City Council and Concurrent Authorities
June 9, 2026

N-C-129-60-20-41-WP-TM-GW Supply Redundancy Eval

EVALUATION METHODOLOGY AND CRITERIA
The purpose of this evaluation was to identify the additional groundwater wells and/or improvements that would be needed to maintain reliable water supply during a complete loss of surface water supplies.

The analysis assumes zero surface water availability, representing a conservative planning scenario consistent with the City’s redundancy and resiliency objectives as well as previous experiences.

The evaluation approach follows the performance and operational criteria established in the 2021 WMP and 2022 Water Master Plan Update (WMPU), updated to reflect current well inventory information provided by City staff in 2025. Two planning scenarios were evaluated:
• Near-term (2030). Used to establish the near-term level of groundwater capacity needed to reliably meet current system demands.
• Buildout (2040). Used to determine the additional improvements required to maintain redundancy under future growth conditions. Buildout demands were consistent with the 2022 WMPU. These demands assume some development changes, further detailed in the Water Demands section.

For each scenario, total firm groundwater capacity was compared to maximum day demand, assuming no surface water supply. Firm capacity was defined as 85 percent of active well capacity, consistent with the City’s planning assumptions. New wells were assumed to provide a firm capacity of approximately 1,500 gallons per minute (gpm) each (assumes a total capacity of 1,765 gpm for each well).

Groundwater well capacities and operational status were updated based on the Well Rehabilitation Status List provided by City staff in March 2025. To optimize improvements and minimize capital cost, wells were identified for potential rehabilitation if they were inactive, less than 40 years old, and located on parcels of at least 0.5 acre, providing sufficient space for the addition of treatment systems and maintenance access.

WATER DEMANDS
For this evaluation, near-term (2030) demands were used to reflect the current pace of development within the City. Several development projects throughout the City have advanced sooner than anticipated in the 2021 WMP, resulting in higher projected system demands sooner than what was assumed in the 2021 WMP. To align groundwater redundancy planning with the accelerated development trends, the near-term demand condition was used in lieu of existing demands. Table 1 summarizes the near-term (2030) demands.

Table 1. Near-Term (2030) Water Demands
Area
Average Day Demand,
mgd(a)
Maximum Day Demand,
mgd(b)
Peak Hour Demand,
mgd(c)
North Stockton 23.8 38.1 59.5
South Stockton(d) 9.8 14.9 26.5
Total 33.6 53.0 86.0
(a) Average day demand based on the 5-year average production from 2015 through 2019, scaled to include a 10 percent demand rebound factor. Refer to Chapter 3 from the 2021 WMP.
(b) Maximum day demand calculated using a peaking factor of 1.6 and 1.7 times the average day demand for North and South Stockton, respectively.
(c) Peak hour demand calculated using a peaking factor of 2.5 and 3.3 times the average day demand for North and South Stockton, respectively.
(d) Demands associated with the Niagara Bottling Facility (Existing Planned and the Additional) are non-peaked constant demands.

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Revised buildout (2040) demands, consistent with West Yost’s 2022 evaluation of future development changes1, are summarized in Table 2. These projections reflect updated assumptions for future development. In North Stockton, demands from the Bear Creek South and Origone Subdivision projects were added. In South Stockton, demands from the Food Production Business and Niagara Bottling Facility projects were added, and demands associated with the Mariposa Lakes project were removed to reflect updated service area boundaries.

Table 2. Revised Buildout (2040) Water Demands
Area
Average Day Demand,
mgd(a)
Maximum Day Demand,
mgd(b)
Peak Hour Demand,
mgd(c)
North Stockton(d) 30.5 48.9 76.2
South Stockton(e) 14.1 19.6 33.1
Total 44.6 68.5 109.3
(a) Average day demand based on the 5-year average production plus demands associated with all developments that will be completed by 2040.
(b) Maximum day demand calculated using a peaking factor of 1.6 and 1.7 times the average day demand for North and South Stockton, respectively. Refer to footnote (e) for more details.
(c) Peak hour demand calculated using a peaking factor of 2.5 and 3.3 times the average day demand for North and South Stockton, respectively.
(d) See "Bear Creek South Development Water System Evaluation" Technical Memorandum (West Yost Associates, 03/03/2022), refer to Table 2. Origone Subdivision demand projected based on land use information from the 2011 Origone Ranch Specific Plan and water use factors from the City's 2021 WMP. Refer to footnote (e) for more details. (e) See "Food Production Business Project Impact Evaluation to the South Stockton Water System" Technical Memorandum (West Yost Associates, 07/01/2022) Table 2. See "Additional Niagara Bottling Facility Demand Impact Evaluation to the South Stockton Water System" Technical Memorandum (West Yost Associates, 07/22/2022) Table 2. Demands associated with the Niagara Bottling Facility (Existing Planned and the Additional) are non-peaked constant demands. Food production business demand is constant and nonpeaked. Demands exclude Mariposa Lakes.

The two demand conditions summarized in Tables 1 and 2 are the basis for the subsequent supply capacity evaluation, which quantifies the number of new or rehabilitated wells required to provide firm groundwater capacity equivalent to near-term (2030) and buildout (2040) maximum day demands with no surface water supplies.

EXISTING GROUNDWATER SUPPLIES
A summary of current groundwater well facilities, including status, capacity, and rehabilitation potential, is provided in Table 3. Groundwater facility information was updated based on the Well Rehabilitation Status List provided by City staff via email on March 18, 2025. The list included current well capacities, operational status, and site characteristics such as parcel size and well age.

Wells were reviewed to identify opportunities for rehabilitation or replacement to improve system reliability and cost efficiency. Wells were considered suitable for rehabilitation if they were inactive, less than 40 years old, and located on parcels of at least 0.5 acre, providing sufficient space for the addition of treatment systems and maintenance access.

Based on discussions with City staff, Wells 25 and 30 in North Stockton were identified as the most suitable sites for near-term improvement. Well 25 is proposed for on-site replacement due to existing mechanical 1 West Yost. December 2022. Water System Impact Evaluation of Future (2040) Development Changes.

Technical Memorandum.

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issues, while Well 30 is a candidate for treatment installation to address 1,2,3-TCP. As a result, only Well 30 was considered a viable for rehabilitation. Improvements to Well 25 would essentially result in a new well facility.

Overall, the existing active groundwater capacity has decreased slightly since completion of the 2021 WMP. In North Stockton, the total active well capacity is now approximately 18,300 gpm (26 mgd), compared to about 19,500 gpm (28 mgd) reported in the 2021 WMP. This reduction is primarily attributed to several wells that have since become inactive or require mechanical repair or treatment, including Wells 24, 25, and 30. In South Stockton, the total active capacity is approximately 6,000 gpm (8.6 mgd), which is similar to the 5,900 gpm (8.5 mgd) reported in the 2021 WMP.

Table 3. Summary of Well Facilities(a)
Well
Number
Parcel
Size, ac(b)
Well
Status
Well Age,
years Notes
2025
Well
Pump
Capacity,
gpm
Firm
Active
Well
Capacity,
gpm(c)
Rehabilitation
or
Replacement
Candidate(d)
North Stockton
3R 1.84 Active – 2,000 1,700 –
10R 6.84 Active – 3,200 2,720 –
15 0.11 Standby 50 Manganese Tier 2
violation 1,805 – Unlikely
18 2.63 Active 69 800 680 –
19 0.17 Active 47 1,780 1,513 –
20 0.18 Inactive 47
Iron and
manganese Tier 2
violation
1,800 – Unlikely
21 5 Active 47 1,800 1,530 –
24 0.28 Inactive 43 Bad motor 430 – Unlikely
25 5.36 Inactive 41
Mechanical issues
(current well pumps
mud)
1,600 –
Potential
Replacement
26 0.19 Inactive 38 Mechanical issues 1,970 – Unlikely
27 0.24 Active 40 2,200 1,870 –
28 0.14 Standby 28 1,2,3-TCP 1,600 – Unlikely
29 6.36 Active 25 2,500 2,125 –
30 7.6 Standby 22 1,2,3-TCP 2,200 –
Potential
Treatment
31 0.18 Active 21 2,000 1,700 –
32 0.57 Active 21 2,000 1,700 –
Existing Groundwater Well Capacity (Active) 18,280 15,538 Existing Groundwater Well Capacity (Inactive or Standby) 11,405 9,694 Existing Groundwater Well Capacity
(Inactive or Standby and Candidate for Rehabilitation) 2,200 1,870 Well 30 is the
only
recommended
candidate for
rehabilitation
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Table 3. Summary of Well Facilities(a)
Well
Number
Parcel
Size, ac(b)
Well
Status
Well Age,
years Notes
2025
Well
Pump
Capacity,
gpm
Firm
Active
Well
Capacity,
gpm(c)
Rehabilitation
or
Replacement
Candidate(d)
South Stockton
SSS #1 0.14 Inactive 41 Iron 1,000 – Unlikely
SSS #2 0.15 Standby 72 1,2,3-TCP 1,295 – Unlikely
SSS #3 0.14 Active 36 PFOA/PFAS 2,000 1,700 –
SSS #8 5.69 Active 25 PFOA/PFAS 1,500 1,275 –
SSS #9 0.22 Active 21 2,500 2,125 –
Existing Groundwater Well Capacity (Active) 6,000 5,100 Existing Groundwater Well Capacity (Inactive or Standby) 2,295 1,951 Existing Groundwater Well Capacity
(Inactive or Standby and Candidate for Rehabilitation) 0 0 (a) Status and pump capacities were updated based on ‘Well Rehabilitation List v2025.xlsx’, provided by the City in March 2025. (b) Parcel sizes assumed based on County of San Joaquin District Viewer, accessed on July 31, 2025. (c) Consistent with assumptions in the WMP, firm active well capacity is 85 percent of the active well capacity. (d) Wells selected for rehabilitation based on age (less than 40 years old) and parcel size (at least 0.5 acres).

SUPPLY CAPACITY EVALUATION
The 2021 WMP evaluated total supply capacity based on a combination of surface water and groundwater sources. For this evaluation, only groundwater supplies were considered to determine the additional capacity needed to meet system demands during a complete loss of surface water supplies. The analysis was performed for both the near-term (2030) and buildout (2040) demand conditions to identify the well rehabilitations and new wells required to maintain reliable service.

Consistent with City planning criteria, firm groundwater capacity was assumed to be 85 percent of total active well capacity. For inactive or standby wells, firm capacity was also assumed to be 85 percent of their rated capacity, if reactivated. New wells were assumed to have a design capacity of 1,800 gallons per minute (gpm) and a firm capacity of 1,500 gpm.

These assumptions were applied to both demand scenarios to estimate total firm groundwater capacity and to identify capacity deficits under each condition. The results are summarized in the following sections.

Near-Term Water Supply Redundancy Evaluation
Table 4 summarizes the results of City’s ability to meet maximum day demands, with current groundwater facilities under near-term demand conditions. As shown, the existing firm well capacity is approximately

22.4 mgd in North Stockton and 7.3 mgd in South Stockton, compared to maximum day demands of

38.1 mgd and 14.9 mgd, respectively. This results in capacity deficits of 15.7 mgd in North Stockton and

7.6 mgd in South Stockton.

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To address these deficits, the following improvements are recommended:
• North Stockton
— Rehabilitate Well 30 with treatment to restore capacity. — Construct seven new wells to provide additional groundwater supply capacity. • South Stockton
— Construct four new wells, likely with treatment.

These improvements would increase firm capacity by approximately 17.8 mgd in North Stockton and

8.6 mgd in South Stockton, resulting in surpluses of 2.1 mgd and 1.1 mgd, respectively.

Table 4. Near-Term Supply Capacity Evaluation
Component North Stockton, mgd South Stockton, mgd
Existing Firm Surface Water
Treatment Plant Capacity 0.0 0.0
Existing Firm Well Capacity 22.4 7.3
Near-Term (2030)
Maximum Day Demand 38.1 14.9
Supply Surplus (Deficit) (15.7) (7.6)
Additional Firm Capacity from
Recommended Rehabilitated Wells

2.7 (1 well, Well 30)
No rehabilitation candidates
Additional Firm Capacity from
Recommended New Wells

15.1 (7 wells)

8.6 (4 wells with treatment)
Revised Supply Surplus (Deficit) 2.1 1.1
Buildout Water Supply Redundancy Evaluation
Table 5 summarizes the results of the City’s ability to meet maximum day demands under buildout (2040) conditions using groundwater-only. The analysis excludes demands associated with the Mariposa Lakes development, which is outside the City’s service area. As shown in the table, the firm groundwater capacity remains approximately 22.4 mgd in North Stockton and 7.3 mgd in South Stockton, while maximum day demands increase to 48.9 mgd and 19.6 mgd, respectively. This results in deficits of

26.5 mgd in North Stockton and 12.3 mgd in South Stockton.

To address these deficits, the following additional improvements are recommended, assuming the existing-condition improvements are completed:
• North Stockton
— Construct five additional new wells to provide increased capacity for buildout demands. • South Stockton
— Construct two additional new wells with treatment to provide additional firm capacity.

These improvements would increase firm capacity by approximately 25.9 mgd in North Stockton and

13.0 mgd in South Stockton, resulting in surpluses of 2.1 mgd and 0.7 mgd, respectively.

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Table 5. Buildout Supply Capacity Evaluation
Component North Stockton, mgd South Stockton, mgd
Buildout Firm Water Treatment
Plant Capacity 0.0 0.0
Buildout Firm Well Capacity 22.4 7.3
Buildout Maximum Day Demand 48.9 19.6
Supply Surplus (Deficit) (26.5) (12.3)
Additional Firm Capacity from
Recommended Rehabilitated Wells

2.7 (1 well, Well 30)
No rehabilitation candidates
Additional Firm Capacity from
Recommended New Wells

25.9 (12 wells)

13.0 (6 wells with treatment)
Revised Supply Surplus (Deficit) 2.1 0.7
Summary of Improvements
The recommended groundwater improvements for near-term (2030) and buildout (2040) conditions are summarized in Table 6. The program includes well rehabilitation, new well construction, and treatment upgrades required to provide sufficient firm groundwater capacity under groundwater-only conditions.

These improvements collectively increase the City’s firm groundwater capacity in both service areas, ensuring that maximum day demands can be met under near-term (2030) and buildout (2040) conditions.

Table 6. Summary of Groundwater Well Improvements
Timeframe North Stockton South Stockton
Near-Term (2030)
• 1 well rehabilitation (Well 30)
• 7 new wells
• 12,370 gpm of additional firm capacity
• No rehabilitation candidates
• 4 new wells
• 6,000 gpm of additional firm capacity
Buildout (2040) • 5 additional wells
• 7,500 gpm of additional firm capacity
• 2 additional wells
• 3,000 gpm of additional firm capacity
Total
• 1 well rehabilitation (Well 30)
• 12 new wells
• 19,870 gpm of additional firm capacity
• 6 new wells
• 9,000 gpm of additional firm capacity
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Sensitivity Evaluation
The analysis described above assumes no surface water availability to represent the most conservative condition and ensure reliable service during critical events. This evaluation also considered scenarios where partial surface water supplies from the SEWD and the DWTP could remain available. These conditions were reviewed to provide the City with planning bookends that could be considered if some amount of surface water was assumed to be available. Two sensitivity scenarios were evaluated:
• 25 percent scenario: Assumes 25 percent of DWTP capacity (7.5 mgd) and 25 percent of SEWD’s available capacity (70 percent of demand), or 3.7 mgd under near-term and buildout conditions.
• 33 percent scenario: Assumes 33 percent of DWTP capacity (10 mgd) and 33 percent of SEWD’s available capacity, or 5.0 mgd under near-term and buildout conditions.

Table 7 summarizes the reduced well requirements under these partial surface water availability conditions. The corresponding cost impacts are discussed in the Capital Cost Estimates section.

Table 7. Summary of Groundwater Well Improvements under Sensitivity Scenarios Timeframe North Stockton South Stockton
25 Percent Available Scenario
Near-Term (2030)
• 1 well rehabilitation (Well 30)
• 3 new wells
• 6,400 gpm of additional firm capacity
• No rehabilitation candidates
• 2 new wells (with treatment)
• 3,000 gpm of additional firm capacity
Buildout (2040) • 5 additional new wells
• 7,500 gpm of additional firm capacity
• 2 additional new wells (with treatment)
• 3,000 gpm of additional firm capacity
Total
• 1 rehabilitation (Well 30)
• 8 new wells
• 13,900 gpm of additional firm
capacity
• 4 new wells (with treatment) 6,000 gpm
of additional firm capacity
33 Percent Available Scenario
Near-Term (2030)
• 1 well rehabilitation (Well 30)
• 2 new wells
• 4,900 gpm of additional firm capacity
• No rehabilitation candidates
• 2 new wells (with treatment)
• 3,000 gpm of additional firm capacity
Buildout (2040)
• 5 additional new wells
• 7,500 gpm of additional firm capacity
• 2 additional new wells (with treatment)
• 3,000 gpm of additional firm capacity
Total
• 1 well rehabilitation (Well 30)
• 7 new wells
• 12,400 gpm of additional firm capacity
• 4 new wells (with treatment) 6,000 gpm
of additional firm capacity
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CAPITAL COST ESTIMATES
Opinions of probable capital costs were developed for the recommended groundwater improvements to provide the City with a planning-level estimate for budgeting for additional redundancy in the water supply system. These opinions reflect the cost of constructing, rehabilitating, and treating groundwater wells necessary to meet system demands under both near-term (2030) and buildout (2040) groundwater-only conditions.

The opinions of probable costs were prepared in accordance with AACE guidelines for a Class 5 estimate, appropriate for master planning and conceptual-level evaluations. Unit costs and contingency factors were based on the City’s Cost Estimating Assumptions presented in Appendix D of the 2021 WMP2 and escalated to April 2025 dollars using the Engineering News Record 20-City Construction Cost Index.3 Table 8 presents the total estimated capital costs under groundwater-only conditions, and Figure 1 illustrates how costs vary with different levels of surface water availability. The total cost to achieve complete groundwater redundancy is approximately $150 million through buildout, representing the most conservative planning condition. When 25 or 33 percent of surface water capacity remains available, total redundancy costs are reduced to approximately $101 million and $95 million, respectively. The difference between these two partial-supply scenarios is relatively small, indicating limited additional benefit from higher levels of available surface water. Achieving complete redundancy would require a significantly higher level of capital expenditure, approximately 50 percent greater than under the 25 or 33 percent availability conditions.

Table 8. Estimated Capital Cost of (Full Redundancy) Groundwater Improvements Assuming No Surface Water Supplies, million dollars(a)
Timeframe North Stockton South Stockton Total
Near-Term (2030) $52.2 $42.3 $94.5
Buildout (2040) $34.0 $21.2 $55.2
Total $86.2 $63.5 $149.7
(a) Unit costs based on April 2025 20-City Construction Cost Index for San Francisco (15,263). (b) Costs include contingency markups of 35 percent for construction and 45 percent for other project costs (engineering costs, construction management, and program implementation costs). (c) Estimated construction costs do not reflect an adjustment to account for the current economic bidding climate. 2 West Yost. January 2021. City of Stockton Water Master Plan Update, Appendix D. 3 The following unit cost assumptions were used: $6.80 million to install a new well without treatment; $4.54 million to rehabilitate an existing well; $3.78 million to add optional granular activated carbon (GAC) treatment to an existing well; and $10.58 million to install a new well with GAC treatment. Unit costs include contingency markups of 35 percent for construction and 45 percent for other project costs (engineering costs, construction management, and program implementation costs).

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Figure 1. Total Cost of Redundancy for Various Surface Water Availability (Curtailment) Scenarios

FINDINGS AND RECOMMENDATIONS
Findings and recommended improvements from this evaluation are summarized in Table 9 below. These conclusions are based on the supply capacity evaluations presented in Tables 4 and 5, the recommended improvements summarized in Table 6, and the opinions of probable capital costs presented in Table 8.

Together, these results define the groundwater improvements required for the City to achieve full redundancy under groundwater-only conditions.
• The total estimated cost for the recommended improvements is approximately $94.5 million under near-term conditions and an additional $55.2 million under buildout conditions. • As shown on Figure 1, the sensitivity evaluation indicates that partial surface water availability would reduce total cost. If the City has confidence that some surface water treatment capacity will remain available during emergency events, a lower level of investment could be considered. Under the 25 and 33 percent availability scenarios, total costs are reduced to approximately $101 million and $95 million, respectively. Although the difference between these two scenarios is small, achieving complete redundancy would require approximately 50 percent greater investment to ensure full reliability under a groundwater-only condition.

42.3 21.2 21.2

52.2 25.0 18.2

21.2 21.1

21.1 34.0

34.0 34.0
0 20
40 60
80 100
120
140
160
0% Available 25% Available 33% Available
Capital Cost (M$)
Surface Water Availability
South - Near Term North - Near Term
South - Revised Buildout North - Revised Buildout
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• Other Recommended Actions:
— Perform detailed condition assessments of existing wells prior to rehabilitation to evaluate structural integrity, equipment condition, and remaining useful life.

Assessment results should be used to determine whether rehabilitation is technically and economically feasible or if well replacement is warranted. — Conduct a well siting study to identify and secure parcels suitable for new groundwater production wells in both North Stockton and South Stockton. The study should evaluate site feasibility based on parcel size, available utilities, hydrogeologic conditions, proximity to existing infrastructure, and potential need for water treatment. — Coordinate with developers to ensure that land for future groundwater production wells and related infrastructure is identified and dedicated as part of the development entitlement process.
— Establish a phased implementation plan for well rehabilitation and new construction that prioritizes projects based on condition, remaining useful life, system benefit, and available funding.

Table 9. Summary of Recommended Improvements for Full Supply Redundancy Timeframe Service Area Recommended Improvements
Incremental
Increase in Firm
Capacity, mgd
Estimated Capital
Cost, million dollars
Near-Term
(2030)
North
• Rehabilitate Well 30 with
treatment
• Construct 7 new wells
(including Well 33)

17.8 52.2
South
• Construct 4 new wells with
treatment (including
Well SSS10)

8.6 42.3
Subtotal – Near-Term 26.4 $94.5
Buildout
(2040)
North • Construct 5 additional
new wells 8.1 34.0
South • Construct 2 additional new
wells with treatment 4.4 21.2
Subtotal – Buildout 12.5 $55.2
Total Estimated Capital Costs $149.7
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ATTACHMENT F: SEWD CONTRACT
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ATTACHMENT G: WID CONTRACT
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AGREEMENT FOR PURCHASE OF WATER FROM

WOODBRIDGE IRRIGATION DISTRICT BY THE CITY OF
This Agreement is made and entered into between Woodbridge Irrigation District and the City of Stockton, adjoining public entities located within the County of San Joaquin, State of Califomia,this '62a dayof ~ O f\ l.AO-.,f' '{ ,2008.

Background Recitals
a. The City of Stockton obtains a portion of its municipal water supply from wells located within the City, extracting the water from the underground aquifer, which is replenished in part by flows of the Mokelumne River. Stockton desires to acquire a supplemental surface water supply to offset current groundwater pumping as part of its overall conjunctive use program.
b. Because of substantial population growth and increasing water demands in the Stockton metropolitan area, the City is also developing its Delta Water Supply Project to divert surface water from the San Joaquin River, and has obtained Permit 21176 from the State to divert water for that Project. The City needs to supplement that surface water supply in the periods of each year when the diversion of water from that source is restricted by the terms of the City's Water Permit.
c. Woodbridge Irrigation District (District or WID) is an irrigation district that is organized and existing under Division 11 of the California Water Code (Sections 20500 et seq).

The District is located immediately west of the City of Lodi and immediately north of the City of Stockton. The District diverts water from the Mokelumne River at Woodbridge Dam, located in the NE 1/4 of the SE 1/4 of Section 34, Township 4 N, Range 6 E, MDBM, for irrigation of a net area of 19,370.3 acres within a gross area of 40,441.77 acres and that are located within Townships 2 N, 3 N, 4 N and 5 N, Ranges 5 E, 6 E and 7 E, MDBM. d. The District diverts its water supply from the Mokelumne River under pre-1914 appropriative rights for the diversion of water up to 300 cubic feet per second (cfs). The District's pre-1914 rights are overlapped by the District License No. 5945 for the appropriation of 300 cfs per annum from February 1 to October 31 for irrigation use, supplemented by License No. 8214 for the diversion of an additional 114.4 cfs from May 1 to August 31 of each year and from November 1 of each year to January 31 of the succeeding year. The combined rights under the two Licenses together with the District's pre-1914 rights are limited to a maximum diversion of 414.4 cfs.
e. The District, following the East Bay Municipal Utility District's (EBMUD) building of the Pardee and Camanche Reservoirs on the Upper Mokelumne River, entered into Agreements with EBMUD in 1938 after Pardee's completion and again in 1965 after the completion of Camanche, which acknowledged the priority of some of the District rights to the EBMUD rights, and under which agreements EBMUD releases a Regulated Base Supply of water each year from Camanche Reservoir for diversion by the District at Woodbridge Dam for irrigation use.
::ODMA \GRPWISE\COS.MU D.MUD _Li brary: 122607.1
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f. The District's demand for water from the Mokelumne River under its water rights has begun to diminish by reason of the District's water conservation programs, including the conversion of field funow and flood inigation methods of application to water applied by drip inigation and micro-sprinklers, which reduce the amount of applied water for crops. Reductions in the delivery of inigation water have also occuned and are continuing to occur by reason of the number of inigated acres being reduced as a result of urbanization of lands in the southern part of the District which are being annexed by the City of Stockton. g. By reason of the anticipated reductions in water usage within the District, the District has dete1mined that it will have surplus water in ce1iain amounts available under its water entitlements from the Mokelumne River, and the water that would be delivered to the City by this Agreement will be surplus to the needs of the landowners and water users within the District as required by Section 22259 of the Water Code. The District's conveyance facilities traverse the northerly portion of the City of Stockton, and the District could deliver water diverted from the Mokelumne River under its water rights to Stockton at a location along the District's canal system indicated in this Agreement.
h. The City of Stockton desires to contract with the District for the purchase of water from the District for use within the City service area, for which the City will pay on the basis and pursuant to the conditions hereinafter set forth.

NOW, THEREFORE, WOODBRIDGE IRRIGATION DISTRICT (DISTRICT) AND THE CITY OF STOCKTON (CITY) AGREE AS FOLLOWS:

1. Water to be Made Available to City and Payment. Beginning on January 1, 2009, and continuing through the te1m of this Agreement, the District shall make available to the City out of District's Regulated Base Supply, 6,500 acre-feet per annum under the terms and conditions herein set forth. In consideration thereof, the City will pay the District annually the sum of $200 per acre-foot for such water or $1,300,000 (ONE MILLION THREE HUNDRED THOUSAND DOLLARS) annually. Payments thereon of $325,000 (THREE HUNDRED TWENTY FIVE THOUSAND DOLLARS) quarterly are due and payable in advance beginning on the first day of each calendar quarter, commencing on January 2, 2009. Said payments shall be made i1Tespective of whether the City takes the water made available to it under this Agreement and inespective of whether the District has water available to it under this Agreement for delivery to the City, provided that the District shall make its best efforts to provide to the City the amounts of water provided for in this Agreement.

In lieu of delivering water in 2009, the quarterly payments made to the District in 2009 shall be used by the District for the improvements to be made by the District to the Wilkerson Canal as provided in paragraph 2 below, and any right of way costs that may be incuned, in order to deliver the water to the City. Any funds remaining after the completion of such capital improvements shall be refunded to the City.

After 2009, for each quarter-year payment made by the City prior to the completion and commencement of operation of the City's initial phase of the DWSP (not to exceed a total of ::ODM A \GRPWISE\COS.MUD.MUD _Library: 122607. 1
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eight calendar quaiiers), the City shall be entitled to one-fourth of its annual water entitlement that year (1,625 acre-feet) as a carryover credit, to be delivered thereafter at not to exceed a total of 2,000 acre-feet per year, to be provided in years when District has the additional water available to make such deliveries, as provided in paragraph 6.a. hereof.

2. Point of Delivery and Times and Amounts of Delivery. The District agrees to deliver the water to the City from the District's Wilkerson Lateral canal, at the northwest comer of the City's parcel located in the East ½ of the NE ¼ of Section 33, T 3 N, R 6 E, MDB&M (APN 059-030-02, formerly owned by Rodao ), as shown in Exhibit A attached hereto. The water will be delivered during the period from March 1 through July 31 of each year, at a uniform rate of delivery, 24 hours per day, throughout the month. The District shall make needed capacity improvements to the Wilkerson lateral, using therefore the proceeds of the payments by the City to the District during the initial year (2009) under the Agreement, as set forth in Section 1 above.

The improvements to be made and the schedule for the improvements shall be prepared by the District and shall be approved by the City. The cost of the improvements needed to the Wilkerson Lateral in order to deliver the water to the City shall be at the cost of the City.

The City shall construct at its sole cost and expense the facilities needed to measure and take delivery of water from the District Canal system at a mutually agreed-upon location at the above-described point of delivery, and the design, construction and operation thereof shall be approved by the District. The City will be responsible for all costs of operation, repair, maintenance and replacement of such facilities. The measurement facilities shall be recalibrated annually at the City's expense as requested by the District and the District shall have a continuing right to test the accuracy of such facilities. a. The City shall provide the District, as soon as possible after January 1 of each year, and in any event not later than February 15 of each year, an estimate of the amount of water anticipated to be needed by the City during each month of that year from March 1 through July 31, which scheduling will be subject to the District's approval. The District will supply such water on said approved monthly schedule pursuant to and as limited by the terms, conditions and limitations of this Agreement; provided that the City shall to the extent that its operations will permit, schedule the taking of as much of its entitlement to water from the District that year prior to July 1 as is feasible, but in any event not less than 3,000 acre feet. The delivery of 6,500 acrefeet of water will be made each year in approximately the following amounts each month. The parties may jointly agree to variations in the monthly delivery schedule amounts subject to the availability of water.

Estimated Deliveries
Month
March
April
May
June
July
Total (not to exceed)
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3 Amount (af)
1,000 ±
1,000 ±
3,000 ±
1,500±
1,000 ±
6,500
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Orders for water deliveries and changes thereto must be made upon a 72-hour notice placed in person or by phone with the District on any business day (Monday-Friday) and between the hours of 8 AM to 12 PM and 1 PM to 5 PM. No water orders to tum water on or off or change the rate of delivery shall be left with an answering machine or faxed to the District. Delivery of water shall be at a constant rate until changed by proper notice. b. At such times as it is possible for the District to deliver any of the 6,500 acre-feet of water to the City dming the period from August 1 to October 15, and also at such times as the District has additional water available and can deliver water in excess of 6,500 acre feet during the period from March 1 through October 15, then by mutual agreement of the parties, delivery of such water to the City may be made by the District. The City shall pay the District $100 per acre foot for any such additional water delivered to the City in excess of 6,500 acre-feet. c. The determination of whether any such water is available for delivery to the City shall be made solely by the District. In the event that both the City of Stockton and the City of Lodi under their respective Agreements request additional water during the same period(s) that additional water is available for delivery, the water shall be apportioned between them if necessary in the manner and times that they shall agree upon. In the event they do not agree, such water shall be apportioned between them by the District 50/50, i.e., one-half to Lodi and one-half to Stockton; provided that, if such apportionment would result in either party losing any deficiency curtailment water banked to the credit of that party because of non-use within the required eight-year period under Section 6.b., that party shall have a first right to such p01tion of the available water that will avoid such loss.
d. The water furnished by the District under this Agreement shall be used or furnished by the City only for domestic, municipal, industrial, irrigation and other beneficial uses. The City shall have no right to sell or transfer any of its entitlement to water from the District under the Agreement, permanently or on interim basis, or to use any of said water outside of the City, without the District's prior approval.
e. The District further agrees that it will, during the term of this Agreement at the City's request, divert from the Mokelumne River at the District's Woodbridge Dam and wheel and convey through the District's canal system to the City's delivery point any non-District water acquired by or available to the City, subject to the District having available capacity for that purpose and subject to the City paying a per-acre-foot charge in an amount which the District determines to be its costs for such service. The District's cost for such service in year 2007 would be $20 per acre-foot. There would be no wheeling charge for District water in the event the City purchases some of the District water that is under the purchase contract of the City of Lodi.
f. Commencing on January 1 of 2010, and on January 1 of each year thereafter, the amounts payable to the District under paragraph 1, and the amounts payable to the District under subparagraphs 2.b. and 2.e., shall be increased by two percent per year above the amounts payable during the preceding calendar year. In the event that the annual change in the Consumer Price Index (CPI-W, unadjusted U.S. average) published in December of each year by the United : ODMA\GRPWISE\COS.MUD.MUD_Library: 122607 .1
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States Bureau of Labor Statistics, commencing in December of the preceding year, has increased more than two (2) percent above the December Index of the prior year, the increases in the amounts payable in the ensuing year shall be in the percentage of that increase; provided that any such annual increase shall not exceed five percent (5%). g. The payments by the City to the District under this Agreement shall be deemed to include the payment during the term of the Agreement of all District groundwater recharge fees on parcels within the City of Stockton which are also located within the boundary of the District.

3. Term of Agreement and Right to Purchase Additional Water. a. This Agreement shall be effective from the date of execution hereof, and shall remain in effect for a term of forty ( 40) years from said date. b. Upon receipt by the District of written notice and request for renewal from the City at least two years in advance of the termination of the Agreement, the District agrees to negotiate with the City for a renewal of this Agreement for an additional forty (40) year term, on terms and conditions that are reasonable and equitable and which are satisfactory to the District. c. Right to Purchase Additional Water. The City shall have the further right during the initial term of this Agreement to buy up to an additional 6,500 acre-feet of water from the District based upon the annexation of additional lands within the District to the City of Stockton after the completion and commencement of operation of the initial phase of the City's Delta Water Treatment Plant, and which as a result of such annexation will be taken out of agricultural production, as follows. For each acre of land so annexed after such date which is now zoned agricultural and which has been irrigated with District water:
• and for which a tentative subdivision map is approved for such acreage for use other than agriculture,
• and which is to be served a water supply by the utility water system now serving lands within City of Stockton,
the City will be entitled to purchase an additional 3.0 acre-feet of water per such acre from the District, on the same terms and subject to the same conditions herein applicable to the 6,500 acre-feet under this Agreement.

4. City Payments to be Made from City's Water System Revenues. The City shall make payments under this Agreement solely from the Revenues of the Stockton Municipal Water System. The City hereby pledges the Revenues to the payments required hereunder. Nothing herein shall be construed as prohibiting the City from using any other funds and revenues for purposes of satisfying any provisions of this Agreement. So long as the City is in compliance with all of it obligations hereunder, such pledge shall not prevent its application of Revenues to other operating expenses of the Stockton Municipal Water System or, subject to the payment of such operating expenses, to other lawful purposes, or impair the rights of any recipient of Revenues lawfully so applied. District agrees that it will subordinate the pledge of Revenues hereunder to any bond or bonds issued for the purpose of financing capital improvements to the ::ODMA \GRPWISE\COS.MUD.MUD _Library: 122607. I
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City's Municipal Water System for a period not to exceed three years from the effective date of this Agreement.
"Revenues" means "all gross income and revenue received or receivable by the City from the ownership and operation of the Stockton Municipal Water System, which gross income and revenue shall be calculated in accordance with generally accepted accounting principles, including all rates, fees, and charges received by the City for water service and connection and hook-up fees and all other income and revenue howsoever derived by the City from the ownership and operation of or arising from the Stockton Municipal Water System, but excluding in all cases any proceeds or taxes and any refundable deposits made to establish credit, federal or state grants, or advances or cont1ibutions in aid of construction." "Stockton Municipal Water System" means "the municipal water system of the City existing on the effective date of this Agreement and all additions, betterments, extensions and improvements thereto hereafter acquired or constructed."

5. No Pe1manent Water Right, and Dry Year Curtailments. The District has determined that the water to be made available annually for delivery to the District pursuant to this Agreement will be surplus to the needs of the District during the term of this Agreement. The parties further agree that no permanent right to the water supplied by the District shall accrue to the City except pursuant to and as limited by the terms of this Agreement. a. The District agrees that it will deliver up to 6,500 acre-feet per annum to the City under this Agreement except in years when forecasted runoffs in the Mokelumne Watershed by DWR and EBMUD, beginning with the February 1 forecast by DWR and EBMUD indicates that the inflow to Pardee Reservoir as of July 1 may be less than a total quantity of 375,000 acre-feet (in which case the District's Regulated Base Supply of 60,000 acre feet under its Agreements with East Bay Municipal Utility District is reduced by thirty-five percent (35%)). In such years, the District may reduce the amount of water to be provided under this Agreement by up to fifty percent (50%), as follows. Beginning in March and in each ensuing month through July when the forecasts in those months continue to indicate that the July 1 inflow may be less than 375,000 acre-feet, the District may reduce the amount of water to be provided during those months under paragraph 2.a. by up to fifty percent (50%). In the event that any ensuing monthly forecast indicates that the estimated July 1 inflow will not be less than 375,000 acre-feet, City will be entitled to have the amount of its delivery under paragraph 2.a. for that month. The remainder of any undelivered amount under paragraph 2.a., by reason of the curtailments for that year shall be included as makeup deficiency water under paragraph 6.a. unless it was delivered later in that deficiency year. There shall be no reduction in the amount of the City's annual payment to the District in such years under paragraph 1.
b. The City shall have no claim for damages for breach arising from the unavailability of water from the District or for the District's inability to deliver water to the City due to failure of faci lities, intervening acts, or actions of any state or federal agency exercising jurisdiction or claiming an interest and/or right to reduce or modify operations and quantities of water otherwise available to District, and any legal action, legislation, ruling or determination adverse to the ::ODMA\GRPWISE\COS.MUD.MUD_Library: 122607. I
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District affecting the agreement and beyond the reasonable control of the District. District shall make good faith efforts to vigorously oppose such reductions.

6. Can-yover of Entitlements. Unused water may not be carried over by the City from year to year except that the right to receive water may be "banked" for later use, as follows:
a. For each calendar quarter beginning January 1, 2010 in which payments to District are made under paragraph 1 of this Agreement but in which the City is unable to take water deliveries under the Agreement because the commencement of operations of the initial phase of the City's DWSP has not begun, the City may carry over and have credit for one-fourth of its annual water entitlement, not to exceed a total of 13,000 acre-feet. The District will make this water available for later delivery during the initial 40-year term of this Agreement, not to exceed 2,000 acre-feet per year, at such times as the District has extra water available as determined solely by the District. There will be no additional charge for the delivery of such banked water. b. If delivery of water to the City is curtailed by District's maintenance or other District activities or by reason of a dry year condition as provided in paragraph 5.a. and is not used later in that year, then the City may carry over and have credit for the amount of such curtailment for later delivery at such time(s) as the District has extra water available as determined solely by the District. Any City credits for curtailed segments of carryover water shall expire at the end of eight (8) years from the end of the period in which the curtailment for the segment of curtailed water occun-ed. Such credits for the delivery of curtailed carryover water which accrue less than eight years immediately preceding the termination date of this Agreement, may extend beyond the termination of this Agreement and be utilized within eight years from the year of their accrual at such time(s) as the District has extra water available as dete1mined solely by the District. There will be no additional charge for the delivery of such banked water. c. The detennination of whether any such banked water or curtailment water is available for delivery shall be made solely by the District, and shall be taken by the City in the years that the District detem1ines that it is available, at the times and in the amounts determined by the District after consulting with the City on the times and amounts that is most convenient to the City.
d. In the event that both the City of Stockton and the City of Lodi request water banked to their respective credits during the same period(s) that the water is available for delivery, the water shall be apportioned between them if necessary in the manner and times that they shall agree upon. In the event they do not agree, the available water shall be apportioned between them 50/50 by the District, or one-half to each; provided that, if such apportionment would result in either party losing any deficiency curtailment water banked to the credit of that party because of non-use within the required eight-year period under Section 6.b above, that party shall have a first right to such portion of the available water that will avoid such loss. e. Except as provided in subparagraph a, no credits shall accrue for water that 1s available to but is unused by the City.
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7. Water Quality, Temporary Interruptions, and Responsibility for the Water Beyond Point of Delivery.
a. The water being supplied to the City is raw water diverted from the Mokelurnne River, and the character or quality of the water furnished hereunder may vary from time to time.

District does not guarantee in any respect the character or quality of the water furnished pursuant to this Agreement, provided that the District shall not apply or use any chemicals within the Canal section used to deliver water to the City that the City determines to be deleterious to the quality of the water for the uses made by the City of such water. b. It is agreed that there may be, in addition to shortages of water, temporary discontinuance or reduction of water to be furnished for the City as herein provided, for purposes of investigation, inspection, maintenance, repair or replacement as may be necessary of any of the facilities used by the District for furnishing water to the City. The District agrees to provide the City notice of such temporary discontinuance or reduction of water as soon as such information is available to the District.
c. The City shall hold the District harmless from and defend the District from all claims or expenses on account of damage or claim of damage of any nature whatsoever from which there is legal responsibility, including property damage, personal injury or death, arising out of or connected with the delivery, control, carriage, handing, use, or disposal or distribution of water furnished hereunder beyond the point of delivery of water into the City's system from the District's Canal System.

8. Arrearage in Payments. No water shall be furnished to the City during any period in which the City may be in aiTears in payment of charges accruing hereunder after the determination on the amount thereof as above provided. Interest on arrearage in payment shall be charges at a rate of 1-1/2% per month and compounded monthly, commencing 45 days after the due date of the payment.

9. Assignment. The provisions of this contract shall apply to and bind the successors and assigns of the respective paiiies hereto; but no assignn1ent or transfer of this contract or any part thereof or interest therein by the City shall be valid unless and until approved in writing by the District; and no assignn1ent of the obligation to provide or deliver the water shall be assignable by the District without the consent of the City.

10. CEOA and Validation of Agreement.
a. The parties agree that the District will be Lead Agency for purposes of compliance with any requirements of the California Environmental Quality Act pertaining to the execution of this Agreement by each party. District and City acknowledge and agree that the obligations of the parties under this Agreement are conditioned on District and City completing, proceedings under CEQA in connection with the Agreement and the expiration of the applicable period for any challenge to the adequacy of District's and City's compliance with CEQA without any challenge being filed. District and City shall select a qualified environmental consultant acceptable to both to prepare the underlying documentation for District's review and ::ODMA \GRPWISE\COS.M UD.M UD _Library: 122607. I
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consideration as may be required by CEQA and applicable law. City shall direct the qualified environmental consultant and both City and the environmental consultant shall coordinate the preparation of the environmental analysis with District to ensure an adequate and complete consideration of potential environmental impacts. Any documentation submitted by City shall be sufficient for District to make a fair decision in accordance with applicable law. Neither party shall be bound hereby unless and until District's compliance with CEQA is completed and there is no possibility of a challenge pursuant to CEQA. The obligations of each party shall be conditioned upon the result of CEQA compliance not imposing any obligations or conditions upon that party's performance that are unacceptable to that party. District and City acknowledge that any modifications to the proposed project resulting from District's compliance with CEQA may necessitate amendments to this Agreement in a mutually acceptable manner. b. A validation action may be brought to determine the validity of this agreement pursuant to Section 22670 of the Water Code and Sections 860 et seq of the Code of Civil Procedure, within the 60-day time limit of Section 860. In the event any such action is brought, then the agreement and the parties' obligations hereunder shall be conditioned upon the entry of a judgment affirming the validity of the agreement. In the event the validation judgment contains conditions or restrictions which impose upon either party costs, requirements, obligations or limitations in their perfomrnnce of the agreement or upon their operations or property interests which were not reasonably anticipated by that party as a consequence of this Agreement and which are in that party's judgment unacceptable or otherwise not in the best interests of that party, that party shall have the right to terminate this Agreement, and in that event neither paiiy shall have any further liability or obligation to the other party hereunder.

11. Fees and Costs. Any fees, costs or expenses, including attorney fees, administrative costs, and consultant fees, incurred by the District to effect the sale of water to the City, together with CEQA and any other regulatory approval, shall be paid by District and City on a 50/50 basis. The City shall not be required to contribute to any fees or costs incurred by District relating to other issues or disputes that may arise in any of said proceedings not directly relating to City's use of District water. District shall provide to City invoices and accountings of said fees and expenses on a quarterly basis.

12. City Use of District Rights of Way. The District agrees to cooperate with City and to agree to the City's use of any District right of way along the District's Canal System needed by the City for the conveyance or distribution of water it obtains from the District. Nothing herein wainnts or guarantees that the District has the ability or authority to allow such use under its interest in its rights of way.

13. Entire Agreement. This Agreement contains the full and entire Agreement of the parties and there are no other conditions, either explicit or implied, nor any warranties or promises other than those contained within the written terms of this Agreement.

14. Time of the Essence. Time is of the essence in the performance of this Agreement.

15. Nonwaiver. The failure of either party to enforce or abide by a term or condition of this Agreement shall not constitute a waiver of that term or condition unless a written Agreement ::ODMA \GRPWISE\COS.MUD.MUD _Library: 122607. 1
9 EXHIBIT 1
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is prepared specifically providing for the waiver or forgiveness of that term and such Agreement is executed by each party hereto.

16. Date of Execution. The date of execution of this Agreement is the date of execution by the party last signing the Agreement. City shall execute this Agreement within sixty (60) days after its approval for execution by the District, and upon City's failure to do so, District shall not be obligated to enter into this Agreement.

17. Lodi's Prior Rights. City acknowledges that District has an existing Agreement with the City of Lodi dated May 13, 2003, to sell 6,000 acre-feet of water per annum to Lodi, and the City acknowledges the receipt of said Agreement, as amended on j A-!'J 1,\/~Y I 1g ) ),(,O~ . City further acknowledges that by reason thereof, this Agreement to sell such water to the City of Stockton and the providing of water to Stockton hereunder is subordinate to the District's obligations to deliver such amount of water to Lodi under the Lodi Agreement as set forth in Section 4( c) of the Lodi Agreement, as amended. The District has offered the additional 6,500 acre-feet of water to be sold to Stockton, and Lodi has declined to exercise its right of first refusal to purchase the additional water.

IN WITNESS WHEREOF, the parties hereto have executed this instrument on the 22- day of ;.\,t,.- J VML-".'.\ , 2008.

Attest:
c:a.4&~
Andrus Christensen, Secretary
, City Attorney
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10 WOODBRIDGE IRRIGATION DISTRICT
By~ ~ ~ = ~ ~ ~ ---· _
William Stokes, President

CITY OF STOCKTON, A MUNICIPAL

CORPORATION
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ATTACHMENT H: SMC CHAPTERS 13.28 AND 13.32
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CHAPTER 13.28

WATER CONSERVATION
§ 13.28.010. Definitions.

Unless the context requires otherwise, the following definitions shall be used in the interpretation and construction of this chapter. Words used in the present tense include the future; the singular number includes the plural and the plural the singular. "Alternate water source" means water from sloughs, canals, streams, rivers or nonpotable wells which is acquired with permission from the responsible owner or agency with jurisdiction.
"Director" means the Director of Municipal Utilities of the City. "Person" means any individual, firm, organization, partnership, association, trust, company, business, corporation, public entity, political entity, or any agent thereof. "Reclaimed" and "reclaimed water" refer to the process of reusing the soap/water solution and to that portion of the soap/water solution which is recaptured, processed, and reused at a non-self service commercial car wash facility. "Recycled water" means water from the City of Stockton Regional Wastewater Control Facility supplied from designated hydrants under permit from the State Regional Water Quality Control Board.
"Waste" means any inefficient or unreasonable use of or unreasonable method of use of water.
"Water" means any water used in the City.
(Prior code § 9-710)
§ 13.28.020. Application of regulations.

The provisions of this chapter shall apply to all persons using water in the City regardless of whether any person using water shall have a contract for water service with the City. Notwithstanding other provisions of this code inconsistent with the chapter, the provisions of this chapter shall supersede and prevail until termination of this chapter, except during a declared water shortage emergency, Stage 2, 3, 4, 5 or 6, in which event the provisions of Chapter 13.32 shall prevail.
(Prior code § 9-711; Ord. 2022-07-12-1503 C.S. § 2)
§ 13.28.030. Regulations.

A. It is unlawful for any person to use, permit or allow the use of water in any of the following manners:

1. Hosing off sidewalks, driveways, and other hardscapes;

2. Washing automobiles or boats with hoses not equipped with a shut-off nozzle;

3. Using non-recirculated water in a fountain or other decorative water feature; City of Stockton, CA
§ 13.28.010 § 13.28.030
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4. Watering lawns in a manner that causes runoff, or within 48 hours after measurable precipitation; and

5. Irrigating ornamental turf on public street medians.

B. It is unlawful during the period May 1st to November 1st of each year for any person to use, permit or allow the use of water in any of the following manners:

1. Any use of potable water from any fire hydrant is prohibited except by regularly constituted fire protection agencies for fire suppression purposes or by the responsible water agency, when alternate water sources or reclaimed water sources are available. In the absence of alternate water sources or recycled water sources, potable water from any fire hydrant may be used provided a permit for such use is approved by the Fire Department and the responsible water agency.

