gustine was a stagnation in population from 2020 to 2025 as shown in Table 2-1.
15

3.0 Existing Water System
This chapter describes the City's existing water system facilities. This is based on reviewing previous reports, maps, plans, operating records, and discussions with City staff. Figure 3-1 shows the City's existing water system facilities as of December 2025.

3.1 Water Supply Facilities
The City depends solely on groundwater supplied from four wells located throughout the water service area. They are Wells 4, 5, 6 and 7 as shown in Table 3-1. The flow rates of the wells range from 600 to 1, l 00 gpm for a total of approximately 3,200 gpm. The static water depths vary from 24 to 27 feet whilst the pumped water depths generally range from about 26 to 37 feet below ground surface.

Table 3-1. Existing Groundwater Wells
Well Well Depth, Static Water Pumping Water Flow Rate,
No. ft Depth, ft Depth, ft gpm
4 250 27.0 26.7 700
5 450 26.4 37.0 1,100
6 250 24.0 26.5 800
7 209 26.0 28.0 600
Total 3,200
Well 4 is located near Meredith Avenue and Linden Avenue at the southeast comer of Harry P Schmidt Park. It was constructed in 1996 as a replacement for another well which failed because of excessive sand infiltrating into the well casing and declining water production. Well 4 has also developed problems of excessive sand infiltrating the well casing. It also has elevated nitrate levels even though this has not exceeded the Maximum Contaminant Level (MCL). The flow rate is 700 gpm.

Well 5 is located near East Avenue and East Wallis Avenue. It was constructed in 1999. Water samples have repeatedly been around 1,200 mg/L for Total Dissolved Solids which is higher than the MCL of 1,000 mg/L. The maximum rated pumping capacity is 1,700 gpm but the actual flow rate is approximately 1,100 gpm. Well 5 is equipped with a variable frequency drive (VFD) to control the flow of water into the water distribution system based on water system pressure.

The VFD enables the pumps to accommodate fluctuating water system demands.

Well 6 is located near Fourth A venue and Second Street. It was constructed in 1999. It has elevated nitrate levels even though it has not exceeded the Maximum Contaminant Level. The flow rate is 800 gpm.
16

Well 7 was constructed in 2012 at the southwest comer of Harry P Schmidt Park. It has a 75 horse power motor. The maximum rated pumping capacity is 800 gpm but the actual flow rate is approximately 600 gpm. It is equipped with a VFD to control the flow of water into the water distribution system to accommodate fluctuating water system demands.

3.2 Water Distribution System & Storage Facility
The City's water distribution system consists of a single pressure zone because the terrain is generally flat with an average ground elevation of about 102 feet above mean sea level. The ground elevation generally ranges from about 98 to 114 feet above mean sea level. The water distribution system facilities are described below.

Water Pipelines
The City's water system pipelines generally range from 4 to 12 inches in diameter. They are made of cast iron, asbestos cement, and polyvinyl chloride (PVC). The oldest portions of the water distribution system were installed in the 1950s and are mainly asbestos cement and some cast iron pipes. Some of these pipelines, especially the asbestos cement, are prone to failures.

They have been repaired several times where leaks and ruptures have occurred. The newer pipelines are PVC and installed in the Northwest and Southern parts of the City.

A study conducted by Bedesen-Cardoza-Andrews, Inc., in 1990 and the 2002 Water Master Plan recommended that 12-inch distribution mains be installed around the perimeter of the City to improve fire flow and system pressures. The pipeline loop has been completed except for a section in the Northeast of the City. The remaining incomplete section is approximately 1,800 linear feet and along North Avenue, beginning just west of State Route 33 and extending east to East A venue.

Water Service Connections
The City's water distribution system has a total of 1,920 service connections as shown in Table 3-2. All the residential and commercial/institutional connections are metered. However, four of the five agricultural connections are not metered.

Table 3-2. Water Service Connections
Type Count Comment
Agriculture 1 Metered
Agriculture 4 Unmetered
Commercial/Institutional 92 Metered
Residential 1,823 Metered
Total 1,920
17

Water Storage Facility
The City has a 72,500-gallon water storage tank located west of Third A venue and Sixth Street.

It has dimensions as shown in Table 3-3. The tank fills and drains based on the relative hydraulic grade line of the connecting pipelines. It serves only as an equalization tank because of its small volume.

Table 3-3. Potable Water Storage Facilities
Storage Capacity Diameter Height MSL Elevations (feet)
Facility Address (MG) (feet) (feet) Ground Base Overflow Tank Third A venue 0.0725 21 28 100 162 190
and Sixth Street
18

4.0 Water Demand
This chapter presents the existing and future water demands of the City of Gustine. These water demand calculations are needed to identify the required water supplies and infrastructure to serve existing and future water users. This analysis includes an evaluation of historical water production and water demand projections for the future.

4.1 Historical Water Production
Annual groundwater production data from the City's operational records from 2015 to 2024 is summarized in Table 4 1. The total water production has remained fairly constant at an average of about I, 148 acre-feet per year (afy) over the past decade.

Table 4-1. Historical Water Production
Annual Production, Annual Production,
Year afy MG
2015 1,056 344
2016 764 249
2017 1,060 345
2018 1,176 383
2019 2,065 673
2020 1,166 380
2021 1,127 367
2022 948 309
2023 1,016 331
2024 1,103 359
Average 1,148 374
(Water Production data compiled from City records.

The water production records used for the 2002 Water Master Plan, shown in Table 4 2, were compared with the more recent data in Table 4-1. It is shown that the average water production has remained constant despite a 15 percent increase in population over the same period.

Table 4-2. Historical Water Production\
Annual Production, Annual Production,
Year afy MG
1998 1,034 337
1999 1,163 379
2000 1,227 400
2001 1,371 447
Average 1,199 391
Water Production data compiled from 2002 Water Master Plan. 19

Water production in the City can be explained by the reduction in water use because of the installation of customer meters in 2007 and the implementation of mandatory water conservation measures because of drought.

California experienced three prolonged drought periods after the development of the 2002 Water Master Plan. It began with a drought that lasted from 2007 to 2009. Customer water meters were installed by the City in 2007. Another drought followed from 2012 to 2016. Finally, the most recent drought occurred from 2020 to 2022. These droughts resulted in the promotion of water conservation programs across the State to make water conservation a way of life.

The California State Water Resources Control Board (Water Board) has a mandate from Senate Bill 1157 of 2022 to reduce indoor residential water use through new and phased standards. The Water Board established 55 gallons per capita per day (gpcd) as the standard from 2022 through 2024. The standard from 2025 to 2029 is 47 gpcd with a 42 gpcd target from 2030 onwards. This makes a total of about 24 percent reduction in residential water use from 2022 to 2030. These regulations require water purveyors to meet efficiency standards, not individual residents, and will be enforced through reporting and penalties if they fail to meet their targets.

4.2 Unaccounted-for Water
Unaccounted-for water is the volume of water produced or purchased by a utility but not sold to paying customers, representing a loss from physical (leaks) and/or commercial (water theft, meter inaccuracies, and billing errors) sources. The term is often used interchangeably with the more precise concept of Non-Revenue Water (NRW), though NRW technically includes authorized unbilled uses like firefighting and system flushing, which are sometimes counted separately from losses.

The City's total annual water production was compared with the annual customer metered water data from 2020 to 2024 as shown in Table 4-3. The average unaccounted-for water is approximately 30 percent. This is significantly higher than the typical 5 percent unaccountedfor water for well managed water systems.

Table 4-3. Unaccounted for Water
Annual Water Annual Customer Unaccounted-for Unaccounted for Year Production, MG Metered Water, MG Water,MG Water,%
2020 380 250 130 34
2021 367 258 109 30
2022 309 243 66 21
2023 331 226 105 32
2024 359 237 122 34
Average 349 243 106 30
20

The high unaccounted-for in the City shows that it has significant leaks within its water distribution system. Indeed, the oldest portions of the water distribution system installed in the 1950s are prone to failures. These have been repaired several times where leaks and ruptures have occurred in the past. The City can reduce these losses through leak detection, meter testing, infrastructure maintenance, consumer engagement, and pipeline replacement programs.