2. For exterior irrigation, including, but not limited to, public, private, and commercial locations, except as follows:
a. Irrigation shall be prohibited between the hours of 11:00 a.m. to 6:00 p.m. b. To conduct exterior irrigation in such a manner or extent that allows water to run off or escape from the premises or to be wasted. c. Exceptions to the above regulations:
i. Drip and/or mist irrigation systems.
ii. During the initial 21-day period of establishment for new plantings the above regulations shall not apply.
iii. Other uses which cannot reasonably comply with the above regulations due to the large size, normal hours of use or type of use of the area to be irrigated may be excepted upon approval by the Director of a water conservation plan which meets the goals of reduction and conservation.

3. To allow the escape of water through leaks, breaks, or malfunction within the water user's plumbing or distribution system for any period of time within which such break or leak should reasonably have been discovered and corrected. It shall be presumed that a period of 24 hours after the water user discovers such break, leak, or malfunction, or receives notice from the City, any water provider or enforcement authority of such condition, whichever occurs first, is a reasonable time within which to correct such condition or to make arrangements for correction.

4. The operation of any non-self service commercial car wash unless the soap/ water solution for such use is reclaimed. If a reclaimed water system cannot be installed, the car wash operator shall submit a plan satisfactory to the Director to modify operation of the facility to reduce its usage of water by at least 20 percent of its usage during the same month of the prior year for comparable City of Stockton, CA
§ 13.28.030 § 13.28.030
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(Prior code § 9-712; Ord. 2017-08-22-1403 C.S. § 2)
§ 13.28.035. Water conservation—Exterior irrigation.

Notwithstanding any other provision of this code, exterior irrigation shall be limited as follows:
business volume. If there is no history of prior use, the operator shall provide to the Director data comparable to such history to establish its base monthly usage.

5. Restaurants shall serve water to customers only upon request.

6. Use of water for cleaning building or mobilehome exteriors shall be prohibited except as follows:
a. With the use of a bucket and sponge; or
b. For the preparation of such exterior surfaces for the purpose of repair or repainting with the use of a pressurized washing device equipped with a quick acting positive shut off.

7. Use of potable water for dust control purposes except for public health or safety purposes. Reclaimed, recycled or other nonpotable water may be used for such purposes so long as such water is not wasted.

8. The indiscriminate running of water or washing with water not otherwise prohibited above which is wasteful and without reasonable purpose.

9. Exception. The above regulations shall not apply to users or uses when the source of water is other than:
a. A public water system as defined in California Code of Regulations Section 64555(a)(23); or
b. A groundwater aquifer used by a public water system.

C. The draining and/or refilling of all existing swimming pools, whether public, private or commercial, shall be prohibited between June 1st and October 1st except for protection of public health and safety.

A. For landscape irrigation, the following schedule shall be enforced to promote water conservation:

1. For even numbered addresses, exterior irrigation is permitted only on Wednesday and Sunday.

2. For odd numbered addresses, exterior irrigation is permitted only on Tuesday and Saturday.

3. For parcels that do not have a street address, exterior irrigation is permitted only on Wednesday and Sunday.

City of Stockton, CA
§ 13.28.030 § 13.28.035
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(Ord. 2022-07-12-1503 C.S. § 3)
§ 13.28.040. Regulations.

During the period of November 1st through April 30th, it is unlawful for any person to use, permit, or allow the use of water as set out in Section 13.28.030 except that no restriction as to the hours of irrigation shall be imposed. (Prior code § 9-712.1)
§ 13.28.050. Water rates and surcharges.
(Prior code § 9-713)

4. No exterior irrigation is permitted on Monday, Thursday, or Friday.

5. Exterior irrigation shall be prohibited between the hours of 8:00 a.m. to 6:00 p.m.

B. To prevent the unreasonable use of water and to promote water conservation, the use of potable water is prohibited for the irrigation of non-functional turf at commercial, industrial, and institutional sites. The use of water is not prohibited by this section to the extent necessary to ensure the health of trees and other perennial non-turf plantings or to the extent necessary to address an immediate health and safety need. Non-functional turf means turf that is solely ornamental and not regularly used for human recreational purposes or for civic or community events.

Non-functional turf does not include sports fields and turf that is regularly used for human recreational purposes or for civic or community events.

A. Whenever the City becomes aware of a person violating, causing or permitting a violation of the provisions of this chapter, a written notice stating the nature of the violation shall be delivered to the person at the premises by personal service or by first class mail and by posting in a conspicuous location at said premises. A copy of the notice shall be mailed to the person who is regularly billed for use of water at said premises.

B. All notices provided for by this section may be served as an addendum to the regular water service bill. All such notices may be given to any other person known to the City who is responsible for the violation or the correction thereof.

C. The notice shall describe the nature of the violation and order that said violation be corrected, cured or abated immediately or within such specified period as the City believes is reasonable under the circumstances.

D. Upon occurrence of a second violation or failure to immediately correct, cure or abate a violation, a second notice shall be served, as provided above, ordering the immediate correction, cure or abatement of the violation and imposing a surcharge of $100.00 per day for each day the violation continues. The surcharge may be added to the next regular billing for water service.

City of Stockton, CA
§ 13.28.035 § 13.28.060
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§ 13.28.060. Discontinuance of service.

Upon a determination by the Director that a person has consumed water in violation of any of the provisions of this chapter, the Director may issue an order to cease and desist from such violation, and further order such person to comply forthwith with such provisions or otherwise to take appropriate remedial or preventive action. If, after the issuance of a cease and desist order, such person continues to consume or use, or again consumes or uses water in violation of any such provisions, the Director may, subject to the provisions for notification and hearing hereafter set forth, discontinue water service to the premises of such person.
(Prior code § 9-714)
§ 13.28.070. Procedure for discontinuance of service.

Prior to the discontinuance of water service to any premises, the Director shall give written notice of intention to discontinue such service, and of hearing to be held by the Director upon the question of termination, not less than 10 days prior to such hearing. A person determined to be in violation of the provisions of this chapter, the owner of the premises (if not such person), and such other persons as the Director may deem appropriate, shall be heard at the hearing on the question of termination. If, upon completion of the hearing, the Director finds that no violation has occurred, the Director shall order that the service shall not be terminated. If, upon completion of the hearing, the Director determines that such violation has occurred, or is occurring, the Director may order the water service to be terminated, or may order that service be terminated within a specified period of time unless such violation or the conditions or activities causing such violations cease forthwith or within a specified period of time, or the Director may make such other order as deemed appropriate under the circumstances and in furtherance of the purposes and intent of this chapter. (Prior code § 9-714.1)
§ 13.28.080. Appeal.

Any person aggrieved by a determination, order, or directive of the Director made pursuant to the provisions of Sections 13.28.060 and 13.28.070 may appeal such determination, order, or directive to the City Manager. Written notification of such appeal shall be filed with the City Clerk within 10 days after notification of the determination, order, or directive of the Director, and shall set forth in detail the facts and reasons supporting the appeal. Hearing on the appeal shall be held by the City Manager or the designee within 10 days from the date of filing the notice of appeal. The appellant, the Director, and such other persons as the City Manager or the City Manager's designee may deem appropriate, shall be heard at the hearing on appeal. Upon conclusion of hearing the appeal, the City Manager or the designee may affirm, reverse or modify the determination, order or directive of the Director as deemed just and equitable, and in furtherance of the provisions, purposes, and intent of this chapter. During the pendency of any such appeal, the determination, order or directive of the Director shall remain in full force and effect. The City Manager's or the designee's action on the appeal shall be final.
(Prior code § 9-715)
City of Stockton, CA
§ 13.28.060 § 13.28.090
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§ 13.28.090. Violation an infraction.

Any person violating any of the provisions of this chapter shall be deemed guilty of an infraction. Each day such violation is committed or permitted to continue shall constitute a separate offense and shall be punishable as such. Said violation shall be in addition to the surcharges and disconnection procedure established hereinabove. (Prior code § 9-716)
§ 13.28.100. Powers and duties of the Director.

The Director of Municipal Utilities is hereby authorized to and may enforce all the provisions of this chapter. For such purposes, the Director shall have the powers and discretion of a law enforcement officer. The Director, and duly delegated representatives, pursuant to the provisions of Section 836.5 of the Penal Code of the State of California, are hereby authorized to arrest a person without a warrant whenever there exists reasonable cause to believe the person has in his or her presence violated any provision of this chapter which is an infraction. Upon making such arrest, the Director or the delegated representative shall prepare a citation and release the person arrested pursuant to Section 853.6 of the Penal Code of the State of California. The provisions of Sections 836.5 and 853.6 of the Penal Code are hereby adopted by reference as part of this section.
(Prior code § 9-717)
§ 13.28.110. Remedies cumulative.

The remedies and penalties provided for in this chapter shall be cumulative and shall be in addition to any or all other remedies available to the City. (Prior code § 9-719)
City of Stockton, CA
§ 13.28.090 § 13.28.110
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CHAPTER 13.32

WATER SHORTAGE EMERGENCIES
§ 13.32.010. Purpose and scope.

This chapter adopts regulations to deal with water shortage emergency conditions which exist within the City and the City's water service areas, as declared by resolution of this City Council. These regulations shall become effective with the effective date of the ordinance codified in this chapter. A water shortage emergency declaration shall be in effect upon proper findings made by the City Council after a public hearing and shall remain in effect until the City Council finds and declares by resolution that the water shortage emergency condition has abated, has changed in degree or no longer exists. (Prior code § 9-730)
§ 13.32.020. Findings.

The City Council finds, determines, and declares that the following shall occur prior to enforcement of the provisions of this chapter:
(Prior code § 9-731)
A. The City Council shall conduct duly noticed public hearings for the purpose of determining whether a water shortage emergency condition exists and, if so, the degree of the emergency and what regulations and restrictions should be enforced in response to the shortage.

B. The City Council shall adopt a resolution which declares that a water shortage emergency condition exists, the facts and conclusions which support such a declaration and that the ordinary water demands and requirements of water consumers within the City cannot be satisfied.

C. The regulations set forth herein are necessary and proper to protect and conserve the water supply for human consumption, sanitation, and fire protection during the duration of the water shortage emergency condition.

D. The regulations set forth herein shall remain enforceable to the extent declared by the City Council and until such time as the City Council finds that the water shortage emergency no longer exists.

E. During the existence of a declared water shortage emergency, the provisions of this chapter shall take precedence over the provisions of the City's Water Conservation Ordinance, Stockton Municipal Code Chapter 13.28, as now enacted or hereafter amended. The provisions of the Water Conservation Ordinance shall continue in effect except where provisions of this chapter are different. Within areas of the City where water service is provided by any other water provider, the provisions of this chapter as to prohibited uses and waste shall be applicable. The Water Conservation Ordinance shall remain in effect except where more stringent requirements are set out herein.

City of Stockton, CA
§ 13.32.010 § 13.32.030
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§ 13.32.030. Definitions.

The following terms are defined for the purposes of this chapter:
"Allocation" means the calculated percentage of the amount of water delivered to each customer's property during the corresponding monthly billing period of the base year for which no penalty or surplus use charge shall be imposed. "Applicant" means a person, firm, partnership, business, corporation, district or governmental agency that requests or receives water service from the City. "Base year" means the calendar year of 1987 or any other period established by resolution of the City Council.
"Customer" means any person, firm, partnership, business, corporation, district, or governmental agency that receives water from the City ("City") Water Utility. "Director" means the Director of the Municipal Utilities Department of the City. "Process water" means water used to manufacture, alter, convert, clean, grow, heat or cool a product, including water used in laundries and car wash facilities. "Water" means water used in or supplied by the City.
(Prior code § 9-732)
§ 13.32.040. Additional limits on water use available to all water users.

During Stage 2, 3, 4, 5 and 6 emergencies, the following wasteful uses shall be prohibited in addition to the prohibitions and limitations stated in the Water Conservation Ordinance, Stockton Municipal Code Chapter 13.28. In the event the provisions of the section are inconsistent with the Water Conservation Ordinance, this section shall prevail.

A. Any use of potable water from any fire hydrant is prohibited, except by regularly constituted fire protection agencies for fire suppression purposes or by the responsible water agency, when alternate water sources or recycled water sources are available. In the absence of alternate water sources or reclaimed water sources, use of potable water from a hydrant may be used provided a permit for such use is approved by the Fire Department and the responsible water agency.

B. Use of potable water for dust control purposes except for public health or safety purposes. Reclaimed, recycled or other nonpotable water may be used for such purposes so long as such water is not wasted.

C. Irrigation of exterior landscaping, turf areas, open ground, crops, trees, grass, lawn, groundcover, shrubbery, or decorative plantings between the hours of 8:00 a.m. and 6:00 p.m. except irrigation by drip or mist irrigation systems shall not be restricted as to hours.

D. Irrigation of exterior landscaping, turf areas, open ground, crops, trees, grass, lawn, groundcover, shrubbery, or decorative plantings in such a manner or extent that allows water to run off or escape from the premises or to be wasted.

City of Stockton, CA
§ 13.32.030 § 13.32.040
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(Prior code § 9-733; Ord. 2022-07-12-1503 C.S. § 4)
§ 13.32.050. Water allocations—City water utility.
(Prior code § 9-734)
§ 13.32.060. Stages of water shortage emergency.

The following stages of water shortage emergency are established. Upon declaration of the City Council that an emergency condition exists, as provided in Sections 13.32.010 and 13.32.020, the City Council shall declare the degree of emergency and identify the applicable stage and the regulations which shall be enforceable for each respective stage.

During Stages 2, 3, 4, 5 and 6 additional restrictions on water use shall be enforceable as stated in Section 13.32.040.

E. Violation of the above stated provisions shall be unlawful and an infraction.

A. The following classes of water use are established:

1. "Residential" which shall consist of water service to land improved with structures designed to serve as a residence for human habitation.

2. "Multiple-family residential" which shall consist of water service to land improved with structures designed to serve as a residence for more than a single-family, including apartments, condominiums, townhouses, mobilehome parks, and the like where more than one unit is served by a single meter.

3. "Nonresidential" which shall consist of water service to land improved with structures designed to serve for uses other than residential uses and land without structures but used for agricultural purposes. The following kinds of water use are, without limitation, designated as nonresidential: commercial, industrial, agricultural, municipal, schools, and churches.

4. "Process water users" which shall consist of nonresidential users which utilize water primarily to manufacture, alter, convert, clean, grow, heat, or cool a product, including laundries and vehicle wash facilities.

B. No customer shall use City water for permitted uses in excess of the respective allocation for each class of service within each stage of water shortage emergency.

A. Stage 1—Mandatory Water Conservation. Upon a finding made by the City Council that a Stage 1 water shortage emergency exists, the regulations set out in the Water Conservation Ordinance, Stockton Municipal Code Chapter 13.28, as presently enacted or amended shall be enforceable as to all water users.

B. Stage 2—Water Shortage Emergency. Upon declaration of the City Council that a Stage 2 water shortage emergency exists, the following regulations shall be applicable to all customers of the City's water system:

1. Residential Accounts. Residential accounts shall use 20 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year. Notwithstanding this City of Stockton, CA
§ 13.32.040 § 13.32.060
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provision, no residential account shall receive an allocation of less than 600 cubic feet (6 CCF) of water per billing period.

2. Multiple-Family Residential Accounts. Multiple-family residences which are served by a single meter shall use 20 percent less than the total quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period during the base year. Notwithstanding this provision, no multiple-family residential account shall receive a monthly allocation of less than 400 cubic feet (4 CCF) of water per unit served on a single meter.

3. Nonresidential Accounts. Nonresidential accounts shall use 20 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year.

4. Process-Water User Accounts. Process-water users shall use 20 percent less than the quantity of water as recorded by meter during the corresponding billing period during the base year.

C. Stage 3—Water Shortage Emergency. The following regulations shall be applicable to all customers of the City's water system:

1. Residential Accounts. Residential accounts shall use 30 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year. Notwithstanding this provision, no residential account shall receive an allocation of less than 600 cubic feet (6 CCF) of water per billing period.

2. Multiple-Family Residential Accounts. Multiple-family residences which are served by a single meter shall use 30 percent less than the total quantity of water delivered to the customer's property as recorded by the meter during the corresponding billing period during the base year. Notwithstanding this provision, no multiple-family residential account shall receive a monthly allocation of less than 400 cubic feet (4 CCF) of water per unit served on a single meter.

3. Nonresidential Accounts. Nonresidential accounts shall use 30 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year.

4. Process-Water User Accounts. Process-water users shall use 30 percent less than the quantity of water as recorded by meter during the corresponding billing period during the base year.

D. Stage 4—Water Shortage Emergency. The following regulations shall be applicable to all customers of the City's water system:

1. Residential Accounts. Residential accounts shall use 40 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year. Notwithstanding this City of Stockton, CA
§ 13.32.060 § 13.32.060
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provision, no residential account shall receive an allocation of less than 600 cubic feet (6 CCF) of water per billing period.

2. Multiple-Family Residential Accounts. Multiple-family residences which are served by a single meter shall use 40 percent less than the total quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period during the base year. Notwithstanding this provision, no multiple-family residential account shall receive a monthly allocation of less than 400 cubic feet (4 CCF) of water per unit served on a single meter.

3. Nonresidential Accounts. Nonresidential accounts shall use 40 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year.

4. Process-Water User Accounts. Process-water users shall use 40 percent less than the quantity of water as recorded by meter during the corresponding billing period during the base year.

E. Stage 5—Water Shortage Emergency. The following regulations shall be applicable to all customers of the City's water system:

1. Residential Accounts. Residential accounts shall use 50 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year. Notwithstanding this provision, no residential account shall receive an allocation of less than 600 cubic feet (6 CCF) of water per billing period.

2. Multiple-Family Residential Accounts. Multiple-family residences which are served by a single meter shall use 50 percent less than the total quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period during the base year. Notwithstanding this provision, no multiple-family residential account shall receive a monthly allocation of less than 400 cubic feet (4 CCF) of water per unit served on a single meter.

3. Nonresidential Accounts. Nonresidential accounts shall use 50 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year.

4. Process-Water User Accounts. Process-water users shall use 50 percent less than the quantity of water as recorded by meter during the corresponding billing period during the base year.

F. Stage 6—Water Shortage Emergency. The following regulations shall be applicable to all customers of the City's water system:

1. Residential Accounts. Residential accounts shall use 60 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year. Notwithstanding this City of Stockton, CA
§ 13.32.060 § 13.32.060
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(Prior code § 9-735; Ord. 2022-07-12-1503 C.S. § 5)
§ 13.32.070. Establishment of customer allocation.
(Prior code § 9-736)
§ 13.32.080. Request for increase in allocation.
provision, no residential account shall receive an allocation of less than 600 cubic feet (6 CCF) of water per billing period.

2. Multiple-Family Residential Accounts. Multiple-family residences which are served by a single meter shall use 60 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period during the base year. Notwithstanding this provision, no multiple-family residential account shall receive a monthly allocation of less than 400 cubic feet (4 CCF) of water per unit served on a single meter.

3. Nonresidential Accounts. Nonresidential accounts shall use 60 percent less than the quantity of water delivered to the customer's property as recorded by meter during the corresponding billing period of the base year.

4. Process-Water User Accounts. Process-water users shall use 60 percent less than the quantity of water as recorded by meter during the corresponding billing period during the base year.

A. The Director shall classify each customer and calculate each customer's allocation.

Each customer shall be notified of the Director's determination by mail deposited in the United States Postal Service.

B. Establishment of Allocations With No Customer Use History.

1. Residential. All residential customers with no water use history at the current property address shall be assigned an allocation for single- or multiple-family residential accounts, as determined by the Director, on the basis of usage by similarly situated customers or on such other basis as may be fair and equitable under all the circumstances.

2. Other Use Classifications. In order to determine water use allocations for a new nonresidential use customer, for a change in property use, or for a customer with no water use history at the current property address, an application by the customer shall be submitted to the Director designating the intended use of the property, the square footage, and number of employees. An allocation will be determined by the Director after reviewing the above factors as well as comparing water use for similar types of construction and property uses, averaging the water use and applying the appropriate percentage reduction to this amount.

A. All applicants for an increase in allocation must submit an application in writing to the City Department of Municipal Utilities on an application form provided by the City of Stockton, CA
§ 13.32.060 § 13.32.080
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(Prior code § 9-737)
§ 13.32.090. Appeals.

City.

B. Requests for increased allocations will be reviewed by the Water Conservation Officer for recommendation to the Director for approval, modified approval, or denial. Requests for increased allocations in excess of the historical use may be recommended for approval for reasons outlined in subsection D of this section.

C. All residential applicants for an additional allocation based on additional persons residing at a residence shall show proof of residency for all residents at that property.

D. Water allocations may be adjusted by the Director upon written application where the requested adjustment is found to be reasonably necessary. Factors for consideration shall include without limitation:

1. Additional people residing full time at that residence.

2. Unusual medical needs.

3. Change of property use.

4. Where a City audit of nonresidential customer's water-using appliances and usage shows that all reasonable conservation measures are being employed and the applicant provides a conservation plan demonstrating the measures employed and compliance with the plan.

5. Where a nonresidential customer has demonstrated growth in business volume over the base year in providing a water-related service to the public, the allocation may be based upon 1990 annual water use.

6. Hospitals, health care facilities, nursing care facilities, health clinics, and similar users may be excepted from the percentage reductions providing that a water conservation plan demonstrating reductions in consumption to the maximum extent feasible without jeopardizing patient care is prepared and approved by the Director.

E. A decision in writing shall be mailed to the applicant within 15 days of receipt of the application.

A. Procedure. Any customer may appeal for reconsideration of the Director's classification of use, allocation or determination of a request for an increase in allocation on the basis of hardship or incorrect calculation. Appeals for reconsideration shall be processed as set forth below.

1. Any customer appealing for reconsideration of the classification or allocation shall do so in writing to the Director by either using forms provided by the City or by letter setting forth in detail the reasons for the appeal.

City of Stockton, CA
§ 13.32.080 § 13.32.090
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(Prior code § 9-738)
§ 13.32.100. Enforcement and penalties.

2. The appeal for reconsideration shall be reviewed by the City Department of Municipal Utilities and a site visit scheduled if required.

3. If an appeal for reconsideration is sustained, a condition of approval may include a requirement for the installation of water efficient plumbing fixtures and/or irrigation systems.

4. A staff committee or designee of the Director and the Director shall review all appeals for reconsideration and make decisions on the appeal.

5. If an applicant disagrees with the Director's decision, the decision may be appealed in the same procedural manner as specified in subsection A of this section to the City Manager or a designee, whose decision shall be final. If an appeal to the City Manager is requested, the customer shall be notified of a hearing date by mail. Such hearing shall be scheduled within 10 days of filing the appeal. A decision shall be forwarded to the applicant within 15 days of the date of the hearing.

B. Each appeal to the City Manager shall be accompanied by an appeal fee in an amount to be set by resolution of the City Council from time to time to defray the additional costs to the City.

A. The first billing period after the effective date of the Council's declaration of a water shortage emergency or the effective date stated in said resolution shall be considered an adjustment period during which no penalties will be imposed for water usage in excess of the allocation.

B. Beginning with the second billing period after the effective date and except as provided in subsection C of this section, any customer who exceeds the established allocation in any monthly billing cycle shall pay an excess use charge in addition to all other charges. The excess use charge shall be based on a rate schedule as specified from time to time by resolution of the City Council.

C. No excess use charge shall be imposed in the following circumstances:

1. Multiple-family residential customers whose consumption is 400 cubic feet (4 CCF) per unit or less during any billing period;

2. All other customers whose consumption is 600 cubic feet (6 CCF) or less during any billing period.

D. Installation of Flow Restrictor.

1. After the issuance of one written warning for violation of the provisions of this chapter, or for any use of water which is prohibited, the City may install a flow restricting device on the customer's water service which shall remain in place for a period of not less than 48 hours and until the customer has paid the City of Stockton, CA
§ 13.32.090 § 13.32.100
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(Prior code § 9-739)
removal charges set forth below. The device shall not be removed except by the City.

2. If the customer, after removal of a flow restricting device by the City, shall again violate the provisions of this ordinance or the Water Conservation Ordinance, the City may install a flow restricting device which shall remain for a period of at least two weeks and until payment for removal by the City.

3. Further violations, removal of or by-passing the flow restricting device may result in termination of water service. Upon a determination by the Director that service shall be terminated, written notice of intent to disconnect shall be mailed to the customer. Said notice shall be mailed to the resident and any other person or entity known to the City who is responsible for the violation or correction of the violation, including the property owner in the case of rentals.

A request for hearing on the discontinuance of service shall be requested within five days of mailing the notice. A hearing before the Director shall be held within three days of expiration of the period for requesting a hearing. The Director's final decision shall be mailed to the responsible parties within three days of the hearing. If the final decision is to discontinue service, the discontinuance shall not occur less than three days after mailing of the Director's final decision.

4. Removal Charges. The charge for removal of a flow restricting device shall be based on a rate schedule as established from time to time by resolution of the City Council. In the case of rentals, the person or entity occupying the premises and the owner shall be jointly and severally responsible for payment of said costs.

City of Stockton, CA
§ 13.32.100 § 13.32.100
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ATTACHMENT I: 2021 COS WATER MASTER PLAN UPDATE
2021
EXHIBIT 1
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CITY OF STOCKTON
Water Master Plan Update
JANUARY 2021
EXHIBIT 1
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EXHIBIT 1
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Water Master Plan Update

PREPARED FOR
City of Stockton
Municipal Utilities Department
FINAL REPORT | JANUARY 2021
EXHIBIT 1
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Water Master Plan Update
Prepared for
City of Stockton
Municipal Utilities Department
Project No. 129-60-20-41
01-27-21
Project Manager: Elizabeth Drayer, PE Date
01-27-21
QA/QC Review: Polly Boissevain, PE Date
EXHIBIT 1
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EXECUTIVE SUMMARY .................................................................................................................. ES-1 Water Master Plan Update Purpose and Objectives ........................................................................ ES-1 Projected Future Land Use ................................................................................................................ ES-2 Projected Future Water Production Requirements.......................................................................... ES-4 Recommended Existing and Future Water System Improvements.................................................. ES-7 Recommended Existing System Improvements ....................................................................... ES-11 Recommended Near-Term (2030) System Improvements....................................................... ES-12 Recommended Future (2040) System Improvements.............................................................. ES-13 Basis of Recommendations............................................................................................................. ES-13 Introduction..................................................................................................................1-1

1.1 Water Master Plan Update Purpose .............................................................................................1-1

1.2 Water Master Plan Objectives and Priorities................................................................................1-1

1.3 Previous and On-Going Studies.....................................................................................................1-3

1.3.1 2008 Water Master Plan......................................................................................................1-3

1.3.2 Envision Stockton 2040 General Plan ..................................................................................1-4

1.3.3 Water Cost of Service Rate Study ........................................................................................1-7

1.3.4 2020 Urban Water Management Plan.................................................................................1-7

1.3.5 Wastewater Master Plan Update ........................................................................................1-7

1.4 Report Organization ......................................................................................................................1-8

1.5 Acknowledgments.........................................................................................................................1-9 Existing Water System...................................................................................................2-1

2.1 Existing Water Service Areas.........................................................................................................2-1

2.2 Existing Water Supplies.................................................................................................................2-3

2.2.1 Surface Water Supply...........................................................................................................2-3

2.2.1.1 Delta Water Treatment Plant.....................................................................................2-3

2.2.1.2 Stockton East Water District ......................................................................................2-4

2.2.2 Groundwater Supply............................................................................................................2-4

2.3 Existing Water System Facilities....................................................................................................2-4

2.3.1 Groundwater Wells..............................................................................................................2-5

2.3.2 Storage Reservoirs and Reservoir Pump Stations................................................................2-8

2.3.3 Transmission and Distribution Pipelines............................................................................2-10 Water Demands............................................................................................................3-1

3.1 Historical Water Production and Use............................................................................................3-1

3.1.1 Historical Annual Water Production ....................................................................................3-1

3.1.2 Per Capita Water Use...........................................................................................................3-8

3.1.3 Historical Water Consumption...........................................................................................3-11

3.1.4 Non-Revenue Water ..........................................................................................................3-12

3.2 Peak Water Use ...........................................................................................................................3-13 EXHIBIT 1
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3.2.1 Maximum Day and Peak Hour Demand.............................................................................3-14

3.2.2 Recommended Demand Peaking Factors..........................................................................3-14

3.2.3 Maximum Day and Peak Hour Diurnal Demand................................................................3-15

3.3 Existing and Future Land Use and Growth Projections...............................................................3-16

3.3.1 Existing Land Use ...............................................................................................................3-16

3.3.2 Projected Future Land Use.................................................................................................3-16

3.4 Water Use Factors.......................................................................................................................3-20

3.4.1 Residential Water Use Factors...........................................................................................3-21

3.4.2 Non-Residential Water Use Factors...................................................................................3-22

3.4.3 Irrigation Water Use Factors..............................................................................................3-22

3.4.4 Recommended Water Use Factors....................................................................................3-23

3.5 Future Water Demands and Required Water Production...........................................................3-23

3.5.1 Existing Baseline Production..............................................................................................3-23

3.5.2 Additional Water Demand for Planned Future Development...........................................3-24

3.5.3 Water Production Requirements for Near-Term (2030) Conditions.................................3-24

3.5.4 Water Production Requirements for Future (2040) Conditions........................................3-25

3.6 Comparison to the 2008 WMP, the 2015 UWMP and the 2018 Utility Master Plan Supplements...............................................................................................................................3-26 Water Supply ................................................................................................................4-1

4.1 Water Supply Overview.................................................................................................................4-1

4.2 Surface Water Supply from the San Joaquin River........................................................................4-2

4.2.1 Water Right Permit ..............................................................................................................4-2

4.2.2 Delta Water Treatment Plant ..............................................................................................4-2

4.2.3 Supplemental Raw Water Supply from Woodbridge Irrigation District..............................4-4

4.2.4 COSMUD Water Supply from the DWTP..............................................................................4-4

4.3 Water Supply from the Stockton East Water District....................................................................4-5

4.3.1 Water Supply Contract.........................................................................................................4-5

4.3.2 New Hogan Reservoir ..........................................................................................................4-5

4.3.3 New Melones Reservoir.......................................................................................................4-6

4.3.4 COSMUD Water Supply from SEWD....................................................................................4-6

4.4 Groundwater.................................................................................................................................4-7

4.4.1 Groundwater Basin Management .......................................................................................4-7

4.4.2 COSMUD Groundwater Use.................................................................................................4-9 Water System Performance and Operational Criteria .....................................................5-1

5.1 Water System Reliability and Water Quality.................................................................................5-3

5.2 Fire Flow Requirements.................................................................................................................5-3

5.3 Water System Supply Capacity......................................................................................................5-4

5.3.1 Maximum Day Demand .......................................................................................................5-4

5.3.2 Maximum Day Demand plus Fire Flow ................................................................................5-5

5.3.3 Peak Hour Demand ..............................................................................................................5-5 EXHIBIT 1
1645

5.4 Critical Supply/Pumping Facilities.................................................................................................5-6

5.5 Pumping Facility Capacity..............................................................................................................5-6

5.6 Storage Facility Capacity................................................................................................................5-6

5.6.1 Operational Storage.............................................................................................................5-7

5.6.2 Fire Flow Storage .................................................................................................................5-7

5.6.3 Emergency Storage ..............................................................................................................5-7

5.6.4 Emergency Groundwater Storage Credit.............................................................................5-8

5.6.5 Treated Surface Water Supply Credit ..................................................................................5-8

5.6.6 Total Storage Capacity Recommended................................................................................5-9

5.6.7 Storage Operational Strategies............................................................................................5-9

5.7 Water Transmission and Distribution Pipeline Sizing....................................................................5-9

5.7.1 Water Transmission System...............................................................................................5-10

5.7.1.1 Average Day Demand...............................................................................................5-10

5.7.1.2 Maximum Day Demand............................................................................................5-10

5.7.1.3 Peak Hour Demand...................................................................................................5-10

5.7.2 Water Distribution System.................................................................................................5-10

5.7.2.1 Maximum Day Demand plus Fire Flow.....................................................................5-10

5.7.2.2 Peak Hour Demand...................................................................................................5-11

5.7.3 Other Recommended Criteria............................................................................................5-11 Hydraulic Model Update and Calibration .......................................................................6-1

6.1 Hydraulic Model Background ........................................................................................................6-1

6.2 Hydraulic Model Update Methodology.........................................................................................6-1

6.3 Hydraulic Model Update ...............................................................................................................6-2

6.3.1 Model Pipeline Configuration Update .................................................................................6-2

6.3.2 Pipeline Roughness Characteristics .....................................................................................6-4

6.3.3 Water Demand Allocation ...................................................................................................6-4

6.3.4 Elevation Extraction.............................................................................................................6-4

6.3.5 Water System Facilities........................................................................................................6-5

6.3.6 Hourly Pattern Development...............................................................................................6-5

6.3.6.1 North Stockton ...........................................................................................................6-5

6.3.6.2 South Stockton ...........................................................................................................6-7

6.4 Hydraulic Model C-Factor Calibration ...........................................................................................6-7

6.4.1 Development of Hydrant (C-Factor) Tests...........................................................................6-7

6.4.2 Hydrant (C-Factor) Test Results.........................................................................................6-10

6.4.3 Hydraulic Model C-Factor Calibration Findings and Conclusions......................................6-10

6.5 Hydraulic Model Extended Period Simulation (EPS) Calibration.................................................6-12

6.5.1 Hydraulic Model EPS Calibration Results...........................................................................6-14

6.5.1.1 North Stockton .........................................................................................................6-14

6.5.1.2 South Stockton .........................................................................................................6-14

6.5.2 Hydraulic Model EPS Calibration Findings and Conclusions..............................................6-15 EXHIBIT 1
1646
Existing Water System Analysis......................................................................................7-1

7.1 Existing Water Demands ...............................................................................................................7-1

7.2 Existing Water Supply and Water System Facility Capacity Evaluation ........................................7-3

7.2.1 Supply Capacity Evaluation..................................................................................................7-3

7.2.2 Pumping Capacity Evaluation...............................................................................................7-5

7.2.3 Storage Capacity Evaluation ................................................................................................7-7

7.3 Existing Water Distribution System Performance Evaluation .......................................................7-9

7.3.1 Normal Operations – Maximum Day Demand with Peak Hour...........................................7-9

7.3.1.1 Evaluation Overview...................................................................................................7-9

7.3.1.2 Evaluation Results ....................................................................................................7-10

7.3.2 Emergency Operations – Maximum Day Demand Plus Fire Flow......................................7-14

7.3.2.1 Evaluation Overview.................................................................................................7-14

7.3.2.2 Fire Flow Evaluation Results.....................................................................................7-14

7.4 Summary of Findings and Recommendations for the Existing Water System............................7-19 Future Water System Analysis .......................................................................................8-1

8.1 Future Water System Description .................................................................................................8-1

8.2 Future Water Demands.................................................................................................................8-4

8.3 Future Water Supply and Water System Facility Capacity Evaluation..........................................8-5

8.3.1 Supply Capacity Evaluation..................................................................................................8-6

8.3.2 Pumping Capacity Evaluation...............................................................................................8-9

8.3.3 Storage Capacity Evaluation ..............................................................................................8-12

8.4 Future Water Distribution System Performance Evaluation.......................................................8-16

8.4.1 Normal Operations – Maximum Day Demand with Peak Hour.........................................8-16

8.4.1.1 Evaluation Overview.................................................................................................8-16

8.4.1.2 Near-Term (2030) System Evaluation Results..........................................................8-17

8.4.1.3 Future (2040) System Evaluation Results.................................................................8-17

8.4.2 Emergency Operations – Maximum Day Demand Plus Fire Flow......................................8-24

8.4.2.1 Evaluation Overview.................................................................................................8-24

8.4.2.2 Near-Term (2030) System Evaluation Results..........................................................8-24

8.4.2.3 Future (2040) System Evaluation Results.................................................................8-25

8.5 Summary of Findings and Recommendations for the Future Water System..............................8-28

8.6 Other Planned or Recommended Improvements.......................................................................8-30 Recommended Water System Capital Improvement Program.........................................9-1

9.1 Cost Estimating Assumptions........................................................................................................9-1

9.2 Summary of Recommended Capital Improvement Program........................................................9-2

9.2.1 Summary of Estimated Capital Costs...................................................................................9-2

9.2.2 Recommended Existing System Improvements ..................................................................9-4

9.2.3 Recommended Near-Term (2030) System Improvements..................................................9-7

9.2.4 Recommended Future (2040) System Improvements.........................................................9-9

9.3 Basis of Recommendations ...........................................................................................................9-9 EXHIBIT 1
1647
Financial Plan ............................................................................................................10-1

10.1 Introduction...............................................................................................................................10-1

10.2 Key Assumptions .......................................................................................................................10-1

10.3 Historical Review .......................................................................................................................10-1

10.4 Development of the Financial Plan ...........................................................................................10-2

10.4.1 Revenues..........................................................................................................................10-3

10.4.2 Operations and Maintenance ..........................................................................................10-3

10.4.3 Capital Funding Plan ........................................................................................................10-3

10.4.4 Debt Service .....................................................................................................................10-8

10.4.5 Reserve Funds..................................................................................................................10-8

10.5 Summary of the Financial Plan..................................................................................................10-8

10.6 Connection Fees......................................................................................................................10-10

10.7 Summary..................................................................................................................................10-10

LIST OF TABLES
Table ES-1. Future Planned Development within the COSMUD Water Service Area ....................... ES-4 Table ES-2. Existing Baseline Production (5-year Average from 2015 to 2019) with Demand Rebound .......................................................................................................... ES-5 Table ES-3. Projected Water Production Requirement for Near-Term (2030) Conditions............... ES-5 Table ES-4. Projected Water Production Requirement for Future (2040) Conditions...................... ES-6 Table 1-1. General Plan Goals, Policies and Actions Related to Water Service ..................................1-5 Table 2-1. North Stockton Well Facilities............................................................................................2-6 Table 2-2. South Stockton Well Facilities............................................................................................2-7 Table 2-3. City of Stockton Water Storage Reservoirs ........................................................................2-8 Table 2-4. City of Stockton Reservoir Pump Stations..........................................................................2-9 Table 2-5. City of Stockton Distribution System Pipeline Diameters................................................2-10 Table 2-6. City of Stockton Distribution System Pipeline Installation Year.......................................2-12 Table 3-1. Historical Water Production...............................................................................................3-3 Table 3-2. Historical COSMUD Water Production Comparison...........................................................3-8 Table 3-3. Historical Water Production, Population and Per Capita Water Use.................................3-9 Table 3-4. COSMUD Customer Types as of December 2019.............................................................3-11 Table 3-5. COSMUD Consumption by Customer Type ......................................................................3-12 Table 3-6. Non-Revenue Water.........................................................................................................3-13 Table 3-7. Summary of Historical Maximum Day and Peak Hour Peaking Factors...........................3-14 Table 3-8. Recommended Demand Peaking Factors.........................................................................3-15 EXHIBIT 1
1648
Table 3-9. Future Incremental Development Summary....................................................................3-17 Table 3-10. Future Planned Development within the COSMUD Water Service Area .......................3-20 Table 3-11. Maximum Allowable Water Use Factor for Irrigation....................................................3-22 Table 3-12. Recommended Water Use Factors.................................................................................3-23 Table 3-13. Existing Baseline Production (5-year Average from 2015 to 2019) with Demand Rebound ..........................................................................................................3-24 Table 3-14. Future Additional Water Demand..................................................................................3-24 Table 3-15. Projected Water Production Requirement for Near-Term (2030) Conditions...............3-25 Table 3-16. Projected Water Production Requirement for Future (2040) Conditions......................3-25 Table 5-1. Summary of Recommended Water System Performance and Operational Criteria .........5-2 Table 5-2. Recommended Fire Flow Requirements for Future Development....................................5-4 Table 6-1. Hydrant Test Locations and Status.....................................................................................6-9 Table 6-2. Summary of Hydrant Test Calibration Results..................................................................6-11 Table 7-1. Existing COSMUD Baseline Demands.................................................................................7-1 Table 7-2. Comparison of Available versus Required Supply Capacity................................................7-4 Table 7-3. Comparison of Available versus Required Pumping Capacity............................................7-6 Table 7-4. Comparison of Available versus Required Storage Capacity..............................................7-8 Table 7-5. Recommended Existing COSMUD Water System Pipeline Improvements......................7-16 Table 7-6. Summary of Recommended Existing System Improvements ..........................................7-19 Table 8-1. Projected Near-Term (2030) COSMUD Water System Demands.......................................8-4 Table 8-2. Projected Future (2040) COSMUD Water System Demands..............................................8-4 Table 8-3. Near-Term (2030) Comparison of Available versus Required Supply Capacity .................8-7 Table 8-4. Future (2040) Comparison of Available versus Required Supply Capacity ........................8-8 Table 8-5. Near-Term (2030) Comparison of Available versus Required Pumping Capacity ............8-10 Table 8-6. Future (2040) Comparison of Available versus Required Pumping Capacity...................8-11 Table 8-7. Near-Term (2030) Comparison of Available versus Required Storage Capacity..............8-14 Table 8-8. Future (2040) Comparison of Available versus Required Storage Capacity.....................8-15 Table 8-9. Summary of Recommended Near-Term (2030) and Future (2040) System Improvements.....................................................................................................8-28 Table 9-1. Summary of Improvement Costs by Water Service Area and Time Frame........................9-2 Table 9-2. Existing System Capital Improvements..............................................................................9-5 Table 9-3. Near-Term (2030) System Capital Improvements..............................................................9-8 Table 9-4. Future (2040) System Capital Improvements...................................................................9-11 Table 10-1. Historical Revenue Requirement....................................................................................10-2 EXHIBIT 1
1649
Table 10-2. Projected Water Revenues.............................................................................................10-4 Table 10-3. O&M Expenses ...............................................................................................................10-5 Table 10-4. Capital Improvement Plan..............................................................................................10-7 Table 10-5. Revenue Requirement Summary ...................................................................................10-9

LIST OF FIGURES
Figure ES-1. Summary of Future Developments ............................................................................... ES-3 Figure ES-2. Comparison of Previous and Current Population and Water Production Requirements............................................................................................................... ES-7 Figure ES-3. Recommended System Improvements......................................................................... ES-9 Figure ES-4. Recommended Pipeline Rehabilitation Program ........................................................ ES-10 Figure 2-1. Water Service Areas..........................................................................................................2-2 Figure 2-2. Existing Water System.....................................................................................................2-11 Figure 2-3. System Pipelines by Decade of Installation.....................................................................2-13 Figure 3-1. Historical Monthly Water Production for North Stockton................................................3-4 Figure 3-2. Historical Monthly Water Production for South Stockton................................................3-5 Figure 3-3. Historical Monthly Water Production for the Walnut Plant Area.....................................3-6 Figure 3-4. Historical Monthly Water Production for COSMUD..........................................................3-7 Figure 3-5. Comparison of Historical Per Capita Demand, Average Day Production and Population......................................................................................................................3-10 Figure 3-6. North Stockton and South Stockton Maximum Day Diurnal Patterns............................3-15 Figure 3-7. Summary of Future Developments.................................................................................3-18 Figure 3-8. Comparison of Previous and Current Population and Water Production Requirements.................................................................................................................3-27 Figure 4-1. Water Supply System ........................................................................................................4-3 Figure 4-2. Eastern San Joaquin Groundwater Subbasin ....................................................................4-8 Figure 6-1. Summary of Model Pipeline Updates ...............................................................................6-3 Figure 6-2. Diurnal Patterns during Calibration Day (June 23, 3030)..................................................6-6 Figure 6-3. Hydrant Test Location Map...............................................................................................6-8 Figure 6-4. Hydrant Pressure Recorder Map.....................................................................................6-13 Figure 7-1. Existing Water System.......................................................................................................7-2 Figure 7-2. Existing System Maximum Day Demand Minimum System Pressure.............................7-11 Figure 7-3. Existing System Maximum Day Demand Average System Pressure ...............................7-12 Figure 7-4. Existing System Maximum Day Demand Reservoir Level Results...................................7-13 EXHIBIT 1
1650
Figure 7-5. Existing System Maximum Day Demand Fire Flow Results.............................................7-15 Figure 7-6. Existing System Pipeline Improvements .........................................................................7-17 Figure 7-7. Existing System Fire Flow Results with Priority 1 and 2 Pipeline Improvements ...........7-18 Figure 8-1. Near-Term and Future System..........................................................................................8-3 Figure 8-2. Near-Term (2030) System Maximum Day Demand Minimum System Pressure............8-19 Figure 8-3. Near-Term (2030) Maximum Day Demand Reservoir Level Results...............................8-20 Figure 8-4. Buildout (2040) System Maximum Day Demand Minimum System Pressure................8-21 Figure 8-5. Buildout (2040) System Maximum Day Demand Minimum System Pressure with Improvements................................................................................................................8-22 Figure 8-6. Future (2040) System Maximum Day Demand Reservoir Level Results.........................8-23 Figure 8-7. Near-Term (2030) System Maximum Day Demand Fire Flow Results............................8-26 Figure 8-8. Buildout (2040) System Maximum Day Demand Fire Flow Results................................8-27 Figure 8-9. Future System with Improvements.................................................................................8-29 Figure 9-1. Recommended System Improvements.............................................................................9-3 Figure 9-2. Recommended Pipeline Rehabilitation Program..............................................................9-6

LIST OF APPENDICES
Appendix A. Hydrant Testing and Hydrant Pressure Recorder Placement Plan for Model Calibration Appendix B. Hydraulic Model Calibration Results – North Stockton Appendix C. Hydraulic Model Calibration Results – South Stockton Appendix D. Cost Estimating Assumptions
Appendix E. Financial Plan Worksheets
EXHIBIT 1
1651

LIST OF ACRONYMS AND ABBREVIATIONS
AACE Association for the Advancement of Cost Engineering 9-1 AC Asbestos Cement 2-12
ADD Average Day Demand 3-14
afy Acre Feet Per Year 3-8
AMI Advanced Metering Infrastructure 8-30
AWWA American Water Works Association 3-12
AWWA M32 American Water Works Association Manual of Practice 32 6-1 BAT Best Available Technology 8-12
CACWD Calaveras County Water District 4-5
Cal Water California Water Service 2-3
CIP Capital Improvement Program 7-16
City City of Stockton 1-1
COSMUD City of Stockton Municipal Utilities Department 1-1 CSJWCD Central San Joaquin Water Conservation District 4-6 CVP Central Valley Project 4-6
CWC California Water Code 4-2
DDW Division of Drinking Water 2-5
Delta Sacramento-San Joaquin Delta 4-1
DJWWTP Dr. Joe Waidhofer Water Treatment Plant 2-4
DSC Debt Service Coverage 10-2
DU Dwelling Unit 3-20
DWR Department of Water Resources 1-6
DWSP Delta Water Supply Project 2-3
DWSP SWSF Delta Water Supply Project Surface Water Supply Fee 10-6 DWTP Delta Water Treatment Plant 2-3
EGWC Emergency Groundwater Storage Credit 7-7
ENR CCI Engineering News Record Construction Cost Index 9-1 EPA Environmental Protection Agency 5-3
EPS Extended Period Simulation 6-1
FMS Fourteen-Mile Slough 2-5
fps Feet Per Second 5-10
ft/kft Feet Per Thousand Feet 5-10
FTE Full-Time Equivalent 10-1
FY Fiscal Year 10-1
GAC Granular Activated Carbon 2-4
GIS Geographic Information System 6-1
gpcd Gallons Per Capita Per Day 3-13
gpd Gallon Per Day 3-21
gpm Gallons Per Minute 2-5
GPU General Plan Update 3-1
GSP Groundwater Sustainability Plan 4-8
EXHIBIT 1
1652
GWA Eastern San Joaquin Groundwater Authority 4-8
HDR High Density Residential 3-21
IPS Intake Pump Station 2-3
lf Linear Feet 9-9
M Million 9-2
MDD Maximum Day Demand 3-14
MDR Medium Density Residential 3-21
MFR Multi-Family Residential 3-21
MG Million gallons 2-3
mgd Million Gallons Per Day 2-3
MWELO Model Water Efficiency Landscape Ordinance 3-22
NFPA National Fire Protection Association 5-7
NMFS National Marine Fisheries Service 4-2
NOAA National Oceanic and Atmospheric Administration 4-2 NRW Non-Revenue Water 3-12
NW Northwest 2-5
O&M Operations and Maintenance 5-6
PHD Peak Hour Demand 3-14
psi Pounds Per Square Inch 5-3
PVC Polyvinyl Chloride 2-12
R&R Rehabilitation and Replacement 7-14
SB Senate Bill 3-8
SCADA Supervisory Control and Data Acquisition 6-2
SEWD Stockton East Water District 2-3
SFR Single Family Residential 3-21
SGMA Sustainable Groundwater Management Act 4-7
SOI Sphere of Influence 1-3
SOI/MSR April 2020 Sphere of Influence Plan/Municipal Service Review Report 3-16 SSS South Stockton System 2-5
SWRCB State Water Resources Control Board 5-3
TCP 1,2,3-Trichloropropane 8-12
TSWC Treated Surface Water Supply Credit 7-7
USACE United States Army Corps of Engineers 4-5
USBR United States Bureau of Reclamation 4-5
UWMP Urban Water Management Plan 1-6
WID Woodbridge irrigation District 2-3
WR Weston Ranch 2-5
WUF Water Use Factor 3-20
EXHIBIT 1
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WATER MASTER PLAN UPDATE PURPOSE AND OBJECTIVES
The purpose of this Water Master Plan Update for the City of Stockton (City) is to evaluate the existing water system infrastructure and address potential impacts of near-term and long-term planned growth to develop a comprehensive guide for the City’s water system capital improvement program. The City’s Municipal Utilities Department (COSMUD) operates the City’s water system which serves customers in both North Stockton (serving primarily residential customers) and South Stockton (serving a mix of residential and industrial customers). Central Stockton is served by a separate water system operated by the California Water Service (Cal Water). Within Central Stockton, COSMUD operates the Walnut Plant System comprised of residential customers and the Diamond Walnut processing facility; however, the Walnut Plant System has not been evaluated as part of this Water Master Plan Update. This Water Master Plan Update only addresses the COSMUD North Stockton and South Stockton water service areas.