4.3 Existing Water Demand
The existing water demand needed for master planning can be calculated by using the City's water production as a surrogate for water demand. Three types of water demand are generally used for master planning, including Average Day Demand (ADD), Maximum Day Demand (MDD), and Peak Hour Demand (PHD). These demands are used to determine water supply needs and to evaluate and size water distribution pipelines and storage facilities.

According to California Code of Regulations, Title 22 (California Water Code), Section 64554(b )(2) that regulates public water systems, MDD and PHD are calculated for the highest water usage month during the last ten years as follows:
• To calculate the MDD, multiply the average daily usage during the highest month by a peaking factor of 1.5.
• To calculate the PHD, determine the average hourly flow during MDD and multiply by a peaking factor of 1.5.

The average day demand of the City of Gustine according to the California Water Code is 1,133 gpm as shown in Table 4-4.

Table 4-4. Water Demand
Maximum Average Day
Average Average Maximum Peak
Year
Maximu Month Demand,
Day Day Day Hour
m Month Production, gal gal/d Demand, Demand, Demand, Demand, MGD gpm gpm gpm
2016 May 29,223,100 942,681 0.94 655 982 1,473
2017 August 67,316,101 2,171,487 2.17 1,508 2,262 3,393 2018 June 45,667,889 1,473,158 1.47 1,023 1,535 2,302
2019 July 74,786,333 2,412,462 2.41 1,675 2,513 3,769
2020 August 54,249,658 1,749,989 1.75 1,215 1,823 2,734 2021 August 45,710,557 1,474,534 1.47 1,024 1,536 2,304 2022 July 49,768,437 1,605,433 1.61 1,115 1,672 2,508
2023 August 45,471,699 1,466,829 1.47 1,019 1,528 2,292 2024 July 47,997,417 1,548,304 1.55 1,075 1,613 2,419
2025 June 45,725,401 1,475,013 1.48 1,024 1,536 2,305
Average 50,591,659 1,631,989 1.63 1,133 1,700 2,550
21

4.4 Future Water Demand Projections
The future water demand of the City was calculated based on land use. Water demands were projected for each undeveloped land use identified in the City's buildout area. This future water usage was then added to the existing water demand to calculate the total water demand at buildout of the City.

Undeveloped Land
The undeveloped land within the City's Buildout area is shown in Table 4-5 based on the 2002 Water Master Plan. However, over the past two decades since the 2002 Water Master Plan, much of the City's residential land use growth has been infill development including areas to the northwest of the City. Therefore, the undeveloped residential land identified in the 2002 Water Master Plan has largely remained undeveloped. Of this undeveloped land, the City has recently annexed about 128 acres for residential development in the southeastern part of the City as shown in Figure 4-1.

Furthermore, about 51 acres of agricultural commercial (Commercial and Industrial in Table 4-5) development has occurred to the southeast of the City. The last column of Table 4-5 summarizes the undeveloped land to be planned for under this Master Plan.

Table 4-5. Undeveloped Areas
2002 Master Plan Developed Land Current
Undeveloped Land, Since 2002, Undeveloped Land,
Land Use acres acres acres
Residential 580 0 580
Commercial 82 I 1 71
Industrial 300 40 260
Parks/Greenway/Open Space 44 0 44
Total 1,006 55 955
Unit Water Demands
Land use demand calculation is accomplished by estimating unit water demand factors for each land use type and multiplying the factors by the total area of the corresponding land use type.

Unit water demand factors were identified for the City's land use types in the 2002 Water Master Plan as shown in Table 4-6. The Buildout unit water demands of the City were calculated by assuming a 24 percent demand reduction for residential land use and parks and half of that for commercial and industrial based on the Water Board's water conservation mandates. 22

Table 4-6. Unit Water Demands
Ultimate Buildout Unit
Land Use 2002 Unit Demand, gpm/acre Demand, gpm/acre
Residential 1.44 1.09
Commercial 1.74 1.52
Industrial 1.74 1.52
Parks/Greenway/Open 2.79 2.11
Space
The projected buildout water demands of the City based on the unit water demand for each land use are shown in Table 4-7. The total water demand due to the undeveloped lands is about 1,233 gpm.

Table 4-7. Undeveloped Land Water Demands
Existing Unit Demand, Undeveloped Area, Water Demand, gpm Land Use gpm/acre acre
Residential 1.09 580 635
Commercial 1.52 71 108
Industrial 1.53 260 397
Parks/Greenway/Open 2.11 44 93 Space
Total 955 1,233
Historical and Projected Water Demands
The historical and projected water demands of the City are summarized in Table 4-8. The total water demand of the City is projected to more than double from 2024 to Buildout.

Table 4-8. Historical and Projected Water Demand
Planning Horizon
2002 Water 2024 Ultimate
Demand Type Master Plan (Existing) Buildout
Annual Production, afy 1,371 1,148 2,392
Average Day Demand (ADD), gpm 1,000 1,133 2,366
Average Day Demand, mgd 1.44 1.63 3.41
Maximum Day Demand (MDD), mgd" 2.88 2.45 5.11
Peak Hour Demand (PHD), gpm! 4,000 2,550 5,324
l•lADD calculated as average daily water use in maximum month and not as an average of annual water use. (MDD calculated as 1.5 times ADD in current Water Master Plan but as 2 times ADD in 2002 Water Master Plan. «CPHD calculated as 1.5 times MDD in current Water Master Plan but as 2 times MDD in 2002 Water Master Plan. 23

Per Capita Water Demand
Demand calculations were performed for the City based on total population. A per-capita water use factor is calculated by dividing the total annual water demand within a service area by the corresponding year's population.

The City's per-capita water use from 1998 to 2001 during the 2002 Water Master Plan averaged 227 gallons per capita per day (gpcd) as shown in Table 4-9. Water use over the most recent 10 years has trended downwards and averaged 170 gpcd. This is a 25 percent reduction in water use per person and reflects the effect of water metering and water conservation measures.

Table 4-9. Per-Capita Water Use for City of Gustine
Year Annual Water Annual Water City Population Per Capita Production, afy Production, Water Use,
MG gpcd
1998 1,035 337 4,377 211
1999 1,164 379 4,473 232
2000 1,228 400 4,862 225
2001 1,372 447 5,071 242
2015 1,056 344 5,851 161
2016 764 249 5,933 115
2017 1,059 345 5,991 158
2018 1,176 383 6,061 173
2019 2,066 673 6,070 304
2020 1,167 380 6,079 171
2021 1,127 367 6,103 165
2022 949 309 6,005 141
2023 1,016 331 5,978 152
2024 1,102 359 6,035 163
1998-2001 Average (4 years) 1,200 391 4,696 227
2015-2024 Average (10 years) 1,148 374 6,011 170
Buildout Population Based Water Demand Projection
The Buildout population of the City is projected to be about 12,674 assuming the same population density as the existing land use. The population-based water demand can then be calculated by multiplying the average per-capita water use by the projected Buildout population to estimate the future water demand as shown in Table 4-10. The total annual water use of the City is projected to be about 2,413 afy.
24

Table 4-10. Projected Gustine Buildout Water Demand Based on Population Per Capita Total Annual Total Annual
Projected Buildout Water Demand, Demand, Demand,
Population gpcd MG afy
12,674 170 786 2,413
Comparison of Land Use and Population Based Demand Projections A comparison of the projected demand for the City based on land use and population is shown in Table 4-11. This shows a difference of approximately 0.9 percent which is insignificant. This confirms that the unit land use demand factors used in distributing water demand in the hydraulic model are reasonable.

Table 4-11. Comparison of Ultimate Buildout Water Demand Projection Methods Land Use Based Water Demand, Population Based
Planning Horizon afy Water Demand, afy" Percent Difference Buildout 2,392 2,413 0.9
<•I Obtained from Table 4-8.
(b)Obtained from Table 4-10.
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5.0 Water Supply
This chapter describes the water supply required to satisfy the existing and future water demands of the City of Gustine. An evaluation of the sources of water supplies provides the basis for the planning of water supply infrastructure. This chapter focusses on water supply sources, quantity, quality, and reliability.

5.1 Groundwater Basin
The City currently relies solely on groundwater for its water supply. The groundwater is abstracted from the underlying Delta-Mendota Sub basin, which is part of the larger San Joaquin Valley Groundwater Basin. This subbasin is situated in the San Joaquin River hydrologic region, located along the western side of the San Joaquin Valley. The Delta-Mendota Subbasin encompasses 764,964 acres (1,195 square miles) and covers parts of Stanislaus, Merced, Madera, Fresno, and San Joaquin counties.