The City’s last Water Master Plan was completed in 2008. Since that time, the City has experienced growth, constructed a surface water treatment plant, and completed an update to its General Plan (the Envision Stockton 2040 General Plan), which provides the framework for future development in the City through 2040. The Delta Water Treatment Plant was completed in 2012 which provides the City with a new treated surface water supply in North Stockton to supplement its other water supplies. Since the completion of the 2008 Water Master Plan, the State endured five years of drought starting in 2012, including the driest four consecutive years in California history. These unprecedented conditions led to statewide mandated water conservation, significant surface water supply reductions and curtailments and legislation establishing new statewide water efficiency standards.

All of these factors have led to a need to reassess the City’s water needs, priorities and strategies and reevaluate the need for water system infrastructure improvements to ensure a safe and reliable water supply to support the City’s existing and future residents and businesses.

The primary objectives of this Water Master Plan Update, along with the chapters in which these topics are discussed, are as follows:
• Describe the existing COSMUD water system and facilities (Chapter 2) • Evaluate historical and existing water demands to understand recent water use trends, per capita water use and water use by customer type (Chapter 3) • Develop future water demand projections for near-term (2030) and future (2040) conditions based on future planned development in the COSMUD water service areas and updated unit water use factors developed based on recent water use trends (Chapter 3) • Review the City’s existing water supplies and the opportunities and constraints associated with each supply source (Chapter 4)
• Review existing City and industry water system standards and refine performance and planning criteria under which the COSMUD water system will be evaluated and recommendations for future facilities will be formulated (Chapter 5) • Update and calibrate the City’s water system hydraulic model to provide an updated, accurate tool for evaluating various water system demand and operational scenarios (Chapter 6)
EXHIBIT 1
1654
• Evaluate the need for new water system facilities (including pipelines, supply facilities, storage facilities and pumping facilities) to meet existing, near-term (2030) and future (2040) water demands within the COSMUD water service areas (Chapters 7 and 8) • Develop a capital improvement program and financial plan for implementation of recommended water system improvements (Chapters 9 and 10)

PROJECTED FUTURE LAND USE
Future growth and land uses within the City are defined in the Envision Stockton 2040 General Plan (2040 GPU), which summarizes anticipated development within sixteen Study Areaslocated throughout the City.

These areas have been specifically identified as being most likely to develop by 2040. In addition to these Study Areas, the City has identified, or is actively working with several project proponents to identify, future development areas that are either within existing City Limits or outside of City Limits but within the General Plan Sphere of Influence. The April 2020 Sphere of Influence Plan/Municipal Service Review Report (SOI/MSR) defines the anticipated level of development and municipal service needs for near-term (2030) development. Approximately 31,442 planned residential dwelling units are planned in the COSMUD water service area, which is about 77 percent of the total planned residential dwelling units City-wide. The locations of the Study Areas and proposed future development areas are shown on Figure ES-1.

For the purposes of this Water Master Plan Update, it was assumed that the Mariposa Road Community will be developed by 2040, based on the most recent land use plan, and be served entirely by COSMUD.

This future development is one of the largest drivers for future growth within the COSMUD South Stockton water service area. In addition, although this development area is located within both the COSMUD water service area and the Cal Water service area, for the purposes of this Water Master Plan Update, it was conservatively assumed that the COSMUD would serve the entire Mariposa Road Community area. As described further below and in Chapter 8, any recommended future water system improvements associated with the Mariposa Road Community should be reviewed and confirmed prior to facility design and construction based on future confirmed development plans.

EXHIBIT 1
1655
0 0.75 1.5
Miles
§¨¦5
¬«99
¿
Thornton Road and
Eight Mile Road
Arco Station Project
¿
Crystal Bay
¿
Airport Way and
Sperry Road
Commercial Project
¿ University Park
¿ Tuscany Cove
Tra Vigne
¿
Sanchez-Hoggan
Annexation Project
¿
Sanchez-Hoggan
Annexation Project
¿
Veterans Affairs
Medical Campus
¿
See Note 1
CarMax ¿ Superstore
¿
Century Mobile
Home Park
¬«4
¿
Weston Ranch
Towne Center
¿
Mariposa
Industrial Park
See Note 5
¿
Niagara Bottling
Facility
See Note 6
¿
Tidewater
Crossing
¿
Tidewater
Crossing

F A I R C H I L D L N

E I G H T M I L E R D

A U S T IN R D
P E R

S H I N
G
A
V E
P
A

C I F I C
A
V E

L O W E R S A C R A M E N T O R D

E L D O R A
D
O S T

L A T H R O P R D

A S H L E Y L N

H A R N E Y L N

F R E M O N T S T

H A M M E R L N
C

A L I F O

R N I A S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

M A R C H L N

J A C O B S R D
S T
A

N DR E W S D
R

L O U I S E A V E
R

O B E R T S R D
E L D
O
R
A
D
O S T

C H E R O K E E
R D

B R O O K S I D E R D

U N D I N E R D
B S T

T H O R N T O N R D

W A T E R L O O R D
H A

R L A N R
D

A I R P O
R T W
A
Y

A R M S T R O N G R D

C R O C K E R R D
M
A
N

T H E Y R
D

L I V E O A K R D

B E A R C R E E K L E V E E R D

E I G H T M I L E R D

W E S T
L
N

D A V I S R D

A L P I N E R D

H I L D R E T
H
L
N

K A I S E R R D

I N L A N D D R

H O L T R D

R I N D G E R D
W I NG

L E V E E RD
Sanctuary
Delta Cove
Mariposa
Road
Community
Westlake
Villages
Cannery
Park
North Stockton
Projects III
Airpark 599
NorCal
Logistics
Center
South Stockton
Commerce Center
Study
Area16
Study
Area16
Study
Area16
Study
Area14
Study
Area13
Study Area12
Study Area11
Study
Area10
Study
Area9
Study
Area8 Study Area7
Study Area6 Study
Area5
Study Area4
Study
Area3
Study Area2
Study Area1
Study Area1
Study Area1
Study
Area15
Study Area15
Study Area15
Figure ES-1
Summary of
Future Developments
City of Stockton
Water Master Plan Update
Study Area Within City's Sphere
of Influence
Study Area Outside of City's
Sphere of Influence
Major Development
Cal Water Service Area
COSMUD Water Service Area
City of Stockton Limits
City of Stockton Sphere of
Influence
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\FES_1_FutLandUse.mxd - mmcwilliams - 1/26/2021 Notes:

1. The southern portion of the Tra Vigne development, generally south of Bear Creek, does not have active specific plans, but is anticipated to be Low Density Residential in the future. For the purposes of 2020 WMPU, no demand was added for the area south of Bear Creek.

2. The portion of Study Area 1, west of Davis Road, does not have an associated future land use plan. Water demands for Study Area 1 planned land use are assumed to be in the area south of Eight Mile Road.

3. Study Areas 4 through 11, Study Area 13, Open Window, University Park, and Tuscany Cove are not within the COSMUD Water Service Area.

4. Study Area 2, Study Area 3, Study Area 12, Study Area 14, and Mariposa Road Community are only partially within the COSMUD Water Service Area.

5. Mariposa Industrial Park extents based on City provided project information, provided to West Yost on 10/29/2020.

6. Niagara Bottling Facility included as part of future development based on City Will Serve Letter, provided to West Yost on 10/15/2020.

7. The major developments and study areas displayed were confirmed with City Planning Staff as future projects to be included in the 2020 WMPU. Future developments are preliminary and subject to change.

Upon City approval, infrastructure required to serve a development and impacts to the existing water system will need to be confirmed.

Future development in areas not designated as major developments or study areas will need to be evaluated when development plans are available.

8. Refer to Table 3-9 in the 2020 WMPU for planned land use (dwelling units and acreage) for each proposed development or study area shown.

EXHIBIT 1
1656
Table ES-1 summarizes the future planned development within the COSMUD water service area by land use designation consistent with the 2040 GPU and SOI/MSR Report. North Stockton will experience the largest increase in residential development. The largest planned development is the Sanctuary Project in North Stockton. It will consist of single-family, multi-family, park, and commercial land uses. In addition to the Mariposa Road Community, South Stockton will see an increase in commercial and industrial development in the near-term and in the future with several planned projects.

Table ES-1. Future Planned Development within the COSMUD Water Service Area(a) Future Land Use Designation Units
Near-Term (2030) Total
Development
Future (2040) Total
Development
North Stockton
Single Family Residential DU 2,100 16,700
Multi Family Residential DU 500 4,212
Commercial Acres 23 167
Industrial Acres 0 0
Parks Acres 41 451
South Stockton
Single Family Residential DU 0 8,955(b)
Multi Family Residential DU 0 1,575(b)
Commercial Acres 55 273
Industrial Acres 1,354 1,753
Parks Acres 9 224
(a) Based on the Study Areas and future development plans identified in the 2040 General Plan and April 2020 SOI/MSR Report and confirmed with the City’s Community Development Department in July 2020 (see Table 3-9 for additional information). (b) All of Single Family and most of Multi Family is associated with Mariposa Road Community.

PROJECTED FUTURE WATER PRODUCTION REQUIREMENTS
Water demands were projected for near-term (2030) and future (2040) conditions for the COSMUD water service areas using the adopted water use factors applied to the proposed future development.

Future water production requirements were then estimated by adding the future water demand projections and future non-revenue water to the existing baseline production.

Table ES-2. summarizes the existing baseline production for the overall COSMUD water service area and shows that the total existing baseline production for this Water Master Plan Update is 31,495 acre-feet per year (afy), or 28.1 million gallons per day (mgd). This can be compared to the existing baseline production from the 2008 Water Master Plan which was 36,380 afy, or about 32.5 mgd. This indicates that existing baseline production for this Water Master Plan Update, which includes a 10 percent demand rebound factor to account for post-drought water use increases, is about 13 percent lower than the 2008 Water Master Plan baseline production, reflecting improved water use efficiencies and on-going water conservation by the COSMUD water customers since the 2008 Water Master Plan.

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Table ES-2. Existing Baseline Production (5-year Average from 2015 to 2019) with Demand Rebound Water Service Area
Existing Average
Historical Production
(2015 – 2019), afy (a)
Demand Rebound
(10 percent of Average
Historical Production), afy
Existing Baseline
Production, afy
North Stockton 23,450 2,345 25,795
South Stockton 5,182 518 5,700
Total, afy 28,632 2,863 31,495
Total, mgd 25.6 2.6 28.1
(a) Includes Non-Revenue Water
As shown in Table ES-3, by 2030, the water production requirement is projected to increase by approximately 20 percent systemwide. North Stockton’s production requirement is projected to increase by 3.3 percent and South Stockton’s production requirement is projected to increase by 93.5 percent from the existing baseline production.

Table ES-3. Projected Water Production Requirement for Near-Term (2030) Conditions Parameter North Stockton, afy South Stockton, afy Total COSMUD, afy Existing Baseline Production
(refer to Table ES-2.)
25,795 5,700 31,495
Additional Near-Term Demand by 2030
(refer to Table 3-15)
781 4,903 5,684
Future Non-Revenue Water (8%) 68 426 494
Total Production Requirement, afy 26,644 11,029 37,673
Total Production Requirement, mgd 23.8 9.8 33.6
Percent Increase from
Existing Baseline Production 3.3% 93.5% 19.6%
As shown in Table ES-4, by 2040, the water production requirement is projected to increase by approximately 53 percent systemwide. North Stockton’s production requirement is projected to increase by 27 percent and South Stockton’s production requirement is projected to increase by 171 percent from the existing baseline production. The large increase in South Stockton’s projected production requirement is due to the assumption that the Mariposa Road Community will be fully built by 2040 and served completely by COSMUD.

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Table ES-4. Projected Water Production Requirement for Future (2040) Conditions Parameter North Stockton, afy South Stockton, afy Total COSMUD, afy Existing Baseline Production
(refer to Table ES-2.)
25,795 5,700 31,495
Additional Future Demand by 2040
(refer to Table 3-16)
6,457 8,949 15,405
Future Non-Revenue Water (8%) 561 778 1,340
Total Production Requirement, afy 32,813 15,427 48,240
Total Production Requirement, mgd 29.3 13.8 43.1
Percent Increase from
Existing Baseline Production 27.2% 170.6% 53.2%
As shown above, the total future 2040 water production requirement presented in this Water Master Plan Update is 48,240 afy (43.1 mgd). This is compared to the total future 2035 water production requirement from the 2008 Water Master Plan which was estimated to be 110,000 afy (98.2 mgd). This represents a 56 percent drop, which is partially attributed to a decrease in existing water production from 2008 to 2019 (35.6 mgd in 2008 vs. 27.4 mgd in 2019), as well as a drop in unit water use factors due to improved water use efficiency (described in Chapter 3). However, the majority of the drop in the projected water production requirement can be attributed to the significant reduction in expected development by 2040, both in terms of the area to be developed and the projected population. Based on the planned future development identified in the Envision Stockton 2040 General Plan Update and April 2020 MSR/SOI Report, the anticipated gross development area by 2040 is 77 percent less than the 2008 Water Master Plan future gross development area. Associated with this reduced development area, there is approximately a 25 percent decrease in projected City-wide population from the 2035 General Plan to the Envision Stockton 2040 General Plan Update.

Figure ES-2 compares the City-wide population projections in the 2035 General Plan, the Envision Stockton 2040 General Plan Update and the 2015 UWMP, as well as the COSMUD water production requirements from the 2008 Water Master Plan, 2015 UWMP and this Water Master Plan Update. As shown, water production requirements have dropped significantly since the 2008 Water Master Plan was prepared. As shown on Figure ES-2, the water production requirements in the 2015 UWMP and this Water Master Plan Update generally align as similar population projections were assumed.

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Figure ES-2. Comparison of Previous and Current Population and Water Production Requirements The drop in future water production requirements from the 2008 Water Master Plan is reflected by less extensive recommendations for future water system improvements as described in Chapter 8 of this Water Master Plan Update.

RECOMMENDED EXISTING AND FUTURE WATER SYSTEM

IMPROVEMENTS
Chapter 9 presents the recommended capital improvement program (CIP) for the COSMUD existing, nearterm (2030) and future (2040) water system, based on the evaluations described in Chapters 7 and 8.

A summary of the recommended improvement projects, along with estimates of probable construction costs is provided for each proposed improvement project. It also identifies which costs should be allocated to existing water customers and which costs should be allocated to future development. Discussion of the proposed financial plan to fund the recommended improvement projects, including a discussion of the Water Rate Study which has been prepared in parallel with this Water Master Plan Update, is provided in Chapter 10.

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The following sections summarize the recommended existing, near-term (2030) and future (2040) water system improvements. Recommendations in this Water Master Plan Update were developed to:
• Replace aging and smaller diameter pipelines as part of a focused rehabilitation and repair (R&R) program to improve system operations and reliability • Optimize the use and rehabilitation of existing facilities (e.g., existing inactive groundwater wells) to meet future needs without adversely impacting existing water rates • Coordinate existing and near-term improvements with the on-going Water Rate Study to ensure that recommendations can be adequately funded
• Identify future water system improvements required to support and be funded by future development
It should be noted that the recommended water system improvements described in this Water Master Plan Update are significantly less extensive than those recommended in the 2008 Water Master Plan due to the following:
• Lower water demand projections associated with the reduced growth rate included in the Envision Stockton 2040 General Plan
• Lower existing demand conditions (and subsequent maximum day and peak hour demands) due to due to recent and continuing water use efficiencies • The proposed rehabilitation of existing inactive wells instead of the construction of new wells in South Stockton
• The availability of the Delta Water Treatment Plant (DWTP) to supply treated surface water in North Stockton water service area as the primary water supply, supplemented by groundwater supplies
• The ability to maximize the use of Stockton East Water District (SEWD) supplies in both South Stockton and North Stockton with the construction of the North Stockton Pipeline Hypochlorite Facility
Figure ES-3 presents overall recommendations for existing, near-term (2030) and future (2040) for the COSMUD North Stockton and South Stockton water service areas. Figure ES-4 presents the Priority 1 and 2 pipelines and age for the COSMUD pipelines for the recommended Priority 3 pipeline Rehabilitation and Replacement (R&R) Program.

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UT
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J A C K T O N E R D

F R E M O N T S T

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M A R I P O S A
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H O W A R D R D

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H A R L A N R D
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W
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K A I S E R R D
Stockton
East Water
District
Well SSS8
Well SSS2
30"
24"
24"
16"
24"
16"
24"
16"
24"
12"
16"
1 12" 2"
24"
16"
Well SSS3
Well SSS9
Well SSS10
24"
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Mariposa
New Well
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R I N D G E R D
14 Mile
Slough

SAN JOAQUIN RIVER

C ALAVERAS RIVER
Northwest
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #28
Well #15
16"
12"
8"
24"
12"
8"
16"
12"
12"
12"
8"
12"
12"
12"
12"
12"
16"
12"
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #33
Well #10R
24"
16"
12"
16"
12"
30"
16"
12"
16"
18"
16"
36"
18"
24"
16"
16"
12"
16"
16"
12"
42"
18"
18"
18"
18"
12"
16" 16"
18"
12"
16"
16"
16"
16"
16"
Northeast
36"
36"
Figure ES-3
Future System
With Improvements
City of Stockton
Water Master Plan Update
Pipelines
Existing
Existing System Improvements
Near-Term (2030) Improvements
Future (2040) Improvements
Future Development Pipelines
Wells
") New or Rehabilitated Near-Term (2030)
") New or Rehabilitated Future (2040)
") Active Existing
!( Backup Power Near-Term (2030)
!( Backup Power Future (2040)
TU Existing Reservoir & Pump Station
UTFuture (2040) Reservoir & Pump Station
Q3 Water Treatment Plant
COSMUD Service Boundary
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_9_FutureSystemWithImprove.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Near-term (2030) and future (2040) development pipelines are based on previous development plans.

Pipe layout and sizing will be finalized by developers/project proponents as development plans are finalized.

2. As discussed in the chapter, a groundwater study is recommended to identify which specific wells should be rehabilitated. For the purposes of this figure, Wells 15 and 28 have been identified, as these are the only standby wells. Other wells (i.e. inactive wells) may be recommended to be rehabilitated.

3. Other improvements not shown include: Improvements to the IPS and pipelines, Priority 3 Pipeline Improvements, DWTP Campus Improvements, Groundwater Recharge Basins, Metering/AMI Improvements.

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TU
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J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

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Stockton
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District
Well SSS2
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Well SSS3
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R I N D G E R D
14 Mile
Slough

SANJOAQUIN RIVER

CALAVERAS RIVER
Northwest
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #28
Well
#15
Well #16 Well #24
Well #9
Well #20
Well #26
Well #1
Well #4
Well #25
Well #11
Well #7
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well #30
Well #31
Well #32
Well #10R
Figure ES-4
Recommended Pipeline
Rehabilitation Program
City of Stockton
Water Master Plan Update
Priority 1 and 2 Pipelines
Priority 3 Pipelines by Decade of Installation
1950s or Earlier or Unknown
1960s - 1970s
1980s or Later
Existing Pipelines
COSMUD Service Boundary
Q3 Water Treatment Plant
TU Existing Reservoir & Pump Station
Wells
") Active
") Inactive
") Standby
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F9_2_RecExistSysImp.mxd - wjones - 1/6/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Priority 1 and 2 pipelines are recommended to be completed by 2030.

2. Priority 3 pipelines are recommended to be completed over a 40 year replacement cycle.

These pipelines can be further prioritized based on age (as shown) and/or leak history. Pipelines installed after the 1980s are recommended to be further evaluated by condition to determine if replacement is really needed. For the purposes of developing a CIP, these pipelines have been included in Priority 3 improvements.

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Recommended Existing System Improvements
Chapter 7 provides a summary of the evaluation of the existing COSMUD water system and its ability to meet recommended water system planning and design criteria described in Chapter 5. In general, the analysis recommends the following:
• Pipelines. Development of a Rehabilitation and Replacement (R&R) Program is recommended for both the North Stockton and South Stockton water service areas. The intent of this program is to replace older and undersized pipelines on a proactive and programmatic basis before they fail and require more expensive emergency repair and replacement, as well as to improve flows throughout the system. This should also include mains running through private property or through levies, or those that have known tree root damage. Pipelines were generally prioritized into the following areas:
— Priority 1: Pipelines in this category address areas where existing available fire flow capacity is less than 50 percent of the recommended criteria. — Priority 2: Pipelines in this category address areas where existing available fire flow capacity is between 50 and 75 percent of the recommended fire flow criteria. — Priority 3: This category contains the remaining smaller diameter pipelines (generally pipelines less that 8-inch diameter1).

An asset management plan should be developed so recommended pipeline improvements can be further refined by considering likelihood of failure (e.g., age, condition, leak history, etc.) and consequence of failure (e.g., disruption of water service to critical facilities, potential for damage to adjacent land use and facilities, etc.) to further refine and define program priorities and implementation.
• Supply (Wells). It is recommended that the COSMUD design and construct Well SSS10, as well as equip the well with backup power to address the existing storage capacity deficit.

As discussed in Chapter 7, much of the COSMUD water distribution system is older and was designed to earlier fire flow standards in place at the time the pipelines were constructed. Approximately 28 percent of the COSMUD system was installed in the 1970s or earlier, totaling approximately 164 miles of pipeline in the North Stockton and South Stockton water service areas. Due to the age of the pipelines, it is recommended that the COSMUD begin a comprehensive pipeline R&R program. As presented above, it is recommended that the program be prioritized as shown on Figure ES-4 to address areas where existing available fire flow is less than recommended criteria in place for future development. 1 As noted in Chapter 7, smaller diameter (less than 8-inch diameter) are allowed per COSMUD standard specifications provided that all capacity requirements are met. For the purposes of this Water Master Plan Update and for budgeting purposes, it is assumed that all small diameter pipelines are replaced with 8-inch diameter pipelines.

EXHIBIT 1
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Recommended Near-Term (2030) System Improvements
Chapter 8 provides a summary of the evaluation of the COSMUD water system and its ability to support near-term (2030) demands while meeting recommended water system planning and design criteria described in Chapter 5. In general, the analysis recommended the following:
• Supply (Wells). To address storage needs resulting from projected near-term (2030) demands and to address existing aging groundwater supply facilities, improvements to the following well facilities are recommended:
— In North Stockton, rehabilitate two existing wells to address older/aging well facilities and maintain groundwater supply reliability.
— In South Stockton, equip existing Wells SSS3 and SSS9 with backup power to access groundwater storage during emergencies and mitigate the projected storage deficit. — In South Stockton, rehabilitate existing Well SSS2, and equip with backup power, to access groundwater storage during emergencies and mitigate the projected storage deficit.

Improvements in North Stockton address older/aging infrastructure and should be allocated to existing water customers. Improvements in South Stockton are triggered by increased demands associated with future development and should be allocated to future development and paid through connection fees.

In addition to the above listed capacity related improvements, other improvements were identified through discussions with COSMUD staff. These projects are included to improve system and/or water supply reliability and are summarized below. These improvements are assumed to be funded by existing water customers. • Groundwater Study. A comprehensive groundwater supply study is recommended to investigate existing facility conditions, capacity and water quality/regulatory trends. The outcome of the study would identify recommendations for rehabilitation of wells in North Stockton and South Stockton, including identifying appropriate wellhead treatment (at each location or centralized at a reservoir site).
• Intake Pump Station and Pipeline Upgrade. Ground settlement at the Intake Pump Station (IPS) site has required the interim repair and adjustment of station infrastructure and the 54-inch raw water pipeline that supplies the DWTP. It is recommended that the COSMUD perform additional studies to develop a long-term strategy including appropriate design features and construct improvements to station infrastructure and the raw water pipeline. • DWTP Campus Improvements. COSMUD plans to develop an overall DWTP Campus to centralize treatment and distribution staff. These campus improvements would result in both management and operational efficiencies.
• Groundwater Storage Bank Study. A groundwater storage bank/recharge basins study is recommended to address future supply reliability by expanding/augmenting its conjunctive use portfolio, allowing for the flexibility of banking unused supply for use at a later time. • Advanced Metering Infrastructure (AMI) Study. An AMI Study, design, and implementation project is recommended to improve metering technology to allow for enhanced demand tracking, management, and water loss identification.

EXHIBIT 1
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Recommended Future (2040) System Improvements
Chapter 8 provides a summary of the evaluation of the COSMUD water distribution system and its ability to support future (2040) demands while meeting recommended water system planning and design criteria described in Chapter 5. In general, the analysis recommended the following:
• Storage and Pumping. To address future storage needs associated with future development, the following is recommended:
— In North Stockton, a new 4.0 MG Northeast Reservoir and associated 12.0 mgd pump station — In South Stockton, a new 3.5 MG Mariposa Road Community Reservoir and associated

12.0 mgd pump station
• Supply (Wells). To offset storage reservoir size and/or address the projected storage deficit, access groundwater storage during emergencies, and improve water supply reliability, the following are recommended:
— In North Stockton, construct and equip the planned Well 33 with backup power — In South Stockton, construct and equip a new well within the Mariposa Road Community development area, with backup power.
— In South Stockton, rehabilitate existing Well SSS8 and equip with backup power • Pipelines. To address high velocities observed in transmission pipelines downstream of the DWTP, it is recommended that 5,800 linear feet (lf) of 36-inch diameter pipelines be constructed.

Since the above listed recommendations are triggered by future demands, they should be allocated to future development and funded by connection fees.

BASIS OF RECOMMENDATIONS
The evaluations described in this Water Master Plan Update and the recommended capital improvement plan presented are based on several key assumptions which are described throughout this report. These assumptions include the timing, type and extent of future development projects within the COSMUD North Stockton and South Stockton water service areas. The current assumptions for future planned development, used for this Water Master Plan Update, are described in Chapter 3. Should these assumptions change (e.g., development timing is expedited or delayed, future planned land uses are changed, or the extent of development is changed or does not occur at all) the timing, need and sizing for water system improvements may be affected. Before COSMUD proceeds with the design and construction of recommended water system improvements, future development plans and associated water system facility capacity needs should be reviewed and confirmed.

In particular, as described in this Water Master Plan Update, the Mariposa Road Community is a large potential future development area in South Stockton. The development area’s previous entitlement has expired, and therefore it is not known if this project area will be developed or if it will be developed as previously planned. For the purposes of this Water Master Plan Update, it was assumed that the Mariposa Road Community will be developed by 2040, based on the most recent land use plan, and be served entirely by COSMUD. This future development area is one of the largest drivers for future growth within the COSMUD South Stockton water service area. In addition, although this development area is physically located within both the COSMUD water service area and the Cal Water service area, for the purposes of EXHIBIT 1
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this Water Master Plan Update, it was conservatively assumed that the COSMUD would serve the entire Mariposa Road Community area. As described in Chapter 8, and as summarized above, future water system improvements have been identified to serve the future Mariposa Road Community area. However, before COSMUD proceeds with the design and construction of water system improvements for the Mariposa Road Community, actual development plans and associated facility capacity needs should be reviewed and confirmed.

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Introduction

1.1 WATER MASTER PLAN UPDATE PURPOSE
The purpose of this Water Master Plan Update for the City of Stockton (City) is to evaluate the existing water system infrastructure and address potential impacts of near-term and long-term planned growth to develop a comprehensive guide for the City’s water system capital improvement program. The City’s Municipal Utilities Department (COSMUD) operates the City’s water system which serves customers in both North Stockton (serving primarily residential customers) and South Stockton (serving a mix of residential and industrial customers). Central Stockton is served by a separate water system operated by the California Water Service (Cal Water). Within Central Stockton, COSMUD operates the Walnut Plant System comprised of residential customers and the Diamond Walnut processing facility; however, the Walnut Plant System has not been evaluated as part of this Water Master Plan Update. This Water Master Plan Update only addresses the COSMUD North Stockton and South Stockton water service areas.

The City’s last Water Master Plan was completed in 2008. Since that time, the City has experienced growth, constructed a surface water treatment plant, and completed an update to its General Plan (the Envision Stockton 2040 General Plan), which provides the framework for future development in the City through 2040. The Delta Water Treatment Plant was completed in 2012 which provides the City with a new treated surface water supply to supplement its other water supplies.

Since the completion of the 2008 Water Master Plan, the State endured five years of drought starting in 2012, including the driest four consecutive years in California history. These unprecedented conditions led to statewide mandated water conservation, significant surface water supply reductions and curtailments and legislation establishing new statewide water efficiency standards.

All of these factors have led to a need to reassess the City’s water needs, priorities and strategies and reevaluate the need for water system infrastructure improvements to ensure a safe and reliable water supply for the City’s existing and future residents and businesses.

1.2 WATER MASTER PLAN OBJECTIVES AND PRIORITIES
The primary objectives of this Water Master Plan Update for the City of Stockton are to:
• Describe the existing COSMUD water system and facilities • Evaluate historical and existing water demands to understand recent water use trends, per capita water use and water use by customer type
• Develop future water demand projections for near-term (2030) and future (2040) conditions based on future planned development in the COSMUD water service areas and updated unit water use factors developed based on recent water use trends • Review the City’s existing water supplies and the opportunities and constraints associated with each supply source
• Review City and industry water system standards and refine performance and planning criteria under which the COSMUD water system will be evaluated and recommendations for future facilities will be formulated
• Update and calibrate the City’s water system hydraulic model to provide an updated, accurate tool for evaluating various water system demand and operational scenarios EXHIBIT 1
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• Evaluate the need for new water system facilities (including pipelines, supply facilities, storage facilities and pumping facilities) to meet existing, near-term (2030) and future (2040) water demands within the COSMUD water service areas • Develop a capital improvement program and financial plan for implementation of recommended water system improvements
This Water Master Plan Update has been prepared to be consistent with the mission of the City’s Municipal Utilities Department:

The City of Stockton Municipal Utilities Department’s mission is to provide high-quality drinking water on demand; collect, treat, and dispose of wastewater; and collect and dispose of stormwater, all in accordance with applicable regulations and responsible business practices.

Based on discussions with City staff, key priorities for the Water Master Plan Update include the following:
• Develop a Water Master Plan that reflects the strength and robustness of the City’s water system and facilities
• Clearly define long-term water supply and infrastructure needs so that water system infrastructure is neither undersized nor oversized
• Develop an updated hydraulic model that accurately represents the water distribution system, identifies deficiencies, allows for accurate assessment of needed infrastructure to serve proposed future development projects, and that can be easily updated to evaluate future changes
• Develop an updated Capital Improvement Plan that is consistent with projected water demands and proposed future development that can be used to inform water rates and connection fees
• Develop a Water Master Plan that is a user-friendly reference tool for both City staff and the development community
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1.3 PREVIOUS AND ON-GOING STUDIES

1.3.1 2008 Water Master Plan
The City’s previous Water Master Plan was completed in
2008 and was developed to support future development
in accordance with the City’s 2035 General Plan. The 2008 Water Master Plan addressed the following issues:
• The need for supplemental water supplies to
meet existing and future water demands and
to increase supply reliability;
• The continued use of groundwater as a
supply source;
• The need for additional transmission mains,
distribution pipelines, interconnections,
pumping capacity, wells and storage facilities
to meet the needs of existing customers and future development; and, • The need to implement a planned capital improvement program to meet the needs of the existing water system and to accommodate future growth.

Since the completion of the 2008 Water Master Plan, the City completed the Delta Water Treatment Plant, which provides the City with a new treated surface water supply. Also, the City has updated its General Plan to provide guidance for future development within the City’s Sphere of Influence.

As noted above, this Water Master Plan Update is a comprehensive update that refines unit water demand factors based on recent and projected water use trends and patterns to develop future demand projections, reflects the construction of the City’s Delta Water Treatment Plant, updates the City’s water system hydraulic model to evaluate system capacity, and reflects updates to future development plans to provide an evaluation of future water system needs. As described in Chapter 3 of this Water Master Plan Update, future water demands in the COSMUD water service areas are projected to be significantly lower than the water demand projections included in the 2008 Water Master Plan, primarily due to reduced growth projections within the City as reflected in the Envision Stockton 2040 General Plan. This results in significantly less extensive recommendations for water system improvements to support future water demands as compared to the 2008 Water Master Plan.

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1.3.2 Envision Stockton 2040 General Plan
In March 2016, the City commenced an update of the 2035 General Plan. The updated plan, the Envision Stockton
2040 General Plan, was adopted in December 2018. The
2040 General Plan process included a comprehensive
evaluation of the City’s planning boundaries, including the City’s Sphere of Influence (SOI). A key objective of the update was the establishment of a strategy for urban
growth that both reflected the community’s vision and
supported the City’s Climate Action Plan. This objective was achieved through extensive community outreach and
engagement, resulting in a land use plan that emphasizes infill development in the City’s core and supports
employment and economic development citywide.

The 2040 General Plan land use map depicts proposed
land use for Stockton within the SOI to accommodate
the growth projected by the San Joaquin Council of
Governments (SJCOG). Between 2020 and 2040, SJCOG
projects that Stockton’s population will grow by 102,898 to a total of 432,627 (equating to an annualized growth rate of 1.44 percent). This projection reflects growth
rates that are lower than what occurred in the early 2000s and what was previously anticipated in the 2035 General Plan which had projected a population of 580,000 by 2035.2 Other highlights of the 2040 General Plan are summarized below:
• The General Plan increases allowable residential densities and intensity of development downtown and in the surrounding greater downtown area. Infill policies are prevalent, particularly for downtown and South Stockton.
• Compared to the previous 2035 General Plan, the land use plan reduces by almost 8,000 acres (12 square miles) the amount of agricultural land that could be developed with urban land uses.
• Compared to the previous 2035 General Plan, the projected Citywide population at buildout of the General Plan has been reduced by 25 percent.
• The General Plan features a new policy to create an Ag Belt between Stockton and Lodi in collaboration with Lodi, the County, and property owners. • The General Plan provides guidance for reevaluating the City’s public infrastructure, such as roadways and water and sewer distribution systems, which will help the City to determine whether the capital and ongoing maintenance cost of infrastructure can be supported by development projects.
2 Stockton General Plan 2035 Goals & Policies Report, Community Development Objectives (page B-2), December 2007.

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As part of the General Plan preparation, Utility Master Plan Supplements were prepared to assess the needed utility infrastructure improvements to support the planned development envisioned in the General Plan. As part of the Potable Water Master Plan Supplement3, water demand projections were prepared and water system infrastructure capacity was evaluated for the land use alternatives considered, and recommendations were developed for updating backbone infrastructure plans to reflect the adopted land use plan (additional discussion of the water demand projections developed for the Utility Master Plan Supplements is provided in Chapter 3). The 2040 General Plan Update also included the preparation of an Infrastructure Financing Strategy to address these infrastructure needs.

The City’s General Plan is built on a number of goals and policies that are related to the provision of safe and reliable water supplies. Included in the Safety Element of the City’s General Plan is Goal SAF-3: Clean Water. Access to safe water is a fundamental human need for both physical and social health. Maintaining clean water supplies requires constant vigilance, significant expenditures, and sometimes changes in behavior, especially as the impacts of human activities become more pervasive. Water supply, quality, and distribution are vital to Stockton’s ability to serve its population now and in the future. Regulatory pressures, droughts, and saline intrusion affecting groundwater supplies have already strained the region’s water supplies. As a result, the City has focused attention on the availability of existing surface water supplies and is cooperating with other agencies in the region to manage groundwater resources at a sustainable yield.

Table 1-1 summarizes the General Plan goals, policies and actions related to water service within the City.

Table 1-1. General Plan Goals, Policies and Actions Related to Water Service General Plan Policy General Plan Action
Land Use Element: Goal LU-5: Protected Resources
Protect, maintain, and restore natural and cultural resources Policy LU-5.1: Integrate nature into
the city and maintain Stockton’s
urban forest
Action LU-5.1C: Require landscape plans to incorporate native and drought-tolerant plants in order to preserve the visual integrity of the landscape, conserve water, provide habitat conditions suitable for native vegetation, and ensure that a maximum number and variety of well-adapted plants are maintained.

Policy LU-5.2: Protect natural
resource areas, fish and wildlife
habitat, scenic areas, open space
areas, agricultural lands, parks, and
other cultural/historic resources
from encroachment or destruction
by incompatible development.

Action LU-5.2H: Comply with applicable water conservation measures.

Action LU-5.2I: Coordinate with water agencies and non-profit organizations to promote public awareness on water quality and conservation issues and consistency in water quality impacts analyses.

Policy LU-5.4: Require water and
energy conservation and efficiency in
both new construction and retrofits.

Action LU-5.4A: Require all new development, including major rehabilitation, renovation, and redevelopment, to adopt best management practices for water use efficiency and demonstrate specific water conservation measures.
3 Stockton General Plan Update – Potable Water Master Plan Supplement, prepared by West Yost Associates, December 12, 2017.

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Table 1-1. General Plan Goals, Policies and Actions Related to Water Service General Plan Policy General Plan Action
Land Use Element: Goal LU-6: Effective Planning
Provide for orderly, well-planned and balanced development Policy LU-6.1: Carefully plan for
future development and proactively
mitigate potential impacts
Action LU-6.1B: Monitor the rate of growth to ensure that it does not overburden the City’s infrastructure and services and does not exceed the amounts analyzed in the General Plan EIR.

Action LU-6.1D: Require that all utility connections outside the city limit be for land uses that are consistent with the General Plan.

Action LU-6.1E: Do not approve new development unless there is infrastructure in place or planned and funded to support the growth.

Action LU-6.1F: Evaluate and implement adjustments to the Public Facilities Fee structure to encourage development in areas where infrastructure is already present and ensure that non-infill development pays its fair share of anticipated citywide capital facilities and operational costs.

Policy LU-6.3: Ensure that all
neighborhoods have access to wellmaintained public facilities and utilities that meet community
service needs.

Action LU-6.3A: Require development to mitigate any impacts to existing sewer, water, stormwater, street, fire station, park, or library infrastructure that would reduce service levels.

Action LU-6.3B: Ensure that public facilities, infrastructure, and related land area and other elements are designed, and right-of-way is acquired, to meet 2040 planned development requirements to avoid the need for future upsizing or expansion, unless planned as phased construction.

Action LU-6.3C: Coordinate, to the extent possible, upgrades and repairs to roadways with utility needs, infrastructure upgrades, and bicycle and pedestrian improvements (i.e., “dig once”).

Safety Element: Goal SAF-3: Clean Water
Sustain clean and adequate water supplies
Policy SAF-3.1: Secure long-term
renewable contracts and related
agreements to ensure that surface
water rights will be available to meet
projected demand.

Action SAF-3.1A: Actively participate in appropriate forums designed to discuss and solve regional water supply and quality issues.

Policy SAF-3.2: Protect the
availability of clean potable water
from groundwater sources.

Action SAF-3.2A: Continue to cooperate with San Joaquin County and Cal Water to monitor groundwater withdrawals and ensure that they fall within the target yield for the drinking water aquifer.

Policy SAF-3.3: Encourage use of
recycled (“gray”) water for
landscaping irrigation to reduce
demand on potable supplies.

Action SAF-3.3A: Require new development to install non-potable water infrastructure for irrigation of large landscaped areas where feasible.

Action SAF-3.3B: Investigate and implement Code amendments to allow installation of dual plumbing and/or rainwater capture systems to enable use of recycled water and/or captured rainwater generated on- site.

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1.3.3 Water Cost of Service Rate Study
In parallel with this Water Master Plan Update, HDR is preparing an update of the City’s Water Cost of Service Rate Study. Water rate studies typically review and analyze updated cost information from administration, production, distribution, maintenance of existing and future capital project improvements and regulatory requirements. In addition, debt service coverage and purchase water costs are also included. The new cost of service rate study will determine if a water rate increase is warranted based on new cost information.

This Water Master Plan Update provided a list of recommended water system improvements which will be considered in the Water Cost of Service Rate Study as appropriate. As described in Chapter 9, water system improvements are recommended to meet both existing and future system needs. System improvements needed to meet existing system needs are allocated to existing users and are to be funded through water rates. System improvements needed to expand the production and distribution system to meet future system needs to serve future planned development are allocated to future users and are to be funded through water service connection fees. Water service connection fees are not a part of the Water Cost of Service Rate Study.

HDR has prepared a summary of the proposed financial plan to fund water system improvements. This is provided in Chapter 10 of this Water Master Plan Update.

1.3.4 2020 Urban Water Management Plan
The Urban Water Management Planning Act requires every urban water supplier in California that either provides over 3,000 acre-feet of water annually, or serves more than 3,000 urban connections, to prepare and adopt an Urban Water Management Plan (UWMP) that includes specified content, including an urban water shortage contingency analysis. The adopted UWMP must be submitted to the California Department of Water Resources (DWR) and other entities. Urban water suppliers are required to submit an UWMP every five years. The 2020 UWMP is due to DWR on July 1, 2021.

Work performed for this Water Master Plan Update will inform the development of the City’s 2020 UWMP, including water demand projections and projected water supplies.

1.3.5 Wastewater Master Plan Update
In parallel with this Water Master Plan Update, an update to the City’s Wastewater Master Plan is also being prepared by West Yost. Where applicable, work on both master plans has been coordinated to ensure that the two plans are consistent in their assumptions, projections and recommendations where appropriate. In particular, it is important is to ensure that water demand projections and wastewater flow projections are coordinated so that both systems can be appropriately planned to meet the needs of the City’s residents and businesses.

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1.4 REPORT ORGANIZATION
This Water Master Plan Update is organized into the following chapters:

Chapter 1: Introduction Describes the purpose, objectives and priorities for the Water Master Plan Update, its relationship to other ongoing studies, report organization and acknowledgments Chapter 2: Existing Water
System
Provides background information on the existing COSMUD
water service areas, water supplies and water system
facilities
Chapter 3: Water Demands Presents historical, current and projected future water demands based on planned future development in
accordance with the City’s Envision 2040 General Plan
Chapter 4: Water Supply Provides an overview of the existing COSMUD water supply sources and plans to optimize available water
supplies for the future
Chapter 5: Design/System
Performance Criteria
Defines the recommended performance and operational
criteria for the COSMUD water system, including supply, storage and pumping capacity, fire flow requirements,
minimum and maximum system pressures, and maximum
pipeline velocity and head loss
Chapter 6: Hydraulic Model
Update and Calibration
Describes the update, refinement and calibration of the COSMUD existing water distribution system hydraulic
model used to analyze the COSMUD distribution system
performance
Chapter 7: Existing Water
System Analysis
Describes the evaluation of the existing COSMUD water
system in comparison to the criteria developed in
Chapter 5 and provides recommendations for existing
system improvements
Chapter 8: Future Water System
Analysis
Describes the evaluation of the COSMUD water system
and its ability to meet projected future water demands in comparison to the criteria developed in Chapter 5 and
provides recommendations for future system
improvements
Chapter 9: Recommended
Water System Capital
Improvement Program
Provides a detailed summary of recommended capital
improvements for the COSMUD water system to meet
existing and projected future demands
Chapter 10: Financial Plan Provides an overview of funding options to implement the recommended capital improvements for the COSMUD
water system
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The following appendices to this Water Master Plan Update contain additional technical information, assumptions and calculations:

Appendix A: Hydrant Testing and
Hydrant Pressure Recorder
Placement Plan for Model
Calibration
Outlines the hydrant testing that was performed in
June 2020 and the associated collection of water
distribution system pressure data using hydrant pressure recorders to obtain data needed to calibrate the COSMUD water system hydraulic model to actual system conditions as described in Chapter 6
Appendix B: Hydraulic Model
Calibration Results – North
Stockton
Presents results from the hydraulic model calibration
process for the North Stockton water system comparing
model-predicted results to field-collected data as
described in Chapter 6
Appendix C: Hydraulic Model
Calibration Results – South
Stockton
Presents results from the hydraulic model calibration
process for the South Stockton water system comparing
model-predicted results to field-collected data as
described in Chapter 6
Appendix D: Cost Estimating
Assumptions
Describes cost estimating assumptions used to estimate
construction costs for recommended water system
improvements as described in Chapter 9
Appendix E: Financial Plan
Worksheets
Provides the worksheets prepared by HDR in support of
the financial plan presented in Chapter 10 and the water rate study being prepared in parallel with this Water
Master Plan Update

1.5 ACKNOWLEDGMENTS
The development of this Water Master Plan Update would not have been possible without the focused involvement and assistance of City staff. In particular, the following staff provided comprehensive information, significant input and important insights throughout development of this Water Master Plan Update:

John Abrew Director of Municipal Utilities Department
Ariana Adame Planning Manager, Community Development Department Gemma Biscocho Senior Civil Engineer, Engineering Division (Project Manager for Water Master Plan Update)
Juan Chavez Engineering Services Manager, Engineering Division Lance Cook Water Systems Superintendent, Water Field Office Matt Diaz Planning Manager/Advanced Planning, Community Development Department
Ali Gharegozloo Principal Engineer, Engineering Division Eric Houston Chief Plant Operator, Water Treatment Plant EXHIBIT 1
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Stephen Kenning Assistant Director of Municipal Utilities Department Mel Lytle Assistant Director of Municipal Utilities Department Mitchell Maidrand Deputy Director of Municipal Utilities Department, Water Resources Division
Jeff Marasovich CMMS/SCADA Systems Manager
Michael McDowell Deputy Director of Planning and Engineering, Community Development Department
Ann Okubo Associate Civil Engineer, Engineering Division Rudy Quinones Water Systems Supervisor, Water Field Office Travis Small Plant Operations Supervisor, Water Treatment Plant Danny Trejo Program Manager III, Water Resources Division EXHIBIT 1
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Existing Water System
This chapter describes the COSMUD existing water system, which generally serves the northern and southern areas of Stockton. System information is based on a review of previous studies, design reports, maps, plans, operating records, and discussions with the COSMUD staff. Key sections of this chapter include:
• Existing Water Service Areas
• Existing Water Supplies
• Existing Water System Facilities

2.1 EXISTING WATER SERVICE AREAS
The City is located in the Central Valley of California and is the County seat for San Joaquin County.

California State Highway 99 and Interstate 5 run north and south through the City on the east and west boundaries, respectively, and California State Highway 4 (the Crosstown Freeway) connects the two. The San Joaquin River flows from the south and terminates at the Delta area of Central Stockton.

As shown on Figure 2-1, the City of Stockton can be generally divided into three distinct water service areas:
• North Stockton: Served by the COSMUD, with the exception of several small developed areas (“islands”) served by San Joaquin County4.
• Central Stockton: Served by the California Water Service (Cal Water). • South Stockton: Served by the COSMUD.

This Water Master Plan Update only addresses the areas served by the COSMUD within the General Plan SOI, which includes most of North and South Stockton. In general, the North Stockton water service area is primarily residential and is bounded by Eight Mile Road to the north, Cascade and Columbia Railroad to the east, the Calaveras River to the south and the City limits to the west. Since the completion of the previous Water Master Plan, residential developments off of Eight Mile Road have continued to develop.