Sustainable Groundwater Management Act
The State of California enacted the Sustainable Groundwater Management Act (SGMA) in 2014 for the management of groundwater in the State. The goal of SGMA is to achieve sustainable groundwater basins, enhance local management of groundwater consistent with rights to use or store groundwater and establish standards for effective and continuous management of groundwater.

The Delta-Mendota Sub basin has been identified by the Department of Water Resources (DWR) as critically overdrafted under SGMA. A critically overdrafted subbasin is one where ongoing pumping of groundwater far exceeds the natural rate of replenishment, leading to significant and potentially permanent negative environmental, social, and economic impacts. These impacts, often referred to as "undesirable results" can include chronic lowering of groundwater levels, land subsidence, depletion of surface waters, reduced groundwater quality, and seawater intrusion in coastal areas.

Groundwater Sustainability Agencies
The City of Gustine became a Groundwater Sustainability Agency but entered into an agreement with the San Joaquin River Exchange Contractors Water Authority Groundwater Sustainability Agency (SJREC GSA) to develop a joint Groundwater Sustainability Plan (GSP) for the management of its groundwater. The SJREC GSA Group developed a GSP in 2019 that was submitted to DWR but was determined to be incomplete in 2022, leading to a notice of intent for an amended plan.
26

There are 23 GSAs in the Delta-Mendota Sub basin, many of which developed their individual GSPs which were deemed incomplete by DWR. Consequently, a Delta-Mendota Subbasin Coordination Committee was formed that recommended that all 23 GSAs in the Subbasin adopt a new, single GSP which will serve as a roadmap for the GSAs to achieve groundwater sustainability. The Delta-Mendota Subbasin completed a single GSP, incorporating previous efforts and addressing earlier deficiencies. It was recommended for adoption by the participating GSAs in July 2024 and pending a review from the State.

5.2 Subsurface Geologic Conditions
The Delta-Mendota Subbasin is underlain by unconsolidated continental deposits and alluvium from the Tulare Formation, which form two primary aquifer systems separated by the Corcoran Clay confining layer. Excessive groundwater pumping, particularly during droughts, has led to a major issue with land subsidence throughout the basin.

The subbasin's groundwater is divided into two principal systems by the Corcoran Clay. The Corcoran Clay is a low-permeability clay layer. It acts as a regional confining unit and is present across much of the basin at depths between 100 and 500 feet. It separates the Upper and Lower Aquifers.

There is an Upper Aquifer which is a semi-confined zone that extends from the water table to the top of the Corcoran Clay, consisting of younger and older alluvium and the upper Tulare Formation. A very shallow, unconfined zone with low hydraulic conductivity exists within 25 feet of the surface in some areas.

The Lower Aquifer is a confined aquifer located below the Corcoran Clay and extends to the base of fresh water. It generally has a higher transmissivity than the Upper Aquifer. The bottom of the sub basin is defined as the interface with saline water of marine origin, typically found within the San Joaquin Formation. The base is identified at a total dissolved solids (TDS) concentration of 3,000 mg/L.

5.3 Well Production
Average well yields in the Delta-Mendota Subbasin vary by usage, with typical irrigation and municipal wells yielding between 800 to 2,000 gpm. Private domestic wells often have lower average yields of around 400 to 600 gpm, although yields can vary significantly from 20 to 5,000 gpm depending on location and specific conditions.

There are currently no known physical or legal constraints to limit the City's use of water from the Delta-Mendota Sub basin. However, this could change after a review of the joint GSP developed by the GSAs in the Delta-Mendota Sub basin. Furthermore, if adequate recharge does not occur in the future to limit overdraft, existing wells may need to be deepened to sustain 27

required pumping levels. Deepening of wells has the potential to contribute to poorer water quality, land subsidence, and higher pumping costs for the City.

5.4 Groundwater Levels
Groundwater levels in the Delta-Mendota Subbasin have historically fluctuated, but extensive pumping during droughts has led to significant and renewed land subsidence. While imported surface water in the 1970s helped groundwater levels recover, dry periods and reduced water availability have caused renewed declines and compaction. Current efforts under SGMA aim to halt overdraft and bring the basin into balanced levels of pumping and recharge. The static water depths in Gustine currently vary from 24 to 27 feet below ground surface.

5.5 Groundwater Quality
The quality of the existing groundwater sources through buildout is expected to be adequate.

However, there are several groundwater constituents, which lead to groundwater quality concerns in the area.

The City of Gustine currently meets state requirements for safe drinking water for both Primary Drinking Water Standard and Secondary Drinking Water Standard. While the recommended limits can be exceeded based on water availability, the upper limits of secondary standards can only be exceeded temporarily until alternate sources come on line.

The major water quality constituents of concern in the City's wells are high concentrations of salinity as measured by total dissolved solids (TDS) and high concentrations of nitrates, chlorides and sulfates. Based on a 200 I study of groundwater conditions, groundwater meeting the secondary drinking water MCLs appears to be more abundant to the west and southwest of parts of the City (Schmidt, 2001). The east and northeast portions of the City were to be avoided.

It was estimated that production could double to about 2,400 acre-feet without serious water quality problems. This should be adequate to support the buildout water demands of the City.

A source water assessment was completed for the City of Gustine Wells in March of 2003 by the Water Board. The groundwater sources are considered most vulnerable to the following activities associated with contaminants detected in the water supply; animal feeding operations, lagoons/liquid waste, fertilizers/herbicides/pesticides applications and sewer collection systems.

In addition, the sources are considered most vulnerable to: automobile gas stations, dry cleaners, known contaminated plumes and leaking underground storage tanks.

In 2023, Specific Conductance and Total Dissolved Solids were detected at levels above the maximum contaminant level (MCL). The Specific Conductance and Total Dissolved Solids secondary MCLs are set to protect from unpleasant aesthetic effects such as color, taste, odor and the staining of plumbing fixtures (e.g., tubs and sinks) and clothing while washing. A violation 28

of these MCLs does not pose a risk to public health. No action to lower these levels has been required at the time.

5.6 Water Supply Reliability
It was estimated that the groundwater sub basin below the City of Gustine could support about 2,400 acre-feet of water abstraction without serious water quality problems. This water supply should be adequate for the Buildout water demands of the City. However, some factors could affect the City's water supply reliability.

The factors affecting water supply reliability include legal, environmental, water quality, water quantity and climate change. The City's water supplies are vulnerable to seasonal or climatic variations. There are two aspects of supply reliability that can be considered. The first relates to immediate service needs and is primarily a function of the availability and adequacy of the supply facilities. The second aspect is climate-related, and involves the availability of water during mild or severe drought periods.

Climate change may add many new uncertainties to the challenges of planning, and irrespective of the debate associated with the sources and cause of increasing concentrations of greenhouse gasses, changes in weather could significantly affect water supply planning. Since climatic pressures could potentially affect supply reliability, continual attention to this issue will be necessary in the future. Strategy topics for the City to consider include:
• Water Conservation and Technology
• Reduce Groundwater Pumping
• Water Efficient Landscapes
• Water Conservation Development Review Policies

5.7 Future Water Supply
In the immediate future (next 10 years), the City could continue to rely solely on groundwater.

However, the City may want to diversify its water supplies by implementing conjunctive use combining groundwater with surface water, if water quality or restrictions from SGMA arise.

Surface water supplies could likely be delivered from the California Aqueduct or the Delta Mendota System. However, the availability of these water supplies is sometimes subject to drought and environmental restrictions.
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6.0 Water System Design and Operational Criteria
Design and operational criteria are required to evaluate the capabilities of water distribution systems and to guide the planning and design of water system infrastructure. Therefore, a set of criteria was developed for the City of Gustine's water distribution system. It is based on industry standards such as American Water Works Association (A WW A) Standards, California Department of Public Health [CDPH] Guidelines, California Fire Code, and discussions with City staff.