The South Stockton water service area is largely comprised of residential (on the west side) and industrial and agricultural land uses. The South Stockton water service area is generally bounded by French Camp Slough to the north, City limits to the east and south, and the San Joaquin River to the west. 4 Two of the County islands in North Stockton (Colonial Heights and Lincoln Village) receive water that is delivered by the COSMUD.

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Figure 2-1
Water Service Areas
City of Stockton
Water Master Plan Update
City of Stockton Limits
City of Stockton Sphere of Influence
California Water Service Area
San Joaquin County (served by COSMUD)
San Joaquin County
City of Stockton Municipal Utilities Department
Stockton East Water District
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F2_1_WaterServiceAreas.mxd - mmcwilliams - 1/13/2021 EXHIBIT 1
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2.2 EXISTING WATER SUPPLIES
The COSMUD water service areas are served by an existing water supply portfolio comprised of a conjunctive use system, which includes:
• Surface water from the San Joaquin River that is diverted at the Intake Pump Station on Empire Tract located in Sacramento-San Joaquin Delta (Delta) and treated at the City’s Delta Water Treatment Plant (DWTP), with supplemental surface water from the Mokelumne River diverted and conveyed by Woodbridge Irrigation District (WID), and treated at the City’s DWTP, when the City’s supplies from San Joaquin River are curtailed • Treated surface water from the Stockton East Water District (SEWD) conveyed from the New Melones (Stanislaus River) and New Hogan (Calaveras River) Reservoirs • Groundwater pumped by the COSMUD from City-owned and operated wells in the underlying Eastern San Joaquin Groundwater Subbasin
Details regarding these water supply sources are provided in Chapter 4. The water supply and treatment facilities are described as follows.

2.2.1 Surface Water Supply
The City’s surface water supply is from three primary sources: surface water diverted from the San Joaquin River treated at the City’s DWTP, surface water from the Mokelumne River diverted and conveyed by Woodbridge Irrigation District and treated at the City’s DWTP, and treated surface water from SEWD.

Due to differing disinfection processes that present water quality issues related to low chlorine residual and disinfection byproducts, COSMUD provides water from the DWTP only in its North Stockton water distribution system. Water from SEWD can be conveyed to both North and South Stockton distribution systems. At the time of preparation of this Water Master Plan Update, the COSMUD is in the process of implementing the North Stockton Pipeline Hypochlorite Facility that would allow SEWD supplies to be conveyed to the North Stockton system and combined with DWTP-produced water supply (this project is discussed further in Chapter 4).

2.2.1.1 Delta Water Treatment Plant
The San Joaquin River provides the largest portion of the City’s potable water supply. When the City received its water rights permit in 2006, the City implemented the Delta Water Supply Project (DWSP) to construct its DWTP north of Stockton, the Intake Pump Station (IPS) at the southwest tip of Empire Tract, and associated water supply infrastructure. The DWTP was completed in 2012. Since that time, the COSMUD has diverted water from the San Joaquin River via the IPS and treats the water at the DWTP for an increasing portion of its water supply.

The DWTP has a current treatment capacity of 30 million gallons per day (mgd). In 2019, it produced 68 percent of the COSMUD water supply. The DWTP treatment process includes ozone oxidation and disinfection and membrane filtration with chlorine added as a residual disinfectant. Treated water is stored in a 4-million-gallon (MG) storage tank and aqueous ammonia is added to provide a chloramine residual before distribution to the North Stockton water service area.

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As described further in Chapter 4, the City’s water supply from the San Joaquin River is curtailed annually from February 15 to June 15 due to environmental restrictions. During this period, the COSMUD obtains raw water from WID to augment its water supply. WID conveys raw water through its Wilkinson Canal and Pixley Lateral Pipeline to the DWTP for treatment.

2.2.1.2 Stockton East Water District
SEWD is a wholesale water supplier that provides treated potable water to the urban water retailers within the Stockton Metropolitan Area, including COSMUD, Cal Water, and two small maintenance districtsin San Joaquin County. SEWD’s Dr. Joe Waidhofer Water Treatment Plant (DJWWTP) has a current capacity of 60 mgd and is located in Central Stockton. In 2019, SEWD produced approximately 20 percent of the COSMUD water supply.

The SEWD receives water from New Melones (Stanislaus River) and New Hogan (Calaveras River) Reservoirs.

Diverted wateris temporarily stored in three small earthen reservoirs at the DJWWTP. The South, North and Intake reservoirs contain 30, 24, and 26 MG of raw water when full, respectively. The treatment process is comprised of coagulation, flocculation, sedimentation, filtration, and disinfection. Granular activated carbon (GAC) is used for removing organic contaminants and controlling taste and odor problems, while chlorine gas is used for disinfection. Recently, SEWD has proposed to change the DJWWTP disinfection process from chlorine gas to liquid sodium hypochlorite. Treated water is then pumped into the distribution system manifold from a 20 MG underground finished water reservoir. The manifold splits the flow in the South Stockton Aqueduct, the Cal Water distribution system, and the North Stockton Aqueduct.

The COSMUD supplies SEWD treated water to its South Stockton water service area. At the time of preparation of this Water Master Plan Update, the COSMUD has commenced construction of the North Stockton Pipeline Hypochlorite Facility that would allow SEWD water suppliesto be conveyed to the North Stockton system and combined with the DWTP-produced water supply. This project is discussed in further detail in Chapter 4 (Section 4.2.1).

2.2.2 Groundwater Supply
The COSMUD operates groundwater wells in both the North and South Stockton water service areas. Both water service areas generally rely on treated surface water year-round for their primary supply, but it is supplemented with groundwater to meet increased water demands primarily in the summer months or during dry years when available surface water supplies may be limited. Wells are also depended on for emergency supply in the event of surface water supply interruptions.

2.3 EXISTING WATER SYSTEM FACILITIES
As described above, the COSMUD operates a water distribution system that contains two water service areas: North Stockton and South Stockton. The two water service areas are connected to one another by the Stockton Aqueduct; however, water supplies in the two water service areas do not currently comingle due to the higher pressure from SEWD in South Stockton which prevents water from North Stockton from flowing into the South Stockton area. The lowest ground surface elevation (at mean sea level) is on the western side of the system and the highest elevation (36 feet above mean sea level) is on the eastern side of the system.

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2.3.1 Groundwater Wells
There are currently twelve (12) operational (i.e., active or standby) groundwater wells in North Stockton with design capacities ranging from 800 to 3,200 gallons per minute (gpm). The ten (10) active wells have a total production capacity of 29.1 mgd and the two (2) standby wells have a total production capacity of

4.5 mgd, for a total available capacity of approximately 33.6 mgd. The North Stockton system also includes ten (10) inactive wells, which are currently not permitted by the Division of Drinking Water (DDW). Although the total active well capacity is 29.1 mgd, actual groundwater production is less due the fact that the DWTP provides the majority of the supply in North Stockton. Table 2-1 summarizes the information on the North Stockton wells.

There are currently four (4) operational (i.e., active or standby) groundwater wells in South Stockton. The design capacities range from 1,400 to 2,800 gpm. The two (2) active wells have a total production capacity of 6.9 mgd, and the two (2) standby wells have a production capacity of 3.3 mgd. The South Stockton system also has one (1) inactive well, which is currently not permitted for use. Similar to North Stockton, although the total active well capacity is 6.9 mgd, actual groundwater production is less due to the fact that the SEWD DJWWTP provides the majority of the supply in South Stockton. Table 2-2 summarizes the information on the South Stockton wells which are designated as South Stockton System (SSS) wells.

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Table 2-1. North Stockton Well Facilities
Well
Number Location
Installed
HP
Pumping
Capacity,
gpm(a)
Year
Drilled
Depth,
ft
Well
Status
Well
Age,
years
Backup
Power
Installed
1 Rivara Road 40 648 1954 268 Inactive 66 No
3R West Lane 200 2,000 -- -- Active -- Yes
4 Villa Dorado Park 75 1,050 1965 602 Inactive 55 No
7 Galloway Drive 40 550 1963 238 Inactive 57 No
9 Don Carlos Drive 50 540 1955 290 Inactive 65 No
10R Valverde Park 200 2,000 -- -- Active -- No
11 Inglewood 75 1,100 1958 317 Inactive 62 No
15(a) Mosher Slough and
WPRR 150 1,805 1975 600 Standby 45 No
16 Lower Sacramento
Road
200
(gas) 2,000 1976 600 Inactive 44 No
18 Hickock Drive 60 800 1956 211 Active 64 No
19 1233 Sutherland 200 2,000 1978 500 Active 42 No
20(a) West Lane/
Summerview Drive
200
(gas) 1,800 1978 545 Inactive 42 No
21 Cortez Park 200 2,000 1978 500 Active 42 No
24 Saffron Way 150 1,040 1982 495 Inactive 38 No
25 Panella Park 200
(gas) 1,600 1984 570 Inactive 36 No
26 Hammer and
EBMUD N/A 1,970 1987 450 Inactive 33 No
27 Bonaire Circle 200 2,000 1985 575 Active 35 No
28 Wild Grape Drive 120 1,295 1997 560 Standby 23 No
29 Autumn Oak Place 200 3,200 2000 500 Active 20 Yes
30 Grider Way 200 2,200 2003 540 Active 17 Yes
31 Ivano Lane 200 2,000 2004 410 Active 16 Yes
32 North State Route 99
(West Frontage Road) 200 2,000 2004 480 Active 16 Yes
Total Active Well Pumping Capacity, gpm 20,200
mgd 29.1
Total Standby Well Pumping Capacity, gpm 3,100
mgd 4.5
Source: Status and backup power are based on City of Stockton’s Permit Amendment dated January 7, 2020 (active wells are highlighted in green) and other information is based on the City of Stockton's 2008 Water Master Plan. (a) Well capacities based on the most recent capacity reported on “Well Rehabilitation List Status 103020.xlsx”, provided to West Yost on October 30, 2020.

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Table 2-2. South Stockton Well Facilities
Well
Number Location
Installe
d HP
Pumping
Capacity,
gpm(a)
Year
Drilled
Depth,
ft
Well
Status
Well
Age,
years
Backup
Power
Installed
SSS 1(a) 4728 Quantas Lane 200 1,000 1984 600 Inactive 36 No SSS 2(a) 4605 W Highway 99
Frontage Road 100 1,295 1953 172 Standby 67 No
SSS 3 4748 Frontier Way 200 2,000 1989 625 Active 31 Yes SSS 8(a) 4120 Pock Lane 250 1,010 2000 410 Standby 20 No SSS 9 B Street 200 2,800 2004 372 Active 16 No
Total Active Well Pumping Capacity, gpm 4,800
mgd 6.9
Total Standby Well Pumping Capacity, gpm 2,305
mgd 3.3
Source: Status and backup power are based on City of Stockton’s Permit Amendment dated January 7, 2020 (active wells are highlighted in green) and other information is based on the City of Stockton's 2008 Water Master Plan (a) Well capacities based on the most recent capacity reported on “Well Rehabilitation List Status 103020.xlsx”, provided to West Yost on October 30, 2020.

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2.3.2 Storage Reservoirs and Reservoir Pump Stations
The North Stockton water system has a total available storage capacity of 16.2 MG. Three 3.4 MG storage reservoirs are located at the Northwest (NW) Reservoir site and two 3 MG storage reservoirs are located near Fourteen-Mile Slough (FMS). The South Stockton water system has a total available storage capacity of 6 MG, with two 3 MG storage reservoirs located at Weston Ranch (WR). Table 2-3 summarizes the information for each storage facility. Each reservoir has an altitude valve which opens to fill the reservoir based on reservoir levels. Generally, these valves are equipped with sustaining features that allow the altitude valve to maintain a minimum upstream pressure, thereby avoiding low system pressures during fill cycles.

Table 2-3. City of Stockton Water Storage Reservoirs
Reservoir
Name Tank
Reservoir
Type
Reservoir
Material
Year
Installed
Diameter,
feet
Overflow
Elevation,
feet
Bottom
Elevation,
ft
Nominal
Storage
Capacity,
MG
North Stockton
Northwest
1 Cylindrical Steel 1996 120 45.9 4.9 3.4
2 Cylindrical Steel 1996 120 45.9 4.9 3.4
3 Cylindrical Steel 2008 120 45.9 4.9 3.4
Fourteen-Mile
Slough
1 Cylindrical Steel 1995 120 35 0 3.0
2 Cylindrical Steel 1995 120 35 0 3.0
South Stockton
Weston Ranch
1 Cylindrical Steel 1995 135 44 15 3.0
2 Cylindrical Steel 2010 135 44 15 3.0
Total Storage Capacity, MG 22.2
EXHIBIT 1
1685
There is a pump station at each of the reservoir sites to pump the stored water from the at-grade reservoirs into the distribution system during higher system demands. Table 2-4 summarizes the information for each reservoir pump station. As shown on Table 2-4, the North Stockton area has a total and firm pumping capacity of 39,750 gpm (57.2 mgd) and 31,450 gpm (45.3 mgd), respectively. The South Stockton area has a total and firm pumping capacity of 12,000 gpm (17.3 mgd) and 9,000 gpm (13.0 mgd), respectively.

Table 2-4. City of Stockton Reservoir Pump Stations
Pump Station Location Pump No.

Nominal
Capacity,
gpm Horsepower
Total
Capacity,
gpm
Firm
Capacity(a)
gpm
North Stockton
Northwest
10001 North I-5
Frontage Road
1 5,000 200
25,200 20,200
2 3,800 150
3 3,800 127
4 3,800 127
5 3,800 150
6 5,000 200
Fourteen-Mile Slough
5656 Feather River Drive
1 3,300 150
14,550 11,250
2 3,300 150
3 2,650 125
4 2,650 125
5 2,650 125
South Stockton
Weston Ranch
750 French Camp Road
1 3,000 125
12,000 9,000
2 3,000 125
3 3,000 125
4 3,000 125
(a) Firm capacity is the total installed capacity with the largest pump out of service.

EXHIBIT 1
1686

2.3.3 Transmission and Distribution Pipelines
The COSMUD water transmission system consists of 16- to 48-inch diameter pipelines. The North Stockton water service area is connected to the SEWD DJWWTP via a 48-inch diameter pipeline and connected to the DWTP via a 42-inch diameter pipeline. The South Stockton water service area is connected to the SEWD DJWWTP via the 42-inch diameter pipeline. The COSMUD water distribution system consists of pipelines with diameters less than 16 inches. Most of the service laterals branch off of 8-inch and 12-inch diameter pipelines. Table 2-5 provides a summary of distribution system pipelines by pipe diameter. As shown on Table 2-5, about 60 percent of the distribution system is comprised of pipelines which are 8-inches in diameter or less. Figure 2-2 shows the existing water distribution system.

Table 2-5. City of Stockton Distribution System Pipeline Diameters(a) Pipeline Diameter Length of Pipeline Percent in
Inches feet miles Water System
North Stockton
4 or less 67,736 12.8 2.2
6 309,182 58.6 10.0
8 1,156,797 219.1 37.5
10 to 12 616,959 116.8 20.0
Greater than 12 but less than 24 102,600 19.4 3.3
24 or greater 171,447 32.5 5.6
Unknown 16,441 3.1 0.5
North Stockton Subtotal 2,441,164 462.3 79.2%
South Stockton
4 or less 7,386 1.4 0.2
6 35,779 6.8 1.2
8 249,737 47.3 8.1
10 to 12 127,325 24.1 4.1
Greater than 12 but less than 24 128,966 24.4 4.2
24 or greater 83,814 15.9 2.7
Unknown 7,770 1.5 0.3
South Stockton Subtotal 640,777 121.7 20.8%
Total 3,081,941 584 100.0%
(a) Data summarized from the City of Stockton's GIS pipeline feature class provided April 2020. Only pipelines with an FEA Code for "encased city line" or "city line" are included. Pipelines with an unspecified/blank diameter or a diameter of zero are included in the Unknown category.

EXHIBIT 1
1687
")
") ")
")
")
")
")
")
") ")
")
")
")
") ")
")
")
")
")
")
")
") ")
")
")
")
")
UT
UT
UT
Q3
Q3
§¨¦5
ÄÆ4
ÄÆ99
14 Mile
Slough
Northwest
Weston Ranch
Well #28
Well
SSS2
Well #15

A R C H A I R P O R T R D

D A G G E T T
R D

M O R A D A L N

A R C H

A I R P O R T R D

F R E M O N T S T

M A R K E T

M A I N S T
S T

E I G H T M I L E R D

D R M A R T I N

L U T H E R K I N G

J R B L V D

C H A R T E R W A Y

W A S H I N G T O N S T

C A L I F O R N I A S T

F I L B E R T
S T

P E R S H I N G A V E

M A I N S T

H U N T E R
S T

C E N T E R S T

D A V I S R D

M A T H E W S
R D

H A R D I N G
W A Y

F A R M I N G T O N R D

A L P I N E A V E

M O R A D A
L N

P A C I F I C A V E

E L D O R A D O S T

B E N J A M I N

H O L T D R

W I L S O N
W A Y

S I E R R A

N E V A D A S T

A I R P O R T W A Y

W E B E R
A V E

O A K S T P A R K S T

B U C K L E Y

C O V E W A Y

H O L M A N R D

H A M M E R L N

A L P I N E A V E

E L D O R A D O S T

C O U N T R Y

C L U B B L V D

F R E N C H C A M P R D

W I L S O N W A Y

S W A I N R D

M A R C H L N

T H O R N T O N R D

N A V Y D R

C H E R O K E E R D

M A R I P O S A R D

M A N T H E Y R D

R O T H R D

D I A M O N D
S T

A R C H R D

W A T E R L O O R D

W E S T L N

P O R T O F

S T O C K T O N E Y

H A R L A N R D

M A R I P O S A
R D
Well #16 Well #24
Well #9 Well
#20
Well #26
Well #1 Well #4
Well #25
Well SSS1
Well #11
Well #7
Well SSS8
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well SSS3
Well #29
Well #03R
Well SSS9
Well #30
Well #31
Well #32
Well #10R
Figure 2-2
Existing Water System
City of Stockton
Water Master Plan Update
Q3 Water Treatment Plant
UT Storage Tank and Pump Station
") Active Well
") Inactive Well
") Standby Well
Pipelines
Less than 12 inches
12 - 14 inches
16 - 22 inches
24 inches or greater
COSMUD Water Service Boundary
California Water Service
San Joaquin County (served by COSMUD)
San Joaquin County
Stockton East Water District
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F2_2_ExistingSystem.mxd - bvera - 11/18/2020 0 0.6 1.2
Miles
EXHIBIT 1
1688
Age and material of pipeline is not well documented in the City’s GIS system. In previous studies, pipeline install dates were estimated based on construction of nearby buildings. This information was correlated back to the COSMUD water system to gain an estimate of the age of water system pipelines, assuming that both systems were constructed around the same time. Table 2-6 and Figure 2-3 summarize pipelines by approximate installation decade ranges. Based on conversations with COSMUD Operations staff, pipeline materials predominantly consist of asbestos cement (AC) and polyvinyl chloride (PVC). Based on the City’s GIS, there are also small amounts of cast iron, ductile iron, concrete lined and coated, and steel pipelines. In general, pipelines constructed before the mid-1980s generally consist of AC. Around the mid1980s and thereafter, COSMUD transitioned to primarily PVC.

Table 2-6. City of Stockton Distribution System Pipeline Installation Year(a) Decade of Pipeline Installation
Length of Pipeline Percent of
feet miles Water System
North Stockton
1950s or earlier 109,632 20.7 3.6
1960s 161,722 30.6 5.2
1970s 535,088 101.3 17.4
1980s 320,196 60.6 10.4
1990s 353,192 66.9 11.5
2000s 672,891 127.4 21.8
2010s 37,837 7.2 1.2
Unknown 250,606 47.5 8.1
North Stockton Subtotal 2,441,164 462.3 79.2%
South Stockton
1960s 8,816 1.7 0.3
1970s 51,879 9.8 1.7
1980s 11,202 2.1 0.4
1990s 219,430 41.6 7.1
2000s 184,289 34.9 6.0
2010s 13,087 2.5 0.4
Unknown 152,075 28.8 4.9
South Stockton Subtotal 640,777 121 20.8%
Total 3,081,941 584 100.0%
(a) Data summarized from the City of Stockton's GIS pipeline feature class and the PipelineInstallDate.dbf file, provided April 2020. Only pipelines with an FEA Code for "encased city line" or "city line" are included. Pipelines with an installation year of zero are shown in the Unknown category.

EXHIBIT 1
1689
TU
Q3
§¨¦5
ÄÆ99

A R C H A I R P O R T R D

A R C H

A I R P O R T R D

M A I N S T

D R M A R T I N

L U T H E R K I N G

J R B L V D

C H A R T E R W A Y

W A S H I N G T O N S T

C A L I F O R N I A S T

F I L B E R T
S T

P E R S H I N G
A V E

M A R I P O S A
R D

M A I N S T

H U N T E R
S T

C E N T E R S T

M A T H E W S
R D

F A R M I N G T O N R D

E L D O R A D O S T

W I L S O N
W A Y

S I E R R A

N E V A D A S T

A I R P O R T W A Y

W E B E R
A V E

O A K S T

P A R K S T

M A I N S T

F R E N C H C A M P R D

N A V Y D R

M A R I P O S A R D

M A N T H E Y
R D

R O T H R D

D I A M O N D
S T

A R C H R D

M A R I P O S A
R D
Weston Ranch
Stockton
East Water
District
TU
TU
Q3
Q3
§¨¦5
ÄÆ99
14 Mile
Slough
Northwest

M O R A D A L N

F R E M O N T S T

M A I N S T

E I G H T M I L E R D

C E N T E R S T E L D O R A D O S T

C A L I F O R N I A S T

F I L B E R T
S T

P E R S H I N G A V E

W I L S O N
W A Y

M A I N S T

D A V I S R D

H A R D I N G
W A Y

A L P I N E A V E

P A C I F I C A V E

B E N J A M I N H O L T D R

A I R P O R T W A Y

W E B E R
A V E

O A K S T

M A I N S T

B U C K L E Y

C O V E W A Y

H O L M A N R D

H A M M E R L N

A L P I N E A V E

E L D O R A D O S T

C O U N T R Y

C L U B B L V D

L O W E R S A C R A M E N T O R D

W I L S O N W A Y

S W A I N
R D

M A R C H L N

T H O R N T O N R D

C H E R O K E E R D

W A T E R L O O R D

W E S T L N
Delta Water
Treatment
Plant
Stockton
East Water
District
Figure 2-3
System Pipelines by
Decade of Installation
City of Stockton
Water Master Plan Update
Q3 Water Treatment Plant
TU Storage Tank and Pump Station
No Date Available
1940s or earlier
1950s
1960s
1970s
1980s
1990s
2000s
2010s
COSMUD Water Service Boundary
California Water Service
San Joaquin County (served by COSMUD)
San Joaquin County
Stockton East Water District
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F2_3_PipeAge.mxd - mmcwilliams - 12/15/2020 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
Notes:

1. Pipeline information is from StocktonWaterSystem.gdb and PipelineInstallDate.dbf provided by the City in April 2020.

NORTH STOCKTON

SOUTH STOCKTON
EXHIBIT 1
1690
Water Demands
This chapter describes the COSMUD historical, current and projected near-term and future water demands.

The projected near-term and future demands are based on refined water use factors and planned future development from the City’s recently updated 2040 General Plan Update (GPU) along with other specific planned development projects the City has identified. Projected near-term and future water demands will be used to evaluate the future water production required and the adequacy of the COSMUD available water supplies and capacity of the COSMUD water system to reliably deliver water to its customers.

The following sections of this chapter present the COSMUD historical and current water demands, along with planned future development, projected water demands, and future water production required for the near-term (2030) and future (2040) timeframes:
• Historical Water Production and Use
• Historical Peak Water Use
• Existing and Future Land Use and Growth Projections
• Water Use Factors
• Future Water Demands and Required Water Production
• Comparison to the 2008 WMP, the 2015 UWMP and the 2018 Utility Master Plan Supplements

3.1 HISTORICAL WATER PRODUCTION AND USE
The following sections summarize the historical water production for the COSMUD water service areas which include generally North and South Stockton and the Walnut Plant water service area in Central Stockton that is surrounded and served by the California Water Service (Cal Water) through a wheeling agreement.

3.1.1 Historical Annual Water Production
Historically, the COSMUD has obtained purchased water from SEWD and groundwater produced by the COSMUD groundwater wells. In 2012, the DWTP was completed and began delivering treated surface water to the COSMUD North Stockton water service area. After introducing surface water from DWTP in the North Stockton water service area, the COSMUD slowly reduced its supplies from SEWD until June 2016, at which point it solely depended on DWTP and local groundwater supplies in the North Stockton water service area, and utilized supplies from SEWD only in the South Stockton water service area. The primary reason for the use of DWTP supplies in North Stockton and SEWD supplies in South Stockton is due to differing disinfection processes that present water quality issues related to low chlorine residual and the potential for formation of disinfection byproducts. This is described further in Chapter 4.

EXHIBIT 1
1691
Table 3-1 summarizes the annual water production for the COSMUD North and South Stockton water service areas, as well as the Walnut Plant Area located in Central Stockton5. In North and South Stockton, a surface water to groundwater mix of approximately 74 and 26 percent, respectively, was supplied from 2006 to 2010. When the DWTP came online in 2012, the COSMUD began utilizing more surface water, approximately 90 percent of the overall production, but the supply mix dropped back down to about 76 percent surface water due to the drought. The five-year average surface water supply has averaged approximately 86 percent. The reliance on groundwater has decreased since 2012 with the availability of additional surface water supplies treated at the DWTP.

Figure 3-1 displays the monthly water production from 2006 through 2019 for the COSMUD North Stockton water service area. Prior to 2012, North Stockton relied on water supply from SEWD and groundwater wells. Since 2012, North Stockton has transitioned to relying on water supply from the DWTP supplemented by groundwater wells. The highest average day water production occurred in 2007 with a total of 28.4 mgd. The lowest average day water production occurred in 2015 with a total of 19.6 mgd. In 2019, the average day water production was 21.9 mgd. Water production decreased from 2007 to 2015, attributed to the 2008 economic downturn, the recent drought, and water conservation measures implemented due to the drought. Since 2015, there appears to be a rebound in water production in North Stockton from pre-drought conditions, but water demands are still below pre-drought conditions.

Figure 3-2 displays the monthly water production from 2006 through 2019 for the COSMUD South Stockton water service area. South Stockton is supplied by SEWD, supplemented by groundwater. The DWTP does not supply South Stockton since it is not hydraulically connected. The highest average day water production occurred in 2007 and 2008 with a total of 7.1 mgd. The lowest average day water production occurred in 2015 with a total of 3.8 mgd produced, at the height of the drought. In 2019, the average day water production was 5.3 mgd. The same trends occurred in South Stockton as in North Stockton, and there was a steady decrease in water production from 2007 through 2015 and then a rebound from 2015 to 2019.

Figure 3-3 displays the monthly water production from 2006 through 2019 for the COSMUD Central Stockton water service area. The Walnut Plant Area in Central Stockton relies exclusively on water purchased from SEWD and wheeled through the Cal Water system. The Walnut Plant Area is hydraulically isolated from the North and South Stockton water service areas. The highest average day water production occurred in 2006 with a total of 0.4 mgd. The Walnut Plant Area has since experienced an overall decrease in water demand. In 2019, the average day water production was 0.2 mgd.

Figure 3-4 displays the monthly water production from 2006 through 2019 for the entire COSMUD water service area. The highest average day production, systemwide, occurred in 2007 with a total of 35.8 mgd produced for the COSMUD. The lowest average day production occurred in 2015 with only 23.5 mgd produced. Since 2015, the average day production has been increasing and in 2019, 27.4 mgd of water was produced for the COSMUD.
5 As noted in Chapter 1, the Walnut Plant Area has not been evaluated in this Water Master Plan Update. However, discussion of water production for the Walnut Plant Area has been included here as it is part of the total COSMUD water production.

EXHIBIT 1
1692
Table 3-1. Historical Water Production(a)
SEWD, af DWSP, af Groundwater, af Total, af
Surface Water
Percent of Total, af
Groundwater
Percent of Total, af SEWD, af Groundwater, af Total, af Surface Water
Percent of Total, af
Groundwater
Percent of Total, af SEWD, af DWSP, af Groundwater, af Total, af Surface Water
Percent of Total, af
Groundwater
Percent of Total, af
2006 18,010 0 11,309 29,320 61% 39% 4,079 2,009 6,088 67% 33% 407 22,496 0 13,319 35,815 63% 37% 2007 20,461 0 11,326 31,787 64% 36% 7,101 876 7,977 89% 11% 311 27,873 0 12,202 40,075 70% 30% 2008 21,364 0 10,280 31,644 68% 32% 7,157 841 7,998 89% 11% 256 28,776 0 11,121 39,897 72% 28% 2009 21,985 0 6,810 28,795 76% 24% 6,845 698 7,542 91% 9% 241 29,072 0 7,508 36,579 79% 21% 2010 22,730 0 5,034 27,764 82% 18% 6,820 439 7,260 94% 6% 236 29,786 0 5,473 35,260 84% 16% 2011 22,001 0 5,797 27,798 79% 21% 7,483 211 7,694 97% 3% 234 29,718 0 6,008 35,727 83% 17% 2012 17,546 9,559 3,219 30,325 89% 11% 6,360 175 6,535 97% 3% 240 24,146 9,559 3,394 37,100 91% 9% 2013 10,564 15,463 3,772 29,799 87% 13% 6,288 314 6,602 95% 5% 291 17,143 15,463 4,085 36,692 89% 11% 2014 9,391 9,598 6,842 25,831 74% 26% 5,165 386 5,551 93% 7% 220 14,777 9,598 7,228 31,603 77% 23% 2015 2,211 14,059 5,641 21,911 74% 26% 3,241 978 4,219 77% 23% 182 5,634 14,059 6,619 26,312 75% 25% 2016 139 18,922 3,569 22,629 84% 16% 4,822 179 5,002 96% 4% 214 5,175 18,922 3,748 27,845 87% 13% 2017 2 20,843 2,852 23,696 88% 12% 5,190 114 5,304 98% 2% 241 5,433 20,843 2,965 29,241 90% 10% 2018 0 21,229 3,206 24,435 87% 13% 5,426 30 5,456 99% 1% 212 5,639 21,229 3,236 30,103 89% 11% 2019 0 20,809 3,770 24,579 85% 15% 5,920 8 5,928 100% 0% 176 6,096 20,809 3,778 30,684 88% 12% Average 11,886 9,320 5,959 27,165 78% 22% 5,850 518 6,368 92% 8% 247 17,983 9,320 6,478 33,781 81% 19% 5-Year Average 470 19,172 3,807 23,450 84% 16% 4,920 262 5,182 94% 6% 205 5,595 19,172 4,069 28,837 86% 14% (a) Source: Data for 2009-2019 (City Monthly Month_Year.xlsx) provided by City staff in May 2020.

North Stockton South Stockton Total
Year
Walnut Plant Area
(SEWD), af
N - 129 - 60-20-41 - E - 6 - 3 - F6-2
City of Stockton
Water Master Plan Update
Last Revised: 01-26-21
EXHIBIT 1
1693
Last Revised: 09-02-16; o\c\418\02-14-36\e\T120\Ch3_TablesandFigures.xlsx 2006: 26.2 mgd
2007: 28.4 mgd 2008: 28.2 mgd
2009: 25.7 mgd 2010: 24.8 mgd 2011: 24.8 mgd 2012: 27.1 mgd 2013: 26.6 mgd 2014: 23.1 mgd
2015: 19.6 mgd 2016: 20.2 mgd 2017: 21.2 mgd 2018: 21.8 mgd 2019: 21.9 mgd -40-30-20-10010203040
0 200400600800
1,0001,2001,4001,600
January 2006
March 2006
May 2006
July 2006
September 2006
November 2006
January 2007
March 2007
May 2007
July 2007
September 2007
November 2007
January 2008
March 2008
May 2008
July 2008
September 2008
November 2008
January 2009
March 2009
May 2009
July 2009
September 2009
November 2009
January 2010
March 2010
May 2010
July 2010
September 2010
November 2010
January 2011
March 2011
May 2011
July 2011
September 2011
November 2011
January 2012
March 2012
May 2012
July 2012
September 2012
November 2012
January 2013
March 2013
May 2013
July 2013
September 2013
November 2013
January 2014
March 2014
May 2014
July 2014
September 2014
November 2014
January 2015
March 2015
May 2015
July 2015
September 2015
November 2015
January 2016
March 2016
May 2016
July 2016
September 2016
November 2016
January 2017
March 2017
May 2017
July 2017
September 2017
November 2017
January 2018
March 2018
May 2018
July 2018
September 2018
November 2018
January 2019
March 2019
May 2019
July 2019
September 2019
November 2019
Annual Average Day Water Production, mgd
Water Production, MG
Month
SEWD DWTP Groundwater Annual Average Day Production
Figure 3-1
Historical Monthly
Water Production
for North Stockton
City of Stockton
Water Master Plan Update
Notes:1. Source: Data for 2009-2019 (City Monthly Month_Year.xlsx) provided by City staff in May 2020.

2. Abbreviations: MG = million gallons; mgd = million gallons per day; SEWD = Stockton East Water District; DWTP = Delta Water Treatment Plant.

EXHIBIT
1 1694
Last Revised: 09-02-16; o\c\418\02-14-36\e\T120\Ch3_TablesandFigures.xlsx 2006: 5.4 mgd
2007: 7.1 mgd 2008: 7.1 mgd
2009: 6.7 mgd 2010: 6.5 mgd 2011: 6.9 mgd
2012: 5.8 mgd 2013: 5.9 mgd
2014: 5 mgd
2015: 3.8 mgd
2016: 4.5 mgd 2017: 4.7 mgd 2018: 4.9 mgd
2019: 5.3 mgd
-8-6-4-202468
0 50
100150200250300350400
January 2006
March 2006
May 2006
July 2006
September 2006
November 2006
January 2007
March 2007
May 2007
July 2007
September 2007
November 2007
January 2008
March 2008
May 2008
July 2008
September 2008
November 2008
January 2009
March 2009
May 2009
July 2009
September 2009
November 2009
January 2010
March 2010
May 2010
July 2010
September 2010
November 2010
January 2011
March 2011
May 2011
July 2011
September 2011
November 2011
January 2012
March 2012
May 2012
July 2012
September 2012
November 2012
January 2013
March 2013
May 2013
July 2013
September 2013
November 2013
January 2014
March 2014
May 2014
July 2014
September 2014
November 2014
January 2015
March 2015
May 2015
July 2015
September 2015
November 2015
January 2016
March 2016
May 2016
July 2016
September 2016
November 2016
January 2017
March 2017
May 2017
July 2017
September 2017
November 2017
January 2018
March 2018
May 2018
July 2018
September 2018
November 2018
January 2019
March 2019
May 2019
July 2019
September 2019
November 2019
Annual Average Day Water Production, mgd
Water Production, MG
Month
SEWD Groundwater Annual Average Day Production
Figure 3-2
Historical Monthly Water
Production for South Stockton
City of Stockton
Water Master Plan Update
Notes:1. Source: Data for 2009-2019 (City Monthly Month_Year.xlsx) provided by City staff in May 2020.

2. Abbreviations: MG = million gallons; mgd = million gallons per day; SEWD = Stockton East Water District.

EXHIBIT
1 1695
Last Revised: 09-02-16; o\c\418\02-14-36\e\T120\Ch3_TablesandFigures.xlsx 2006: 0.4 mgd
2007: 0.3 mgd
2008: 0.2 mgd 2009: 0.2 mgd 2010: 0.2 mgd 2011: 0.2 mgd 2012: 0.2 mgd 2013: 0.3 mgd
2014: 0.2 mgd
2015: 0.2 mgd
2016: 0.2 mgd
2017: 0.2 mgd
2018: 0.2 mgd
2019: 0.2 mgd
-0.5-0.4-0.3-0.2-0.10.00.10.20.30.40.5
02468
101214161820
January 2006
March 2006
May 2006
July 2006
September 2006
November 2006
January 2007
March 2007
May 2007
July 2007
September 2007
November 2007
January 2008
March 2008
May 2008
July 2008
September 2008
November 2008
January 2009
March 2009
May 2009
July 2009
September 2009
November 2009
January 2010
March 2010
May 2010
July 2010
September 2010
November 2010
January 2011
March 2011
May 2011
July 2011
September 2011
November 2011
January 2012
March 2012
May 2012
July 2012
September 2012
November 2012
January 2013
March 2013
May 2013
July 2013
September 2013
November 2013
January 2014
March 2014
May 2014
July 2014
September 2014
November 2014
January 2015
March 2015
May 2015
July 2015
September 2015
November 2015
January 2016
March 2016
May 2016
July 2016
September 2016
November 2016
January 2017
March 2017
May 2017
July 2017
September 2017
November 2017
January 2018
March 2018
May 2018
July 2018
September 2018
November 2018
January 2019
March 2019
May 2019
July 2019
September 2019
November 2019
Annual Average Day Water Production, mgd
Water Production, MG
Month
SEWD Annual Average Day Production
Figure 3-3
Historical Monthly Water Production
for the Walnut Plant Area
City of Stockton
Water Master Plan Update
Notes:1. Source: Data for 2009-2019 (City Monthly Month_Year.xlsx) provided by City staff in May 2020.

2. Abbreviations: MG = million gallons; mgd = million gallons per day; SEWD = Stockton East Water District.

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Last Revised: 09-02-16; o\c\418\02-14-36\e\T120\Ch3_TablesandFigures.xlsx 2006: 32 mgd
2007: 35.8 mgd 2008: 35.6 mgd
2009: 32.7 mgd 2010: 31.5 mgd 2011: 31.9 mgd 2012: 33.1 mgd 2013: 32.8 mgd 2014: 28.2 mgd
2015: 23.5 mgd 2016: 24.9 mgd 2017: 26.1 mgd 2018: 26.9 mgd 2019: 27.4 mgd -50-40-30-20-1001020304050
0 200400600800
1,0001,2001,4001,6001,8002,000
January 2006
March 2006
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July 2008
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March 2009
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July 2010
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November 2010
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November 2018
January 2019
March 2019
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July 2019
September 2019
November 2019
Annual Average Day Water Production, mgd
Water Production, MG
Month
SEWD DWTP Groundwater Annual Average Day Production
Figure 3-4
Historical Monthly Water
Production for COSMUD
City of Stockton
Water Master Plan Update
Notes:1. Source: Data for 2009-2019 (City Monthly Month_Year.xlsx) provided by City staff in May 2020.

2. Abbreviations: MG = million gallons; mgd = million gallons per day; SEWD = Stockton East Water District; DWTP = Delta Water Treatment Plant; COSMUD = City of Stockton MunicipalUtility District.

EXHIBIT
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Table 3-2 summarizes the historical water production by water service area. It compares the baseline water production established in the 2008 WMP to the historical average production (2006 to 2019) and the most recent 5-year average production (2015 through 2019). In general, the COSMUD has experienced a decrease in water production compared to the 2008 WMP baseline production. As discussed later in this chapter, due to the trend in water production increasing from 2015 through 2019, a 10 percent rebound factor will be applied to the 5-year average production from 2015 through 2019 to establish the existing baseline production.

Table 3-2. Historical COSMUD Water Production Comparison(a) Timeline North Stockton, afy South Stockton, afy Total, afy 2008 WMP Baseline Production(b) 30,380 6,000 36,380
Historical Average Production (2006 to 2019) 27,165 6,368 33,533 5-Year Average Production (2015 through 2019) 23,450 5,182 28,632 Percent Difference between the Recent 5-Year
Average Production and the 2008 WMP
Baseline Production
-23% -14% -21%
(a) Does not include production for the Walnut Plant Area which is minimal and was not evaluated in this Water Master Plan Update. (b) From Table 3-9 of the 2008 WMP; reflects average of 2004 and 2005 production. afy = acre feet per year

3.1.2 Per Capita Water Use
Historical per capita water use for the COSMUD water service areas from 2006 to 2019 is presented in Table 3-3 and on Figure 3-5. The per capita water use shown is based on total water production for the COSMUD water service areas (representing all water uses, including all residential and non-residential uses) divided by the COSMUD water service area population. The COSMUD per capita water use has decreased from a maximum of 209 gallons per capita per day (gpcd) in 2007 and 2008 to 153 gpcd in 2019.

Recent water use has decreased significantly as indicated by the average per capita water use for the last five years (2015 to 2019), which is equal to 147 gpcd. This lower per capita water use is primarily a response to increased water conservation efforts during and since the recent drought.

In November 2009, Senate Bill X7-7 (SB X7-7), the Water Conservation Act of 2009, was signed into law as part of a comprehensive water legislation package. The Water Conservation Act addressed both urban and agricultural water conservation and set a goal of achieving a 20 percent statewide reduction in urban per capita water use by December 31, 2020. To meet the urban water use target requirement, each retail supplier was required to adopt an interim per capita water use target for 2015 and a final per capita water use target for 2020. The City’s adopted targets were 172 gpcd for 2015 and 165 gpcd for 2020.6 As shown in Table 3-3, the City’s 2015 per capita water use was 138 gpcd, well below and in compliance with the City’s 2015 goal of 172 gpcd. Although 2020 production data was not available for incorporation into this Water Master Plan Update, it is anticipated that the City’s 2020 per capita water use will be in compliance with the City’s 2020 goal. Additional discussion regarding the City’s compliance with SB X7-7 is provided in the City’s 2015 Urban Water Management (UWMP).
6 City of Stockton, 2015 Urban Water Management Plan, Table 4-1.

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Table 3-3. Historical Water Production, Population and Per Capita Water Use Year
Average Day Water
Production, mgd(a)
COSMUD Water Service
Area Population(b)
Per Capita Water Use,
gpcd
2006 32.0 172,895 185
2007 35.8 170,944 209
2008 35.6 170,017 209
2009 32.7 170,153 192
2010 31.5 178,387 176
2011 31.9 172,941 184
2012 33.1 172,347 192
2013 32.8 171,816 191
2014 28.2 171,183 165
2015 23.5 170,417 138
2016 24.9 172,706 144
2017 26.1 174,995 149
2018 26.9 177,284 152
2019 27.4 179,573 153
(a) Source: Production data are from the consumption, production, and meter data tables in WaterTable.xlsx, provided by the City in May 2020. (b) Source: Population numbers from 2009 to 2015 are from the City’s 2015 UWMP for the COSMUD water service area only. Population numbers from 2016 to 2019 were linearly interpolated, using the 2020 population estimate provided in the 2015UWMP.

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Figure 3-5. Comparison of Historical Per Capita Demand, Average Day Production and Population EXHIBIT 1
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3.1.3 Historical Water Consumption
The COSMUD tracks its water consumption through customer meter records. As of 2019, the COSMUD has approximately 49,200 metered water use accounts that serve various customer types. Table 3-4 summarizes the number of customers by meter type. As shown in Table 3-4, the predominant customer type in the COSMUD water service area is residential (either single family or multi-family), which accounts for approximately 95 percent of the total number of water meters. The COSMUD also serves residential customers that are located in unincorporated pockets of San Joaquin County that lie within the COSMUD water service area. Non-residential metered accounts make up approximately 5 percent of the total metered accounts.

Table 3-4. COSMUD Customer Types as of December 2019(a) Customer Type Number of Meters
Customer Type as a Percent
of Total Accounts
Residential
Single Family and Multi-Family 46,739 95%
Non-Residential
Industrial 19 <1%
Commercial and Institutional 1,487 3%
Irrigation 912 2%
Non-Residential Subtotal 2,418 5%
Total 49,157 100%
(a) Source: Data is from the consumption, production, and meter data tables in the WaterTable.xlsx, provided by the City in May 2020.

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Table 3-5 summarizes the COSMUD water consumption by customer type from 2017 through 2019.

Residential customers account for an average of 69 percent of the total consumption, but make up approximately 95 percent of the total metered accounts as described above. Non-residential customers account for about 31 percent of the total consumption, but make up only 5 percent of the total metered accounts.

Table 3-5. COSMUD Consumption by Customer Type(a)
Customer Type
Consumption, af
2017 2018 2019
Residential
Single Family 14,698 15,077 14,930
Metered to SJ County 1,573 1,422 1,671
Multi Family 2,729 2,772 2,799
Residential Subtotal 19,000 19,272 19,400
Residential Percent of Total 70.4% 69.5% 68.9%
Non-Residential
Commercial/Institutional 4,265 4,569 4,811
Irrigation 2,816 3,037 3,137
Other (Industrial) 785 790 713
Hydrants Meters/Jumpers 117 45 88
Non-Residential Subtotal 7,984 8,440 8,748
Non-Residential Percent of Total 29.6% 30.5% 31.1%
Residential & Non-Residential Total 26,984 27,712 28,148 (a) Source: Data is from the consumption, production, and meter data tables in the WaterTable.xlsx, provided by the City in May 2020. (b) San Joaquin County meters are assumed to be residential.

3.1.4 Non-Revenue Water
Non-Revenue water (NRW) is the difference between the quantity of water produced and the quantity of water consumed or metered. Customer water use typically does not equal the total water production because of unmeasured system losses. These "lost" flows, previously referred to as unaccounted for water, are now referred to as NRW. Water utilities strive to minimize the amount of NRW; however, it is difficult to eliminate entirely. There are various reasons why the total customer water use is less than the total amount of water produced by the City. The most common reasons for NRW are due to system losses such as leakage, errors in measurement, and unmetered usage as discussed in detail below:
• Leakage: Leakage is frequently the largest component of NRW and includes losses from distribution and transmission mains, customer service laterals up to the meter, and tanks.

The amount of leakage varies from system to system, but there is a general correlation between the age of a system and the amount of NRW. Other factors affecting leakage include system pressure (the higher the pressure, the more leakage), frequency of main and service pipe breaks, and the extent of leakage detection and control policies.

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• Errors in Measurement: Flow measurements are not always exact, and thus metered customer usage may contain inaccuracies. Some flow meters under-register actual usage at low flow rates, especially as they age.
• Unmetered Usage: COSMUD may have unauthorized, unmetered connections or other types of unmetered water use. Not all unmetered usage is due to water theft, as fire hydrants, blow-offs, and other maintenance appurtenances are typically not metered.

An estimate of NRW is required for water system planning to project future water production needs, as a system will always have some amount of water loss. NRW ranging from 5 to 10 percent is typical for many water utilities. At the time this Water Master Plan Update was being prepared, the State Water Resources Control Board was in the process of developing water loss performance standards to minimize water waste through system leaks. This is consistent with recommendations from the American Water Works Association (AWWA) which call for the development of system-specific loss targets and key performance indicators for assessing water loss.7 Adoption of a proposed regulation is anticipated by July 2021.8 Table 3-6 summarizes the non-revenue water for the COSMUD system from 2017 through 2019 by comparing water production to water consumption. Based on the 2017, 2018 and 2019 water consumption versus water production, the NRW is approximately 8 percent of the water production. The NRW will be accounted for when projecting the future water production required for near-term (2030) and future (2040) conditions.

Table 3-6. Non-Revenue Water(a)
Year Production, afy Consumption, afy NRW, afy(b)
NRW as a Percent of
Production
2017 29,241 26,984 2,256 7.7%
2018 30,103 27,712 2,390 7.9%
2019 30,684 28,148 2,534 8.3%
(a) Source: Production data are from the consumption, production, and meter data tables in WaterTable.xlsx, provided by COSMUD in May 2020. (b) Water loss is equal to production minus consumption.

3.2 PEAK WATER USE
Water system facilities are generally sized to meet peak demand conditions. The peaking conditions of most concern for facility sizing (e.g., supply, pumping and storage) are typically Maximum Day plus Fire Flow demand or Peak Hour demand. This section reviews historical peak water use for the COSMUD water service areas, and includes discussion of the maximum day demand, peak hour demand and hourly variations of demand during the maximum demand day.
7 Key Performance Indicators for Non-Revenue Water, AWWA Water Loss Control Committee Report, November 2019. 8 SWRCB Fact Sheet on Water Loss Performance Standards, November 18, 2020.

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3.2.1 Maximum Day and Peak Hour Demand
Table 3-7 summarizes the average, maximum day, and peak hour demands and the corresponding peaking factors from 2018 and 2019. Only 2018 and 2019 were considered, as this is most representative of recent water use trends after the recent drought. 2020 data was not available for evaluation in this Water Master Plan Update and would likely not be representative of normal system conditions due to the impacts of stay-athome orders and business closures in response to the COVID-19 pandemic. West Yost reviewed the COSMUD-provided SCADA data to identify historical maximum day and peak hour demands for the respective water service areas. Separate peaking factors for the North Stockton and South Stockton water service areas were calculated as these areas currently operate hydraulically separate from one another. In the 2008 WMP, peaking factors were developed on a systemwide basis since SEWD supplied both water service areas.