The criteria are summarized in Table 6-1 and include the following components:
• Fire Flow Requirements
• Water Supply Capacity
• Pumping Facility Capacity
• Water Storage and System Peaking Capacity
• Water Transmission and Distribution Pipeline Sizing
Table 6-1. Planning and Design Criteria
Component Criteria
I Comments
I
Fire Flow Requirement (flow [gpm]@ duration [hours))
I 500 gpm @ 0.5 hours
Single-Family Residential 1,000 gpm @ I hours (nonsprinklered) (sprinklered) - - ---- -
Multi-Family Residential 1,500 gpm@ 2 hours (nonsprinklered) 750 gpm@ I hours I (sprinklered)
1,500 gpm @ 1.5 hours
Commercial 3,000 gpm @ 3 hours (nonsprinklered) (sprinklered) based on review on a case-to-case
basis
1,750 gpm @1.5 hours
Industrial I Institutional 3,500 gpm@ 3 hours (nonsprinklered) (sprinklered) based on review on a case-to-case
basis
Water Supply Capacity
Reliable Water Production Provide capacity equal to peak hour demand I Pumping Facility Capacity
Provide capacity equal to maximum day plus fireflow
Pump Capacity or peak hour demand whichever is greater, with largest pump out of service
-- ---
Backup Power
To ensure pumping capacity equal to maximum day
demand plus fire flow
-- ----
Water Storage and System Peaking Capacity
.
,-
Operational Flow
, .,
20% of Maximum Day Demand
Fire Flow 3,500 gpm @ 3 hours= 0.63 MG
,_
---- -
Emergency Flow I 00% of Average Day Demand
- - -
Total Water Storage and System Operational Flow+ Fire Flow+ Emergency Flow Reduce to accommodate
Peaking Capacity for groundwater storage
,_
- -- -- ----
30

Component Criteria Comments
Water Transmission Pipeline Sizing
Diameter Larger than 12 inches in diameter
Average Day Demand Conditions
Minimum Pressure [psi] 40
Maximum Pressure [psi] 75
--
Maximum Velocity [ft/sec] 3
Maximum Day Demand Conditions
- • Minimum Pressure [psi] 40
Maximum Velocity [ft/sec] 5
Peak Hour Demand Conditions []
Minimum Pressure [psi] I 40 I I
Maximum Velocity [ft/sec] 7 I
Hazen Williams "C" Factor 130
Pipeline Material I Ductile Iron Pipe
: 12" or larger are DIP
Water Distribution Pipeline Sizing
Diameter S a�er than 12 inches in diameter_
-- - I
- -
Average Day Demand Conditions
Minimum Pressure [psi] 40 I
Maximum Pressure [psi] 75 I
Maximum Velocity [ft/sec] 5
Maximum Day w/ Fire Flow Demand
Conditions
-- ---
Minimum Pressure [psi] 30 With largest pump out of
service
Maximum Velocity [ft/sec] 10
Peak Hour Demand Conditions
Minimum Pressure [psi] 40 With largest pump out of
service
- ,
- .

I -
Maximum Velocity [ft/sec]
Minimum Pipeline Sizes
Low Density Residential I 8 inches in diameter or larger ! Commercial 12 inches in diameter or larger
Industrial 12 inches in diameter or larger
Distribution to cul-de-sac / dead end 6 inches in diameter or larger I Beyond last fire hydrant street
--
Distribution to fire hydrants 8 inches in diameter or larger Hazen Williams "C" Factor 140, 130
-- I Pipeline Material PVC, DIP

6.1 Fire Flow Requirements
i
Fire flow is the flow rate at a hydrant, measured at 20 pounds per square inch (psi) residual pressure, that should be available for firefighting. This is necessary for the protection of property within a jurisdiction against fire. The availability of adequate fire flow for buildings within a city reduces risk and therefore property insurance costs.
31

The determination of fire flow is not an exact science; however, having some level of information provides a consistent way of choosing the appropriate fire flow for buildings throughout a jurisdiction. The 2022 California Fire Code, Title 24, Part 9 (CFC) Appendix B Fire Flow Requirements for Buildings provides a tool for the use of jurisdictions in determining their fire flow requirements. Consequently, a typical set of criteria is proposed for the City based on the 2022 CFC and presented in Table 6-2.

The required fire flow for one- and two-family dwellings and townhouses is 1,000 gpm for one hour with no automatic sprinkler system. These homes are generally less than 3,601 square feet.

The 2022 CFC allows for a maximum reduction of 50% with dwellings with sprinkler systems.

The land uses in the City and their corresponding unsprinklered and sprinklered fire flows and durations are shown in Table 6-2.

Table 6-2. Fire Flow Requirements(a.b)
Fire Flow,(" Duration, Minimum Storage
Land Use gpm hours Volume, MG
Single Family Residential 1,000/500 1.0/0.5 0.06
Multi-Family Residential 1,500/750 2.0/1.0 0.18
Commercial 3,000/1,500 3.0/1.5 0.54
Industrial 3,50011,750 3.0/1.5 0.63
Institutional 3,50011,750 3.0/1.5 0.63
( Construction type and fire area are not generally known during the development of a master plan; consequently, fire flow requirements set forth in this table are based on previous estimates for these land use types in similar communities.

Cbl Unique projects or projects with alternate building materials may require higher fire flows and should be reviewed by the Fire Marshal on a case-by-case basis (e.g., proposed commercial/industrial areas and schools). (cl Specific fire flows are determined from Appendix B of the 2022 CFC and depend on construction type and building area. (dl A 50 percent reduction in fire flow may be allowed if a building is fully sprinklered.

The minimum fire flows are assumed to be met concurrently with the Maximum Day Demand of the City, while maintaining a minimum residual system pressure of 20 psi throughout the City.

Fire flows and the expected duration have been used to establish minimum water storage requirements as shown in Table 6.2.

6.2 Water Supply and Pumping Capacity
Sufficient water system pumping capacity, in conjunction with available gravity storage, should be provided to meet the greater of the Maximum Fire Flow concurrent with the Maximum Day Demand or Peak Hour Demand of the City. The greater of the demands should be met assuming that the largest pump in the water system is in standby mode. 32

Maximum Day Demand Plus Fire Flow
Typical industry standards require that a City's water system have the capability to supply sufficient water to meet the City's Maximum Day Demand plus the Maximum Concurrent Fire Flow. Specific fire flows should be evaluated assuming the largest pump is offline (i.e., firm capacity of the pump station) regardless of whether or not fire flow is provided by gravity storage or booster pump station. This ensures the reliability of these systems to provide sufficient flow during emergency fire flow conditions. Pump stations without backup power capability (either an onsite generator or adaptor for a plug-in generator) should not be considered to be available during fire flow analysis.

Peak Hour Demand
Peak Hour Demand should be met from a combination of supply sources and potable water storage reservoirs if feasible. This assumes that the City has potable water storage. However, Gustine has minimal water storage. Therefore, it is recommended that it achieves a water supply capacity equal to Peak Hour Demand until it constructs additional above ground water storage facilities.

6.3 Water Storage and System Peaking Capacity
The A WW A recommends that the total treated water storage capacity requirements for a water system comprises the following components:
• Operational storage
• Fire storage
• Emergency storage
A discussion of these three components is as follows.

Operational Storage
Water demands generally vary over any 24-hour period creating a diurnal curve. Higher water demands occur during the early morning hours when people are irrigating landscape and getting ready for work or school. Water demands then decline to a nominal baseline level (depending on the proximity to and water use patterns of adjacent commercial/industrial areas) and then begin to increase again depending on outside water needs (and corresponding temperature) until it reaches a higher water demand in the early evening hours as people return home from work or school. Throughout the year, the peaks of this cycle will vary according to customer needs, thereby creating Maximum Day and Peak Hour Demands.
33

Typically, water treatment plants, supply turnouts, and/or groundwater wells are operated at a constant baseline rate over a 24-hour period and augmented by flow from water storage tanks during higher daily demand periods. Storage tanks are normally refilled when demands drop below the baseline water production flow rate.

The storage used to meet water demand above the baseline demand is called operational storage.

The operational storage requirements are calculated based on the diurnal demand in a service area. If sufficient data is not available to develop a diurnal demand, the recommended volume of water to be held in reserve for operational storage should be at least equal to 25 percent of the total volume of water used on a maximum day. It is recommended that until the City constructs above ground water storage, it can meet the operational storage requirements by providing additional well capacity of 20 percent of Maximum Day Demand with the largest well out of service.

Fire Storage
The fire flow requirements for the City have been determined in Table 6-2 based on the 2022 CFC. It shows flow (in gpm) for land use type (i.e. residential, commercial, industrial, etc.).