Table 3-7. Summary of Historical Maximum Day and Peak Hour Peaking Factors Year
Average Day
Demand
(ADD), mgd
Maximum Day
Demand
(MDD), mgd
Peak Hour
Demand
(PHD), mgd
Maximum Day
Peaking Factor
(MDD/ADD)
Peak Hour
Peaking Factor
(PHD/ADD)
North Stockton
2018 21.8 33.3 50.2 1.5 2.3
2019 21.9 30.8 48.1 1.4 2.2
South Stockton
2018 4.9 8.7 16.0 1.8 3.3
2019 5.3 9.0 14.8 1.7 2.7

3.2.2 Recommended Demand Peaking Factors
Table 3-8 summarizes the recommended peaking factors for this WMP. These peaking factors will be subsequently used to evaluate and size distribution system pipelines, storage and reservoir pumping facilities, as well as define water supply needs and capacity requirements.

For planning purposes, the maximum day peaking factors for North Stockton and South Stockton are recommended to be 1.6 and 1.7, respectively. The recommended peaking factors for North and South Stockton are similar to the previous systemwide peaking factor of 1.7 used in the 2008 WMP. For North Stockton, while the historical maximum day peaking factors have been slightly less than the recommended factor of 1.6, the 1.6 factor is recommended as it is anticipated that water use might continue to rebound somewhat. For South Stockton, the historical peaking factor of 1.7 is considered to be appropriate even though the 2018 factor was calculated to be 1.8.

The peak hour peaking factors for North Stockton and South Stockton vary, as the land uses are distinctly different between the two water service areas. The recommended peak hour peaking factor for North Stockton is 2.5 times average day and the recommended peak hour peaking factor for South Stockton is

3.3 times average day. In the 2008 WMP, the peak hour demand was not calculated due to insufficient data. The adopted peak hour peaking factor in the 2008 WMP was estimated to be 3.5 times average day, systemwide, based on a single data point. The reduction in the North Stockton peak hour peaking factor is attributed to lower overall water use, particularly irrigation water use. The slight reduction in the South Stockton peak hour peaking factor reflects a decrease in large industrial customers in South Stockton.

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Table 3-8. Recommended Demand Peaking Factors
Demand Condition Peaking Factor(a)
Maximum Day Demand
North Stockton 1.6 times Average Day Demand
South Stockton 1.7 times Average Day Demand
Peak Hour Demand
North Stockton 2.5 times Average Day Demand
South Stockton 3.3 times Average Day Demand

3.2.3 Maximum Day and Peak Hour Diurnal Demand
The maximum day demand (including the peak hour) diurnal was developed by reviewing SCADA data from 2018 and 2019. The diurnal pattern was then subsequently adjusted so that it is consistent with the peaking factors that are summarized above in Table 3-8. Figure 3-6 shows the maximum day with peak hour diurnal pattern developed as part of this Water Master Plan Update. This diurnal pattern is separate from the diurnal pattern developed for the model calibration (discussed in Chapter 6) and is subsequently used in Chapters 7 and 8 for the existing and future distribution system evaluations, respectively.

Figure 3-6. North Stockton and South Stockton Maximum Day Diurnal Patterns

0.0 0.5

1.0 1.5

2.0 2.5
12:00 AM 3:00 AM 6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM 9:00 PM 12:00 AM Peaking Factor
Time of Day
North Stockton South Stockton
EXHIBIT 1
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3.3 EXISTING AND FUTURE LAND USE AND GROWTH PROJECTIONS The following sections discuss the existing and projected future land use for the COSMUD water service area.

3.3.1 Existing Land Use
Generally speaking, North Stockton is primarily comprised of residential land uses and South Stockton is mostly comprised of industrial and commercial uses with some residential uses (with most residential uses being located in the Weston Ranch development area).

Water use for developed parcels within the COSMUD water service area is captured by the metered water consumption data. This water consumption data (described in Section 3.1.3) was spatially located by linking metered billing/consumption data to the COSMUD meter shapefile. This data was used to update the water system hydraulic model, which is discussed in Chapter 6.

3.3.2 Projected Future Land Use
Future growth and land uses are defined in the City’s 2040 GPU, which summarizes anticipated development within sixteen Study Areas. These areas have been specifically identified as being most likely to develop by 2040. In addition to these Study Areas, the City has identified, or is actively working with several project proponents to identify, future development areas that are either within existing City Limits or outside of City Limits but within the General Plan Sphere of Influence (SOI). The April 2020 Sphere of Influence Plan/Municipal Service Review Report (SOI/MSR Report) defines the anticipated level of development and municipal service needs for near-term (2030) development. The 2040 GPU and SOI/MSR Report provide for a total of 40,900 new residential dwelling units city-wide. Projects contained in the SOI/MSR Report were assumed to be completed in the near-term (by 2030), and other planned projects were assumed to be built in the future (by 2040). Near-term (2030) and future (2040) projects are indicated in Table 3-9.

West Yost compared the planned development projects listed in both the 2040 GPU and the SOI/MSR Report to the future planned developments listed on the City’s Planning webpage to determine if projected land use has changed since the completion of the 2040 GPU. Future development plans and land uses were reviewed and confirmed with City Community Development Department staff in July 2020.

Table 3-9 provides a summary of planned future development projects within the entire City area, and identifies those projects that are within the COSMUD water service area along with their land use type and projected dwelling units and/or acreage and estimated time of completion (near-term vs. future).

New project information obtained from the City’s Planning webpage review is noted in the table footnotes. Projected residential acreages and dwelling units and non-residential acreages summarized in this table are net new or incremental. Figure 3-7 shows the approximate locations and boundaries for the projects that are listed in Table 3-9.

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Single Family (Dwelling
Units)
Single Family
(Developable Gross
Acres)
Multi-Family Family
(Dwelling Units)
Multi-Family Family
(Developable Gross
Acres)
Parks (Developable
Gross Acres)
Commercial
(Developable Gross
Acres)
Industrial (Developable
Gross Acres)
Total Area
(Developable Gross
Acres)
Study Areas
Study Area 1 - Eight Mile Road Area COSMUD 100% North 13% 1,379.0 232.1 1,197.7 73.2 157.0 0.6 0.0 462.9 Study Area 2 - Pacific Avenue Corridor COSMUD Cal Water 5% North 0% 0.0 0.0 5.5 0.2 0.0 0.2 0.0 0.4 Study Area 3 - West Lane and Alpine Road Area(e) COSMUD Cal Water 10% North 0% 7.7 6.0 68.0 2.2 0.0 0.6 0.0 8.8 Study Area 4 - Port/Waterfront Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 5 - El Dorado/Center Corridors Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 6 - Miner/Weber Corridors Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 7 - Wilson Way Corridor Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 8 - I-5/Highway 4 Interchange Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 9 - Railroad Corridor at California Street Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 10 - I-5 and Charter Way Area Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 11 - Charter Way/MLK Jr Blvd Corridor Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 12 - Airport Way Corridor COSMUD Cal Water 20% South 0% 0.0 0.0 21.5 0.9 0.0 2.0 2.6 5.6 Study Area 13 - Mariposa and Charter Area Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 14 - East Weston Ranch COSMUD Cal Water 100% South 0% 0.0 0.0 0.0 0.0 0.0 14.8 0.0 14.8 Study Area 15 - South of French Camp Road COSMUD 100% South 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Study Area 16 - E French Camp Rd Area COSMUD 100% South 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Subtotal (Study Areas) 1,386.7 238.1 1,292.6 76.5 157.0 18.3 2.6 492.5 Approved/Pending Development Projects Within City Limit Westlake Villages COSMUD 100% North 0% 2,630.0 680.0 0.0 0.0 12.8 0.0 0.0 692.8 Delta Cove COSMUD 100% North 0% 1,164.0 132.7 381.0 47.6 57.7 2.6 0.0 240.6 North Stockton Projects III COSMUD 100% North 0% 2,220.0 355.0 0.0 0.0 0.0 0.0 0.0 355.0 Cannery Park COSMUD 100% North 0% 981.0 272.0 210.0 16.0 0.0 104.0 0.0 392.0 Nor Cal Logistics Center(f) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 0.0 325.0 325.0 Crystal Bay COSMUD 100% North 0% 951.0 19.4 392.0 78.7 10.0 0.0 0.0 108.1 Sanctuary COSMUD 100% North 0% 5,452.0 1,026.0 1,618.0 67.4 193.0 35.5 0.0 1,321.9 Tidewater Crossing(g) COSMUD 100% South 50% 0.0 0.0 0.0 0.0 17.2 20.3 792.0 829.5 Open Window Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Weston Ranch Town Center COSMUD 100% South 0% 0.0 0.0 0.0 0.0 0.0 41.5 0.0 41.5 Airport Way and Sperry Road Commercial Project(h) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 2.0 0.0 2.0Tuscany Cove(i) Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0CarMax Superstore Project(j) COSMUD 100% North 100% 0.0 0.0 0.0 0.0 0.0 10.6 0.0 10.6Thornton and Eight Mile Road Development(k) COSMUD 100% North 100% 0.0 0.0 0.0 0.0 0.0 2.1 0.0 2.1 University Park(l) Cal Water 0% -- 0% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Subtotal (Approved/Pending Projects Within City Limit) 13,398.0 2,485.1 2,601.0 209.7 290.7 218.6 1,117.0 4,321.0 Approved/Pending Development Projects Outside City Limit but Within Sphere of Influence Mariposa Road Community(m) COSMUD Cal Water 100% South 0% 8,955.0 939.0 1,553.0 585.0 206.3 150.0 0.0 1,880.3 Airpark 599(n) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 5.4 259.7 265.1Tra Vigne(o) COSMUD 100% North 100% 1,165.0 260.7 340.0 11.7 20.4 10.4 0.0 303.2Mariposa Industrial Park(p) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 0.0 203.5 203.5Sanchez-Hoggan Annexation Project(q) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 0.0 169.8 169.8Century Mobile Home Park(r) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Veterans Affairs Medical Campus(s) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 37.0 0.0 37.0 Niagara Bottling Plant(t) COSMUD 100% South 100% 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Subtotal (Approved/Pending Projects Outside City Limit but Within Sphere of Influence) 10,120.0 1,199.7 1,893.0 596.7 226.7 202.8 632.9 2,858.9 Remaining Development Outside of Study Areas and Outside of Approved/Pending Projects COSMUD 50% North 100% 750.6 635.2 0.0 0.0 0.0 0.0 0.0 635.2 25,655.3 4,558.2 5,786.6 882.9 674.3 439.7 1,752.5 8,307.6 2,099.7 927.0 499.9 21.5 49.9 77.8 1,353.9 2,430.1
Table 3-9. Future Incremental Development Summary
Study Area or Development Name(u) Water Service Provider Percentage Within
COSMUD Water Service
Area COSMUD Area
Percent Developed by
2030
Future Incremental Development
Grand Total 2040 (Buildout)
Grand Total 2030 (Near-Term)
(a) Developable gross acres is defined as the existing or planned total developable area associated with the stated land use types (e.g., Single Family, Multi Family, Commercial, Industrial) and does not represent the Total Area. Therefore, developable gross area does not include other area associated with other land use types such open space, mixed use, roads, etc.(b) Existing Dwelling Units/Developable Gross Acres is defined as the count of units or sum of area that is currently developed. (c) Net New Dwelling Units/Developable Gross Acres is defined as the total incremental new units/area of the associated land use type that is planned to be added (or removed if it is being redeveloped).(d) 2040 Dwelling Units/Developable Gross Acres is defined as the total anticipated unit count or area of the associated land use type that is expected by 2040. This is calculated by summing Existing with Net New. (e) Updated per Calaveras Estates IV Initial Study/Mitigated Negative Declaration report (IS/MND) (October 2017). Project is contained within Study Area 3. (f) Updated per NorCal Logistics Draft Environmental Report (February 2015). Developable gross acres for industrial land use, 325 acres, includes the Niagara Bottling Plant. (g) Exhibit C-2 City of Stockton Rezone (VVH Engineers, February 2019). A large portion of Tidewater Crossing is now the South Stockton Commerce Center.(h) Updated per Airport Way and Sperry Road Commercial Project IS/MND (January 2018). (i) Updated per Tuscany Cove IS/MND (March 2018). (j) Updated per CarMax Auto Superstore DEIR (November 2018). (k) Updated per Thornton Road and Eight Mile Road Arco Station Project IS/MND (October 2017). (l) Update per University Park Master Development Plan (December 2003).(m) Not updated, values reflect the previous planning efforts described in the 2018 Placeworks Utility Supplement. The development's entitlement has expired. For the purposes of this water master plan, it is assumed that the Mariposa Road Community will be served entirely by COSMUD for water.(n) Updated per land use plan as of 10/15/2019, assuming all phases (Phases 1 through 3) are built.(o) Updated per Tra Vigne EIR Table 2-2 (April 2018) and Exhibit 4.1 (NorthStar Engineering Group, September 2019).(P) Updated per Annexation Application (Septermber 2020).(q) Updated per Sanchez-Hoggan Annexation DEIR (March 2020).(r) Century Mobile Home Park Consolidation with the City of Stockton Water Main Extension Project (Blackwater Engineers, March, 2015)(s) Updated per Veterans Affairs Clinic Off-Site Improvement Project DEIR (September 2019). (t) Niagara Bottling Plant acreage not known. Project proponents have requested a maximum capacity of 1,800 gpm, assumed to be non-peaked. See footnote f.(u) The major developments and study areas listed in Table 3-7 were confirmed with City Planning Staff as future projects to be included in the 2020 WMPU. The future developments are preliminary and subject to change. Upon City approval, infrastructure required to serve a development and impacts to the existing water system will need to be confirmed. Future development in areas not designated as major developments or study areas will need to be evaluated when development plans are available. Refer to Figure 3-7 for the approximate location of each future development and study area.

N - 129 - 60-20-41 - E - 3 - T3-9
City of Stockton
Water Master Plan Update
Last Revised: 01-15-2021

EXHIBIT
1 1707
0 0.75 1.5
Miles
§¨¦5
¬«99
¿
Thornton Road and
Eight Mile Road
Arco Station Project
¿
Crystal Bay
¿
Airport Way and
Sperry Road
Commercial Project
¿ University Park
¿ Tuscany Cove
Tra Vigne
¿
Sanchez-Hoggan
Annexation Project
¿
Sanchez-Hoggan
Annexation Project
¿
Veterans Affairs
Medical Campus
¿
See Note 1
CarMax ¿ Superstore
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Century Mobile
Home Park
¬«4
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Weston Ranch
Towne Center
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Mariposa
Industrial Park
See Note 5
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Niagara Bottling
Facility
See Note 6
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Crossing
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Projects III
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Figure 3-7
Summary of
Future Developments
City of Stockton
Water Master Plan Update
Study Area Within City's Sphere
of Influence
Study Area Outside of City's
Sphere of Influence
Major Development
Cal Water Service Area
COSMUD Water Service Area
City of Stockton Limits
City of Stockton Sphere of
Influence
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F3_7_FutLandUse.mxd - mmcwilliams - 1/26/2021 Notes:

1. The southern portion of the Tra Vigne development, generally south of Bear Creek, does not have active specific plans, but is anticipated to be Low Density Residential in the future. For the purposes of 2020 WMPU, no demand was added for the area south of Bear Creek.

2. The portion of Study Area 1, west of Davis Road, does not have an associated future land use plan. Water demands for Study Area 1 planned land use are assumed to be in the area south of Eight Mile Road.

3. Study Areas 4 through 11, Study Area 13, Open Window, University Park, and Tuscany Cove are not within the COSMUD Water Service Area.

4. Study Area 2, Study Area 3, Study Area 12, Study Area 14, and Mariposa Road Community are only partially within the COSMUD Water Service Area.

5. Mariposa Industrial Park extents based on City provided project information, provided to West Yost on 10/29/2020.

6. Niagara Bottling Facility included as part of future development based on City Will Serve Letter, provided to West Yost on 10/15/2020.

7. The major developments and study areas displayed were confirmed with City Planning Staff as future projects to be included in the 2020 WMPU. Future developments are preliminary and subject to change.

Upon City approval, infrastructure required to serve a development and impacts to the existing water system will need to be confirmed.

Future development in areas not designated as major developments or study areas will need to be evaluated when development plans are available.

8. Refer to Table 3-9 in the 2020 WMPU for planned land use (dwelling units and acreage) for each proposed development or study area shown.

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Since COSMUD only serves the North Stockton and South Stockton areas, with Cal Water providing water service to the Central Stockton area, West Yost determined which future planned developments will be served by COSMUD, and which future planned developments are only partially within the COSMUD water service area. Approximately 31,442 planned residential dwelling units are planned in the COSMUD water service area, which is about 76 percent of the total planned residential dwelling units City-wide.

It should be noted that portions of Study Areas located outside the General Plan SOI (e.g., portions of Study Areas 1 and 15) have not been evaluated in this Water Master Plan Update. Similarly, areas within the General Plan SOI which are not designated as Study Areas or planned development projects have not been evaluated in this Water Master Plan Update as development of these areas was not anticipated in the 2040 GPU. Any future development in these areas will need to be evaluated when land use plans are developed to determine the impacts on the COSMUD water system and identify any required water system improvements.

The Mariposa Road Community in South Stockton is a large future development area that will likely consist of a mix of single family residential, multi-family residential, parks, and commercial land uses. The development area’s previous entitlement has expired, and therefore it is not guaranteed that this project area will actually be developed, or be developed as previously planned. For the purposes of this Water Master Plan Update, it was assumed that the Mariposa Road Community will be developed by 2040, based on the most recent land use plan, and be served entirely by COSMUD. This future development is one of the largest drivers for future growth within the COSMUD South Stockton water service area. In addition, although this development area is located within both the COSMUD water service area and the Cal Water service area, for the purposes of this Water Master Plan Update, it was conservatively assumed that the COSMUD would serve the entire Mariposa Road Community area. As described further in Chapter 8, any recommended future water system improvements associated with the Mariposa Road Community should be reviewed and confirmed prior to facility design and construction based on future confirmed development plans.

Table 3-10 summarizes the future planned development within the COSMUD water service area by land use designation. North Stockton will experience the largest increase in residential development. The largest planned development is the Sanctuary Project in North Stockton. It will consist of single-family, multi-family, park, and commercial land uses. In addition to the Mariposa Road Community, South Stockton will see an increase in commercial and industrial development in the near-term and in the future with planned projects such as the NorCal Logistics Center and the South Stockton Commerce Center.

As noted in Table 3-9, the Niagara Bottling Plant Project is included in the industrial acreage for the NorCal Logistics Center; however, the water demands for this project are specific to the proposed operations of the project and have been estimated separately. Updated plans for this facility have not been formally submitted to the COSMUD; however, project proponents have specified a desired water capacity of 1,800 gpm. This value was used in the water demand projections discussed in subsequent sections.

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Table 3-10. Future Planned Development within the COSMUD Water Service Area(a) Future Land Use Designation Units
Near-Term (2030)
Total Development
Future (2040)
Total Development
North Stockton
Single Family Residential DU 2,100 16,700
Multi Family Residential DU 500 4,212
Commercial Acres 23 167
Industrial Acres 0 0
Parks Acres 41 451
South Stockton
Single Family Residential DU 0 8,955(b)
Multi Family Residential DU 0 1,575(b)
Commercial Acres 55 273
Industrial Acres 1,354 1,753
Parks Acres 9 224
(a) Based on the Study Areas and future development plans identified in the 2040 General Plan and April 2020 SOI/MSR Report and confirmed with the City’s Community Development Department in July 2020 (see Table 3-9 for additional information). (b) All of the Single Family Residential and most of the Multi Family Residential is associated with the Mariposa Road Community.

DU = Dwelling Unit

3.4 WATER USE FACTORS
To develop land use-based water demand projections, water use factors are applied to the projected land uses (refer to Section 3.3.2 Projected Future Land Use). To develop water use factors, COSMUD staff provided West Yost with the following data:
• 2018 - 2020 water meter records with Location IDs
• Spatially-located water meter locations with Location IDs and APNs • City of Stockton 2040 General Plan (2040 GPU) land use maps in GIS format • City of Stockton April 2020 Sphere of Influence Plan/Municipal Service Review Report Water use factors were then determined by using the following methodology:
• Annual water meter records were first linked to the spatially-located water meter locations by using the Location ID
• Spatially-located water meter locations were then linked to the parcel file with the City’s 2040 GPU land use designations by using the APN
This process provided the means to calculate water use factors for each land use designation defined in the 2008 WMP by using the total water use data from the water meter records that have been linked to parcels assigned with a 2040 GPU land use designation and dividing that by the corresponding linked acreage. The area-based water use factors (WUFs) were then compared with the water use factors EXHIBIT 1
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reported in the 2008 WMP for most land use designations. It should be noted that the 2008 WMP only developed area-based WUFs. Current land use information, specifically for residential land uses, is projected in terms of dwelling units. Therefore, area-based WUFs for residential land uses were developed for the sole purpose of comparison to the 2008 WMP factors.

In addition, land use designations defined in the 2008 WMP do not entirely align with the current, simplified land use designations contained in the 2040 GPU. Similar to the area-based factors above, WUFs were developed using the 2008 WMP and 2035 GP report for the purposes of comparison. Recommended factors were developed to coordinate with the designations contained in the 2040 GPU. The following subsections provide additional details on how unit water use factors were developed for the residential and non-residential land use designations.

3.4.1 Residential Water Use Factors
Single family residential and multi-family residential WUFs were developed using the 2018 and 2019 consumption data and compared to the water use factors developed in the 2008 WMP.

Single family residential (SFR) land uses were assumed to include low density residential and condominium land uses (defined previously in the 2008 WMP). The calculated area-based SFR WUF (2.2 afy/ac) was found to have decreased by approximately 11 percent from the 2008 WMP SFR WUF (2.5 afy/ac). The dwelling unit-based SFR WUF was also calculated using the approximate number of single family residential dwelling units in the COSMUD water service area (as estimated by meter size) and was determined to be 242 gallon per day (gpd)/DU. This number was calculated by summing up all 2018 and 2019 consumption for meters with a City Rate Class Code of Single Family, and dividing it by the number of dwelling units in each respective year.

Multi-family residential (MFR) land uses typically include medium-density (MDR) and high-density (HDR) residential land uses such as apartments, duplexes and triplexes. MFR WUFs were calculated for medium-density and high-density residential land uses with the 2040 GPU land use designations to compare with the 2008 WMP MFR WUF. Based on initial calculations, it was found that the MFR WUFs were significantly higher than the 2008 WMP MFR WUFs and more than the SFR WUFs. However, it is unclear if the 2018 and 2019 consumption data included irrigation water use for multi-family residential accounts. Also, the number of actual dwelling units per MFR account is unclear. Therefore, the MFR WUF was alternatively developed using the State of California’s indoor water use goal of 50 gpcd9 by 2030 and the average number of people per household (estimated to be 3.5 persons 10 ). Therefore, the recommended water use factor for multi-family residential is 175 gpd/DU.

The recommended MFR WUF does not specifically include outdoor irrigation, as the landscaped areas and types of plantings are project specific and not yet known. This water demand component, however, is not anticipated to be large as landscaped areas associated with multi-family residential developments are typically quite small, and the number of planned multi-family residential dwelling units is particularly small when compared to the number of single family residential dwelling units. As development plans are submitted to the City for multi-family residential projects, it is recommended that the City review specific 9 Per Assembly Bill 1668 and Senate Bill 606.
10 The SOI/MSR Report assumed 3.23 persons per household based on the State of California, Department of Finance population and housing estimates. This value was rounded to 3.5 for purposes of estimating the multi-family residential water use factor.

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project details and include irrigation uses based on the proposed landscape plans. The recommended factor for this irrigation component is 2.26 afy/ac, as summarized in Table 3-11 below.

3.4.2 Non-Residential Water Use Factors
Calculated non-residential WUFs were found to have significantly decreased from those defined in the 2008 WMP. For the purposes of this WMP, WUFs for these land use types (i.e., Commercial, Industrial) were taken from the 2008 WMP, and reduced by 30 percent, consistent with water use decreases observed in 2018 and 2019. Resulting WUFs are as follows:
• Commercial: 1.62 afy/ac
• Industrial: 1.40 afy/ac

3.4.3 Irrigation Water Use Factors
The 2018 and 2019 water consumption data did not specify meters for irrigation use or quantify irrigated landscape areas. Based on a spatial review of meters adjacent to parks, the majority of the meters at these locations had an assigned rate class of commercial. Due to the uncertainty of how much water is actually used for irrigation and what the irrigated areas are, the irrigation water use factor was developed using the 2015 Model Water Efficiency Landscape Ordinance (MWELO). New development projects for residential, commercial, industrial and institutional projects requiring a permit, plan check or design review that have 500 square feet or more of landscape are required to comply with the MWELO. The standards to be set shall incorporate the principles of the MWELO, which takes into account evapotranspiration adjustment factors, landscape areas, maximum applied water allowance, reference evapotranspiration, and special landscape area.

Table 3-11 summarizes the maximum allowed potable water use for irrigation for residential (multifamily) and non-residential (e.g., parks) land uses using the MWELO guidelines. These factors should be utilized to estimate irrigation water demands when detailed land use plans which specify landscaping plans are available.

Table 3-11. Maximum Allowable Water Use Factor for Irrigation(a) Land Use Maximum ETAF(b) Water Use Factor, afy/ac
Residential 0.55 2.26
Non-Residential 0.45 1.85
Special Landscape Areas(c) 1.00 4.12
(a) Based on the California Code of Regulations, Title 23 Waters, Division 2 DWR, Chapter 2.7 Model Water Efficient Landscape Ordinance (MWELO), updated 2015.
(b) ETAF = Evapotranspiration Adjustment Factor = (Plant Factor based on Hydrozone Area )/(Irrigation Efficiency) (c) Special Landscape Areas are areas dedicated solely to edible plants, recreational areas, areas irrigated with recycled water, or water features using recycled water.

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3.4.4 Recommended Water Use Factors
Table 3-12 summarizes the recommended water use factors by land use designation. In general, the water use factors have decreased between 10 percent and 30 percent from the 2008 WMP. These refined water use factors are appropriate for use in projecting future water demands as discussed in the following sections.

Table 3-12. Recommended Water Use Factors
Future Land Use Designation
Dwelling Unit Based WUF,
gpd/DU
Area-Based WUF,
afy/acre
Single Family Residential 242 -
Multi-Family Residential 175 -
Commercial - 1.62
Industrial - 1.40
Parks - 1.85

3.5 FUTURE WATER DEMANDS AND REQUIRED WATER PRODUCTION
Water demands were projected for near-term (2030) and future (2040) conditions for the COSMUD water service areas using the adopted water use factors applied to the future proposed development.

Future water production requirements were then estimated by adding the future water demand projections and future non-revenue water to the existing baseline production. The specific steps used in the development of this projection method and the results are discussed below for both near-term (2030) and future (2040) conditions.

3.5.1 Existing Baseline Production
The average annual water production for the North and South Stockton water service areas from 2015 through 2019 (most recent data) was used to establish the existing baseline production. The average annual water production from 2015 through 2019 for the COSMUD water service areas was 25.6 mgd, or 28,632 afy (refer to Table 3-2).

When comparing 2015 use to 2019 use (refer to Table 3-1), there has been about 16 percent increase in water use. Mandatory conservation measures implemented by the City during the recent drought significantly reduced water use, but since the end of the drought the mandatory conservation measures have been relaxed and water use as increased (rebounded) somewhat. Allowing for some continued rebound is recommended as it provides an additional buffer in existing baseline production requirements and helps ensure sufficient supply capacity. A 10 percent demand rebound factor is recommended and will be added to existing water production to establish the existing baseline production.

Table 3-13 summarizes the existing baseline production for the overall COSMUD water service area and shows that the total existing baseline production for this Water Master Plan Update is 31,495 afy, or

28.1 mgd. This can be compared to the existing baseline production from the 2008 WMP which was 36,380 afy, or about 32.5 mgd. This indicates that existing baseline production for this WMP, with the rebound factor included, is about 13 percent lower than the 2008 WMP baseline production, reflecting EXHIBIT 1
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improved water use efficiencies and on-going water conservation by the COSMUD water customers since the 2008 WMP.

Table 3-13. Existing Baseline Production (5-year Average from 2015 to 2019) with Demand Rebound Water Service Area
Existing Average
Historical Production
(2015 – 2019), afy
Demand Rebound
(10 percent of Average
Historical Production), afy
Existing Baseline
Production, afy
North Stockton 23,450 2,345 25,795
South Stockton 5,182 518 5,700
Total 28,632 2,863 31,495

3.5.2 Additional Water Demand for Planned Future Development Based on the projected future growth (Table 3-9) and the updated water use factors (Table 3-12), water demands for near-term (2030) and future (2040) conditions were estimated. Table 3-14 summarizes the additional projected water demand from planned future development for the near-term (2030) and future (2040) timeframes.

Table 3-14. Future Additional Water Demand
Water Service Area
Additional Demand by 2030 (Near-Term) Additional Demand by 2040 (Future) (a)
mgd afy mgd afy
North Stockton 0.7 781 5.8 6,457
South Stockton 4.4 4,903 8.0 8,949
Total 5.1 5,684 13.8 15,405
(a) The additional demand by 2040 (Future) includes the additional demand by 2030 (Near-Term).

It should be noted that the Niagara Bottling Plant Project accounts for about 60 percent of the additional near-term South Stockton demand, and the Mariposa Road Community accounts for approximately 38 percent of South Stockton’s future additional water demand at 2040.

3.5.3 Water Production Requirements for Near-Term (2030) Conditions
Table 3-15 summarizes the projected production requirements within the COSMUD water service area by the near-term (2030) timeframe. The projected near-term (2030) production requirement includes the existing baseline production, the additional near-term (2030) demand and future non-revenue water.

By 2030, the water production requirement is projected to increase by approximately 20 percent systemwide. North Stockton’s production requirement is projected to increase by 3.3 percent and South Stockton’s production requirement is projected to increase by 93.5 percent and from the existing baseline production.

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Table 3-15. Projected Water Production Requirement for Near-Term (2030) Conditions Parameter North Stockton, afy South Stockton, afy Total COSMUD, afy Existing Baseline Production
(refer to Table ES-2.)
25,795 5,700 31,495
Additional Near-Term Demand by 2030
(refer to Table 3-14)
781 4,903 5,684
Future NRW (8%) 68 426 494
Total Production Requirement, afy 26,644 11,029 37,673
Total Production Requirement, mgd 23.8 9.8 33.6
Percent Increase from
Existing Baseline Production 3.3% 93.5% 19.6%

3.5.4 Water Production Requirements for Future (2040) Conditions Table 3-16 summarizes the projected production requirements within the COSMUD water service area by the future (2040) timeframe. The projected future (2040) production requirement includes the existing baseline production, the additional future (2040) demand and future non-revenue water.

By 2040, the water production requirement is projected to increase by approximately 53 percent systemwide. South Stockton’s production requirement is projected to increase by 171 percent and North Stockton’s production requirement is projected to increase by 27 percent from the existing baseline production. The large increase in South Stockton’s projected production requirement is due to the assumption that the Mariposa Road Community will be fully built by 2040 and served completely by COSMUD11.

Table 3-16. Projected Water Production Requirement for Future (2040) Conditions Parameter North Stockton, afy South Stockton, afy Total COSMUD, afy Existing Baseline Production
(refer to Table ES-2.)
25,795 5,700 31,495
Additional Future Demand by 2040
(refer to Table 3-14)
6,457 8,949 15,405
Future NRW (8%) 561 778 1,340
Total Production Requirement, afy 32,813 15,427 48,240
Total Production Requirement, mgd 29.3 13.8 43.1
Percent Increase from
Existing Baseline Production 27.2% 170.6% 53.2%
11As further described in Chapter 8, the future manner and extent of the development of the Mariposa Road Community is uncertain at this time. As such, any future recommended capital improvements required to serve the Mariposa Road Community should be confirmed when development plans are confirmed.

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3.6 COMPARISON TO THE 2008 WMP, THE 2015 UWMP AND THE 2018

UTILITY MASTER PLAN SUPPLEMENTS
This section compares the projections developed for this Water Master Plan Update to previous projections included in the 2008 Water Master Plan, the 2015 UWMP, and the 2018 Utility Master Plan Supplements prepared in support of the Envision Stockton 2040 General Plan.

The total future (2040) water production requirement presented in this Water Master Plan Update is 48,240 afy (43.1 mgd) (see Table 3-16). This is compared to the total future 2035 water production requirement from the 2008 Water Master Plan which was estimated to be 110,000 afy (98.2 mgd). This represents a 56 percent drop, which is partially attributed to a decrease in existing water production from 2008 to 2019 (35.6 mgd in 2008 vs. 27.4 mgd in 2019), as well as a drop in unit water use factors due to improved water use efficiency (described above in Section 3.4). However, the majority of the drop in the projected water production requirement can be attributed to the significant reduction in expected development by 2040, both in terms of the area to be developed and the projected population. Based on the planned future development identified in the Envision Stockton 2040 General Plan Update and April 2020 MSR/SOI Report, the anticipated gross development area by 2040 is 77 percent less than the 2008 Water Master Plan future gross development area. Associated with this reduced development area, there is approximately a 25 percent decrease in projected City-wide population from the 2035 General Plan to the Envision Stockton 2040 General Plan Update.

Figure 3-8 compares the City-wide population projections in the 2035 General Plan, the Envision Stockton 2040 General Plan Update and the 2015 UWMP, as well as the COSMUD water production requirements from the 2008 Water Master Plan, 2015 UWMP and this Water Master Plan Update. As shown, water production requirements have dropped significantly since the 2008 Water Master Plan was prepared. As shown on Figure 3-8, the water production requirements in the 2015 UWMP and this Water Master Plan Update generally align as similar population projections were assumed.

In support of the Envision Stockton 2040 General Plan, Utility Master Plan Supplements were prepared to project future water system infrastructure needs. In the Potable Water Master Plan Supplement, future water demands (water production requirements) were estimated based on the 2040 General Plan land use assumptions and were estimated to be 39.9 mgd for 2040. Although a different methodology was used for the Master Plan Supplement projections, the projection is similar to the 43.1 mgd projected for 2040 in this Water Master Plan Update.

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Figure 3-8. Comparison of Previous and Current Population and Water Production Requirements The drop in future water production requirements from the 2008 Water Master Plan is reflected by less extensive recommendations for future water system improvements as described in Chapter 8 of this Water Master Plan Update.

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Water Supply
This chapter provides an overview of the City’s water supplies which include both surface water supplies and groundwater supplies. The availability and reliability of the City’s water supplies are evaluated in the City’s 2020 Urban Water Management Plan, which was prepared concurrent with this Water Master Plan Update.

4.1 WATER SUPPLY OVERVIEW
The City’s existing water supply portfolio consists of the following sources:
• Surface water from the San Joaquin River that is diverted at the Intake Pump Station on Empire Tract located in the Sacramento-San Joaquin Delta (Delta) and treated at the City’s DWTP, with supplemental surface water from the Mokelumne River diverted and conveyed by WID, and treated at the City’s DWTP, when the City’s San Joaquin River supplies are curtailed
• Treated surface water from the SEWD conveyed from the New Melones (Stanislaus River) and New Hogan (Calaveras River) Reservoirs
• Groundwater pumped by COSMUD from City-owned and operated wells from the underlying Eastern San Joaquin Groundwater Subbasin
Due to differing disinfection processes that present water quality issues related to low chlorine residual and the potential for formation of disinfection byproducts, COSMUD provides water from the DWTP only in its North Stockton water distribution system. Water from SEWD can be conveyed to both the North Stockton and South Stockton distribution systems. SEWD also supplies the City’s Walnut Plant service area in Central Stockton. Cal Water conveys SEWD supply to the Walnut Plant service area via a wheeling agreement with COSMUD. Water supplies from local groundwater wells are used to supply both the COSMUD North Stockton and South Stockton water service areas.

At time of preparation of this Water Master Plan Update, COSMUD is in the process of implementing the North Stockton Pipeline Hypochlorite Facility that will allow SEWD supplies to be conveyed to the North Stockton system and combined with the DWTP-produced water supply. The project is discussed in further detail in Section 4.3.4.

As described in Chapter 3, COSMUD water demands are projected to increase from 30,684 afy in 2019 to 48,240 afy by 2040. At the same time, COSMUD plans to reduce or offset its groundwater use in accordance with groundwater sustainability objectives. Future COSMUD water supply consists of utilizing permit and contract surface water supplies together with the conjunctive use of groundwater resources.

Details about the City’s water supply sources are described in the following sections.

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4.2 SURFACE WATER SUPPLY FROM THE SAN JOAQUIN RIVER
Water supply from the San Joaquin River is a recent addition to the City’s water supply portfolio and currently provides about 68 percent of its total water supply.12 The City diverts water from the San Joaquin River via the IPS at the southwest tip of Empire Tract and treats the water at its DWTP north of Stockton.

The location of the DWTP and its associated intake facility is shown on Figure 4-1. Since the completion of the DWTP in 2012, the Delta has become a major source of water supply for COSMUD. Water supply from the DWTP is currently used in the COSMUD North Stockton system, along with local groundwater.

4.2.1 Water Right Permit
The City’s 1996 water right application with the State Water Resources Control Board (State Water Board) requested an ultimate diversion of 125,900 afy to address the City’s projected long-term demands through 2050. The State Water Board divided the water right application into two separate applications, Application 30531A and 30531B.

Application 30531A proposed diversions of up to 33,600 afy from the Delta and the Place of Use is confined to the City’s 1990 General Plan boundary. Through this application, the City was granted a water right permit under California Water Code Section 1485. The City’s water right permit from the State Water Board was issued on March 8, 2006 under Water Right Permit 21176. Application 30531B, proposed diversions of up to 92,300 afy, is currently unpermitted. The City plans to continue the application process for this application to help meet the City’s future water demands.

Under California Water Code (CWC) Section 1485, Water Right Permit 21176 allows the City to divert from the San Joaquin River as much water as the City’s wastewater treatment plant discharges into the San Joaquin River under an indirect potable reuse strategy. The quantity permitted under Water Right Permit 21176 is not restricted as long as the same amount of wastewater is discharged into the San Joaquin River.

However, it should be noted that Section 1485 water is subject to pumping restrictions in some months due to environmental restrictions.

The City’s supply from the San Joaquin River is curtailed annually from February 15th to June 15th due to U.S. Department of Fish and Wildlife Service, California Department of Fish and Wildlife and National Marine Fisheries Service (NMFS) 13 restrictions. When water diversion is curtailed, the City obtains supplemental water supply from Woodbridge Irrigation District as described below in Section 4.2.3.

4.2.2 Delta Water Treatment Plant
Subsequent to the State Water Board water right permit issuance for Application 30531A, COSMUD proceeded with Phase 1 of its DWTP project with an initial capacity of 30 mgd. The DWTP and its associated intake facility on the San Joaquin River were completed and commenced operation in 2012.

Since completion of the DWTP, the City has exercised its water rights to divert water through its intake facility on the San Joaquin River.
12 Based on 2019 Water Production (see Table 3-1).
13 The National Marine Fisheries Service (NMFS) is also known as National Oceanic and Atmospheric Administration (NOAA) Fisheries.

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WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F4_1_WaterSupplySystem.mxd - wjones - 1/15/2021 Figure 4-1
Water Supply System
City of Stockton
Water Master Plan Update
Notes:

1. Locations and alignments are approximate and based on the Stockton East Water District Urban Water Management Plan and available information on the Delta Water Supply Project.
5 4
99 kton
26 4
Delta Water
Treatment Plant
San Joaquin River
San Joaquin River
Woodbridge Irrigation
District Connection
SEWD Raw Water
Connection Point

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H A R D I N G W A Y

F R E M O N T
S T

M A I N
S T

D R M A R T I N

L U T H E R K I N G

J R B L V D

A R M S T R O N G R D

P E R S H I N G A V E

P A C I F I C
A V E

D A V I S
R D

M A T H E W S
R D

M U L L E R R D
V A N

A L L E N R D

D U N C A N R D

F I N E R D

E L D O R A D O S T

O A K S T

A L P I N E
A V E

W I L S O N
W A Y

G A W N E R D

T H O R N T O N R D

F A I R C H I L D
L N

C H E R O K E E R D

M A R I P O S A
R D

A R C H R D

W A T E R L O O R D

R O B E R T S
R D

B A K E R R D

H E W I T T R D

S T A R K R D

D R A I S A V E

M U R P H Y R D

B A C O N I S L A N D R D
Delta Water
Supply Intake
Pump Station
Peters Pipeline
Intake from Lower
Farmington Canal
Bellota
Intake
and Weir
Intake
from South
Main Canal
Regional Wastewater
Control Plant
Stockton
East Water
District
Wilkerson Lateral
Pixley Pipeline
DWTP Raw Water Pipeline
Bellota Raw Water Pipeline
Peters Raw Water Pipeline
Distribution System Pipelines
Water Treatment Plant
Regional Wastewater Control Plant
Raw Water Connection to WTP
Raw Water Intake
0 1.5 3
Miles
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4.2.3 Supplemental Raw Water Supply from Woodbridge
Irrigation District
In 2008, the City executed a 40-year purchase agreement with WID for 6,500 afy for municipal and industrial water use. WID provides raw water supply to both COSMUD and the City of Lodi. In addition to providing raw water to the two cities, WID provides irrigation supply to agricultural users in its service area. WID’s water supply is from the Mokelumne River.

This water augments supply to the DWTP if the San Joaquin River water is not available due to environmental restrictions. The water is conveyed to the DWTP through WID’s Wilkerson Canal and Pixley lateral pipeline for treatment and conveyance to the water distribution system, as shown on Figure 4-1.

The City’s 2008 contract with WID includes a provision for an increase in water supply as WID-served agricultural lands in the northern part of the City are annexed to the City for municipal and industrial use.

Under this contract, an additional 6,500 afy of WID supply will become available to COSMUD at a rate of

3.0 afy per acre annexed. WID supply may potentially increase from 6,500 afy to 13,000 afy by 2025.14

4.2.4 COSMUD Water Supply from the DWTP
The COSMUD North Stockton water service area currently receives water from the DWTP and groundwater supplies. In 2019, the City treated 20,809 af from the San Joaquin River and WID at the DWTP, providing about 68 percent of the entire COSMUD water demands. 15 For purposes of this Water Master Plan Update, and the water system capacity evaluation and hydraulic analyses described in Chapters 7 and 8, it has been assumed that treated water supplies from the DWTP will be available up to the capacity of the DWTP to meet existing and projected water demands in the North Stockton water service area, together with groundwater supplies. This assumption is based on the nature of the City’s Water Right Permit 21176 (e.g., the indirect potable reuse strategy) and the availability of supplemental water supply from the Woodbridge Irrigation District when water diversion from the San Joaquin River is curtailed. Additional surface water curtailments are possible in dry years and can be offset with additional groundwater use and/or demand reduction through implementation of the City’s Water Shortage Contingency Plan as described in the City’s Urban Water Management Plan. One of the key objectives of the Water Master Plan is to identify needed infrastructure improvements to meet the projected water demands, without demand reduction. Additional discussion regarding this assumption is provided in Chapters 7 and 8.
14 City of Stockton 2015 Urban Water Management Plan, Section 4. 15 2019 Water Production (see Table 3-1).

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4.3 WATER SUPPLY FROM THE STOCKTON EAST WATER DISTRICT
SEWD is a wholesale water supplier that provides treated potable water to the urban water retailers within the Stockton Metropolitan Area, including COSMUD, Cal Water, and two small maintenance districts in San Joaquin County (Urban Contractors). The COSMUD point of connection to SEWD is shown on Figure 4-1. SEWD also supplies irrigation water to agricultural users in San Joaquin County. SEWD receives and treats surface water from New Melones Reservoir and New Hogan Reservoir, through agreements with the United States Bureau of Reclamation (USBR). SEWD has filed several water right applications to divert excess wet weather flow from the Calaveras River, Little Johns Creek, and other tributaries. The applications are currently undergoing the permitting process with the State Water Board.

Although SEWD has groundwater wells, it has not historically pumped groundwater for municipal and industrial use, except during drought and low reservoir levels, and does not plan to do so on a regular basis in the future unless an emergency presents a need.16

4.3.1 Water Supply Contract
To alleviate severe groundwater overdraft in the region, SEWD constructed the DJWWTP with a capacity of 30 mgd and entered into an agreement (Original Contract) with the Urban Contractors to share the cost and deliveries of the DJWWTP in the mid-1970’s. Since that time, additional planning studies demonstrated the need for additional supplemental water supply to meet the future needs of the Stockton Metropolitan Area and the Original Contract was amended in 1987 (Second Amended Contract) to expand SEWD infrastructure and share water deliveries and costs. The DJWWTP has a current capacity of 62 mgd and is located just east of Central Stockton.

In April 2012, prior to the commencement of operation of the DWTP, the Urban Contractors entered into an allocation agreement to revise the provisions for water deliveries and cost sharing in the Second Amended Contract. That allocation agreement was replaced by an October 2019 Reconciliation Agreement between the Urban Contractors, which recognizes supply allocations, varying use and financial obligations between the Urban Contractors and SEWD. The Reconciliation Agreement is currently in effect.

4.3.2 New Hogan Reservoir
The New Hogan Reservoir has a water storage capacity of 317,000 af and receives its water supply primarily from rain runoff fed by the Calaveras River. SEWD is the water master and controls dam releases for irrigation and municipal use for itself and Calaveras County Water District (CACWD) during non-flood control periods. The United States Army Corps of Engineers (USACE) operates the dam for flood control.

Pursuant to an August 25, 1970 Allocation Contract between the USBR, SEWD, and CACWD, 56.5 percent of the yield from New Hogan Reservoir is allocated to SEWD, and the remaining 43.5 percent to CACWD, subject only to storage and release of water for flood control. The total annual supply available for both SEWD and CACWD is approximately 84,100 afy in normal water years. The contract also provides that any water not used by CACWD can be used by SEWD. At the current level of CACWD use, SEWD can rely on about 83,000 afy of supply from the New Hogan Project in normal water years under safe yield operation. 16 SEWD, 2015 Urban Water Management Plan, Section 4.

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However, if CACWD exercises its percentage entitlement (43.5 percent), SEWD’s available supply from this source would be reduced.

4.3.3 New Melones Reservoir
The New Melones Reservoir has a water storage capacity of 2.4 million af and is a part of the Central Valley Project (CVP). It receives water primarily from rain and snowmelt runoff and is fed by the Stanislaus River.

Pursuant to a December 1983 contract with USBR, SEWD and Central San Joaquin Water Conservation District (CSJWCD) are entitled to up to 155,000 af of water annually. SEWD is allocated up to 75,000 afy.

Water allocation amounts are based on the March-September water forecast and the February end of month storage in the New Melones Reservoir each year, to be used for municipal, industrial or agricultural use. This water is subject to cutbacks based on the USBR’s overall CVP operations.

4.3.4 COSMUD Water Supply from SEWD
The COSMUD South Stockton water service area currently receives water from SEWD and groundwater supplies. In 2019, COSMUD use of SEWD water was about 6,100 af, about 20 percent of the COSMUD total supply.17
Historically, SEWD was the sole source of treated surface water to COSMUD and provided a significant portion of the total water supply. The startup and operation of the DWTP in 2012 has provided the COSMUD with a new and reliable source of surface water under water right permit 21176 for current and future use within its service area. In addition, COSMUD will continue to rely on SEWD supplies for a portion of its water supply portfolio provided under the Second Amended Contract (expires in 2035), particularly as development continues in South Stockton.

For the North Stockton system, the planned construction of the North Stockton Pipeline Hypochlorite Facility in 2021, which is designed to improve chloramination disinfection processes, will allow for the integration of DWTP and SEWD water supplies. Once the system is operational, additional SEWD water deliveries into the North Stockton system, particularly in the summer months, will provide for a reduction in groundwater pumping and help manage the sustainability of local groundwater resources.

For the purposes of this Water Master Plan Update, and the water system capacity and hydraulic analyses described in Chapters 7 and 8, it has been assumed that treated water supplies from SEWD will be available to meet up to 70 percent of existing and projected water demands in the South Stockton water service area. This assumption is based on actual curtailments in SEWD deliveries during the recent drought. Remaining demands in the South Stockton water service area will be assumed to be met using groundwater supplies from existing and new groundwater wells. Surface water curtailments are possible in dry years and can be offset with additional groundwater use and/or demand reduction through implementation of the City’s Water Shortage Contingency Plan as described in the City’s Urban Water Management Plan. One of the key objectives of the Water Master Plan Update is to identify needed infrastructure improvements to meet the projected water demands, without demand reduction.