After a fire flow requirement is established, it is multiplied by the required firefighting duration to produce an estimate of the total volume of fire storage required.

I
The highest recommended fire flow requirement in the City of Gustine is 3,500 gpm for a duration of 3 hours for commercial/industrial areas with unsprinklered systems. The resulting minimum volume needed for fire flow storage is therefore 0.63 MG. The need for fire storage can also be offset by additional well capacity similar to operational storage.

Emergency Storage
A reserve of stored water is also required to meet demands during an emergency. An emergency is defined as an unforeseen or unplanned event that may degrade the quality or quantity of potable water supplies available to serve customers. The determination of the required emergency storage is a policy decision based on the assessment of the risk of failures and the desired degree of system reliability. The amount of required emergency storage is a function of several factors including the diversity of the supply sources, redundancy and reliability of the production facilities, and the anticipated length of the emergency outage.

There are three types of emergencies that a water utility typically prepares for:
• Minor emergency. A fairly routine, normal, or localized event that affects a few customers, such as a pipeline break, malfunctioning valve, hydrant break, or a brief power loss. Utilities plan for minor emergencies and typically have staff and materials available to correct them.
34

• Mai or emergency. A disaster that affects an entire or large portion of a water system, lowers the quality and quantity of the water, or places the health and safety of a community at risk. Examples include water treatment plant failures, raw water contamination, major power grid outages, and terrorist threats. Water utilities infrequently experience major emergencies.
• Major disaster. A disaster caused by natural forces or manmade events that create major water utility disruptions. Examples include earthquakes, forest or brush fires, hurricanes, tornados or high winds, floods, and other severe weather conditions such as freezing or drought, and terrorist events.

Typical industry standards were used in developing the emergency storage requirement for the City of Gustine. The A WW A states that no formula exists for determining the amount of emergency storage required so the decision should be made by the utility based on a judgment about the perceived vulnerabilities of its water system. The CDPH, in Title 22 Chapter 16, calls for a minimum emergency water supply in each pressure zone equivalent to the Average Day Demand.

It has been assumed that the emergency storage requirement for the City will be based on minor emergencies and major emergency criteria. It is therefore recommended that the City use CD PH's suggested guideline of having a minimum quantity of emergency storage equivalent to the City's Average Day Demand. However, as long as the City's primary source of supply is groundwater provided by several independently operated deep wells fitted with emergency power systems, the groundwater storage can provide the emergency storage component.

Total Storage Capacity
It is recommended that the City's minimum treated water storage capacity be determined as the sum of the following:
• Operational: Volume of water necessary to meet diurnal peaks observed throughout the day, equivalent to at least 20 percent of the Maximum Day Demand. • Fire Flow: Volume of water necessary to provide the maximum fire flow in the service area multiplied by the duration of the flow rate that must be maintained. • Emergency: Volume of water necessary to provide an Average Day Demand.

The total amount of system storage and peaking capacity required to meet these criteria will change over time as the City continues to grow and water demand increases. The recommended criteria above were used in determining the adequacy of existing water storage in Section 8.3 and in estimating future water storage in Section 9.3.
35

6.3 Water Transmission and Distribution Pipeline Sizing The following criteria were used to size new pipelines for the City. The American Water Works Association Manual 32 's (A WW A M32) criteria for maximum pipeline velocity were taken into account. A WW A M32 recommends that velocity not exceed 8 feet per second for existing pipelines. Furthermore, it recommends maximum velocities of 5 fps and 4 fps for pipelines less than and greater than 12 inches in diameter, respectively.

The City's existing system will be evaluated on a case-by-case basis. For example, if an existing pipeline experiences head loss in excess of the criteria described below during a Maximum Day Plus Fire Flow event, this condition, by itself, does not necessarily indicate a problem as long as the minimum pressure criterion is satisfied. Although these criteria and guidelines have been established and will be used to size new pipelines, the City's existing system will be evaluated using pressure as the primary criterion. Secondary criteria, such as velocity, head loss, age, and material type, may be used as indicators for where water system improvements may be needed.

Water Transmission Pipeline Sizing
The transmission pipelines in the City's water system are defined as 12 inches in diameter or larger. They are designed based on the criteria described below for Average Day, Maximum Day, and Peak Hour Demand conditions.
• Average Day Demand
Service pressures are to be maintained at a minimum of 40 psi. This design criteria balances system performance with economy.

Maximum allowable velocity is 3 feet per second (fps).
• Maximum Day Demand
- Maximum Day Demand is defined as 150 percent of the Average Day Demand based on the City's historical water use.

The minimum allowable water pressure in a transmission main is 40 psi.

The maximum allowable velocity within a transmission main is 5 fps. • Peak Hour Demand
Peak Hour Demand is defined as 225 percent of the Average Day Demand.

The minimum allowable pressure during a Peak Hour Demand is 40 psi.

The maximum allowable pipeline velocity is 7 fps.
36

Water Distribution Pipeline Sizing
Distribution pipelines are smaller than 12 inches in diameter and are sized based on the criteria described below for Average Day, Maximum Day Plus Fire Flow, and Peak Hour Demand conditions.
• Average Day Demand
Service pressures are to be maintained at a minimum of 40 psi and a maximum allowable pressure is 75 psi. This limit represents design criteria that will protect the integrity of the system and improve system reliability.

Maximum allowable velocity within distribution system pipelines is 5 fps. • Maximum Day Plus Fire Flow
Fire flows are assumed to be concurrent with Maximum Day Demand.

Fire flow at residential fire hydrants is a minimum of 500 gallons gpm with a minimum pressure of 20 psi at the flowing fire hydrant (for sprinklered houses).

Fire flow at industrial/institutional fire hydrants is a minimum of 1,750 gpm with a minimum pressure of 20 psi at the flowing fire hydrant ( sprinklered buildings).

The maximum allowable velocity within the distribution system pipelines is 10 fps.

This is greater than the A WW A M32 recommendation of 8 fps but reasonable because this is an emergency situation and occurs for a relatively short period. • Peak Hour Demand
Service pressures are to be maintained at a minimum of 40 psi during Peak Hour Demand to ensure system reliability.

The maximum allowable pipeline velocity is 7 fps.
37

7.0 Hydraulic Model Development
A water system computer was created as part of this Master Plan update to represent existing infrastructure conditions as of October 2025. This chapter describes the model development process including an overview of the hydraulic modeling software, the modeling assumptions, and the element naming conventions used in the City's hydraulic model.

7.1 Modeling Software
The City's water system computer model was created using EPANET Version 2.2 Build 2.2.0. It was developed by the Water Infrastructure Division of the Center for Environmental Solutions and Emergency Response of the United States Environmental Protection Agency. This software transforms information about the physical water system into a mathematical model that solves for various flow conditions.

For each set of specified demands, the model generates information on pressure, flow, velocity, and headloss. These can be used to evaluate the existing water system to identify deficiencies.

The model can also be used to analyze the adequacy of recommended water system improvements for the future.

7.2 Modeling Assumptions
Modeling assumptions are important for developing a computer model and interpreting the results of simulations. The following assumptions were used in developing the City's water system model:
• Headlosses through pipelines were calculated using the Hazen-Williams equation. • Ground surface elevations were estimated using Google Earth and verified with topographic surveys at selected locations throughout the City. The Google Earth elevations were found to be ± 1 feet of the actual surveyed elevations. • Minor losses from pipe bends and fittings were assumed to be negligible. • Pipe length accuracy was assumed to be ±25 feet.
• The water demands in the model were expressed in gallons per minute (gpm). 38

7.3 Hydraulic Model Element Naming Scheme
Models are set up with specific element names representing key hydraulic facilities because this allows the modeler to easily locate specific elements while modeling. As each facility (junctions, reservoirs, tanks, pipes, pumps, and valves) is created, it must be named logically and sequentially. Table 7-1 summarizes the hydraulic element functions.

Table 7-1. Hydraulic Network Elements
Type Description Prefix
Junction Removes (demand) or adds (inflow) water from/to the system J Reservoir Represents an infinite external source of water R Tank Represents finite water storage T
Pipe Conveys water from one junction to another p
Pump
Raises the hydraulic grade to overcome elevation differences and friction PMP losses Valve Controls flow or pressure in the system based on specified criteria V Each element is named numerically and preceded by a hydraulic element prefix to denote facility type as shown in Table 7-2.
39

Table 7-2. Naming Scheme for Hydraulic Network Elements Model Element Naming Scheme
I "115"= Sequential Number
Pipe 7L "p = Pipeline
I [ ""=well o at site
7Welll Reservoir/Well
L"W"=Well
I !-
"115" = Sequential Number
71-115 Junction
L "J"=Node
T-1
Tank
"1" = Site ID
·T -Tank
I !--
"A"= Booster Pump ID
7PMPlA Pump
"1" = Site ID
"PMP" = Pump
__JV-1-1
!-
"1" =Sequential Number
Valve f �-M;,e1D
"y" - Valve
40

7.4 Water System Facilities Creation in Computer Model
The model of the City's water system was created using the City's as-built subdivision maps and discussions with City staff. The model was created to reflect the existing conditions by the addition of facilities as follows.

Pipes
Existing pipelines were added to the computer model in the proper alignment. The input data for the pipelines consisted of length, diameter, material, and pipe C-factor. Pipe C-factors were determined based on pipeline age and material. Pipeline alignments were determined based on as-built drawings.

Junctions
The junctions in the model were assigned elevations based on Google Earth. Demands were assigned to junctions in the model using the land use method. The demands were allocated as described in Section 7 .5. Junction demands were then converted from Average Day Demand to Maximum Day Demand and Peak Hour Demand by applying the appropriate global peaking factor.

Wells and Tanks
Wells were represented in the model using constant head reservoirs with pumped water elevations. Well pump curves were determined using pump test results provided by the City.

Above ground tanks were modeled as varying-head tanks with the appropriate tank dimensions.

7.5 Water Demand Allocation in Computer Model
The steps used to allocate the base (existing average day) demands in the hydraulic model include:
• Assign large water user demands based on actual meter records to their specific junction locations in the computer model.
• Allocate remaining demands (excluding large users identified in step 1) based on land use and water duty factors.

Large Water User Demand Assignment Based on Metered Data The 10 largest water users in the City are shown in Table 7-3. These water users account for approximately 9 percent of the City's 2019/20 total water demand. These were determined 41

based on metered customer data received from the City. These water demands were assigned manually to their respective locations in the model.

Table 7-3. City of Gustine Large Water Users
No. Service Address Total Meter Water Demand, Water Demand, gpm Consumption, HCF gal/day
1 1400 MEREDITH 1,265,257 25,926 36.01
AV
2 370 LINDEN AV 446,816 9,156 19.07
3 3 85 MEREDITH 290,650 5,956 8.27
AV
4 219 LAUREL AV 233,637 4,787 6.65
5 394 WALLIS AV 213,260 4,370 6.07
6 16 WALLIS AV 107,684 2,207 4.60
7 1616 VIA 103,509 2,121 4.42

COLABRJA
8 1507 LUCERNE 91,761 1,880 3.92
AV
9 861 WALLIS AV 91,170 1,868 3.89
10 601 LAUREL AV 97,320 1,841 3.83
Total 2,941,064 60,112 97
Remaining Demand Allocation
The remaining water demands were allocated in the model based on land use. The water demands were allocated based on the nearest node method that represents the demand junction area in the model.
42

8.0 Existing Water System Evaluation
The City of Gustine's existing water system was evaluated based on the design and operational criteria in Chapter 6. The adequacy of the City's water supply/pumping and potable water storage capacities were evaluated. Furthermore, the City's hydraulic model was used to evaluate the existing water distribution system's capacity to supply the required water demands at adequate pressures. The following sections describe the evaluations and the improvements recommended to address water system deficiencies.

8.1 Existing Water Demand
The City's existing potable water demands are summarized in Table 8-1. They represent the total water use of the customers in the City's existing water service area. The evaluations in this chapter are based on the City's water system being able to meet these demands at adequate pressures.

Table 8-1. Existing Water Demand
(Demands based on Chapter 4, Table 4-8 (2024 Conditions).

Demand
Demand Scenario mgd gpm
Average Day 1.63 1,133
Maximum Day 2.45 1,700
Peak Hour -- 2,550
. .

8.2 Existing Water Supply and Pumping Capacity Evaluation The City's water supply and pumping capacity criteria require the existing water system to have sufficient firm pumping capacity to meet Maximum Day Demand plus Fire Flow or Peak Hour Demand, whichever is greater. Firm pumping capacity should account for pumps that are out of service at any given time due to mechanical breakdowns, maintenance, water quality, or other operational issues. The largest well was assumed to be out of service to calculate the firm pumping capacity as shown in Table 8-2.
43

Table 8-2. Existing Water Supply and Pumping Capacity
Existing Maximum Day Existing Peak
Existing Pumping Demand Plus Hour Demand,
Well No. Address Capacity, gpm Fire Flow, gpm gpm
4 700
5 1,100
6 800
7 600
Total Capacity 3,200
Total Firm Capacity" 2,100 5,200 2,550
(Maximum Day Demand of 1,700 gpm plus maximum fire flow of 3,500 gpm (for buildings with no sprinklers). (bJDefined as the total capacity of the individual wells with the largest well pump out of service. For this case Well 5 is the largest well and so was not considered in calculating film pumping capacity.

The City's existing firm pumping capacity of 2,100 gpm is less than the pumping capacity required of 5,200 gpm for the existing service area. New water supply facilities capable of supplying at least 3,100 gpm (5,200-2,100) are needed to meet the water supply and pumping capacity criterion.

8.3 Existing Water Storage Capacity Evaluation
The required water storage capacity of the City's water system consists of the following three components according to the design and operational criteria outlined in Chapter 6:
• Operational Storage: 20 percent of Maximum Day Demand. • Emergency Storage: 100 percent of Average Day Demand. • Fire flow Storage: Maximum fire flow times fire flow duration.

The required water storage capacity was calculated to be 2.75 million gallons (MG) as shown in Table 8-3. However, the available water storage capacity is about 1.34 MG. Therefore, there is a storage deficit of about 1.41 MG. The existing overhead water storage tank of 72,500 gallons was not considered in this calculation because it is so small that it is only used for flow equalization.

Table 8-3. Comparison of Existing Available and Required Storage Capacity Available Storage
Required Storage Capacity, MG
Storage Deficit,
Capacity, MG Operational Fire Flow Emergency Total MG(

1.338 0.489 0.6300 1.632 2.751 1.413
6Available storage from groundwater wells calculated as the firm water supply (largest well assumed out of service) minus ADD. ("Based on required institutional/commercial fire flow of 3,500 gpm flowing for 3 hours per CFC. (Calculated as required storage minus available storage. 44

8.4 Existing Water Distribution System Evaluation
The City's existing water distribution system was evaluated using the hydraulic model created.

The evaluation focused on the ability of the existing water distribution system to supply existing customer water demands at adequate pressures and within allowable pipeline velocities as specified in the design and operational criteria in Chapter 6.

Steady-state hydraulic conditions of the water system were simulated. Steady-state hydraulic conditions mean that flow and other properties, like pressure and velocity, do not change over time at any specific point within the water system. In such a state, the inflow rate equals the outflow rate, and no mass or energy accumulates in the system, which allows for a simplified, instantaneous snapshot of the water system's behavior. The model results are discussed as follows.

Average Day Demand Analysis
The City's existing Average Day Demand allocated in the model was used for this simulation.

The computer simulations show that the service area has pressures above the required minimum of 40 psi with pipeline velocities below the 3-fps maximum velocity criterion. Water system pressures were generally about 60 psi.

Maximum Day Demand Analysis
The City's existing Maximum Day Demand was simulated by applying the peaking factor of 1.5 to the Average Day Demand. All pipeline velocities were below the 5-fps maximum criterion.

Water system pressures ranged from 55 to 60 psi exceeding the minimum pressure criterion of 40 psi.