Additional discussion regarding this assumption is provided in Chapters 7 and 8. 17 Historical Water Production (see Table 3-1)
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4.4 GROUNDWATER
As described in Chapter 2, the City currently has groundwater wells located in the North Stockton and South Stockton systems, as shown on Figure 2-2. These wells are used to pump groundwater to meet peak summer demands or during dry years when available surface water supplies may be limited.

4.4.1 Groundwater Basin Management
The groundwater basin underlying the City is the San Joaquin Valley Basin, Eastern San Joaquin Subbasin (DWR Basin No. 5-22.01) as shown on Figure 4-2. The Subbasin is defined by the areal extent of unconsolidated to semi-consolidated sedimentary deposits that are bounded by the Mokelumne River on the north and northwest; San Joaquin River on the west; Stanislaus River on the south; and consolidated bedrock on the east.

In 2014, the California legislature enacted the Sustainable Groundwater Management Act (SGMA) in response to continued overdraft of California’s groundwater resources. The Subbasin is one of 21 basins and subbasins identified by the DWR as being in a state of critical overdraft. SGMA requires preparation of a groundwater sustainability plan to address measures necessary to attain sustainable conditions in the Subbasin. Sustainability is generally defined as long-term reliability of the groundwater supply and the absence of undesirable results from pumping.

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Figure 4-2. Eastern San Joaquin Groundwater Subbasin
The City has partnered with other users through the Eastern San Joaquin Groundwater Authority (GWA) to manage the groundwater basin. The City, along with fifteen other groundwater users and groundwater sustainability agencies, formed the GWA in 2017 in response to SGMA. In 2019, the GWA completed the Eastern San Joaquin Groundwater Subbasin Groundwater Sustainability Plan (GSP) to achieve groundwater sustainability in the Subbasin by 2040. In general, the GSP shows that groundwater elevations have declined since the 1950’s. Water quality issues were detected on the west side of the Subbasin, some of which are from wells underlying the City. The GSP outlined the need to reduce overdraft conditions and identified 23 projects for potential development, along with management actions, that either replace groundwater use or supplement groundwater supplies to meet current and future water demands. The list of 23 potential projects included in the GSP represent a variety of project types including direct and in-lieu recharge, intra-basin water transfers, demand conservation, water recycling, and stormwater reuse to be undertaken by the member agencies. The GSP determined an estimated pumping EXHIBIT 1
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offset and/or recharge need of 78,000 afy subbasin-wide to achieve sustainability. This amount may be reevaluated after additional data are collected and analyzed.18 In the GSP project list, COSMUD may potentially implement advanced metering infrastructure to reduce groundwater demand. COSMUD also manages its groundwater demands by implementing demand management measures outlined in the City’s Urban Water Management Plan. The demand management measures include: a water waste prevention ordinance, metering, conservation pricing, public education and outreach, programs to assess and manage distribution system real loss, water conservation program coordination and staffing support, water survey programs for residential customers, residential plumbing retrofit, conservation programs for commercial, industrial, and institutional accounts, and landscape conservation programs and incentives.

From 2020 to 2040, members of the GWA, including the City, will be monitoring and reporting their progress on implementing projects and studies and the impacts of their outreach. Evaluation will be conducted every five years.

COSMUD may also manage its groundwater demands by implementing additional conjunctive use projects outlined under the Stockton Delta Water Supply Project Program Environmental Impact Report (April 2005), which include aquifer storage and recovery, other conjunctive use projects outlined within the current Integrated Regional Water Management Plan – 2020 Addendum, and/or collaborative efforts with other Groundwater Sustainability Agencies.

4.4.2 COSMUD Groundwater Use
COSMUD uses groundwater conjunctively with its surface water supply sources, with groundwater generally used to meet increased water demands primarily in the summer months or during dry years when available surface water supplies may be limited. Wells are also depended on for emergency supply in the event of surface water supply interruptions.

Historically, the local groundwater basin provided 100 percent of the COSMUD water supply. However, with SEWD surface water deliveries beginning in the 1980s and the completion and dedication of the DWTP and associated water supply infrastructure, COSMUD reliance on groundwater has been significantly reduced. In 2019, COSMUD pumped only 3,778 af from the groundwater basin, about 12 percent of the COSMUD total water supply.19
In the future, COSMUD plans to use less groundwater in wet and average years. It plans to continue groundwater use to meet peak demand and in dry years to make up for reductions in surface water deliveries. 18 Eastern San Joaquin Groundwater Authority, Eastern San Joaquin Groundwater Subbasin Groundwater Sustainability Plan, November 2019.
19 Historical Water Production (see Table 3-1).

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Water System Performance and Operational Criteria
The purpose of this chapter is to define the recommended performance and operational criteria for the COSMUD water distribution system. These criteria include required fire flow and flow duration, definition of high demand conditions, definition of “emergency events”, system pumping capacity, system storage capacity (including operational, fire flow, and emergency storage components), minimum and maximum system pressures, and maximum pipeline velocity and head loss.

Table 5-1 summarizes the recommended criteria and the following sections of this chapter present the recommended performance and operational criteria for sizing the COSMUD water system:
• Water System Reliability and Water Quality
• Fire Flow Requirements
• Water System Supply Capacity
• Critical Supply Facilities
• Pumping Facility Capacity
• Water Storage Capacity
• Water Transmission and Distribution Pipeline Sizing
EXHIBIT 1
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Component Criteria Remarks / Issues
Fire Flow Requirements (flow [gpm] @ duration [hours])
Single Family Residential 2,000 gpm @ 2 hrs
Multi Family Residential 3,000 gpm @ 3 hrs
Commercial/Office 2,500 gpm @ 4 hrs (with approved automatic sprinkler system) Industrial 4,500 gpm @ 4 hrs (with approved automatic sprinkler system) Institutional 4,500 gpm @ 4 hrs (with approved automatic sprinkler system) Water System Capacity
Maximum Day Demand Provide firm capacity equal to the maximum day demand Met through a combination of surface water treatment plants, and groundwater wells only.

Maximum Day Demand plus Fire Flow Provide firm capacity equal to maximum day demand plus fire flow Met through a combination of surface water treatment plants, and groundwater wells, storage and booster pumping facilities.

Peak Hour Demand Provide firm capacity equal to peak hour demand Met through a combination of surface water treatment plants, and groundwater wells, storage and booster pumping facilities.

Pumping Facility Capacity
Pumping Capacity Provide the greater of maximum day concurrent with fire flow or peak hour demand
Assume firm pumping capacity. Sufficient pumping capacity should also be provided so that the maximum day demand can be supplied using firm pumping capacity with no assistance from storage reservoirs.

Backup Power Equal to the firm capacity of the pumping facility On-site generator for critical stations.(a) Plug in portable generator for less critical stations.

Surface Water Treatment Capacity
Treated Surface Water Supply/Pumping Capacity Provide capacity equal to maximum day demand Water Storage Capacity
Operational 25 percent of maximum day demand
Fire Equal to the largest fire flow requirement and associated duration (e.g., Industrial) 2,000 gpm @ 2 hrs = 0.24 MG
2,500 gpm @ 4 hrs = 0.48 MG
3,000 gpm @ 3 hrs = 0.54 MG
4,500 gpm @ 4 hrs = 0.96 MG
Emergency 1 x average day demand
Emergency Groundwater Credit (EGWC) Equal to the 85 percent of active groundwater supply that can be reliably accessed (facilities equipped with auxiliary power)
Treated Surface Water Credit (TSWC) Equal to the smaller of the available treated surface water supply sources Total Water Storage Capacity Operational + Fire + Emergency - EGWC - TSWC Total storage should be evaluated by pressure zone.

Water Transmission Line Sizing
Diameter 18-inches in diameter or larger Locate new transmission pipelines within designated utility corridors wherever possible.

Average Day Demand Condition
Maximum Pressure [psi] 80 psi
Minimum Pressure [psi] 45 psi
Maximum Head loss [ft/1000 ft] 3 ft/kft
Maximum Velocity [ft/sec] 3 fps
Maximum Day Demand Condition
Minimum Pressure [psi] 45 psi
Maximum Head loss [ft/1000 ft] 3 ft/kft
Maximum Velocity [ft/sec] 5 fps
Peak Hour Demand Condition
Minimum Pressure [psi] 45 psi
Maximum Head loss [ft/1000 ft] 3 ft/kft
Maximum Velocity [ft/sec] 5 fps
Hazen Williams "C" Factor 130
Pipeline Material Ductile Iron, Concrete Cylinder, or Steel Water Distribution Line Sizing
Diameter Less than 18-inches in diameter
Must verify pipeline size with maximum day plus fire flow analysis.

Locate new distribution pipelines within designated utility corridors wherever possible.

Maximum Day w/ Fire Flow Demand Condition
Minimum Pressure [psi] (at fire node) 20 psi
Maximum Head loss [ft/1000 ft] 10 ft/kft
Maximum Velocity [ft/sec] 10 fps
Peak Hour Demand Condition
Minimum Pressure [psi] 45 psi
Maximum Head loss [ft/1000 ft] 7 ft/kft
Maximum Velocity [ft/sec] 7 fps
Hazen Williams "C" Factor 130
Pipeline Material PVC
Other Criteria
Maximum Water Service Pressure 80 psi Per California Plumbing Code, install PRV if service pressure is greater than 80 psi.
• The largest facility that provides water to a particular pressure zone and/or service area; • A facility that provides the sole source of water to single or multiple pressure zones and/or service areas; • A facility that provides water from a water treatment plant or supply turnout; or • A facility that provides water from key groundwater supply wells (determined based on capacity, water quality and location).

The maximum combined storage credit is limited to the recommended emergency storage capacity.

Criteria based on requirements for new development, existing transmission mains will be evaluated on case-by-case basis. Evaluation will include age, material type, velocity, head loss, and pressure.

For consistency in hydraulic modeling.

Table 5-1. Summary of Recommended Potable Water System Performance and Operational Criteria Fire flows based on new development requirements. Existing development will be evaluated on a case by case basis, because of the historical varying standard.

For consistency in hydraulic modeling.
(a) A pumping facility is defined as critical if it provides service to pressure zone(s) and/or service area(s) without sufficient emergency storage and that meet the following criteria:

N129-60 20 41-R-129-WMPU
City of Stockton
Water Master Plan Update
Last Revised: 11-12-20
EXHIBIT 1
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5.1 WATER SYSTEM RELIABILITY AND WATER QUALITY
Attention to enhancing the reliability of the system under all conditions is an important part of maintaining high quality water service. Water system reliability is achieved through a number of system features including: (1) appropriately sized storage facilities; (2) redundant or “firm” pumping capacity, transmission/distribution, and supply facilities where required; and (3) alternative power supplies.

Reliability and water quality are also improved by designing looped water distribution pipelines and avoiding dead-end distribution mains whenever possible. Looping pipeline configurations reduce the potential for stagnant water and the associated problems of poor taste and low chlorine residuals. In addition, proper valve placement is also necessary to maintain reliable and flexible system operation under both normal and abnormal operating conditions.

Water quality standards largely pertain to protecting public health and consistently delivering a satisfactory product to the customer. The U.S. Environmental Protection Agency (EPA) and the State Water Resources Control Board (SWRCB) DDW are the agencies responsible for establishing water quality standards. The EPA and the DDW prescribe regulations that limit the amount of certain contaminants in the water provided by a public water system. The COSMUD, as water purveyor, is responsible for ensuring that the applicable water quality standards and regulations are met at all times.

5.2 FIRE FLOW REQUIREMENTS
The COSMUD is the water purveyor for the northern, southern and Walnut Plant areas of the City, and the City of Stockton Fire Department (Fire Department) is concerned with the availability of adequate water supply during fires. The COSMUD is responsible for water supply and distribution, while the Fire Department establishes minimum water flows required for firefighting purposes.

Both the COSMUD and Fire Department conform to the 2019 California Fire Code and use Appendix B (and Appendix BB) of the code, Fire Flow Requirements for Buildings, to assist in establishing minimum fire flows and durations. The Stockton Municipal Code (Title 15 – Buildings and Construction, Section 15.08.080) specifies the following additional requirements with respect to automatic sprinkler systems:

An automatic sprinkler system shall be installed in all new construction, regardless of occupancy classification, where the total floor area is 6,000 square feet or more. This does not include occupancy classes of A-2/H, I,F-1 and S-1; these occupancies shall be protected as per the California Building and Fire Codes.

When a municipal water system is designated to provide supply during a fire flow condition, it must meet minimum standards for fire flow rate and duration and residual pressure. Specifically, when delivering fire flow, the water system must concurrently meet maximum day demands and maintain at least 20 pounds per square inch (psi) residual pressure for all customer service locations in the distribution system.

Existing pipelines are assumed to meet fire flow standards that were in place at the time of construction, which are generally lower than current standards. Therefore, the evaluation of the COSMUD water system under existing demand conditions presents systemwide available fire flow only and does not recommend pipeline improvements to increase existing fire flow capacity. However, COSMUD can use these results as a guide for sizing pipeline improvements and to develop a rehabilitation and replacement program which prioritizes replacing existing smaller diameter (and typically older) pipelines to improve overall flows throughout the distribution system. This is discussed further in Chapters 7 and 9.

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For the COSMUD, the recommended fire flow requirements for future development are generalized based on land use type, as presented in Table 5-2, since actual future building types are not yet known.

Table 5-2. Recommended Fire Flow Requirements for Future Development(a,b) Land Use
Designation
Non-Sprinklered Sprinklered(c,d)
Fire Flow,
gpm
Duration,
hours
Recommended
Storage, MG
Fire Flow,
gpm
Duration,
hours
Recommended
Storage, MG(j)
Single Family
Residential(e) 2,000 2 0.24 -- -- --
Multi Family
Residential(f) 3,000 3 0.54 -- -- --
Commercial/Office(g) 4,000 4 0.96 2,500(i) 4 0.48
Industrial 8,000 4 1.92 4,500(i) 4 0.96
Institutional(h) 8,000 4 1.92 4,500(i) 4 0.96
(a) Construction type and fire flow calculation 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 and similar communities. (b) Unique projects or projects with alternate materials may require higher fire flows and should be reviewed by the Fire Chief on a case-by-case basis (e.g., proposed commercial/industrial areas and schools). (c) Specific fire flows were estimated from 2019 California Fire Code, Appendix B, and depend on construction type and fire area. These fire flow requirements are based on buildings being fully sprinklered. (d) Normally allows for up to a 50 percent reduction in fire flow if a building is provided with an automatic sprinkler system. However, the CFC also requires that no fire flow be less than 1,000 gpm for single family residential or 1,500 gpm for all other building types. For a more conservative fire flow estimate, Single Family and Multiple Family Residential buildings were considered non-sprinklered for this Water Master Plan.
(e) Single Family Residential includes Residential Estate and Low Density Residential land uses. (f) Multi Family Residential includes Medium and High Density Residential land uses. (g) Commercial/Office includes Commercial or Administrative Professional. (h) Institutional includes schools, hospitals, or other governmental buildings. (i) Fire flow includes a 500 gpm demand for on-site sprinkler flow. (j) Recommended storage volumes do not include the volume associated with 500 gpm sprinkler flow.

As described below, fire flows and the expected duration are also used to establish storage requirements.

5.3 WATER SYSTEM SUPPLY CAPACITY
Maximum day demand, maximum day demand plus fire flow, and peak hour demand conditions will be used to assess the adequacy of the COSMUD water supply and distribution system under existing and future conditions. Adopted peaking factors for maximum day and peak hour demands are discussed in Chapter 3.

The following subsections discuss the assumptions and recommended criteria for each demand condition.

5.3.1 Maximum Day Demand
The COSMUD must be able to provide a firm supply capacity equal to the maximum day demand, which can be met by a combination of treated surface water supplied from the SEWD and DWTP and groundwater wells. Even though the City’s water service areas have seven water storage tanks and associated pump stations, this storage is limited to meeting daily peak demands and only holds one average day of emergency storage and fire flows, and therefore cannot be counted on as a reliable source EXHIBIT 1
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to meet the maximum day demand requirements. In addition, California Code of Regulations requires that system supplies meet the maximum day demand.

Firm groundwater supply capacity assumes that 85 percent of the active COSMUD well capacity (not including standby wells) is available at any given time. An active well is defined as any well that is currently operational. Wells that are abandoned, deemed as standby, 20 or temporarily out of service due to
mechanical breakdowns, routine maintenance, water quality or other operational issues, or wells that pump directly into tanks are not considered active.
21 This conservative planning-level assumption ensures
the reliability and flexibility of the system to provide sufficient supply capacity to meet the maximum day demand, especially considering increasing regulation of groundwater pumping, and aging infrastructure.

5.3.2 Maximum Day Demand plus Fire Flow
In accordance with typical industry standards, the COSMUD water distribution system should have the capability to meet a system demand condition equal to the maximum day demand concurrent with a fire flow event while meeting the recommended system performance criteria (e.g., minimum and maximum system pressures), which are discussed in subsequent sections of this Chapter.

Maximum day demand plus fire flow should be met from a combination of supply sources (i.e., treated surface water from the SEWD and DWTP plus groundwater) and water storage reservoirs. The analysis of fire flow evaluations will be conducted assuming the largest pump at each pump station is offline. In addition, the COSMUD groundwater well system (well pumps) will be assumed to pump at firm capacity during a fire flow evaluation. It is also assumed that reservoir pump stations with only one pump, or without back-up power capability (either an on-site generator or adaptor for a plug-in generator), will not be available during fire flow evaluations. These conservative assumptions ensure the reliability and flexibility of the system to provide sufficient fire flow during emergency conditions.

5.3.3 Peak Hour Demand
Peak hour demand should be met from a combination of supply sources (i.e., treated surface water from the SEWD and DWTP plus groundwater) and water storage reservoirs. Assumptions regarding firm pumping capacity will also apply during a peak hour demand condition. During a peak hour demand condition, the COSMUD water system should be able to meet the recommended system performance criteria (i.e., minimum and maximum system pressures) discussed below in Section 5.7 Water Transmission and Distribution Pipeline Sizing.
20 Standby wells could also be used to meet demands, in an emergency, but these have been conservatively assumed to not be available.
21 Well status is based on the City of Stockton’s Permit Amendment, dated January 7, 2020.

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5.4 CRITICAL SUPPLY/PUMPING FACILITIES
Critical pumping facilities are defined as those facilities that provide service to a water service area(s) without sufficient emergency storage (see Emergency Storage section below) and that meet the following criteria:
• The largest pumping facility that provides water to a particular water service area • A pumping facility that provides the sole source of water to single or multiple water service areas
• A pumping facility that provides water from a water treatment plant or supply turnout • A pumping facility that provides water from key groundwater supply wells (determined based on capacity, water quality and location)
• All reservoir pump stations
All critical pumping facilities should be equipped with an on-site, back-up power generator. At less critical facilities, a plug-in adapter and transfer switch can be used to allow interconnection to a portable generator, which will be brought to the site by COSMUD staff during a prolonged power outage. In addition, portable generator connections will be configured at all reservoir pump stations.

5.5 PUMPING FACILITY CAPACITY
Sufficient water system pumping capacity (finished surface water pump stations, wells, or reservoir pump stations) should be provided to meet the greater of the following two demand conditions:

A maximum day demand concurrent with a fire flow event (e.g., larger industrial fire flow) with reservoir pump stations and well pumps assumed to operate at firm pumping capacity A peak hour demand with reservoir pump stations and well pumps assumed to operate at firm pumping capacity
The highest demand requirement between these two demand conditions sets the water system pumping capacity requirement.

5.6 STORAGE FACILITY CAPACITY
The total treated water storage capacity required is based on the following three major components:
• Operational Storage
• Fire Flow Storage
• Emergency Storage
A discussion of these three storage components, along with a discussion of “credits” for groundwater supply available within each area and treated surface water supply is also discussed below. Also described are potential operational strategies for the COSMUD storage facilities based on seasonal water demand patterns (i.e., winter vs. summer) and the zone within the COSMUD distribution system to help optimize EXHIBIT 1
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system operations by facilitating tank turnover to minimize water quality issues (e.g., stale water, loss of disinfectant residual).

5.6.1 Operational Storage
Over any 24-hour period, water demands will vary. Higher water demands will typically occur during the early morning hours when people are irrigating landscape and getting ready to go to work or school. Water demands will then typically decline to some nominal baseline level (depending on the proximity to adjacent commercial/industrial areas) and will 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.

Usually, water treatment plants, supply turnouts, and/or wells are operated at a constant rate over a 24-hour period (baseline) and augmented by additional flow from storage tanks and/or wells, during high demand periods, as needed. Storage tanks are normally refilled when demands drop below the baseline water production flow rate. The storage volume used to meet these peak demand periods is called operational storage.

Ideally, the operational storage requirement should be calculated based on the diurnal demand pattern within the water service area. If sufficient data is not available to develop a diurnal demand pattern, then the recommended volume of water to be stored as operational storage should be at least equal to 25 percent of the total volume of water needed to meet the water service area maximum day demand.

For this Water Master Plan Update, it is recommended that the COSMUD plan for an operational storage volume equivalent to 25 percent of the maximum day demand.

5.6.2 Fire Flow Storage
As discussed above, fire flow requirements are based on the 2019 California Building Code, generalized to adjacent land uses. These requirements are based on flow (in gpm) for the building/land use type (e.g., commercial, residential, school, industrial), size of building (in square feet), and type of construction (e.g., wood frame, metal, masonry, installation of sprinklers). After a fire flow requirement is established, it is multiplied by the required fire flow duration to produce an estimate of the total volume of fire flow storage required. Table 5-2 presents the recommended fire flow criteria and associated required fire flow storage. As shown in Table 5-2 the largest fire flow event (assuming installation of sprinklers) requires a fire flow storage volume of 0.96 MG.

If unavailable by gravity storage, the fire flow must be supplied with a National Fire Protection Association (NFPA) rated fire pump. If an NFPA-rated fire pump is not used, a pump(s) and motor(s) combination with a backup power source of sufficient capacity to meet the required maximum fire flow and minimum residual pressure requirements as determined by the Fire Department’s Fire Chief will be required.

5.6.3 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. There are three types of emergency events that a water utility typically prepares for:

EXHIBIT 1
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• 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 address them. • Major emergency. A disaster that affects an entire, or large, portion of a water system, lowers the quantity and quality of the water, or places the health and safety of the community at risk. Examples include water treatment plant failures, raw water contamination, or major power grid outages. Water utilities infrequently experience major emergencies.
• Natural disaster. A disaster caused by natural forces or events that create water utility emergencies. Examples include earthquakes, forest or brush fires, hurricanes, tornados or high winds, floods, and other severe weather conditions such as freezing or drought that damage or cause water system facilities to not be able to operate.

No specific standard exists for the amount of emergency storage that a utility should maintain.

Determination of the required volume of emergency storage is a system-specific 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. In developing an emergency storage requirement for the COSMUD, typical industry standards were used. For this Water Master Plan Update, it has been assumed that the emergency storage requirement will be based on maintaining a minimum quantity of emergency storage volume equivalent to one average day demand.

5.6.4 Emergency Groundwater Storage Credit
Based on the available COSMUD groundwater wells, groundwater storage can account for a portion of the recommended emergency storage. The following must be true to use the groundwater supply to offset the need to provide surface storage:
• Groundwater supply is of potable water quality and can be reliably accessed (i.e., wells are equipped with on-site emergency generator or a plug-in adapter and transfer switch) • Groundwater supply is not already being relied upon to meet the COSMUD average day demand requirements
• Sufficient water distribution facilities are available to distribute this water to demand areas It will be assumed that only the firm groundwater supply will be available for an emergency groundwater storage credit to offset the COSMUD emergency storage requirement. For planning purposes, it is assumed that 85 percent of the active and reliable COSMUD groundwater pumping capacity (i.e., capacity of active wells with on-site generators) is available to supplement required emergency storage for one average day.

This conservative assumption accounts for wells out of service for reasons other than power loss (e.g., maintenance, or water quality).

5.6.5 Treated Surface Water Supply Credit
Because the COSMUD has two available surface water treatment plants, and the fact that their source water is independent of one another (Stanislaus and Calaveras Rivers vs. the San Joaquin and Mokelumne Rivers), the capacity of one of the water treatment plants can account for a portion of recommended EXHIBIT 1
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emergency storage. For the purposes of this Water Master Plan Update, it is assumed that the smaller of the two WTPs, will be available to offset a portion of the emergency storage requirement. The full credit only applies if North Stockton and South Stockton are operated as a single zone, with the ability to convey water from north to south and south to north. Currently, COSMUD operatesthe North Stockton and South Stockton systems independent from one another. Due to this limitation, the treated surface water supply credit can only be applied to North Stockton, and is limited to surplus SEWD supply capacity after South Stockton demands are met.

5.6.6 Total Storage Capacity Recommended
The recommended COSMUD potable water storage capacity should be the sum of the following components:
• Operational: Volume of water necessary to meet diurnal peaks observed throughout the day, assumed to be equivalent to at least 25 percent of the maximum day demand • Fire Flow: Volume of water necessary to supply a single large fire flow event • Emergency: Volume of water necessary to provide an average day demand • Emergency Groundwater Storage Credit: Equal to the firm groundwater supply that can be reliably accessed (facilities equipped with auxiliary power); assumed to be 85 percent of the active groundwater pumping capacity
• Treated Surface Water Supply Credit: Equal to the excess capacity available in the smaller of the reliably available treated surface water supply sources (DWTP or SEWD) The recommended storage volume requirements are established to identify infrastructure required to meet the stated operational and emergency conditions. The amount of total system storage and system peaking capacity required to meet these criteria will change over time as the COSMUD potable water demands increase.

5.6.7 Storage Operational Strategies
The operations of the COSMUD storage tanks can be varied seasonally to optimize tank operations and facilitate tank turnover to maintain water quality throughout the system. Based on the criteria discussed above, if water demands are evaluated seasonally (e.g., winter vs. summer), the required operational storage volumes for the winter months would be less than the required storage volumes for the summer months as the water demands are lower. Therefore, storage levels in the tanks could be maintained at lower levels in the winter months to facilitate better tank turnover or selected tanks could be removed from service during the low demand conditions, provided that fire-fighting ability is not compromised.

Similarly, demand patterns in various parts of the COSMUD water system vary and required storage volumes can be tailored to the area served by each tank, in addition to the seasonal demand patterns.

5.7 WATER TRANSMISSION AND DISTRIBUTION PIPELINE SIZING The following criteria will be used as guidelines for sizing new transmission and distribution pipelines.

However, the existing COSMUD water 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 demand plus fire flow event, this condition, by itself, does not necessarily indicate a problem as long as the minimum system pressure criterion is satisfied. Consequently, the existing COSMUD water system will EXHIBIT 1
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be evaluated using pressure as the primary criterion; and secondary criteria, such as velocity, head loss, age, and material type, will be used as indicators to locate where water system improvements may be needed.

New transmission and distribution pipelines to serve the future planning areas within the COSMUD water service areas should be located within designated utility corridors wherever possible. These designated utility corridors should be within public rights-of-way to minimize or eliminate the need for utility easements within private property.

5.7.1 Water Transmission System
Transmission pipelines are generally 18 inches in diameter or larger and should be designed based on the criteria described below for average day, maximum day, and peak hour demand conditions. The criteria reflect industry standards and West Yost’s experience working with the existing COSMUD water system.

5.7.1.1 Average Day Demand
• Pressures should be maintained between a maximum of 80 psi and a minimum of 45 psi • The maximum velocity within transmission pipelines should be 3 feet per second (fps) • Head losses within the transmission system pipelines should be limited to 3 feet per thousand feet (ft/kft) of pipeline

5.7.1.2 Maximum Day Demand
• The minimum of allowable service pressure in the water transmission main should be 45 psi • The maximum velocity within the transmission system pipelines should be 5 fps • Head losses within the transmission system pipelines should be limited to 3 ft/kft of pipeline

5.7.1.3 Peak Hour Demand
• The minimum residual pressure during a peak hour demand should be 45 psi • The maximum velocity within the transmission system pipelines should be 5 fps • Head losses within the transmission system pipelines should be limited to 3 ft/kft of pipeline

5.7.2 Water Distribution System
Distribution pipelines are generally less than 18 inches in diameter and should be sized based on the criteria described below for maximum day demand plus fire flow and peak hour demand conditions. The criteria reflect industry standards and West Yost’s experience working with the existing COSMUD water system.

5.7.2.1 Maximum Day Demand plus Fire Flow
• The minimum allowable residual pressure should be 20 psi at the flowing fire hydrant • The maximum velocity within the distribution system pipelines should be 10 fps, or the head losses within the distribution system pipelines should be limited to 10 ft/kft of pipeline, whichever criteria is more conservative given the specific hydraulic/system condition EXHIBIT 1
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5.7.2.2 Peak Hour Demand
• The minimum residual pressure during a peak hour demand should be 45 psi • The maximum velocity within the distribution system pipelines should be 7 fps, or the head losses within the distribution system pipelines should be limited to 7 ft/kft of pipeline, whichever criteria is more conservative given the specific hydraulic/ system condition

5.7.3 Other Recommended Criteria
It is generally recommended that maximum pressures at customer service locations do not exceed 80 psi.

Should pressures exceed 80 psi at customer service locations, individual pressure regulating valves should be installed in accordance with California Plumbing Code requirements (Section 608.2 Excessive Water Pressure) to avoid potential damage to customer fixtures (e.g., water heaters, hoses).

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Hydraulic Model Update and Calibration
This chapter describes the update, refinement, and calibration of the COSMUD existing water distribution system hydraulic model to reflect existing conditions. The COSMUD water system Geographic Information System (GIS) was used to confirm the configuration of water system facilities in the existing model. The hydraulic model was calibrated to a high degree of accuracy, per general guidelines established by the American Water Works Association Manual of Practice 32 (AWWA M32), and to a level that is acceptable for use for planning purposes or detailed design/operational studies. The resulting updated hydraulic model was subsequently used to evaluate the adequacy of existing and future COSMUD water systems to meet existing and future needs (see Chapters 7 and 8, respectively).

The hydraulic model updates, calibration, and verification efforts are described in the following sections of this chapter:
• Hydraulic Model Background
• Hydraulic Model Update Methodology
• Hydraulic Model Update
• Hydraulic Model C-Factor Calibration
• Hydraulic Model Extended Period Simulation (EPS) Calibration

6.1 HYDRAULIC MODEL BACKGROUND
The COSMUD computerized hydraulic model was originally developed in 1999 using the H2ONET software.

It was updated and dynamically calibrated in 2008 by West Yost as part of the 2008 Water Master Plan.

At that time, it consisted of two separate models: one for North Stockton and one for South Stockton.

Since the 2008 update, new developments have been constructed within the COSMUD water service area and the DWTP was constructed. The hydraulic model was updated to include the DWTP finished water reservoir and pump station. Since the DWTP is a significant new addition to the COSMUD water system, it was important to make sure the hydraulic model was calibrated with this new facility online. In addition, COSMUD is actively working on implementing the North Stockton Pipeline Hypochlorite Facility, which will allow SEWD water supplies to be conveyed from the SEWD DJWWTP to North Stockton. As part of this latest hydraulic model update, the two models for North Stockton and South Stockton were combined into one model to allow for the evaluation of coordinated operations of the North Stockton and South Stockton systems. Also, as described further in Chapter 7, the update of the COSMUD hydraulic model also allows for a systemwide fire flow evaluation to be performed to determine available fire flow capacity for adjacent land uses in the distribution system.

6.2 HYDRAULIC MODEL UPDATE METHODOLOGY
West Yost completed the following tasks to update the COSMUD hydraulic model:
• Used the existing COSMUD water distribution system maps (GIS) to update the existing hydraulic model
• Incorporated new facilities that were constructed and operating as of January 2020; — DWTP finished water reservoir and pump station
— New Weston Ranch reservoir
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• Verified that the existing hydraulic model system configuration (pipeline sizes, alignments, connections, and other facility sizes and locations) is representative of the current COSMUD water system
• Allocated 2019 existing water demands by using the COSMUD water meter information to properly distribute water demands within the hydraulic model • Assigned elevations to junctions using the COSMUD high resolution raster file • Confirmed roughness factors assigned in previous versions of the model using hydrant test results
• Dynamically calibrated the COSMUD water system hydraulic model to simulate pressures, levels and flows observed in the field and recorded by the COSMUD Supervisory Control and Data Acquisition (SCADA) system
To accomplish these tasks, West Yost worked closely with COSMUD staff to obtain and review the following available data:
• As-built information, where needed, such as for the DWTP, Westlake Villages, and the Veterans Affairs Off-Site Utility Improvements
• System operation plans
• Metered account water consumption data
• Historical SCADA system data
• Hydrant flow testing data
• Hydrant pressure data gathered by hydrant pressures recorders (HPRs) The updated hydraulic model was calibrated under summer (maximum day) demand conditions using a developed diurnal demand pattern and an EPS model scenario. The calibration utilized SCADA and field data collected on June 23, 2020, which was the peak demand day concurrent with deployment of HPRs.

6.3 HYDRAULIC MODEL UPDATE
The following sections describe the findings of West Yost’s model review and the specific updates made to the water distribution system hydraulic model.

6.3.1 Model Pipeline Configuration Update
West Yost compared the latest hydraulic model with the GIS geodatabase file provided by COSMUD staff to verify and, if needed, update the pipeline diameters and configurations of the existing model to be consistent with the GIS geodatabase. In addition, West Yost reviewed as-built information for development projects that were in construction or scheduled to be completed soon (e.g., Veterans Affairs facility improvements, etc.). Figure 6-1 summarizes the pipelines that were added or updated with more recent information (pipeline diameters, materials, etc.).

EXHIBIT 1
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") ")
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Q3
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Weston Ranch

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B L V D

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

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S U T T E R S T S A N J O
A

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B S T

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A Y

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K A I S E R R D
Well SSS2
Well SSS1
Well SSS8
Stockton
East Water
District
Well SSS3
Well SSS9
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Well #28
Well
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Well #16 Well #24
Well #9
Well #20
Well #26
Well #1 Well #4
Well #25
Well #11
Well #7
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well
#03R
Well #30
Well #31
Well #32
Well #10R
Figure 6-1
Summary of Model
Pipeline Updates
City of Stockton
Water Master Plan Update
Updated Pipelines
Existing Pipelines (Unaltered)
COSMUD Water Service Boundary
Q3 Water Treatment Plant
TU Storage Tank & Booster Pump Station
Wells
") Active
") Inactive
") Standby
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F6_1_UpdateAreas.mxd - wjones - 11/18/2020 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
EXHIBIT 1
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6.3.2 Pipeline Roughness Characteristics
C-factors indicate the roughness (or smoothness) of the interior of a pipeline. The lower the C-factor, the rougher the pipeline interior and the higher the friction loss in the pipeline. Typically, C-factors are assigned to pipelines based on the characteristics of the pipeline (e.g., age, material type, and size). The COSMUD GIS geodatabase contains limited information on material and pipe age. During the last hydraulic model update, C-factors were assigned on the basis of anticipated material type and were subsequently adjusted based on approximate age (i.e., if one area was older with respect to another, C-factors were reduced slightly in the older area). For the purposes of this update, C-factors were not reassigned, but instead were assumed to be correct and later confirmed as part of the C-factor calibration process which was based on hydrant testing and data collected in the field. The results of that process are discussed further in the Hydraulic Model C-Factor Calibration section below.

6.3.3 Water Demand Allocation
The COSMUD GIS geodatabase contains a feature class for spatially-located water meters. COSMUD staff also provided a spreadsheet containing customer account information and water consumption for 2018-2019. The consumption data was reviewed, and it was determined that the 2019 demands were the most representative to use for the hydraulic model, as this data set contained the latest customer accounts and recently completed developments and was slightly higher than 2018 consumption. Since water meters were already spatially located, approximately 99 percent of the 2019 metered water consumption was able to be linked to the spatially located water meters.

The water use data for 2019 was linked by location ID to the water meter feature class. Then the InfoWater Demand Allocator tool was used to automatically assign the spatially-located demand point to the pipeline closest to its position in the water system.22 The demand allocation results were reviewed to confirm that the demands were allocated appropriately (i.e., demands not placed on large transmission pipelines).

Special attention was paid to locations with parallel pipelines, since several locations include parallel transmission pipelines and distribution system pipelines.

6.3.4 Elevation Extraction
The node features in the hydraulic model require that elevations be assigned to calculate pressures in the system. It is important to use the most accurate elevation data available when assigning elevations to the hydraulic model. The COSMUD provided a raster file that contains elevations for most of the area within the City limits. The raster provided was used to assign elevations to the hydraulic model for junctions, using the Elevation Extractor tool in InfoWater. Elevations assigned in the hydraulic model range from a low of 7.5 feet below sea level in the northwest corner of the distribution system, along Westlake Drive, to a high of 51.5 feet above sea level east of the Stockton East Water District Treatment Plant. 22 The allocator locates the nearest pipeline to assign demands, and then assigns demands to the junctions connected to the pipeline, based on their proximity to the meter.

EXHIBIT 1
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6.3.5 Water System Facilities
After the pipelines and nodes were confirmed in the hydraulic model, major system facilities (i.e., groundwater wells, storage tanks and associated pump stations, and treatment plants) were reviewed in the model to confirm correct configuration. Tank elevations (i.e., base, inlet, and overflow) were confirmed at the various tank locations, based on available information. It should be noted that all tank sites were modeled with one tank that contains an equivalent diameter of all tanks present at that location.

Pump curves and pumping water elevations in the wells were also updated. Pumping water elevations at several North Stockton wells were adjusted (increased) by an average of 50 feet. This increase in groundwater levels can be attributed to North Stockton’s switch to relying primarily on treated surface water rather than groundwater, thus groundwater levels have increased. Pump curves in the hydraulic model were compared to recent pump tests and, where appropriate, were updated using affinity laws to more closely align with operating points recorded during 2019 pump tests.

6.3.6 Hourly Pattern Development
COSMUD staff provided SCADA system data at 15-minute intervals from June 12, 2020 to June 25, 2020, which corresponds with the HPR monitoring period. The SCADA information included flows, tank levels, and pump discharge pressures for all of the facilities in North and South Stockton that were in operation during this monitoring period. To conduct the extended period calibration, West Yost compiled well and treatment plant production, and tank flows, to develop hourly diurnal patterns for both North and South Stockton. The diurnal pattern from June 23, 2020 was chosen for the extended period calibration because the demand on this day approximated a maximum day demand (approximately 44.4 mgd), and the fluctuations throughout the day (peak demand in both North and South Stockton) were the highest compared to the other days in the monitoring period. The following subsections provide the methodology used to develop the diurnal pattern for each water service area.

6.3.6.1 North Stockton
The North Stockton water service area is supplied predominantly from the DWTP, with some water also supplied from existing groundwater wells. The following is a summary of the facilities that supplied water to the North Stockton water service area during the time period monitored:
• Treatment Plants: Delta Water Treatment Plant
• Groundwater Wells: 3R, 29, 30, 31, 32
• Reservoir Pump Stations: Northwest Reservoir, Fourteen-Mile Slough Reservoir Figure 6-2 presents the hourly diurnal pattern assumed for North Stockton. The demand in North Stockton on June 23, 2020 was approximately 36 mgd.

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N - 129 - 60-20-41 - E - 6 - 3 - F6-2
City of Stockton
Water Master Plan Update
Last Revised: 11-05-20

0.0 0.2

0.4 0.6

0.8 1.0

1.2 1.4

1.6 1.8
12:00 AM 3:00 AM 6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM 9:00 PM 12:00 AM Peaking Factor
Figure 6-2. Diurnal Patterns during Calibration Day (June 23, 2020) North Stockton South Stockton
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6.3.6.2 South Stockton
The South Stockton water service area is supplied from the SEWD DJWTP through the South Stockton Aqueduct. The following is a summary of the facilities that supplied water to the South Stockton water service area during the time period monitored:
• Treatment Plants: Stockton East Water District Water Treatment Plant • Groundwater Wells: None
• Reservoir Pump Stations: Weston Ranch
Figure 6-2 contains hourly diurnal pattern assumed for South Stockton. The demand on June 23, 2020 averaged 8.4 mgd.

6.4 HYDRAULIC MODEL C-FACTOR CALIBRATION
The COSMUD hydraulic model was calibrated to confirm that the hydraulic model can accurately represent the operation of the water distribution system under stressed (i.e., fire flow) conditions.

Calibration of the hydraulic model used COSMUD SCADA data and data gathered through hydrant tests and HPRs, as described in the following sections.

6.4.1 Development of Hydrant (C-Factor) Tests
After developing the hydraulic model, 7 locations (and 1 alternate location) were chosen for performing hydrant flow testing as shown on Figure 6-3. Selection of these hydrant test sites was based on specific pipeline size, age, and material type. Pipelines in the COSMUD water system range in size from 2 to 60 inches in diameter. Pipeline materials consist mainly of asbestos cement and PVC that were mostly installed in the 1960s through the 1990s.

C-factors were previously assigned as part of the 2008 Water Master Plan, based in large part on hydrant testing that was conducted at that time, knowledge of material types, and adjustments to C-factors based on age. For this Water Master Plan Update, hydrant tests were used to “spot-check” and confirm the previously assigned pipeline C-factors, and to calibrate the hydraulic model so that it closely represents actual observed pressure conditions in the field. West Yost provided COSMUD with a memorandum detailing the hydrant test procedures before performing the field testing (see Appendix A). Table 6-1 provides the field status of each hydrant test.

EXHIBIT 1
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0 3,000 6,000
Scale in Feet
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Stockton
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Well #28
Well #15
Well #16 Well #24
Well
#20
Well #26
Well #1
Well #4
Well #25
Well #11
Well #7
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well
#21
Well #27
Well #29
Well #30
Well #31
Well #32
Well #10R
1 2
4 5 3
6 8
Figure 6-3
Hydrant Test
Location Map
City of Stockton
Water Master Plan Update
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F6_3_HydrantTestOverallMap.mxd - wjones - 1/6/2021 0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
COSMUD Water Service Boundary
EG!. Hydrant Test Location
Q3 Water Treatment Plant
TU Storage Tank & Booster Pump Station
Wells
") Active
") Inactive
") Standby
Pipelines
Less than or Equal to 12-inch
Greater than 12-inch
0 3,000 6,000
Scale in Feet
EXHIBIT 1
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Table 6-1. Hydrant Test Locations and Status(a)
Test No.

Diameter,
inches
Pipeline
Material Type
Approximate
Age Location Field Status
1 8
Asbestos
Cement
1980s Along Angel Drive Completed
2 6
Asbestos
Cement
1960s Santa Maria Way and
San Lucas Avenue Completed
3 6
Asbestos
Cement
1960s Bonnie Brook Drive and
Oak Creek Drive Completed
4 10 Asbestos
Cement
1970s Along Knickerbocker
Drive Completed
5 8
Asbestos
Cement
1980s Shameran Street and
Sharkon Lane Completed
6 6
Asbestos
Cement
1980s Along Fort
Donelson Drive Completed
7 8 PVC 1990s Along Ishi Gotto Street Completed
8 (Alternate) 8 PVC 1980s Along Boulder
Creek Circle Completed
(a) Seven test locations and one alternative test location were all completed.

Hydrant flow testing was performed on June 24, 2020. Each hydrant test involved flowing water through pipelines of a specific size and material type,
23 and measuring the pressure drops through the pipelines to determine friction losses. The hydrant test procedure consisted of monitoring discharge flow and pressure at the flowing hydrant, and pressure at other hydrants along the supply route to the flowing hydrant.

Static pressures were measured while the flow hydrant was closed, and residual pressures were measured while the hydrant was flowing.

Each hydrant flow test performed was simulated using the hydraulic model of the COSMUD water system.

The differences between observed static and residual pressures for the field hydrant test were calculated and compared to readings predicted by the model. The goal of the calibration effort was to achieve no more than 5 psi differential between the field hydrant test data and the model-predicted results, based on standard engineering practice for model calibration for water system master planning, and is similar to the general guidelines provided in AWWA M32 for developing hydraulic models for planning use.

Results from the hydrant tests are discussed in more detail in the following section. 23 For each hydrant test, system valves were closed as necessary to isolate pipelines of a specific size and material type.

EXHIBIT 1
1746

6.4.2 Hydrant (C-Factor) Test Results
The results of the simulated hydrant flow tests generally confirmed the water system pipeline configuration and the previously assigned C-factors continue to be representative of the existing pipeline roughness. C-factors did not need to be modified for any pipelines in the model. Table 6-2 summarizes the comparisons of field data and model results for the hydrant tests performed.

Only one hydrant test location (Hydrant Test 2 for a 6-inch AC pipeline installed in the 1960s) did not meet the ±5 psi tolerance limit established for calibration. At the observation hydrants furthest from the flowing hydrant (Hydrant 2D), field-observed differential pressures for Hydrant Test 2 were greater than the model-predicted values, and exceeded the tolerance limit of ±5 psi. Observation hydrants 2A, 2B and 2C, however, all calibrated to within the 5 psi tolerance limit. In addition, Hydrant Test 3, which was also a 6-inch diameter AC pipeline approximately built in 1960s, indicated that model-predicted differential pressures were within the 5 psi tolerance limit and confirmed the C-factor. It is suspected that there was a reading error or an incorrect pipeline diameter upstream of Hydrant 2D that resulted in the difference at this hydrant. Therefore, the existing C-factor for AC pipelines is still considered to be accurate.

6.4.3 Hydraulic Model C-Factor Calibration Findings and Conclusions In summary, the results from the hydrant tests indicate that the hydraulic model is calibrated within a 5 psi pressure differential from field-observed data. Of the eight hydrant tests that were conducted, only one hydrant (Hydrant Test 2, D hydrant) did not meet the 5 psi pressure criterion. However, the C-factor for this pipeline was not adjusted because the remaining tests for pipelines with the same pipeline material and age showed alignment between the field-observed and model-predicted results.

The results indicate that the COSMUD hydraulic model can simulate fire flow or other large demand conditions within the COSMUD water system. Based on the results of the hydraulic model calibration, it can be concluded that the hydraulic model results provide a reasonable representation of the COSMUD water distribution system and can be used for planning purposes.

EXHIBIT 1
1747
Residual Pressure, psi
Differential Pressure, psi
(Static - Residual) Static Pressure, psi Residual Pressure, psi Differential Pressure, psi
(Static - Residual)
1 54 14 N/A 54 N/A N/A N/A
1A 53 26 27 53 24 29 -2
1B 54 35 19 53 34 19 0
1C 56 46 10 53 47 6 4
1D 53 51 2 52 50 2 0
2 53 4 N/A 50 N/A N/A N/A
2A 51 15 36 50 14 37 -1
2B 52 26 26 51 26 25 1
2C 55 35 20 51 35 15 5
2D 53 42 11 51 46 5 6
3 52 1 N/A 51 N/A N/A N/A
3A 50 7 43 51 5 46 -3
3B 51 15 37 52 14 37 -1
3C 54 21 33 52 21 31 2
4 50 20 N/A 49 N/A N/A N/A
4A 50 43 8 49 42 7 0
4B 50 45 5 49 43 6 -1
4C 53 49 4 49 45 4 0
4D 50 49 1 49 47 2 -1
5 50 14 N/A 50 N/A N/A N/A
5A 50 36 15 50 36 13 1
5B 48 40 8 50 47 3 5
5C 54 51 3 50 48 2 1
6 55 5 N/A 51 N/A N/A N/A
6A 50 17 33 51 17 34 -1
6B 52 32 21 52 32 19 1
6C 54 44 10 51 43 8 2
7 60 15 N/A 59 N/A N/A N/A
7A 59 24 35 59 25 34 1
7B 60 32 28 59 33 26 2
7C 62 40 22 58 39 19 3
7D 61 44 17 58 42 16 1
8 52 9 N/A 49 N/A N/A N/A
8A 51 24 28 50 22 28 0
8B 52 29 23 50 28 22 1
8C 54 39 16 49 35 14 1
8D 51 47 5 49 45 4 0
Table 6-2. Summary of Hydrant Test Calibration Results
Comparison of Differential
Pressures between Field and
Modeled Data(b)
(a) Location of hydrants can be found in the Hydrant Test Memorandum prepared by West Yost (Appendix A). (b) The goal of the calibration effort is to achieve a differential pressure comparison within 5 psi for the observed hydrants, consistent with requirements in AWWA M32.