Maximum Day Demand plus Fire Flow Analysis
The existing Maximum Day Demand was simulated concurrently with fire flows at selected hydrant locations within the distribution system. A fire flow of 1,000 gpm was simulated for single family residences, 1,500 gpm for multi-family residences, and 3,500 gpm for institutional land uses. It was assumed that the buildings were not sprinklered. 1,000 gpm fire flows were simulated at single family homes in Northwest, Southwest, Northeast, Southeast, and the Southernmost areas along East Wallis Ave. The results show the fire hydrants in these locations could supply the required fire flows while maintaining a residual pressure of 20 psi, except where pipelines were 4-inches. These areas include Wallis Avenue from West Avenue to Railroad Avenue, Ash Avenue, and the alleys between Grove Avenue and Railroad Avenue. This also included the approximately 850 feet 4-inch pipelines along Elm Avenue and Carolyn Drive.
45

1,500 gpm fire flows were simulated at multi-family homes such as Gustine Garden Apartments, Meredith Manor Apartments (fail), and Green Acres Mobile Manor. The results show the fire hydrant off Meredith A venue near Green Acres Mobile Manor should be able to provide the required fire flows. Pipelines that are 8-inches can supply the required fire flows. However, the 4-inch pipelines especially along Carnation Avenue were unable to provide the required fire flows.
3,500 gpm fire flows were simulated at institutions such as Gustine High School, Gustine Elementary School, Gustine Middle School, Gustine Adult School, and Our Lady of Miracles Catholic School. The fire hydrants at these institutions could not supply the required 3,500 gpm fire flows while maintaining a residual pressure of 20 psi. However, they could supply fire flows ranging from 2,000 gpm to 2,500 gpm. These flows exceed the 1,750 gpm flows required, if these buildings have indoor sprinklers.

The results are as follows:
• Gustine High School - 2,000 gpm
• Gustine Elementary School 2,250 gpm
• Gustine Middle School 2,500 gpm
• Gustine Adult School --2,500 gpm
• Our Lady of Miracles Catholic School -- 2,500 gpm
Peak Hour Demand Analysis
The existing Peak Hour Demand was simulated by applying a peaking factor of 2.25 to the existing Average Day Demands in the computer model. The water system pressures were above the 40-psi minimum pressure criterion. Pipelines velocities were well below the maximum 7 fps as required by the City's design and operational criterion.

8.5 Existing Water System Recommendations
The existing water system evaluation showed that the City's water system currently does not have adequate water supply, pumping, and storage capacities. Pipelines that were smaller than 6- inches were inadequate in meeting the required fire flows. Furthermore, aging pipelines were identified as leaky based visible signs on road pavements and analysis of the unaccounted-for water. Improvements are therefore needed to the existing water system to correct the deficiencies identified.

Water Storage and Pumping Capacity Improvements
The water system evaluation showed that the City currently has a water supply and pumping deficit of 3, I 00 gpm. Furthermore, the water storage analysis showed that the City has a storage 46

deficit of about 1.41 MG. The water supply and pumping deficit of 3,100 gpm is larger and so will drive the choice of water system facilities to meet the storage and pumping capacity criteria.

Constructing a 1.0 MG tank with a 1. 7 MGD booster pump station can supply about 1,400 gpm for 12 hours. This leaves a 1,700 gpm (3,100 -1,400) deficit to be met from groundwater wells.

Two wells capable of supplying 850 gpm each can provide the needed 1,700 gpm of water supply and pumping capacity to satisfy the City's criteria.

The improvements are summarized as follows:

1. Two new groundwater wells to supply 850 gpm each.

2. Construct two 0.5 MG at grade tanks plus 0.85 MGD (700-gpm) booster pump stations.

Recommended Water Distribution System Improvements
The water distribution system pipeline improvements needed to repair aging leaky pipelines and increase pipeline sizes to 8-inches to improve fire flows in portions of the City are shown in Figure 8-1. They include:
• Replace 14,000 feet of aging and leaky water mains along SR 33 and 120 corridors with 8-inch diameter pipelines. This includes the replacement of valves and fire hydrants. This includes the approximately 850 linear feet 4-inch diameter pipelines along Elm Avenue and Carolyn Drive.
• Replace 3,900 feet of 4-inch pipelines with 8-inch pipelines as follows:
o 2,200 feet of pipelines on Wallis Avenue from West Avenue to Railroad Avenue. o 350 feet of pipelines on Ash Avenue.
o 450 feet of pipelines on Carnation A venue.
o 900 feet in two alleys between Grove A venue and Railroad A venue Street. • Replace miscellaneous pipelines (leaky or undersized 4-inch pipelines), hydrants, and valves.
47

9.0 Future Water System Analysis
This chapter presents an analysis to size the water infrastructure required to support the future growth of the City of Gustine through Buildout of the City. The future water system configuration comprises all existing operational facilities, recommended facilities to improve the existing water system, plus additional facilities needed to reliably satisfy water demands at buildout.

9.1 Future Water Demand
The Average Day Demand of the City is projected to be 2,366 gpm by Buildout as summarized in Table 9-1. The Average Day Demand, Maximum Day Demand, and Peak Hour Demand were calculated by applying the appropriate peaking factors. These demands formed the basis of the future water system analyses.

Table 9-1. Projected Water Demand
Demand Scenario Buildout
Average Day, gpm 2,366
Maximum Day, gpm 3,549
Peak Hour, gpm 5,324
a/Demands based on Chapter 4.

9.2 Future Water Supply and Pumping Capacity Evaluation The City's water supply and pumping capacity criterion requires the future water system to have sufficient pumping capacity to meet either Maximum Day Demand plus Fire Flow or Peak Hour Demand (whichever is higher). This evaluation was based on the pumping station's ability to deliver firm capacity with the largest pump out of service. The results of the pumping capacity evaluation for Buildout of the City are summarized in Table 9-2.

Table 9-2. Comparison of Buildout Pumping Capacity and Demand Existing & Planned Buildout Maximum Buildout Needed
Firm Pumping Day Demand Plus Peak Hour Pumping
Description Capacity, gpm Fire Flow, gpm" Demand, gpm Capacity, gpm Total Firm Capacity" 5,200 7,049 5,324 1,849
Existing Firm Pumping Capacity was addressed by recommending additional water system facilities in Section 8.5. ib) Based on a Maximum Day Demand of 3,549 gpm and nonsprinklered fire flow of3,500 gpm.

This analysis indicates that the existing and planned pumping capacities do not meet the required pumping capacity for Buildout. An additional pumping capacity of 1,849 gpm is needed. This 48

can be provided from three new groundwater wells supplying about 620 gpm each.

Alternatively, a surface water treatment plant can satisfy this requirement.

9.3 Future Water Storage Capacity Evaluation
Future storage capacity must satisfy the design and operational criteria in Chapter 6, which includes:
• Operational Storage: 20 percent of Maximum Day Demand • Emergency Storage: 100 percent of Average Day Demand
• Fire flow Storage: The required maximum fire flow times the fire flow duration period.

The required storage must be in above ground tanks or groundwater wells. As shown in Table 9-3, the required storage of the City by buildout is approximately 5.1 MG. The City's total existing and planned storage will not be adequate to meet the buildout storage requirements; therefore, a deficit of approximately 2.3 MG will be needed.

Table 9-3. Required Water Storage Capacity by Buildout
Available & Required Storage Capacity, MG
Planned Storage Storage Deficit,
Capacity, MG Operational Fire Flow Emergency Total MG

2.751 1.022 0.630 3.407 5.059 2.308(
Available and planned storage from groundwater wells and storage tank. "Based on required institutional/commercial fire flow of 3,500 gpm flowing for 3 hours per CFC. (·Calculated as required storage minus available storage.

It is recommended that a 1.0 MG at grade tank plus 1.7 MGD (1,400-gpm) booster pump station be constructed at each of the three new well sites.

9.4 Future Water Distribution System Analysis
The City's water distribution system was evaluated using a future water system hydraulic model developed based on the existing model. This evaluation focused on the ability of the proposed water distribution system to meet the design and operational criteria discussed in Chapter 6.

Buildout Water Distribution System
The future model of the City's water system was created by integrating water supply, pumping, and storage facilities proposed in the previous sections. Two main alternatives comprising combinations of water system facilities were explored. These included:
49

Alternative 1: Expansion by New Wells Only
Alternative 1 assumes that the City continues to rely solely on groundwater to meet its water demand by drilling new wells only. This assumes that the groundwater quality continues to be good and there is sufficient groundwater recharge to stabilize groundwater levels. This alternative requires the following by buildout:
• Three 620-gpm groundwater wells.
• Three 1.0 MG at grade tank plus 1. 7 MGD (1,400-gpm) booster pump station ( one at each new well site).
• Construct 43,000 feet of 12-inch pipelines.

Alternative 2: Expansion by Water Treatment Plant, Storage Tanks and Booster Pump Stations
Alternative 2 is based on conjunctive water use relying on a combination of groundwater and treated surface water to meet future water demand. Conversion to surface water requires that the City purchase water supply, construct a 20-inch water transmission main, 8 MGD water treatment plant and a 4 MG water storage tank totaling about $32.5 million according to the 2002 Water Master Plan. Accounting for inflation, this surface water option would cost about $60 million in 2025 dollars.

Even though conjunctive use which adds surface water will provide the City with more flexible water supply sources, the cost together with the challenges of acquiring surface water supplies pose significant challenges. Consequently, it is recommended that the City focuses on expanding its water supply using groundwater wells now. Future water master plans and/or studies can explore the surface water treatment option further, if groundwater conditions deteriorate. so

10.0 Recommended Capital Improvement Program
Chapters 8 and 9 identified the need for additional facilities for the City of Gustine's water distribution system to meet existing and buildout water demands. Figure 10-1 shows the additional facilities recommended to provide the required minimum water system pressures and flows. Table 10-1 shows the associated capital costs for the recommended capital improvements.

Table 10-1. Recommended Water System Capital Improvement Program Number
on Facility Estimated Unit of Unit Cost, Estimated Cost, Drawing Name Item Description Quantity Measure S/unit x$1,000 Improvements to Existing System
Groundwater Wells"
Construct new 850-gpm well at S
Mills Road and south of Sullivan
I Well 8 Road I LS 3,000,000 3,000
Construct new 850-gpm well at
park between Jensen Road and
I Well 9 Delta Mendota Canal I LS 3,000,000 3,000
Subtotal 6,000
Water Storage Tanks+ Booster
Pump Stations

0.5 MG tank+ 0.85 MGD booster
pump station at Well 5 Site on East
2 Avenue I LS 2,500,000 2,500

0.5 MG tank+ 0.85 MGD booster
pump station at Future Well 9 Site
on South A venue near CCID Main
2 Canal I LS 2,500,000 2,500
Subtotal 5,000
Water Pipelines
State Route 33/140 Water Main
Replacement (incl valves and 10,000,00
3 hydrants) 1 LS 0 10,000
4" Water Pipeline Replacement
with 8" (Wallis, Ash, Carnation &
4 2 Alleys) 3,900 LF 250 975
Miscellaneous pipeline, hydrant,
and valve replacements 1 LS 995,000 995
Subtotal 11,970
Existing Improvement Costs 22,970
51

Number
on Facility Estimated Unit of Unit Cost, Estimated Cost, Drawing Name Item Description Quantity Measure $/unit x$1,000 Other Related Project Costs
(65% 14,931
Sub Total 37,901
Buildout
Groundwater Wells!"
1 Well JO Construct new 620-gpm well 1 LS 2,800,000 2,800 1 Well 11 Construct new 620-gpm well 1 LS 2,800,000 2,800 I Well 12 Construct new 620-gpm well I LS 2,800,000 2,800 Subtotal 8,400
Water Storage Tanks+ Booster
Pump Stations

1.0 MG tank+ 1.7 MGD booster
2 pump station at Well 10 Site I LS 4,000,000 4,000

1.0 MG tank+ 1.7 MGD booster
2 pump station at Well 11 Site I LS 4,000,000 4,000

1.0 MG tank+ 1.7 MGD booster
2 pump station at Well 12 Site I LS 4,000,000 4,000
Subtotal 12,000
Water Pipelines
12" diameter distribution main 43,000 LF 350 15,050
Subtotal 15,050
Ultimate Buildout
Improvement Costs 35,450
Other Related Project Costs
(65%) 23,043
Sub Total 58,493
Total 96,393
tal Present installed costs based on a combination of current construction costs and Engineering News Record Estimates. tb) These costs do not include well head treatment.
tc) Other Costs based on the following components: design at l 0%; permitting, regulatory compliance, CEQA at l 0%; construction management at l 0%; program implementation at 5%; project construction contingency at 25%, and land acquisition costs at 5%. 52

10.1 Total Capital Costs
The estimated total capital cost for water system improvements that should be completed by buildout of the City's Sphere oflnfluence is approximately $96.4 million. The costs were developed based on similar construction projects in the Central San Joaquin Valley. All construction costs reflect January 2026 material and labor costs. These costs are to be used for conceptual estimates only and should be updated regularly to keep up with inflation.

10.2 Groundwater Wells
Well construction was assumed to be consistent with and compatible with the look and functionality of current City wells. The costs include test hole drilling, water quality/soil sampling, well drilling, and development as well as the necessary housing, pump, motor, control equipment, discharge piping, SCADA, disinfection equipment, and standby generator. The completed well depth was assumed to be 250 to 500 feet deep based on the existing well information. These costs are representative of construction conducted under normal drilling conditions and would be higher for special or difficult locations. These costs do not account for wellhead treatment.

10.3 Water Storage Tanks and Booster Pump Stations
The cost of the water storage tanks is based on at-grade welded steel or prestressed concrete material. These costs are representative of construction conducted under normal excavation and foundation conditions and would be higher for special or difficult foundation requirements.

Booster pump station costs generally vary considerably, depending on factors such as architectural design, pumping head, and station capacity. Estimated construction costs for the booster pump stations are based on enclosed stations with architectural and landscaping treatment suitable for residential areas. Pump station cost estimates include backup/standby generators and SCADA, and three pumps located adjacent to the storage tanks.

10.4 Water Pipelines
Pipeline costs generally include pipe materials, trenching, placing and jointing pipe, valves, fittings, hydrants, service connections, placing imported pipe bedding, native backfill material, and asphalt pavement replacement, if required. These costs do not include the cost of boring and pipe jacking.

10.5 Other Costs
An additional cost equivalent to 65 percent of the capital cost for the recommended facilities has been included to cover "other" project-related costs such as:
53

• Design at 10 percent.
• Permitting, regulatory compliance, and CEQA at 10 percent. • Construction management at 10 percent.
• Program implementation at 5 percent.
• Project construction contingency at 25 percent.
• Land acquisition costs at 5 percent.

Design services associated with the new facilities include preliminary, conceptual, and final design reports; preparation of drawings and specifications for construction; and start-up services.

Construction management covers such items as contract management and inspection during construction.

Program implementation costs cover such items as legal fees, environmental/CEQA compliance requirements, financing expenses, administrative costs, and interest during construction. Project contingency is for unexpected construction conditions, the need for unforeseen mechanical items, and variations. Land acquisition costs include all property costs associated with the recommended new facilities.

10.6 Implementation Strategy
The timing of the recommended water system facilities is dependent on the rate of city growth, development sequence, and the availability of funding. The capital improvement program is divided into two, including improvements to the existing water system and facilities needed for ultimate buildout. Generally, improvements to the existing water system are paid by existing customers. Therefore, this Water Master Plan is crucial for the determination of the appropriate rates to be paid by customers. The Buildout of the City will be determined by future development and the costs associated with these facilities are usually borne by development and connection fees.

Gustine is a Disadvantaged Community and may not be able to fund the entire capital costs.

Therefore, a combination of Federal and State funding assistance is recommended for the implementation of the project components. Therefore, following the final Water Master Plan report, it is recommended that the City seek funding for detailed design to be shovel-ready as these projects have a higher chance of obtaining funding. 54

11.0 References
City of Gustine (a). City of Gustine General Plan. Gustine, California, February, 2002.

City of Gustine (b). City of Gustine Water Master Plan. Gustine, California, February, 2002.

Kenneth D. Schmidt and Associates. Groundwater Conditions in the Vicinity of the City of Gustine. California. Draft Report. Fresno, California, September 2001. 55

Appendix A

FIGURES
ES-1 City of Gustine Water Master Plan - Location Map
ES-2 City of Gustine Water Master Plan -Buildout Land Use ES-3 City of Gustine Water Master Plan Recommended Capital Improvement Program Facilities 1-1 City of Gustine Water Master Plan -Location Map
2-1 City of Gustine Water Master Plan-Existing Land Use 2-2 City of Gustine Water Master Plan - Buildout Land Use 3-1 City of Gustine Water Master Plan - Existing Water System Facilities 4-1 City of Gustine Water Master Plan - Southeast Annexation 8-1 City of Gustine Water Master Plan - Recommended Improvements to Existing Water System 10-1 City of Gustine Water Master Plan - Recommended Water System Improvements 56

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