Hydrant(a) Field DataStatic Pressure, psi
Modeled Data
Hydrant Flow Test No. 1 [Angel Drive, Between Sutton Way and Otto Drive] Hydrant Flow Test No. 2 [Santa Maria Way and San Lucas Avenue, Between Ponce De Leon Avenue and Don Borgia Way] Hydrant Flow Test No. 3 [Bonnie Brook Drive and Oak Creek Drive, Between Westland Avenue and Meadow Avenue] Hydrant Flow Test No. 4 [Knickerbocker Drive, Between New York Drive and Tam O Shanter Drive] Hydrant Flow Test No. 5 [Shameran Street and Sharkon Lane, Between Montauban Avenue and Hammertown Drive] Hydrant Flow Test No. 6 [Fort Donelson Drive, Between Five Mile Drive and Palmouth Court] Hydrant Flow Test No. 8 [Boulder Creek Circle]
Hydrant Flow Test No. 7 [Ishi Gotto Street, Between Ken Street and Brick and Tile Circle] N - 129 - 60-20-41 - E - 6 - 3 - HPR_Cal_06242020
City of Stockton
Water Master Plan Update
Last Revised: 08-11-20
EXHIBIT 1
1748

6.5 HYDRAULIC MODEL EXTENDED PERIOD SIMULATION (EPS)

CALIBRATION
Calibrating a hydraulic model to replicate field operating conditions requires thorough knowledge of how the water system performs over a range of operating conditions. To ensure that the hydraulic model was correctly configured and capable of producing results that are consistent with those observed from the COSMUD SCADA system and collected in the field, a detailed EPS calibration process for summer conditions was conducted. The calibration was completed using SCADA and field data collected on June 23, 2020. For the EPS calibration, 16 HPRs were deployed to collect supplemental pressure data that was subsequently used to compare model-predicted results at various locations throughout the system, including high and low elevation locations, and locations that are hydraulically distant from supply points.

The locations where the HPRs were set up in the system are shown on Figure 6-4.

The hourly diurnal patterns developed for each water service area, as described in the Hourly Pattern Development section above, were used in the calibration. The model was set up to replicate the system operations by applying controls to facilities based on specific conditions (i.e., pumps on or off based on tank level). Model-predicted results (i.e., facility flows and pressures, tank levels, and system pressures) were plotted and compared to the SCADA system data for the specific dates and field-collected HPR data to verify whether the COSMUD hydraulic model accurately predicts field conditions.

Model-predicted flows and levels were matched as closely as possible and aimed to be within 10 percent of field-recorded data. Pressure trends were checked to see whether results were within ±5 psi of field trends. Adjustments to the model were made, if needed, to better match field data when results from the hydraulic model did not trend well with the field data. Results from the calibration are discussed in the following sections.

EXHIBIT 1
1749
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HPR 04
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Figure 6-4
Hydrant Pressure
Recorder Map
City of Stockton
Water Master Plan Update
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F6_4_HPROverallMap.mxd - wjones - 11/18/2020 South Stockton
North Stockton
0 3,500 7,000
Scale in Feet
COSMUD Water Service Boundary
*G!. HPR Location
Q3 Water Treatment Plant
TU Storage Tank & Booster Pump Station
Wells
") Active
") Inactive
") Standby
Pipelines
Less than or Equal to 12-inch
Greater than 12-inch
0 3,000 6,000
Scale in Feet
EXHIBIT 1
1750

6.5.1 Hydraulic Model EPS Calibration Results
Graphs of the comparisons between model-simulated results and SCADA values, as well as comparisons between model-simulated results and HPR values for the calibration date of June 23, 2020, are provided in Appendix B and Appendix C for facilities in North and South Stockton, respectively. The following summarizes the comparison of hydraulic model results with field data for each water service area.

6.5.1.1 North Stockton
Figures B-1 through B-20 of Appendix B show results for the EPS calibration in North Stockton. In general, COSMUD provides a certain minimum supply for North Stockton from the DWTP. Differences between surface water supply and demand are met through a combination of storage and groundwater. Storage tanks typically drain in the morning and fill in the afternoon. The Northwest and Fourteen-Mile Slough Reservoirs follow a consistent fill and empty cycle to mitigate potential water quality issues.

Figure B-1 shows pressure and flow results for the DWTP. The DWTP, based on SCADA data, maintains a relatively constant pressure of approximately 50 psi and also maintains a relatively constant flow of approximately 20 mgd. In the hydraulic model, the DWTP was set to maintain a downstream pressure of 50 psi. Model-predicted flow from the DWTP did oscillate and is not as consistent as the SCADA data indicates. However, the average supply throughout the day does align well and model-predicted flows are generally within 10 percent of the SCADA-predicted range, which is acceptable per AWWA M32. Pressures are also well within the target tolerance of ±5 psi.

Figures B-2 and B-3 show the tank levels in the Northwest Reservoir and the Fourteen-Mile Slough Reservoir. The model-predicted tank levels generally trended similarly to the field-recorded data for both facilities, within 10 percent of each other.

Figures B-4 through B-8 summarize the flow and pressures from the various COSMUD groundwater wells in North Stockton that were operating that day. The model-predicted flows and pressures generally trended similarly to field-recorded data for both parameters, with flows within 10 percent and pressures within ±5 psi of field-recorded information. It should be noted that the pressure at Well 31 is underpredicted in the model. However, model-predicted pressures at the two nearby HPRs 2 and 7 were within the ±5 psi tolerance of HPR/field-recorded conditions. The low pressure at Well 31 could be due to the elevation of the pressure instrument, or a SCADA reading issue. However, this difference is acceptable because all other facilities calibrated well with respect to pressure and nearby HPRs are within range.

Figures B-9 through B-20 show that the pressure trends collected by the HPRs installed in North Stockton match the pressure results from the model simulation. All model-predicted pressure results are within approximately 5 psi of the field-recorded pressures.

6.5.1.2 South Stockton
Figures C-1 and C-2 show results for the SEWD Water Treatment Plant and Weston Ranch Reservoir, respectively. In general, SEWD provides supply for South Stockton and Weston Ranch is used and filled on an as-needed basis. No wells came on in South Stockton during the calibration day.

EXHIBIT 1
1751
For SEWD, model-predicted flows and pressures generally trended similarly to field-recorded data, with flows within 10 percent and pressures within ±5 psi of field-recorded information. 24 At the Weston Ranch
Reservoir, the model-predicted tank levels also trended similarly to field-recorded data, within 10 percent of each other.

Figures C-3 through C-6 show the pressure trends collected by the HPRs installed in South Stockton compared to the pressure results from the model simulation. In general, the field results match the model-predicted results, with the exception of HPR 13 and HPR 14 between 10:00 am and 1:00 pm. These HPRs are located on the west side of South Stockton, furthest from SEWD and were generally within residential land uses. It is possible that the diurnal demand characteristics in this area are different, therefore the model is predicting pressures lower than observed. While pressures during these times are consistently lower, they are still within ±5 psi tolerance. In addition, model-predicted pressure at HPRs 15 and 16 were well within 1 to 2 psi of field-recorded pressures.

6.5.2 Hydraulic Model EPS Calibration Findings and Conclusions Based on the results of the hydraulic model EPS calibration, it can be concluded that the hydraulic model provides a reasonable representation of the COSMUD water distribution system and can be used for planning evaluations and design/operational analysis for a variety of flow conditions.

Additionally, COSMUD staff should continue to update and verify facilities data and pipeline system configurations in the hydraulic model as facilities are constructed or replaced to maintain a hydraulic model that will continue to accurately represent the COSMUD water distribution system. 24 Based on discussions with City staff, SEWD elevation was adjusted based on HPR information to 27.5 ft msl.

EXHIBIT 1
1752
Existing Water System Analysis
This chapter presents the evaluation of the COSMUD existing water system, as shown on Figure 7-1 and described in Chapter 2, and its ability to meet the recommended performance and operational criteria described in Chapter 5 under various existing water demand conditions. This evaluation includes an analysis of water supply capacity, storage capacity, and pumping capacity, as well as the existing water distribution system’s ability to meet recommended operational and design criteria under maximum day demand, peak hour demand, and maximum day demand plus fire flow scenarios.

West Yost conducted this evaluation using the updated hydraulic model described in Chapter 6, which includes some new water system facilities that the COSMUD is actively working on completing.

Recommendations from this evaluation are used to develop a recommended capital improvement program, which is detailed in Chapter 9.

The following sections present the evaluation methodology and results from the existing water system evaluation:
• Existing Water Demands
• Existing Water Supply and Water System Facility Capacity Evaluation • Existing Water Distribution System Performance Evaluation • Summary of Findings and Recommendations for the Existing Water System

7.1 EXISTING WATER DEMANDS
The COSMUD existing baseline water demands are summarized in Table 7-1. The average day demand for the purposes of this Water Master Plan Update is 28.1 mgd (31,495 afy) and represents the average annual water production from 2015 through 2019 with an added 10 percent demand rebound factor, as described in Chapter 3. Maximum day and peak hour demands were calculated based on the adopted peaking factors of 1.6 and 2.5 times the average day demand, respectively, in North Stockton, and 1.7 and

3.3 times the average day demand, respectively, in South Stockton, as described in Chapter 3.

Table 7-1. Existing COSMUD Baseline Demands(a)
Service Area
Average Day Demand
(ADD)(b)
Maximum Day Demand
(MDD)(c)
Peak Hour Demand
(PHD)(d)
gpm mgd gpm mgd gpm mgd
North Stockton 15,992 23.0 25,587 36.8 39,980 57.6
South Stockton 3,534 5.1 6,007 8.7 11,661 16.8
Total 19,526 28.1 31,594 45.5 51,641 74.4
(a) Does not include water demands for the Walnut Plant Area which are minimal and not evaluated in this Water Master Plan Update. (b) The average day demand is based on the average annual production from 2015 through 2019, scaled to include a 10 percent demand rebound factor as described in Chapter 3.
(c) The maximum day demand is calculated using a peaking factor of 1.6 in North Stockton and 1.7 in South Stockton, times the average day demand.
(d) The peak hour demand is calculated using a peaking factor of 2.5 in North Stockton and 3.3 in South Stockton, times the average day demand.

EXHIBIT 1
1753
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Well #11
Well #7
Well SSS8
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Treatment
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East Water
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Well #19
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Well #29
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Well #30
Well #31
Well #32
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Figure 7-1
Existing Water System
City of Stockton
Water Master Plan Update
Q3 Water Treatment Plant
TU Storage Tank & Booster Pump Station
Wells
") Active
") Inactive
") Standby
Pipelines
Less than 12 inches
12 - 14 inches
16 - 22 inches
24 inches or greater
COSMUD Water Service Boundary
California Water Service
San Joaquin County (served by COSMUD)
San Joaquin County
Stockton East Water District
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F7_1_ExistingSystem.mxd - wjones - 1/22/2021 0 0.6 1.2
Miles
Notes:

1. The Capital Improvement Project (CIP) Waterline Extension for VA Medical Facility in French Camp was included in the existing system evaluation because construction is scheduled to commence March 2021.

EXHIBIT 1
1754

7.2 EXISTING WATER SUPPLY AND WATER SYSTEM FACILITY CAPACITY

EVALUATION
The following evaluations were conducted for the existing water system, with results discussed below:
• Supply Capacity Evaluation
• Pumping Capacity Evaluation
• Storage Capacity Evaluation

7.2.1 Supply Capacity Evaluation
As described in Chapter 5, the recommended supply capacity criterion requires the COSMUD to provide firm supply capacity equal to the maximum day demand. Table 7-2 summarizes existing firm supply capacity compared to existing maximum day demands in North Stockton and South Stockton. The COSMUD water supply is provided by both surface water and groundwater, and their respective firm capacities are summarized as follows.
• For North Stockton, 100 percent of DWTP capacity is assumed for firm surface water supply. • For South Stockton, surface water supply from SEWD was assumed to be limited to approximately 70 percent of the South Stockton maximum day demand. This assumption was made to provide more flexibility under drought conditions when surface water supplies may be curtailed by assuming the use of additional groundwater supplies to meet the remaining 30 percent of the maximum day demand. Refer to Chapter 4 for more discussion regarding this assumption.
• The firm groundwater supply capacity is calculated as 85 percent of the production capacity of active wells (i.e., does not include standby or inactive wells) in North Stockton and South Stockton, respectively. Refer to Chapter 5 for more discussion regarding this assumption.

As shown in Table 7-2, there is a surplus of supply in North Stockton of 17.5 mgd and in South Stockton of

3.3 mgd, respectively. Additional supply capacity from a proposed new well, Well SSS10, is also included in Table 7-2. As discussed in the storage capacity evaluation below, there is a storage capacity deficit in South Stockton. To address the storage capacity deficit in the South Stockton water service area, Well SSS10 is recommended. Well SSS10 is already in the planning stages and it is recommended that the COSMUD continue with development of this well to address the storage capacity deficit, as well as provide additional supply capacity to the South Stockton water service area.

EXHIBIT 1
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Table 7-2. Comparison of Available versus Required Supply Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Supply
Existing Firm Well Supply Capacity [A] 85% of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4 Existing Surface Water Supply [B] Full DWTP Capacity 20,833 30.0 Total Supply Capacity [C] = [A] + [B] 37,749 54.4
Demand
Existing Maximum Day Demand [D] 1.6 times ADD (refer to Table 7-1) 25,587 36.8 North Stockton
Supply Capacity Surplus (Deficit) [E] = [C] – [D] 12,162 17.5 South Stockton
Supply
Existing Firm Well Supply Capacity [F] 85% of the capacity of active wells (Wells SSS3 and SSS9) 4,118 5.9
Existing Surface Water Supply [G] 70% of South Stockton MDD, 8.7 mgd (refer to Table 7-1)
4,205 6.1
Total Supply Capacity [H] = [F] + [G] 8,323 12.0
Demand
Existing Maximum Day Demand [I] 1.7 times ADD (refer to Table 7-1) 6,007 8.7 South Stockton
Supply Capacity Surplus (Deficit) [J] = [H] - [I] 2,316 3.3 Additional Supply
Additional Firm Supply Capacity with
Well SSS10
[K] 85% of the assumed 2,000 gpm
capacity 1,700 2.4
South Stockton
Supply Capacity Surplus (Deficit) with
Existing System Improvements
[L] = [J] + [K] 4,016 5.8
EXHIBIT 1
1756

7.2.2 Pumping Capacity Evaluation
Existing pumping capacity was evaluated to assess its ability to deliver a reliable firm pumping capacity to the COSMUD existing water service areas to meet the greater of either the maximum day demand plus a large fire flow event or the peak hour demand (anywhere within the North or South Stockton water service areas), as described in Chapter 5. Pumping capacity is provided by a combination of supply facilities (i.e., treatment plants and groundwater wells) and reservoir pump stations. Firm pumping capacity provided by treatment plants and groundwater wells is evaluated in a manner identical to the supply capacity evaluation described above. For reservoir pump stations, a reduction in total pumping capacity is assumed to account for pumps that could be out of service due to various operational problems or maintenance at any given time. For both North Stockton and South Stockton, firm booster pumping capacity is defined as the total pump station capacity with the largest pump out of service.

Table 7-3 shows the firm pumping capacity compared to the peak hour demand in North Stockton and South Stockton and indicates there is a surplus of pumping capacity in both the North Stockton and South Stockton water service areas.

EXHIBIT 1
1757
Table 7-3. Comparison of Available versus Required Pumping Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Requirement
Required Maximum Day Demand plus
Fire Flow(a)
[A] MDD (refer to Table 7-1) plus a large industrial
fire flow (4,500 gpm) 30,087 43.3
Existing Peak Hour Demand [B] 2.5 times ADD (refer to Table 7-1) 39,980 57.6 Pumping Capacity Requirement [C] = the greater of [A] or [B] 39,980 57.6 Capacity
Existing Firm Pump Capacity at Reservoir
Sites
[D] Total pump capacity with the largest pump
offline at each reservoir site 31,450 45.3
Existing Firm Pump Capacity at
Treatment Plants
[E] Limited to the existing capacity of the Delta
Water Treatment Plant 20,833 30.0
Existing Firm Well Capacity [F] 85% of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4 Total Existing Available Firm Pumping
Capacity [G] = [D] + [E] + [F] 69,199 99.6
North Stockton
Existing Pumping Capacity Surplus (Deficit) [H] = [G] - [C] 29,219 42.1 South Stockton
Requirement
Required Maximum Day Demand plus
Fire Flow(a)
[I] MDD (refer to Table 7-1) plus a large industrial
fire flow (4,500 gpm) 10,507 15.1
Existing Peak Hour Demand [J] 3.3 times ADD (refer to Table 7-1) 11,661 16.8 Pumping Capacity Requirement [K] = the greater of [I] or [J] 11,661 16.8 Capacity
Existing Firm Pump Capacity at
Reservoir Sites
[L] Total pump capacity with the largest pump
offline at each reservoir site 9,000 13.0
Existing Firm Pump Capacity at
Treatment Plants
[M] 70% of South Stockton MDD
(refer to Table 7-1)
4,205 6.1
Existing Firm Well Capacity [N] 85% of the capacity of active wells (Wells SSS3 and SSS9) 4,118 5.9
Total Existing Available Firm Pumping
Capacity [O] = [L] + [M] + [N] 17,323 24.9
South Stockton
Existing Pumping Capacity Surplus (Deficit) [P] = [O] - [K] 5,662 8.2 Improved Capacity
Additional Firm Capacity with Well SSS10 [Q] 85% of the assumed 2,000 gpm capacity 1,700 2.4 South Stockton
Pumping Capacity Surplus (Deficit) with
Existing System Improvements
[R] = [P] + [Q] 7,362 10.6
(a) The large industrial fire flow does not include demand for on-site sprinkler flow.

EXHIBIT 1
1758

7.2.3 Storage Capacity Evaluation
Water storage provides operational storage to balance differences in demands and supplies, emergency storage in case of a supply failure, and water to fight fires. The COSMUD water system has two sources of available storage: above-ground storage (i.e., storage reservoirs) and storage available in the groundwater basin. Together, these two sources of storage must be sufficient to meet the COSMUD operational, emergency, and fire flow storage criteria.

As introduced in Chapter 5, the COSMUD water storage capacity requirement is as follows:
• Operational storage equal to 25 percent of a maximum day demand • Fire flow storage equal to the largest fire flow rate multiplied by its duration • Emergency storage equal to one average day demand
Because the COSMUD water supply includes groundwater wells and treated surface water, the groundwater basin and treatment facilities can offset some of the required storage in the form of storage credits. A summary of available storage capacity and credits is provided below:
• Existing available storage is defined as the storage provided by all active reservoirs • The Emergency Groundwater Storage Credit (EGWC) equals 85 percent of the active groundwater wells that can be reliably accessed (i.e., well facilities equipped with auxiliary power)
• The Treated Surface Water Supply Credit (TSWC) equals the smaller of the two treatment facilities available in North Stockton. There is no surface water credit available for South Stockton because water from DWTP cannot be transferred to South Stockton, providing no redundant treated surface water supply
• Combined, the EGWC and TSWC cannot exceed the emergency storage requirement The existing water storage facilities, in conjunction with the available EGWC and TSWC, were evaluated to determine whether the COSMUD existing storage capacity provides the recommended operational, emergency, and fire flow storage for existing demands. Table 7-4 provides a comparison of available and required storage and indicates there is a storage capacity deficit in both the North Stockton and South Stockton areas of 3.4 MG and 2.3 MG, respectively.

As previously discussed, the COSMUD is actively working on the design and construction of the North Stockton Pipeline Hypochlorite Facility that would effectively allow SEWD water to be delivered in North Stockton. Once this project is in place, a TSWC would apply to North Stockton of 9.4 MG, maximizing total credits up to the emergency requirement in the North Stockton area and alleviating the storage capacity deficit. To alleviate the storage capacity deficit in South Stockton, it is recommended that the COSMUD continue to proceed with the design and construction of Well SSS10, and to ensure that that this well is equipped with backup power. The addition of backup power improves the reliability of Well SSS10 and allows it to be counted as part of the EGWC. As shown in Table 7-4, completion of these recommended projects mitigates the storage capacity deficit and results in a storage capacity surplus. No additional storage projects are recommended for existing system conditions.

EXHIBIT 1
1759
Table 7-4. Comparison of Available versus Required Storage Capacity Available or Required Capacity Notes/Basis Storage, mg
North Stockton
Requirement
Operational [A] 25% of MDD (refer to Table 7-1) 9.2
Fire Flow [B] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [C] One ADD (refer to Table 7-1) 23.0
Total Storage Requirement [D] = [A] + [B] + [C} 33.2
Capacity
Existing Available Storage Capacity [E] Includes all active reservoirs 16.2 Treated Surface Water Supply Credit [F] No credit taken, as North and South Stockton are currently hydraulically separate 0.0
Emergency Groundwater Storage Credit(e) [G] 85% of the active wells equipped with backup power (Wells 3R, 29, 30, 31, 32) 13.6
Total Storage Capacity [H] = [E] + [F] + [G] 29.8
North Stockton
Existing Storage Capacity Surplus (Deficit) [I] = [H] - [D] (3.4) Improved Capacity
Treated Surface Water Supply Credit
[J] Once the North Stockton Pipeline Hypochlorite Facility is complete, the treated surface water supply credit can be used for North Stockton

9.4 North Stockton
Existing Storage Capacity Surplus (Deficit) with
Additional Treated Surface Water Supply Credit
[K] = [I] + [J] 6.0
South Stockton
Requirement
Operational [L] 25% of MDD (refer to Table 7-1) 2.2
Fire Flow [M] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [N] One ADD (refer to Table 7-1) 5.1
Total Storage Requirement [O] = [L] + [M] + [N] 8.3
Capacity
Existing Available Storage Capacity [Q] Includes all active reservoirs 6.0 Treated Surface Water Supply Credit [R] No credit taken, since North and South Stockton remain hydraulically separate 0.0
Emergency Groundwater Storage Credit(e) [S] 85% of active wells equipped with backup power (none) 0.0 Total Storage Capacity [T] = [Q] + [R] + [S] 6.0
South Stockton
Existing Storage Capacity Surplus (Deficit) [U] = [T] - [O] (2.3) Improved Capacity
Additional Emergency Groundwater Storage
Credit with Well SSS10 [V] 85% of the assumed 2,000 gpm capacity 2.4 South Stockton
Storage Capacity Surplus (Deficit) with Existing
System Improvements
[W] = [U] + [V] 0.1
EXHIBIT 1
1760

7.3 EXISTING WATER DISTRIBUTION SYSTEM PERFORMANCE

EVALUATION
The water distribution system performance evaluation identifies necessary improvements to the COSMUD water distribution system to support the COSMUD existing water demands while meeting the COSMUD recommended water system planning and design criteria, presented in Chapter 5. The following evaluations were performed to assess water distribution system performance under existing water demand conditions:
• Normal Operations – Maximum Day Demand with Peak Hour Scenario: This scenario evaluated service pressures during a peak hour on the maximum day demand condition • Emergency Operations – Maximum Day Demand plus Fire Flow Scenario: This scenario evaluated system fire flow availability under a maximum day demand condition The updated and calibrated water system hydraulic model, as discussed in Chapter 6, was used to evaluate existing water distribution system performance. The existing water system is expected to deliver maximum day with peak hour demand flows and maximum day demand plus fire flow within the acceptable pressure and velocity ranges as identified in the water system performance and operational criteria presented in Chapter 5.

7.3.1 Normal Operations – Maximum Day Demand with Peak Hour The normal operations scenario evaluates the hydraulics of the COSMUD water distribution system under maximum day with peak hour demand conditions (i.e., non-fire). An overview of the evaluation and a discussion of the results are presented in the following sections.

7.3.1.1 Evaluation Overview
An EPS was conducted using the hydraulic model to evaluate system performance under a maximum day with peak hour demand condition. The diurnal pattern previously presented in Chapter 3 was incorporated into the hydraulic model and evaluated for seven consecutive days; however, only results from the last three days of the simulation are presented, as these results are not affected by initial conditions. As shown in Table 7-1, the maximum day demand is calculated using a peaking factor of

1.6 times the average day demand in North Stockton and 1.7 times the average day demand in South Stockton. This results in a total system maximum day demand of 31,594 gpm (41.5 mgd) for the existing system. The peak hour demand is calculated using a peaking factor of 2.5 times the average day demand in North Stockton and 3.3 times the average day demand in South Stockton. This results in a total system peak hour demand of 51,641 gpm (74.4 mgd) for the existing system.

During a maximum day with peak hour demand scenario, a minimum pressure of 45 psi and a maximum pressure of 80 psi is targeted to be maintained at service connections throughout the entire system. In addition, for pipelines, it is recommended that the maximum velocity not exceed 5 fps. The existing system analysis assumes the maximum day and peak hour demand would be met by a combination of surface water treatment plants, active groundwater wells, and storage reservoirs via their associated reservoir pump stations.

EXHIBIT 1
1761

7.3.1.2 Evaluation Results
Results from the maximum day with peak hour demand condition indicate the existing water system generally meets the COSMUD minimum and maximum pressure criterion at most customer service locations. Figure 7-2 presents the minimum instantaneous pressures observed during the EPS simulation.

As shown on Figure 7-2, in general the northeast portion of the North Stockton water service area and a single dead-end customer off a 2-inch diameter pipeline and portions of the central area in the South Stockton water service area do not meet the minimum pressure requirement of 45 psi. However, as shown on Figure 7-3, which presents average system pressures for the maximum demand day, results from the simulation indicate that service connections throughout the entire distribution system meet the minimum pressure requirement of 45 psi, except for a few spots in the northeast portion of the North Stockton water service area and one dead-end pipeline in the South Stockton water service area.

Low pressures in the northeast portion of the North Stockton water service area are largely due to higher elevations and therefore improvements to mitigate low pressures, which occur for an hour or two a day, are cost prohibitive and not recommended. In addition, DTWP discharge pressure could be increased to increase system pressures in the north east portion of North Stockton. However, as shown on Figure 7-3, average pressures remain above 45 psi in the majority of the area. The single low-pressure location in South Stockton is a direct result of head losses (HL/1,000 feet is greater than 7 ft/kft criterion) along the long dead-end 2-inch diameter pipeline. It is recommended that this 2-inch diameter pipeline be replaced with a 4-inch diameter pipeline to mitigate head losses and improve pressures. As discussed in the following sections, it is recommended that this pipeline be replaced as part of the recommended Priority 3 pipeline rehabilitation and replacement program.

Discharge pipelines at groundwater well facilities and reservoir pump stations have maximum velocities that vary between 5.6 and 11 fps. While these velocities exceed maximum recommended velocities, improvements are not recommended at these locations as they are experienced for a short distance and do not impact the primary criterion, customer service pressure. Simulated velocity results for the maximum day with peak hour demand condition indicate that the remaining pipelines within the COSMUD water system meet the velocity criterion of 5 fps, and therefore no pipelines improvements are recommended for the maximum day with peak hour demand condition.

Figure 7-4 shows reservoir water level fluctuations in system reservoirs throughout the EPS. As shown on Figure 7-4, Northwest and Fourteen-Mile Slough Reservoirsfollow a repetitive turnover cycle, cycling at least once a day. In South Stockton, Weston Ranch Reservoir level fluctuations are less cyclical. This is due to the delivery pressure from SEWD and the fact that operations in the South Stockton water service area are based on maximizing use of SEWD supplies. These model-simulated reservoir level trends match operational data provided by the COSMUD. Reservoir turnover at Weston Ranch could be improved if discharge set-points were set higher, butthis would result in applying back-pressure to the SEWD and Cal Watersystems. Current reservoir water level fluctuations, as shown on Figure 7-4, appear to be adequate.

EXHIBIT 1
1762
")
")
UT
Q3
§¨¦5
¬«99

SAN JOAQUINRIVER
Weston Ranch

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H

C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O A Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R

E L D O R A D O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
")
")
")
")
")
")
") ")
")
")
UT
UT
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SANJOAQUIN RIVER

CALAVERAS RIVER

E L D O R A D O S T

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N

W E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T
O
N
R
D
C
H
E
R O
K
E E
R
D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O R D

E I G H T M I L E R D E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well #30
Well #31
Well #32
Well #10R
Figure 7-2
Existing System
Maximum Day Demand
Minimum System Pressure
City of Stockton
Water Master Plan Update
Minimum System Pressure
Less than 40 psi
Between 40 and 45 psi
Between 45 and 50 psi
Between 50 and 55 psi
Greater than 55 psi
Q3 Water Treatment Plant
") Well (Active)
UT Storage Tank & Booster Pump Station
COSMUD Water Service Boundary
Maximum Velocity
Equal to or Less than 5 ft/s
Greater than 5 ft/s
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F7_2_MDDMinResults.mxd - bvera - 1/18/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 52 psi and Stockton East Water District pump station dishcarge pressure was set to 58 psi. Active wells turned on as needed, based on local pressure/time of day.

EXHIBIT 1
1763
")
")
UT
Q3
§¨¦5
¬«99
Weston Ranch

SAN J O AQU IN RIVER

D R M A R T I N L U T H E R K I N G J R

B L V D

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P
R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O A Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R

E L D O R A D O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
")
")
")
")
")
")
") ")
")
")
UT
UT
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SANJOAQUIN RIVER

CALAVERAS RIVER

E L D O R A D O S T

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N

W E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T
O
N
R
D
C
H
E
R O
K
E E
R
D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O R D

E I G H T M I L E R D E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well #30
Well #31
Well #32
Well #10R
Figure 7-3
Existing System
Maximum Day Demand
Average System Pressure
City of Stockton
Water Master Plan Update
Average System Pressure
Less than 40 psi
Between 40 and 45 psi
Between 45 and 50 psi
Between 50 an 55 psi
Greater than 55 psi
Q3 Water Treatment Plant
UT Storage Tank & Booster Pump Station
") Well (Active)
COSMUD Water Service Boundary
Average Velocity
Equal to or Less than 5 ft/s
Greater than 5 ft/s
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F7_3_MDDAvgResults.mxd - bvera - 11/30/2020 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 52 psi and Stockton East Water District pump station dishcarge pressure was set to 58 psi. Active wells turned on as needed, based on local pressure/time of day.

EXHIBIT 1
1764
n\c\129\60-20-41\engr\7
City of Stockton
Water Maste Plan Update
Last Revised: 11-30-20
0 2
4 6
8 10
12 14
16 18
20 22
24 26
28 30
0 6 12 18 24 30 36 42 48 54 60 66 72
Tank Level, feet
Time, hour
Figure 7-4. Existing System Maximum Day Demand Reservoir Level Results Northwest 14-Mile Slough Weston Ranch
EXHIBIT 1
1765

7.3.2 Emergency Operations – Maximum Day Demand Plus Fire Flow The maximum day demand plus fire flow scenario evaluates the existing fire flow availability in the COSMUD distribution system under a maximum day demand condition. An overview of the evaluation and a discussion of the results are presented in the sections below.

7.3.2.1 Evaluation Overview
To evaluate the existing water system fire flow availability, InfoWater’s fire flow module was used to determine the available fire flow at all junctions that represent hydrant locations throughout the system, while maintaining a minimum residual system pressure of 20 psi at all customer service locations. The analysis assumed that reservoir pump stations are operating at their firm pumping capacity. Maximum velocity is not considered in this evaluation because it is a secondary design criterion.

As discussed in Chapter 5, recommended fire flow criteria presented in Table 5-2 are established for future development and do not apply to existing system conditions. Much of the COSMUD water distribution system is older and designed to earlier fire standards in place at the time the pipelines were constructed.

Therefore, the existing fire flow evaluation presents the systemwide available fire flow and how the existing system performs compared to recommended fire flow criteria. Since much of the COSMUD system is older, a rehabilitation and replacement (R&R) program is recommended to replace smaller diameter pipelines (which are typically older) over the next 40 years.

It should be noted that the 2008 WMP did not recommend any improvements for fire flow. The 2008 WMP evaluated fire flows at five key locations in both North Stockton and South Stockton (10 locations total), and since the primary criterion (pressure) was met at those locations, no improvements were recommended. For this Water Master Plan Update, a systemwide fire flow evaluation was performed to determine available fire flow capacity compared to adjacent land uses for the entire distribution system.

While the primary criterion (pressure) continues to be met, at some locations available fire flow is less than the recommended fire flow criteria for new developments of similar land use types. As discussed above and in the following sections, an R&R program is recommended to replace older/smaller diameter pipelines, and it is recommended that replacement of older/smaller diameter pipelines in areas where available fire flow is less than recommended fire flow criteria be prioritized.

7.3.2.2 Fire Flow Evaluation Results
Figure 7-5 presents the available fire flow at each tested junction while maintaining a minimum residual pressure of 20 psi. Results presented on Figure 7-5 are representative of the system’s capacity and do not represent available flow from a specific hydrant. Typically, fire flows exceeding 1,500 gpm are met by multiple hydrants.

As shown on Figure 7-5, there are many locations that do not meet the recommended fire flow criteria.

The majority of the tested locations which do not meet current fire flow criteria are along older and/or small diameter pipelines, areas with larger fire flow requirements (i.e., 4,500 gpm), or areas with a lack of looping where high head losses (due to undersized mains) limit the ability to provide recommended fire flows while maintaining pressures greater than 20 psi. As noted previously, much of the COSMUD water distribution system is older and was designed to earlier fire standards in place at the time the pipelines were constructed.

EXHIBIT 1
1766
")
")
UT
Q3
§¨¦5
¬«99

ASN JO AQ U IN R IV ER

DR M AR TI N L U TH ER KI N G JR
BL V D

AU STI N R D

EI G H TH ST

JACK TO N E R D

FR EM O N T ST

FR EN CH CAM P
R D

M AR I PO SA
R D

H O W AR D R D

SU TTER ST SAN JO AQ U I N ST

M I N ER AV E

N EW CASTL E R D

PO CK L N

N AV Y D R

EL D O R AD O ST

H AR L AN R D
B ST

AI R PO
R
T
W
AY

M AR I PO SA R D KA I SER R D
W eston R anch
Stockton
East W ater
District
W ell SSS3
W ell SSS9
")
")
")
")
")
")
") ")
")
")
UT
UT
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
North w est

SANJOAQ U IN R IV ER

CALAV ER ASR IV ER

EL D O R AD O ST

PER SH I N G
A
V E
PA

C I FI C
A
V E

EL DO R AD O ST

ASHL EY L N
W EST
L N

FR EM O N T ST

H AM M ER L N

SW AI N R D

M I N ER AV E

M AR CH L N
S
T AN

DR E W S DR
T
H
O
R
N
T
O
N
R
D
C
H
E
R O
K
EE
R
D

BR O O KSI DE R D

L I V E O AK R D

AL PI N E R D

W ATER L O O R D

EI G H T M I L E R D EI G H T M I L E R D

AR M STR O N G R D
H

O L T R D

H I L DR ETH L N

R I N DGE R D
Delta W ater
Treatment
Plant
Stockton
East W ater
District
W ell #18
W ell #19
W ell #21
W ell #27
W ell #29
W ell #03R
W ell #30
W ell #31
W ell #32
W ell #10R
Figure 7-5
Existing System
Maximum Day Demand
Fire Flow Results
City of Stockton
W ater Master Plan U pdate
Available flow is ≥100% of criteria
Available flow ≥75% but <100% of criteria
Available flow is ≥50% but <75% of criteria
Available flow is <50% of criteria
Q3 W ater Treatment Plant
UT Storage Tank & Booster Pump Station
") W ell (Active)
COSMU D W ater Service Boundary
Pipeline
Less th an or Equal to 12-inch
Greater th an 12-inch
W EST YOST - N:\Clients\129 Stockton\60-20-41 Stockton W MPU \GIS\MX D\W ater Master Plan\F7_5_FFR esults.mxd - bvera - 1/18/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta W ater Treatment Plant pump station disch arge pressure w as set to 52 psi and Stockton East W ater District pump station dish carge pressure w as set to 58 psi. Active w ells turned on as needed, based on local pressure/time of day.

2. Th e available flow at each junction is th e maximum flow available w h ile maintaining 20 psi residual system pressue.

EXHIBIT 1
1767
As discussed in Chapter 9, an R&R program is recommended to replace older pipelines that are less than 8-inches in diameter25, and these pipelines would be replaced over a 40-year period. The first 10 years of the recommended program prioritizes areas where current available fire flow capacity is less than the recommended fire flow. This should also include mains running through private property or through levies, or those that have known tree root damage. Pipelines were prioritized into the following categories:
• Priority 1: This category addresses areas where existing available fire flow capacity is less than 50 percent of the recommended criteria.
• Priority 2: This category addresses areas where existing available fire flow capacity is between 50 and 75 percent of the recommended fire flow criteria. • Priority 3: This category contains the remaining smaller diameter (i.e., less than 8-inches) pipelines.

An asset management plan should be developed so recommended pipeline improvements can be further refined by considering likelihood of failure (e.g., age, condition, leak history, etc.) and consequence of failure (e.g., disruption of water service to critical facilities, potential for damage to adjacent land use and facilities, etc.) to further refine and define program priorities and implementation. Table 7-5 summarizes the length of Priority 1, 2 and 3 pipelines to be replaced in North Stockton and South Stockton.

Table 7-5. Recommended Existing COSMUD Water System Pipeline Improvements Replacement Pipeline Diameter (inches)
Feet of Pipeline
Priority 1 Priority 2 Priority 3
North Stockton
8-inch 3,585 14,846 -
12-inch 4,364 4,018 330,008
Total 7,949 18,864 330,008
South Stockton
8-inch - 1,249 -
12-inch 4,923 5,445 35,445
Total 4,923 6,694 35,445
Figure 7-6 presents the recommended pipelines in Priority 1 and 2 categories of the recommended R&R program, which are intended to improve fire flow availability as presented in Figure 7-5. Figure 7-7 presents the fire flow results with Priority 1 and 2 R&R improvements assumed to be completed. As shown on Figure 7-7, the majority of the North Stockton and South Stockton water service areas exceeds 75 percent of the recommended fire flow criteria. Along Harland Road, in the South Stockton area, available flows remain below 50 percent of recommended fire flow criteria, even with the Priority 1 and 2 R&R improvements completed. However, a portion of this pipeline is planned to be improved (from a 12-inch diameter to a 16-inch diameter) and is part of the City’s existing Capital Improvement Program (CIP). This improvement would improve fire flow availability to this area. 25 Generally, 8-inch diameter pipelines are recommended as they meet the maximum velocity requirements for residential fire flow events. However, smaller diameter pipelines are allowed (per COSMUD standard specifications) provided that all capacity requirements are met and should be evaluated on a case-by-case basis. For the purposes of this Water Master Plan Update and for budgeting purposes, it is assumed that all small diameter pipelines are replaced with 8-inch diameter pipelines.

EXHIBIT 1
1768
")
")
TU
Q3
§¨¦5
¬«99
Weston Ranch

SAN J O AQUIN RIVER

D R M A R T I N L U T H E R K I N G J R

B L V D

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
")
")
")
")
")
")
") ")
")
")
TU
TU
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SANJOAQUIN RIVER

CALAVERAS RIVER
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #10R
Figure 7-6
Existing System
Pipeline Improvements
City of Stockton
Water Master Plan Update
Pipelines
Existing
Improvement Priority 1
Improvement Priority 2
Q3 Water Treatment Plant
TU Storage Tank & Booster Pump Station
") Well (Active)
COSMUD Water Service Boundary
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F7_6_Imp.mxd - wjones - 11/23/2020 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
EXHIBIT 1
1769
")
")
")
UT
Q3
§¨¦5
¬«99
W eston R anch

SAN JOAQ U INR IV ER

DR M AR TI N L U TH ER KI N G JR
BL V D

CEN TER ST

AU STI N R D

EI G H TH ST

JACK TO N E R D

FR EM O N T ST

FR EN CH CAM P R D

M AR I PO SA
R D

H O W AR D R D

SU TTER ST SAN JO AQ U I N ST

M I N ER AV E

N EW CASTL E R D

PO CK L N

N AV Y D R

EL D O R AD O ST

H AR L AN R D
B ST

AI R PO
R
T
W
AY

M AR I PO SA R D KA I SER R D
Stockton
East W ater
District
W ell SSS3
W ell SSS9
W ell SSS10
")
")
")
")
")
")
") ")
")
")
")
UT
UT
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
North w est

SANJOAQ U IN R IV ER

CALAV ER ASR IV ER
Delta W ater
Treatment
Plant
Stockton
East W ater
District

EL D O R AD O ST

PER SH I N G
A
V E
PA

C I FI C
A
V E

EL DO R AD O ST

ASHL EY L N
W EST
L N

FR EM O N T ST

H AM M ER L N

SW AI N R D

M I N ER AV E

M AR CH L N
S
T AN

DR E W S DR
T
H
O
R
N
T
O
N
R
D
C
H
E
R O
K
EE
R
D

BR O O KSI DE R D

L I V E O AK R D

AL PI N E R D

W ATER L O O R D

EI G H T M I L E R D EI G H T M I L E R D

AR M STR O N G R D
H

O L T R D

H I L DR ETH L N

R I N DGE R D
W ell #18
W ell #19
W ell #21
W ell #27
W ell #29
W ell #03R
W ell #30
W ell #31
W ell #32
W ell #33
W ell #10R
Figure 7-7
Existing System Fire Flow
Results With Priority 1
And 2 Improvements
City of Stockton
W ater Master Plan U pdate
Available flow is ≥100% of criteria
Available flow ≥75% but <100% of criteria
Available flow is ≥50% but <75% of criteria
Available flow is <50% of criteria
Q3 W ater Treatment Plant
UT Storage Tank & Booster Pump Station
") W ell (Active)
COSMU D W ater Service Boundary
Pipeline
Less th an or Equal to 12-inch
Greater th an 12-inch
W EST YOST - N:\Clients\129 Stockton\60-20-41 Stockton W MPU \GIS\MX D\W ater Master Plan\F7_7_FFR esultsImp.mxd - bvera - 1/18/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta W ater Treatment Plant pump station disch arge pressure w as set to 52 psi and Stockton East W ater District pump station dish carge pressure w as set to 58 psi. Active w ells turned on as needed, based on local pressure/time of day.

2. Th e available flow at each junction is th e maximum flow available w h ile maintaining 20 psi residual system pressue.

EXHIBIT 1
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7.4 SUMMARY OF FINDINGS AND RECOMMENDATIONS FOR THE

EXISTING WATER SYSTEM
Findings and recommended improvements for the existing water system are summarized in Table 7-6 below.

These recommendations are used to develop a recommended CIP, which is further described in Chapter 9.

Table 7-6. Summary of Recommended Existing System Improvements Improvement Type Existing System (2020)
North Stockton
Supply • No supply related improvements recommended.

Pumping • No pumping improvements recommended.

Storage • No storage improvements recommended, other than completing the North Stockton Pipeline Hypochlorite Facility which provides for a treated surface water supply credit to offset required storage.

Pipelines • An R&R program is recommended to replace older, undersized pipelines. To prioritize the program, the existing fire flow availability, as compared to recommended fire flow criteria, was used to help prioritize R&R improvements. These improvements are shown on Figure 7-6, colored in red and orange, and are summarized in Table 7-5. • These projects could be further prioritized by targeting areas where the COSMUD has historically had leak and/or main break issues. These improvements are recommended to be implemented over the next ten years and be online by 2030. • Replacement of the remaining small diameter pipelines (i.e., pipelines not specifically identified for replacement) is also recommended.
• It is recommended that an asset management plan be developed so recommended pipeline improvements can be further refined by considering likelihood of failure (e.g., age, condition, leak history, etc.) and consequence of failure (e.g., disruption of water service to critical facilities, potential for damage to adjacent land use and facilities, etc.) to further refine and define program priorities and implementation.

South Stockton
Supply • Construct the new Well SSS10 to mitigate existing storage capacity deficit and improve supply reliability.

Pumping • No pumping improvements recommended.

Storage • Construct the new Well SSS10 and equip with backup power to increase emergency groundwater storage credit by 2.4 MG. For the purposes of this Water Master Plan Update, it was assumed that this well would be able to supply 2,000 gpm.

Pipelines • An R&R program is recommended to replace older, undersized pipelines. To prioritize the program, the existing fire flow availability, as compared to recommended fire flow criteria, was used to help prioritize R&R improvements. These improvements are shown on Figure 7-6, colored in red and orange, and are summarized in Table 7-5. • These projects could be further prioritized by targeting areas where the COSMUD has historically had leaks and/or main break issues. These improvements are recommended to be implemented over the next ten years and be online by 2030. • Replacement of the remaining small diameter pipelines (i.e., pipelines not specifically identified for replacement) is also recommended.
• It is recommended that an asset management plan be developed so recommended pipeline improvements can be further refined by considering likelihood of failure (e.g., age, condition, leak history, etc.) and consequence of failure (e.g., disruption of water service to critical facilities, potential for damage to adjacent land use and facilities, etc.) to further refine and define program priorities and implementation.

EXHIBIT 1
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Future Water System Analysis
This chapter presents the evaluation of the COSMUD water system, and its ability to support projected near-term (2030) and future (2040) demands (described in Chapter 3) while meeting the recommended performance and operational criteria (described in Chapter 5). As noted in Chapter 3, the future water demands projected in this Water Master Plan Update are significantly lower than those projected in the 2008 Water Master Plan, and thus the recommended water system improvements to support projected future demands are significantly less extensive than those recommended in the 2008 Water Master Plan.

This evaluation includes an analysis of water supply capacity, storage capacity, and pumping capacity, as well as the distribution system’s ability to meet recommended operational and design criteria under nearterm and future maximum day demand, peak hour demand, and maximum day demand plus fire flow scenarios. West Yost conducted this evaluation using the updated hydraulic model described in Chapter 6.

The hydraulic model was subsequently updated to include recommended improvements developed as part of the existing water system evaluation (see Chapter 7) and assumes that improvements are completed by the future (2040) timeframe. In addition, West Yost incorporated COSMUD planned capital improvement projects as discussed in the sections below.

Evaluations, findings, and recommendations for addressing future needs identified in the COSMUD North and South Stockton water service areas (for both near-term and future demand conditions) are included in this chapter. Recommendations are used to develop a recommended CIP, which is described further in Chapter 9.

The following sections present the evaluation methodology and results from the future water system analysis:
• Future Water System Description
• Future Water Demands
• Future Water Supply and Water System Facility Capacity Evaluation • Future Water Distribution System Performance Evaluation • Summary of Findings and Recommendations for the Future Water System • Other Planned or Recommended Improvements

8.1 FUTURE WATER SYSTEM DESCRIPTION
As discussed in Chapter 3, near-term (2030) and future (2040) water demand conditions are based on the Envision Stockton 2040 General Plan Update (2040 GPU) land use designations and the SOI/MSR. Both sources define the anticipated future development areas for the near-term (2030) and future (2040) time periods. To support these future development areas, water system infrastructure was extended to these areas to support the future demands. Sizing and layout of these facilities is preliminary and based on the previous 2008 WMP and/or more recent information if available, and is shown on Figure 8-1.

These pipelines serve as a basis for serving future development areas, and thus were included in the hydraulic model to simulate future conditions and allocate future demands. As future development plans are refined, infrastructure needs are expected to change and the COSMUD should require project proponents to confirm that proposed infrastructure meets all design criteria presented in Chapter 5.

EXHIBIT 1
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Figure 8-1 shows the baseline water distribution system network planned for the near-term (2030) and future (2040), prior to identifying capacity improvements. Pipelines in dotted gray summarize pipeline extensions needed to serve near-term (2030) and future (2040) projected demands. Pipelines in green summarize Priority 1 and 2 R&R pipelines recommended in Chapter 7, as well as COSMUD planned capital improvement projects (with project IDs called out) that are identified in the adopted 2019-2024 Capital Improvement Plan. Facilities indicated in green and/or red were assumed to be online for the near-term (2030) time frame. Facilities in orange and/or gray (dashed lines) are assumed to be online for the future (2040) time frame. Additional facilities (e.g., Well 33, Northeast Reservoir) are not shown on this figure as their sizing is determined in the subsequent Facility Capacity sections of this chapter.

EXHIBIT 1
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") ")
")
") ")
")
TU
Q3
§¨¦5
¬«99
Tidewater
Crossing
Niagara
Bottling
Facility
Weston Ranch

SAN JOAQUINRIVER

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P
R D

M A R I P O S A R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O R T W
A
Y

M A R I P O S A R D

K A I S E R R D
Stockton
East Water
District
Well SSS2 Well SSS3
Well SSS1
Well SSS8
Well SSS9
Well SSS10
24"
16"
24"
16"
24"
16"
12"
24"
16"
24"
12"
16"
12"
16"
24"
16"
Study Area16
Study Area15
Study
Area14
Study Area12
Mariposa
Road
Community
Tidewater
Crossing
Airpark 599
NorCal
Logistics
Center
Weston Ranch
Towne Center
Veterans Affairs
Medical
Campus
Airport Way and
Sperry Road
Commercial Project
Sanchez-Hoggan
Annexation
Project
Mariposa
Industrial
Park
South Stockton
Commerce Center
")
") ") ") ")
")
")
")
") ")
")
")
")
")
")
")
")
")
") ")
")
")
")
D D
D D
TU
TU
Q3
Q3
§¨¦5
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E L D

O R A D O S T

P E R S H I N G A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
14 Mile
Slough

SANJOAQUIN RIVER

CALAVERAS RIVER
Northwest
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #16 Well #24 Well #19
Well #9
Well #20
Well #21
Well #26
Well #1
Well #4
Well #25
Well #28
Well #27
Well #11
Well #7
Well
#15
Well #29
Well #03R
Well #30
Well #31
Well #32
Well
#33
Well #10R
16"
12"
8" 12"
8"
12"
12"
8" 16"
12"
12"
12"
12"
12" 12"
24"
16"
12"
30"
16"
12"
18"
16"
36"
18"
16"
12"
16"
16"
12"
18"
16"
18"
18"
12"
16" 16"
42"
18"
16"
16"
12"
12" 16"
16"
16"
16"
Study
Area3
Study Area2
Study Area1
Crystal
Bay
Sanctuary
Delta Cove
Westlake
Villages
Cannery
Park
North
Stockton
Projects III
Tra Vigne
CarMax Superstore
Thornton and Eight
Mile Road Arco
Station Project
Figure 8-1
Near-Term and
Future System
City of Stockton
Water Master Plan Update
Pipelines
Existing
Existing System Improvements
Near-Term (2030) Improvements
Future (2040) Improvements
Future Development Pipelines
Wells
") Proposed
") Active
") Inactive
") Standby
D Abandoned
Q3 Water Treatment Plant
TU Reservoir & Pump Station
COSMUD Service Boundary
City of Stockton Sphere of
Influence
Major Development (Near-Term
& Future)
Study Area Within City's Sphere
of Influence
Study Area Outside of City's
Sphere of Influence
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_1_NearTermFacilities.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
CIP #M18002
CIP #M20004
CIP #M17016
CIP #M18007
CIP
#M18004
CIP
#M18004
CIP #M18006
CIP List:

1. CIP #M17016 includes the installation of an 8"
diameter pipeline along Wolfe Rd & Mathews Rd.

2. CIP #M18002 includes replacement & installation
of a 16" diameter pipelines along I-5 North of
E. Roth Rd.

3. CIP #M18004 includes the decommissioning of
Well Sites 1, 9, 11, and 16.

4. CIP #M18006 includes the equipping of Well
No. 33.

5. CIP #M18007 includes installation of a 16"
diameter water main on Zephyr Road.

6. CIP #M20004 includes a water line extension from
Weston Ranch Reservoir to a point where the
Veterans Affairs facility will connect for
water service.

Notes:

1. Near-term (2030) and future (2040) development pipelines are based on previous development plans. Pipe layout and sizing will be finalized by developers/project proponents as develpment plans are finalized. 24" 24"
24"
18"
EXHIBIT 1
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8.2 FUTURE WATER DEMANDS
Future demand conditions used in the water system evaluation are based on projected land uses and water use factors discussed in Chapter 3. Projected future demands were added to the existing baseline demands (described in Chapter 3 and Chapter 7) to develop projected near-term (2030) and future (2040) scenario water demands. The future water demands were spatially located in the hydraulic model based on the future development land use areas. The COSMUD future water demands for the near-term (2030) and future (2040) scenarios are summarized in Table 8-1 and Table 8-2, respectively.

Table 8-1. Projected Near-Term (2030) COSMUD Water System Demands Service Area
Average Day Demand
(ADD)
(a)
Maximum Day Demand
(MDD)
(b)
Peak Hour Demand
(PHD)
(c)
gpm mgd gpm mgd gpm mgd
North Stockton 16,518 23.8 26,429 38.1 41,296 59.5
South Stockton 6,838 9.8 10,364 14.9 18,425 26.5
Total 23,356 33.6 36,794 53.0 59,721 86.0
(a) The Average Day Demands are based on the existing baseline demands (refer to Table 7-1 in Chapter 7) plus the projected near-term demands(refer to Table 3-15 in Chapter 3).
(b) Maximum day demand calculated using a peaking factor of 1.6 in North Stockton and 1.7 in South Stockton, times the average day demand. (c) Peak hour demand calculated using a peaking factor of 2.5 in North Stockton and 3.3 in South Stockton, times the average day demand.

As indicated in Table 8-1, the COSMUD near-term average day demands are expected to be 33.6 mgd, or a 20 percent increase over existing baseline demands (previously presented in Table 7-1 in Chapter 7).

South Stockton water demands, in particular, are projected to increase by 92 percent by near-term (2030).

Most of the increase is associated with the proposed Niagara Bottling Facility, which makes up for 54 percent of the projected demand increase in South Stockton.

Table 8-2. Projected Future (2040) COSMUD Water System Demands Service Area
Average Day Demand
(ADD)
(a)
Maximum Day Demand
(MDD)(b)
Peak Hour Demand
(PHD)(c)
gpm mgd gpm mgd gpm mgd
North Stockton 20,343 29.3 32,548 46.9 50,857 73.2
South Stockton 9,564 13.8 14,999 21.6 27,421 39.5
Mariposa Road
Community 2,081 3.0 3,538 5.1 6,867 9.9
Remaining South
Stockton 7,483 10.8 11,461 16.5 20,554 29.6
Overall Total 29,907 43.1 47,548 68.5 78,278 112.7
(a) The Average Day Demands are based on the existing baseline demands (refer to Table 7-1 in Chapter 7) plus the projected future (2040) demands (refer to Table 3-16 in Chapter 3).
(b) Maximum day demand calculated using a peaking factor of 1.6 in North Stockton and 1.7 in South Stockton, times the average day demand (c) Peak hour demand calculated using a peaking factor of 2.5 in North Stockton and 3.3 in South Stockton, times the average day demand.

EXHIBIT 1
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As indicated in Table 8-2, the COSMUD future (2040) average day demands are expected to be 43.1 mgd, or a 53 percent increase from existing baseline demands (previously presented in Table 7-1), and a 28 percent increase from near-term (2030) demands. Table 8-2 separates demands associated with the Mariposa Road Community since this future development area makes up a large portion of the future demand and the extent and timing of this development is uncertain. As discussed in the sections below, infrastructure was specifically sized to support the projected demands for Mariposa Road Community summarized in Table 8-2. Should future land use plans change for this future development area, associated infrastructure sizing will need to be reevaluated.

8.3 FUTURE WATER SUPPLY AND WATER SYSTEM FACILITY CAPACITY

EVALUATION
To evaluate the capacity of COSMUD water system facilities to support near-term (2030) and future (2040) demands, the following evaluations were conducted:
• Supply Capacity Evaluation
• Pumping Capacity Evaluation
• Storage Capacity Evaluation
The Mariposa Road Community is anticipated to be developed by the future (2040) time frame. Elevations within this future development area are higher than the existing South Stockton water service area.

Elevations range from 48 to 56 ft msl in this area, compared to a maximum elevation within the existing South Stockton area of 46 ft msl. This increase in elevation results in lower static pressures, as low as 44 psi, based on the current delivery pressure from SEWD (57 psi or about 166 ft hydraulic grade line).

Dynamic pressures (i.e., peak demand conditions with head loss) would be sufficiently lower that they would not meet the recommended criterion for minimum pressure of 45 psi. Therefore, to serve this area it is recommended that a new pressure zone be established, along with associated infrastructure. In general, the following would be required to provide water service for this future development area:
• New Storage Reservoir. This reservoir would be supplied/filled by the existing South Stockton area pipelines.
• New Reservoir Pump Station. This reservoir pump station would pump water from the new storage reservoir and would discharge to the new pressure zone. • Groundwater Well. To reduce the size of the new storage reservoir, a new well is also recommended for this future development area to increase the EGWC. While this well could also offset pumping requirements at the new reservoir pump station, the reservoir pump station is recommended to sized so that it has sufficient pumping capacity to supply the area in the event the new well is offline. This well also provides supply reliability to the future development area, and the South Stockton water service area, by diversifying the water supply for the area and reducing the dependency on SEWD.

EXHIBIT 1
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• Interconnections with existing South Stockton Area. It is recommended that this future development area be interconnected with the existing South Stockton area at a few key locations. These interconnections should be identified as development plans progress and should generally include:
— Pressure Reducing/Sustaining Valves allowing water from the new pressure zone to flow into the existing South Stockton area, in the event pressures drop (i.e., under fire flow conditions) — Check valves allowing water from the existing South Stockton area to flow into the new pressure zone in the event pressures drop in the new pressure zone (i.e., under fire flow conditions)
Sizing for the above listed facilities is based on the currently projected water demands for the Mariposa Community Road area, discussed in Chapter 3, and presented in the following sections. It is expected that land use plans for this area will change in the future. Therefore, projected water demands (and/or timing of future development) within the Mariposa Road Community will need to be reevaluated as future development plans are confirmed, and associated infrastructure sizing (and/or timing) will also need to be reevaluated.

8.3.1 Supply Capacity Evaluation
As described in Chapter 5, the recommended supply capacity criterion requires the COSMUD to provide enough firm supply capacity to equal the maximum day demand. Table 8-3 and Table 8-4 show the firm supply capacity compared to maximum day demand in North Stockton and South Stockton for the near-term (2030) and future (2040) demand conditions, respectively. The COSMUD water supply is provided by both surface water and groundwater, and their respective firm capacities are summarized as follows. • For North Stockton, 100 percent of DWTP is assumed for firm surface water supply. • For South Stockton, surface water supply from SEWD was assumed to be limited to approximately 70 percent of the South Stockton maximum day demand. The approach was undertaken to diversify the water supply portfolio and plan for additional redundant local supplies to meet the remaining 30 percent of a maximum day demand. While this assumption is more conservative than the firm capacity assumption, it provides more flexibility under drought conditions. Refer to Chapter 4 for more discussion regarding this assumption. • The firm groundwater supply capacity is calculated as 85 percent of the production capacity of active wells (i.e., does not include standby or inactive wells) in North Stockton and South Stockton, respectively. Refer to Chapter 5 for more discussion regarding this assumption.

As shown in Table 8-3, there is a surplus of supply in both the North Stockton and South Stockton water service areas, and no additional supply is needed for near-term (2030) conditions. However, as discussed in Chapter 7, the new Well SSS10 is recommended to help meet the existing storage capacity deficit in South Stockton. Similarly, as discussed in the storage capacity evaluation below, there is a storage capacity deficit by the near-term (2030) time frame for which it is recommended that one of the existing standby wells in South Stockton (Well SSS2) be rehabilitated and equipped with backup power. Both the new Well SSS10 and recommended improvements to Well SSS2 provide an additional source of supply which is reflected in Table 8-3.

EXHIBIT 1
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Table 8-3. Near-Term (2030) Comparison of Available versus Required Supply Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Supply
Existing Firm Well Supply Capacity [A] 85 percent of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4 Existing Surface Water Supply [B] Full DWTP Capacity 20,833 30.0 Total Supply Capacity [C] = [A] + [B] 37,749 54.4
Demand
Near-Term Maximum Day Demand [D] 1.6 times ADD (refer to Table 8-1) 26,430 38.1 North Stockton
Supply Capacity Surplus (Deficit) [E] = [C] – [D] 11,319 16.3 South Stockton
Supply
Existing Firm Well Supply Capacity [F] 85 percent of the capacity of active wells (SSS3, SSS9) 4,118 5.9 Existing Surface Water Supply [G] 70 percent of South Stockton MDD, (refer to Table 8-11) 7,255 10.4
Total Supply Capacity [H] = [F] + [G] 11,373 16.4
Demand
Near-Term Maximum Day Demand [I] 1.7 times ADD (refer to Table 8-1) 10,364 14.9 South Stockton
Supply Capacity Surplus (Deficit) [J] = [H] - [I] 1,009 1.5 Additional Supply
Additional Firm Well Supply Capacity from
Well SSS10
[K] 85 percent of the
assumed 2,000 gpm capacity 1,700 2.4
South Stockton Supply Capacity Surplus (Deficit)
with Existing System Improvements [L] = [J] + [K] 2,709 3.9 Additional Firm Well Supply Capacity from
Well SSS2 [M] 85 percent of the capacity of standby Well SSS2 1,101 1.6 South Stockton
Supply Capacity Surplus (Deficit)
with Near-Term System Improvements
[N] = [L] + [M] 3,810 5.5
Table 8-4 summarizes supply capacity evaluation for the future (2040) demand conditions. As shown in Table 8-4, there is surplus supply capacity in both the North Stockton and South Stockton water service areas. Similar to the near-term time frame, at future an additional well in South Stockton is recommended to be rehabilitated and equipped with backup power for the purposes of increasing storage capacity. Well SSS8 is recommended to be rehabilitated by the future (2040) timeframe. While Well SSS8 is not needed for supply purposes, it does provide an additional source of supply which is reflected in Table 8-4.

EXHIBIT 1
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Table 8-4. Future (2040) Comparison of Available versus Required Supply Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Supply
Existing Firm Well Supply Capacity [A] 85 percent of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4
Existing Surface Water Supply [B] Full DWTP Capacity 20,833 30.0 Total Supply Capacity [C] = [A] + [B] 37,749 54.4
Demand
Future Maximum Day Demand [D] 1.6 times ADD (refer to Table 8-2) 32,549 46.9 North Stockton
Supply Capacity Surplus (Deficit) [E] = [C] – [D] 5,200 7.5 Additional Supply
Construction of Well 33 [F] 85 percent of the assumed 1,500 gpm capacity 1,275 1.8 North Stockton
Supply Capacity Surplus (Deficit) with Future
System Improvements
[G] = [E] + [F] 6,475 9.3
South Stockton
Supply
Existing Firm Well Supply Capacity [H] 85 percent of the capacity of active wells (Wells SSS3 and SSS9) 4,118 5.9
Existing Surface Water Supply [I] 70 percent of South Stockton MDD (refer to Table 8-2)
10,499 15.1
Total Supply Capacity [J] = [H] + [I] 14,617 21.0
Demand
Future Maximum Day Demand [K] 1.7 times ADD (refer to Table 8-2) 14,999 21.6 South Stockton
Supply Capacity Surplus (Deficit) [L] = [J] - [K] (382) (0.5) Additional Supply
Additional Firm Well Supply Capacity from
Existing and Near-Term System Improvements
(Wells SSS10 and SSS2)
[M] 85 percent of the assumed 2,000 gpm capacity for
Well SSS10 and existing capacity of Well SSS2 2,801 4.0 South Stockton
Supply Capacity Surplus (Deficit) with Existing
and Near-Term System Improvements
[N] = [L] + [M] 2,419 3.5
Additional Firm Well Supply Capacity to
Improve Future System Storage / Improve
Reliability (Rehabilitate Well SSS8)
[O] 85 percent of the capacity of standby Well SSS8 859 1.2 South Stockton
Supply Capacity Surplus (Deficit) with Future
System Improvements
[P] = [N]+ [O] 3,278 4.7
EXHIBIT 1
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8.3.2 Pumping Capacity Evaluation
Pumping capacity was evaluated to assess the ability of the COSMUD to deliver a reliable firm capacity to meet the greater of either the maximum day demand plus a large fire flow event or the peak hour demand, as described in Chapter 5, under both near-term or future demand conditions. Pumping capacity is provided by a combination of supply facilities (i.e., treatment plants and groundwater wells) and reservoir pump stations. Firm pumping capacity provided by treatment plants and groundwater wells is evaluated in a manner identical to the supply capacity evaluation described above. For reservoir pump stations, a reduction in total pumping capacity is assumed to account for pumps that could be out of service due to various operational problems or maintenance at any given time. For both North Stockton and South Stockton, firm pumping capacity is defined as the total pump station capacity with the largest pump out of service.

Table 8-5 and Table 8-6 show the firm pumping capacity compared to the peak hour demand in North Stockton and South Stockton for the near-term (2030) and future (2040) demand conditions, respectively. For both North Stockton and South Stockton, under both near-term and future demand conditions, there is a surplus of pumping capacity with the storage/well improvements recommended in the storage capacity evaluation section, as described below.

Table 8-6 shows the required pumping capacity associated with the Mariposa Road Community, separate from the remaining South Stockton area. Pumping capacity for this area was evaluated separately because this area would be a new pressure zone and would be supplied by associated facilities, as discussed previously. The controlling scenario for the pumping requirement to this area is the maximum day demand plus fire flow condition, or about 11.6 mgd. As previously discussed, while pumping capacity could be met through a combination of the recommended well and associated reservoir pump station, it is recommended that the reservoir pump station be sized to meet the full pumping requirement in the event the groundwater well is out of service. Therefore, it is recommended that the reservoir pump station be sized at a firm capacity of 12.0 mgd. With the reservoir pump station and well, however, there is a 2.3 mgd pumping capacity surplus.

EXHIBIT 1
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Table 8-5. Near-Term (2030) Comparison of Available versus Required Pumping Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Requirement
Required Maximum Day Demand Plus
Fire Flow(a)
[A] MDD (refer to Table 8-1)
plus a large industrial Fire Flow (4,500 gpm) 30,930 44.5 Required Peak Hour Demand [B] 2.5 times ADD (refer to Table 8-1) 41,296 59.5 Pumping Capacity Requirement [C] = [A] + [B] 41,296 59.5 Capacity
Existing Firm Pump Capacity at Reservoir Sites [D] Total pump capacity with the largest pump offline at each reservoir site 31,450 45.3
Existing Firm Pump Capacity at
Treatment Plants
[E] Limited to the existing capacity of the Delta Water Treatment Plant 20,833 30.0
Existing Firm Well Capacity [F] 85 percent of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4 Total Existing Available Firm Capacity [G] = [D] + [E] + [F] 69,199 99.6 North Stockton
Existing Pumping Capacity Surplus (Deficit) [H] = [G] - [C] 27,903 40.2 South Stockton
Requirement
Required Maximum Day Demand Plus
Fire Flow(a)
[I] MDD (refer to Table 8-1)
plus a large industrial Fire Flow (4,500 gpm) 14,864 21.4 Required Peak Hour Demand [J] 3.3 times ADD (refer to Table 8-1) 18,425 26.5 Pumping Capacity Requirement [K] = [I] + [J] 18,425 26.5 Existing Capacity
Existing Firm Pump Capacity at Reservoir Sites [L] Total pump capacity with the largest pump offline at each reservoir site 9,000 13.0
Existing Firm Pump Capacity at Treatment
Plants
[M] 70 percent of South Stockton MDD
(refer to Table 8-1)
7,255 10.4
Existing Firm Well Capacity [N] 85 percent of the capacity of active wells (Wells SSS3 and SSS9) 4,118 5.9
Total Existing Available Firm Capacity [O] = [L] + [M] + [N] 20,373 29.3 South Stockton
Existing Pumping Capacity Surplus (Deficit) [P] = [O] - [K] 1,948 2.8 Improved Capacity
Additional Firm Well Supply Capacity from
Well SSS10(d) [Q] 85 percent of the assumed 2,000 gpm capacity 1,700 2.4 South Stockton
Pumping Capacity Surplus (Deficit) with Existing
System Improvements
[R] = [P] + [Q] 3,648 5.3
Additional Firm Well Supply Capacity from
Well SSS2
[S] 85 percent of the capacity of
existing standby Well SSS2 1,101 1.6
South Stockton
Pumping Capacity Surplus (Deficit)
with Near-Term System Improvements
[T] = [R] + [S] 4,749 6.8
(a) The large industrial fire flow does not include demand for on-site sprinkler flow.

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Table 8-6. Future (2040) Comparison of Available versus Required Pumping Capacity Available or Required Capacity Notes/Basis
Capacity
gpm mgd
North Stockton
Requirement
Required Maximum Day Demand Plus Fire Flow(a) [A] MDD (refer to Table 8-2) plus a large industrial Fire Flow (4,500 gpm) 37,049 53.4
Required Peak Hour Demand [B] 2.5 times ADD (refer to Table 8-2) 50,857 73.2 Pumping Capacity Requirement [C] = [A] + [B] 50,857 73.2 Capacity
Existing Firm Pump Capacity at Reservoir Sites [D] Total pump capacity with the largest pump offline at each reservoir site 31,450 45.3
Existing Firm Pump Capacity at Treatment Plants [E] Limited to the existing capacity of the Delta Water Treatment Plant 20,833 30.0
Existing Firm Well Capacity [F] 85 percent of the capacity of active wells (Wells 3R, 10R, 18, 19, 21, 27, 29, 30, 31, 32) 16,916 24.4
Total Existing Available Firm Capacity [G] = [D] + [E] + [F] 69,199 99.6 North Stockton
Existing Pumping Capacity Surplus (Deficit) [H] = [G] - [C] 18,342 26.4 Improved Capacity
Construction of Well 33 [I] 85 percent of the assumed 1,500 gpm capacity 1,275 1.8 Construction of Northeast Reservoir Pump Station [J] 12.0 MGD firm capacity, sized based on the ability to fully empty tank in 8 hours 8,333 12.0
North Stockton
Supply Capacity Surplus (Deficit) with Future System
Improvements
[K] = [H] + [I] + [J] 27,951 40.2
South Stockton
Requirement
Required Maximum Day Demand Plus Fire Flow(a) [L] MDD (refer to Table 8-2) plus a large industrial Fire Flow (4,500 gpm) 19,499 28.1
Required Peak Hour Demand [M] 3.3 times ADD (refer to Table 8-2) 24,092 34.7 Pumping Capacity Requirement [N] = [L] + [M] 24,092 34.7 Existing Capacity
Existing Firm Pump Capacity at Reservoir Sites [O] Total pump capacity with the largest pump offline at each reservoir site 9,000 13.0
Existing Firm Pump Capacity at Treatment Plants [P] 70 percent of South Stockton MDD (refer to Table 8-2) 10,499 15.1 Existing Firm Well Capacity [Q] 85 percent of the capacity of active wells (Wells SSS3 and SSS9) 4,118 5.9 Total Existing Available Firm Capacity [R] = [O] + [P] + [Q] 23,617 34.0 South Stockton
Existing Pumping Capacity Surplus (Deficit) [S] = [R] - [N] (474) (0.7) Improved Capacity
Added Firm Well Capacity to Improve Existing and Near-Term System
[T] Additional capacity of Well SSS10, assuming a pumping capacity of 2,000 gpm and rehabilitation of Well SSS2 (85 percent of total capacity assumed for firm capacity)
2,801 4.0
South Stockton
Pumping Capacity Surplus (Deficit)
with Existing and Near-Term System Improvements
[U] = [S] + [T] 2,327 3.4
Added Firm Well Capacity to Improve Future System Storage and Reliability
[V] Rehabilitation of Well SSS8 (85 percent of total capacity assumed for firm capacity) 859 1.2
South Stockton
Pumping Capacity Surplus (Deficit)
with Future System Improvements
[W] = [U] + [V] 3,185 4.6
Mariposa Road Community
Requirement
Required Maximum Day Demand Plus Fire Flow(a) [X] Maximum Day Demand (refer to Table 8-2) plus a large industrial Fire Flow (4,500 gpm) 8,038 11.6
Required Peak Hour Demand [Y] Existing Peak Hour Demand (refer to Table 8-2) 6,867 9.9 Mariposa Road Community
Pumping Capacity Requirement [Z] = [X] + [Y] 8,038 11.6 Improved Capacity
Added Pumping Capacity associated with new 3.5 MG storage reservoir for Mariposa Road Community
[AA] 12.0 MGD firm capacity, sized based on the ability to fully empty tank in 8 hours 8,333 12.0
Additional Capacity from New Well [AB] New well assumed to supply 1,500 gpm (85 percent of total capacity assumed for firm capacity) 1,275 1.8
Mariposa Road Community
Pumping Capacity Surplus (Deficit) with Future System
Improvements
[AC] = [AA] + [AB] - [Z] 1,570 2.3
(a) The large industrial fire flow does not include demand for on-site sprinkler flow.

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8.3.3 Storage Capacity Evaluation
Water storage provides operational storage to balance differences in demands and supplies, emergency storage in case of a supply failure, and water to fight fires. The COSMUD water system has two sources of available storage: above-ground storage (i.e., storage reservoirs) and storage available in the groundwater basin. Together, these two sources of storage must be sufficient to meet the COSMUD operational, emergency, and fire flow storage criteria.

As introduced in Chapter 5, the COSMUD water storage capacity requirement is as follows:
• Operational storage equal to 25 percent of a maximum day demand • Fire flow storage equal to the largest fire flow rate multiplied by its duration • Emergency storage equal to one average day demand
Because the COSMUD water supply includes groundwater wells and treated surface water, the groundwater basin and treatment facilities can offset some of the required storage in the form of storage credits. A summary of available storage capacity and credits is provided below:
• Existing available storage is defined as the storage provided by all active reservoirs • The Emergency Groundwater Storage Credit (EGWC) equals 85 percent of the active groundwater wells that can be reliably accessed (i.e., well facilities equipped with auxiliary power)
• The Treated Surface Water Supply Credit (TSWC) equals the smaller of the two treatment facilities available in North Stockton. There is no treated surface water credit available for South Stockton because water from DWTP cannot be transferred to South Stockton, providing no redundant treated surface water supply. Since the COSMUD aims to maximize its use of SEWD water in South Stockton, the maximum credit that can be taken is difference between the full SEWD capacity (i.e., 30 mgd) and South Stockton maximum day demands. • Combined, the EGWC and TSWC cannot exceed the emergency storage requirement Existing water storage facilities, in conjunction with the available EGWC and TSWC, were evaluated to determine whether the COSMUD existing storage capacity provides the recommended operational, emergency, and fire flow storage for existing demands. Table 8-7 and Table 8-8 provide a comparison of available and required storage capacity for near-term (2030) and future (2040) timeframes, respectively.

As shown in Table 8-7 below, for the near-term demand condition, there is a surplus of storage capacity in North Stockton26 and a storage capacity deficit in South Stockton of 6.1 mgd, with Well SSS10 included as recommended in the existing system analysis. To alleviate the storage capacity deficit in South Stockton, it is recommended that existing and/or rehabilitated groundwater wells be equipped with backup power. The addition of backup power at wells maximizes the COSMUD ability to generate EGWCs.

Existing Wells SSS3 and SSS9 do not currently have backup power and are recommended to be equipped 26 In subsequent sections of this chapter it is recommended that two existing wells be either rehabilitated or replaced in North Stockton by the near-term time frame. A groundwater study is also recommended in subsequent sections of this chapter to identify which wells should be rehabilitated. Capacity increases associated from rehabilitation of these wells are not accounted for and would result in an increased storage capacity surplus.

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with backup power to increase the EGWC for South Stockton. Equipping Wells SSS3 and SSS9 alone does not fully mitigate the projected storage deficit. Therefore, it is recommended that Well SSS2 be rehabilitated back to active status and equipped with backup power. Well SSS2 is currently out of service due to elevated concentrations of 1,2,3-Trichloropropane (TCP). To rehabilitate this well, it is assumed that a granular activated carbon treatment system would be installed since this has been deemed a best available technology (BAT) by California Division of Drinking Water for treatment for TCP27.

As shown in Table 8-8 below, for the future demand condition there is a storage capacity deficit in North Stockton and a slight surplus in South Stockton. To alleviate the storage capacity deficit in North Stockton, it is recommended that COSMUD planned Well 33 be constructed and equipped with backup power. The remainder of the capacity deficit would be mitigated by the new Northeast Reservoir and Reservoir Pump Station. It is recommended that this reservoir and pump station be sized at 4.0 MG, which would be adequate to cover the storage capacity deficit if one of the existing northeast wells is out of service (i.e., Wells 10R, 31, 32, future Well 33), where pressures are lower during maximum day and peak hour conditions.

Although there is a small storage capacity surplus in South Stockton (0.1 mgd), it is recommended that Well SSS8 be rehabilitated back to active status and equipped with backup power. Table 8-7, for the nearterm timeframe, assumes 100 percent of the existing pumping capacity of Well SSS2. However, since Well SSS2 will require wellhead treatment, it is likely that the full capacity of this well will not be recovered, resulting in a storage capacity deficit (since the EGWC will be reduced). Rehabilitating Well SSS8 will provide the COSMUD with additional flexibility in South Stockton if the recovered capacity at Well SSS2 is any less than 100 percent and would ensure that the needed storage capacity is met. In addition, having an additional local supply source also helps to diversify the COSMUD water supply, and further reduces the reliance on SEWD.
27 The existing SSS2 well site is located in a parking lot outside of an industrial building, and therefore cannot accommodate the additional footprint associated with wellhead treatment. It is likely wellhead treatment be sited at the nearby SSS8, which is located at a park and can accommodate the additional footprint associated with wellhead treatment. Therefore, a dedicated pipeline from SSS2 to SSS8 will need to be constructed. This alternative is recommended to be further investigated as part of the recommended Groundwater Study, discussed in subsequent sections. For cost estimating purposes, a new well cost is assumed for this improvement and is discussed in further detail in Chapter 9.

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Table 8-7. Near-Term (2030) Comparison of Available versus Required Storage Capacity Available or Required Capacity Notes/Basis Storage, mg
North Stockton
Requirement
Operational [A] 25 percent of MDD (refer to Table 8-1) 9.5 Fire Flow [B] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [C] One ADD (refer to Table 8-1) 23.8
Total Storage Requirement [D] = [A] + [B] + [C] 34.3
Capacity
Existing Available Storage Capacity [E] Includes all active reservoirs 16.2 Treated Surface Water Supply Credit
[F] Assumes North Stockton Pipeline Hypochlorite Facility is complete, so SEWD is connected to North Stockton. The smaller of the two WTPs (DWTP) can be used for the treated surface water supply credit

10.2 Emergency Groundwater Storage Credit [G] 85 percent of the active wells equipped with backup power (Wells 3R, 29, 30, 31, 32) 13.6
Total Storage Capacity [H] = [E] + [F] + [G] 40.0
North Stockton
Existing Storage Capacity Surplus (Deficit) [I] = [H] - [D] 5.7 South Stockton
Requirement
Operational [J] 25 percent of MDD (refer to Table 8-1) 3.7 Fire Flow [K] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [L] One ADD (refer to Table 8-1) 9.8
Total Storage Requirement [M] = [J] + [K] + [L] 14.5
Capacity
Existing Available Storage Capacity [N] Includes all active reservoirs 6.0 Treated Surface Water Supply Credit [O] No credit taken, since water from DWTP cannot be transferred to South Stockton 0.0
Emergency Groundwater Storage Credit [P] 85 percent of the active wells equipped with backup power (none) 0.0 Total Storage Capacity [Q] = [N] + [O] + [P] 6.0
South Stockton
Existing Storage Capacity Surplus (Deficit) [R] = [Q] - [M] (8.5) Improved Capacity
Added Emergency Groundwater Storage Credit
from Well SSS10 [S] 85 percent of the assumed 2,000 gpm capacity 2.4 South Stockton
Storage Capacity Surplus (Deficit)
with Existing System Improvements
[T] = [R] + [S] (6.1)
Additional Emergency Groundwater Storage Credit
from equipping Wells SSS3 and SSS9 with backup power
[U] 85 percent of the capacity of existing active Wells SSS3 and SSS9 5.9 Additional Emergency Groundwater Storage Credit from
Rehabilitating Well SSS2 [V] 85 percent of the capacity of existing standby Well SSS2 1.6 South Stockton
Storage Capacity Surplus (Deficit)
with Near-Term System Improvements
[W] = [T] + [U] + [V] 1.5
EXHIBIT 1
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Table 8-8. Future (2040) Comparison of Available versus Required Storage Capacity Available or Required Capacity Notes/Basis Storage, mg
North Stockton
Requirement
Operational [A] 25 percent of MDD (refer to Table 8-2) 11.7 Fire Flow [B] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [C] One ADD (refer to Table 8-2) 29.3
Total Storage Requirement [D] = [A] + [B] + [C] 42.0
Capacity
Existing Available Storage Capacity [E] Includes all active reservoirs 16.2 Treated Surface Water Supply Credit
[F] Assumes the North Stockton Pipeline Hypochlorite Facility is complete, so SEWD is connected to North Stockton. The smaller of the two WTPs (DWTP) can be used for the treated surface water supply credit

8.4 Emergency Groundwater Storage Credit [G] 85 percent of the active wells equipped with backup power (Wells 3R, 29, 30, 31, 32) 13.6
Total Storage Capacity [H] = [E] + [F] + [G] 38.2
North Stockton
Existing Storage Capacity Surplus (Deficit) [I] = [H] - [D] (3.8) Improved Capacity
Construction of Well 33 with backup power(e) [J] 85 percent of the capacity of new well (assumed to be 1,500 gpm) 1.8 Construction of Northeast Reservoir [K] Recommended Northeast Reservoir 4 MG nominal capacity, in the event of a well in northeast area is offline 4.0
North Stockton
Buildout Storage Capacity Surplus (Deficit)
with Future System Improvements
[L] = [I] + [J] + [K] 2.0
South Stockton
Requirement
Operational [M] 25 percent of MDD (refer to Table 8-2) 4.1 Fire Flow [N] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [O] One ADD (refer to Table 8-2) 10.8
Total Storage Requirement [P] = [M] + [N] + [O] 15.9
Capacity
Existing Available Storage Capacity [Q] Includes all active reservoirs 6.0 Treated Surface Water Supply Credit [R] No credit taken, since North Stockton and South Stockton remain hydraulically separate 0.0
Emergency Groundwater Storage Credit(e) [S] 85 percent of the active wells equipped with backup power (none) 0.0 Total Storage Capacity [T] = [Q] + [R] + [S] 6.0
South Stockton
Existing Storage Capacity Surplus (Deficit) [U] = [T] - [P] (9.9) Improved Capacity
Added Emergency Groundwater Storage Credit from
Existing and Near-Term System Improvements
(Well SSS10)(e)
[V] 85 percent of the assumed 2,000 gpm capacity 2.4
Additional Emergency Groundwater Storage Credit from
equipping Wells SSS3 and SSS9 with backup power [W] 85 percent of the capacity of existing Wells SSS3 and SSS9 5.9 Additional Emergency Groundwater Storage Credit from
rehabilitating Well SSS2 [X] 85 percent of the capacity of existing standby Well SSS2 1.6 South Stockton
Storage Capacity Surplus (Deficit)
with Existing and Near-Term System Improvements
[Y] = [U] + [V] + [W] + [X] 0.1
Additional Emergency Groundwater Storage Credit from
Well SSS8 [Z] 85 percent of the capacity of existing standby Well SSS8 1.2 South Stockton
Storage Capacity Surplus (Deficit)
with Future System Improvements
[AA] = [Y] + [Z] 1.3
Mariposa Road Community
Requirement
Operational [AB] 25 percent of MDD (refer to Table 8-2) 1.3 Fire Flow [AC] One fire event: 4,000 gpm @ 4 hours (refer to Chapter 5) 1.0 Emergency [AD] One ADD (refer to Table 8-2) 3.0
Mariposa Road Community
Total Storage Requirement
[AE] = [AB] + [AC] + [AD] 5.3
Improved Capacity
New Storage Reservoir for Mariposa Road Community [AF] Recommended Mariposa Reservoir 3.5 MG nominal capacity 3.5 Additional Well to improve supply reliability and to
contribute to emergency groundwater storage credit [AG] 85 percent of the assumed 1,500 gpm capacity 1.8 Mariposa Road Community
Storage Capacity Surplus (Deficit) [AH] = [AF] + [AG] - [AE] 0.0 EXHIBIT 1
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8.4 FUTURE WATER DISTRIBUTION SYSTEM PERFORMANCE

EVALUATION
The water distribution system performance evaluation identifies necessary improvements to the COSMUD water distribution system to support the COSMUD near-term (2030) and future (2040) water demands while meeting the COSMUD recommended water system planning and design criteria, presented in Chapter 5.

The following evaluations were performed to assess water distribution system performance under existing water demand conditions:
• Normal Operations – Maximum Day Demand with Peak Hour Scenario: This scenario evaluated service pressures during a peak hour on the maximum day demand condition. • Emergency Operations – Maximum Day Demand plus Fire Flow Scenario: This scenario evaluated system fire flow availability under a maximum day demand condition.

The water system hydraulic model, updated with the proposed improvements to the existing system from Chapter 7, was used to evaluate the near-term (2030) and future (2040) water system performance.

Additional facilities (i.e., pipes and new wells) to provide service to projected future development areas were also included in the hydraulic model, as shown on Figure 8-1. In addition, recommended improvements identified in the facility capacity evaluation above were also incorporated into the hydraulic model. The water distribution system is expected to deliver maximum day with peak hour demand flows and maximum day demand plus fire flow, at near-term (2030) and future (2040) demand conditions, within the acceptable pressure and velocity ranges as identified in the water system performance and operational criteria presented in Chapter 5.

8.4.1 Normal Operations – Maximum Day Demand with Peak Hour

8.4.1.1 Evaluation Overview
An EPS was conducted using the hydraulic model to evaluate system performance under a maximum day with a peak hour demand condition for both near-term (2030) and future (2040) demand conditions. The diurnal pattern previously presented in Chapter 3 was incorporated into the hydraulic model for both demand conditions and evaluated for seven consecutive days; however, only results from the last three days of the simulations were used, as these results are not affected by initial conditions. Table 8-1 summarizes system demands for the near-term (2030) demand condition and Table 8-2 summarizes system demands for the future (2040) demand condition.

During both a maximum day demand scenario and a peak hour demand scenario, a minimum pressure of 45 psi and a maximum pressure of 80 psi must be maintained at service connections throughout the entire system. In addition, for pipelines, it is recommended that the maximum velocity not exceed 5 fps. The near-term and future system analyses assume the maximum day and peak hour demand would be met by a combination of surface water treatment plants, active groundwater wells, and storage reservoirs via their associated reservoir pump stations.

EXHIBIT 1
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8.4.1.2 Near-Term (2030) System Evaluation Results
Results from the maximum day with peak hour demand condition for near-term (2030) demand conditions indicate that the water distribution system generally meets the COSMUD minimum and maximum pressure criteria at most customer service locations. Figure 8-2 presents the minimum pressures observed during the EPS simulation.

For North Stockton, SEWD is assumed to be supplying North Stockton via the North Stockton Pipeline Hypochlorite Facility as this project is anticipated to be complete by 2030. Discharge pressure at DWTP was increased to 58 psi to limit the supply from SEWD. As a result of SEWD supplying North Stockton and the increase of the DWTP discharge pressure, minimum pressure results for the near-term system generally improve as compared to the existing system evaluation. Minimum pressures in the northeast remain above 50 psi. Maximum pressures throughout the entire service area do not exceed 73 psi (observed in the northwest at low elevations).

For South Stockton, some locations south of Weston Ranch Reservoir and east of Well SSS3 do not meet the minimum pressure criterion but remain predominantly greater than 40 psi. Improvements to address this area are not recommended since all pipeline velocity and head loss gradients in the area meet recommended criteria. In addition, in the future (2040), the nearby Mariposa Road Community pressure zone would have interconnections in these areas with low pressure. These connections would help improve observed low pressures. Distribution system pressures vary from a high of 71 psi in the northwest corner of the South Stockton system to a low of 41 psi east of Well SSS3, with the exception of the customer service location at the end of a 2-inch diameter dead-end pipeline in central South Stockton, previously identified in the existing system analysis.

Discharge pipelines at groundwater well facilities and reservoir pump stations have maximum velocities that vary between 5.6 and 9 fps. While these velocities exceed maximum recommended velocities, improvements are not recommended at these locations as they are experienced for a short distance and do not impact the primary criterion, customer service pressure. Simulated velocity results for the maximum day with peak hour demand condition indicate that the remaining pipelines within the COSMUD water system meet the velocity criterion of 5 fps, and therefore no pipeline improvements are recommended for the maximum day with peak hour demand condition.

Figure 8-3 shows reservoir water level fluctuations in system reservoirs throughout the EPS. As shown on Figure 8-3, the Northwest and Fourteen-Mile Slough Reservoirs follow a repetitive turnover cycle, cycling at least once a day. In South Stockton, Weston Ranch Reservoir level fluctuations are more cyclical due to the increased demand by near-term (2030).

8.4.1.3 Future (2040) System Evaluation Results
Results from the maximum day with peak hour demand condition for the future (2040) demand conditions indicates that the water distribution system generally meets the COSMUD minimum and maximum pressure criteria for at most customer service locations. Figure 8-4 presents the minimum pressures observed during the EPS simulation.

For North Stockton, for this evaluation, it is assumed that SEWD will not supply North Stockton via the North Stockton Pipeline Hypochlorite Facility, and supply from DWTP will be maximized up to 29 mgd. The intent of this assumption was to identify pipeline restrictions downstream of DWTP if the COSMUD maximized surface water supplies from the DWTP. In addition, the new Northeast Reservoir and new Well 33 are assumed to be online, as recommended in the facility capacity evaluation sections. As shown EXHIBIT 1
1788
on Figure 8-4, minimum pressures are slightly less than near-term results, but still generally meet the minimum pressure criterion. A few locations do experience minimum pressures less than 45 psi, but local improvements are not recommended as velocity and head loss criteria in pipelines are met. However, the existing 42-inch diameter transmission pipelines downstream of the DWTP finished water pump station experience velocities greater than 5 fps (up to a maximum of 6.5 fps), the maximum velocity criterion for transmission mains. It is recommended that new 36-inch diameter transmission lines be constructed to provide additional conveyance capacity from the DWTP finished water pump station. Since these pipelines are needed to meet demands in the future and/or to maximize supply from DWTP, these pipelines should be completed by 2040 and are recommended to be coupled with development north of Bear Creek.

Figure 8-5 shows minimum pressure results with these recommended pipelines incorporated.

For South Stockton, results generally look identical to the near-term (2030) minimum pressure results.

The customer service location at the end of a 2-inch diameter dead-end pipeline in central South Stockton continues to experience low pressures, this was previously identified in Chapter 7. It is recommended that this pipeline be replaced as part of the Priority 3 rehabilitation and replacement program discussed in Chapter 7. The Mariposa Road Community area was configured to be served by a recommended new reservoir and associated reservoir pump station, and all pressure and velocity criteria is met under this configuration.

Discharge pipelines at groundwater well facilities and reservoir pump stations have maximum velocities that vary between 5.6 and 9 fps. While these velocities exceed maximum recommended velocities, improvements are not recommended at these locations as they are experienced for a short distance and do not impact the primary criterion, customer service pressure. Simulated velocity results for the maximum day with peak hour demand condition indicate that the remaining pipelines within the COSMUD water system meet the velocity criterion of 5 fps and therefore no pipelines additional improvements are recommended for the maximum day with peak hour demand condition, except for the recommended transmission mains to mitigate velocities observed downstream of the DWTP.

Figure 8-6 shows reservoir water level fluctuations in system reservoirs throughout the EPS. The Northwest, Fourteen-Mile Slough, and proposed Northeast Reservoirs follow a repetitive turnover cycle, cycling at least once a day. In South Stockton, the Weston Ranch and the Mariposa Road Community Reservoirs also follow a repetitive turnover cycle, cycling at least once a day.

EXHIBIT 1
1789
")
")
")
TU
Q3
§¨¦5
¬«99

S AN JOAQUIN RIVER
Weston Ranch

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
Well SSS10
")
")
")
")
")
")
") ")
")
")
TU
TU
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SAN JOAQUIN RIVER

CALAVERAS RIVER
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #10R
Figure 8-2
Near-Term (2030) System
Maximum Day Demand
Minimum System Pressure
City of Stockton
Water Master Plan Update
Minimum System Pressure
Less than 40 psi
Between 40 and 45 psi
Between 45 and 50 psi
Between 50 and 55 psi
Greater than 55 psi
Q3 Water Treatment Plant
TU Reservoir & Pump Station
") Well (Active)
COSMUD Water Service Boundary
Maximum Velocity
Equal to or Less than 5 ft/s
Greater than 5 & Less than 7 ft/s
Greater than 7 ft/s
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_2_MDDMinResults_NTSys.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 58 psi and Stockton East Water District pump station discharge pressure was set to 58 psi. Active wells were turned on as needed, based on local pressure/time of day.

EXHIBIT 1
1790
n\c\129\60-20-41\e\8
City of Stockton
Water Master Plan Update
Last Revised: 12-02-20
0 2
4 6
8 10
12 14
16 18
20 22
24 26
28 30
32 34
36 38
40 0 6 12 18 24 30 36 42 48 54 60 66 72
Tank Level, feet
Time, hour
Figure 8-3. Near Term (2030) Maximum Day Demand Reservoir Level Results Northwest 14-Mile Slough Weston Ranch
EXHIBIT 1
1791
TU
")
")
")
TU
Q3
§¨¦5
¬«99

SAN JOAQUINRIVER
Weston Ranch

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
Well SSS10
Mariposa
TU
")
")
")
")
")
")
") ")
")
")
")
TU
TU
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SANJOAQUIN RIVER

CALAVERAS RIVER
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #33
Well #10R
Northeast
Figure 8-4
Buildout (2040) System
Maximum Day Demand
Minimum System Pressure
City of Stockton
Water Master Plan Update
Minimum System Pressure
Less than 40 psi
Between 40 and 45 psi
Between 45 and 50 psi
Between 50 and 55 psi
Greater than 55 psi
Q3 Water Treatment Plant
TU Reservoir & Pump Station
") Well (Active)
COSMUD Water Service Boundary
Maximum Velocity
Equal to or Less than 5 ft/s
Greater than 5 ft/s & Less than 7 ft/s
Greater than 7 ft/s
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_4_MDDMinResults_BOSys.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 60 psi and Stockton East Water District pump station discharge pressure was set to 58 psi. Active and proposed wells were turned on as needed, based on local pressure/time of day.

EXHIBIT 1
1792
TU
")
")
")
TU
Q3
§¨¦5
¬«99

SAN JOAQUINRIVER
Weston Ranch

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
Stockton
East Water
District
Well SSS3
Well SSS9
Well SSS10
Mariposa
TU
")
")
")
")
")
")
") ")
")
")
")
TU
TU
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SANJOAQUIN RIVER

CALAVERAS RIVER
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #33
Well #10R
Northeast
Figure 8-5
Buildout (2040) System
Maximum Day Demand
Minimum System Pressure
With Improvements
City of Stockton
Water Master Plan Update
Minimum System Pressure
Less than 40 psi
Between 40 and 45 psi
Between 45 and 50 psi
Between 50 and 55 psi
Greater than 44 psi
Q3 Water Treatment Plant
TU Reservoir & Pump Station
") Well (Active)
COSMUD Water Service Boundary
Maximum Velocity
Equal to or Less than 5 ft/s
Greater than 5 & Less than 7 ft/s
Greater than 7 ft/s
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_5_MDDMinResults_BOSys_improv.mxd - wjones - 1/18/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 57 psi and Stockton East Water District pump station discharge pressure was set to 58 psi. Active and proposed wells were turned on as needed, based on local pressure/time of day.

EXHIBIT 1
1793
n\c\129\60-20-41\e\8
City of Stockton
Water Master Plan Update
Last Revised: 12-03-20
0 2
4 6
8 10
12 14
16 18
20 22
24 26
28 30
32 34
36 38
40 0 6 12 18 24 30 36 42 48 54 60 66 72
Tank Level, feet
Time, hour
Figure 8-6. Future (2040) System Maximum Day Demand Reservoir Level Results Northwest 14 Mile Slough Weston Ranch Northeast Mariposa EXHIBIT 1
1794

8.4.2 Emergency Operations – Maximum Day Demand Plus Fire Flow The maximum day demand plus fire flow scenario evaluates the fire flow availability in the COSMUD distribution system under a maximum day demand condition, for both near-term (2030) and future (2040) time frames. An overview of the evaluation and a discussion of the results are presented in the sections below.

8.4.2.1 Evaluation Overview
To evaluate the near-term (2030) and future (2040) water system fire flow availability, InfoWater’s fire flow module was used to determine the available fire flow at junctions that represent hydrant locations throughout the system, while maintaining a minimum residual system pressure of 20 psi at all customer service locations and in new development areas. The analysis assumed that reservoir pump stations are operating at their firm pumping capacity. Maximum velocity is only considered on pipelines within new developments to confirm sizing of new infrastructure. Pipelines in existing areas are evaluated without a maximum velocity constraint because these pipelines were sized to meet standards at the time of their construction.

As discussed in Chapter 5, recommended fire flow criteria presented in Table 5-2 are established for future development land use types. Much of the existing COSMUD water distribution system is older and designed to earlier fire standards in place at the time the pipelines were constructed. The fire flow evaluation presents the systemwide available fire flow compared to recommended fire flow criteria for existing water service areas for comparison purposes only. As previously mentioned in Chapter 7, because much of the COSMUD system is older, a R&R program is recommended to replace smaller diameter pipelines (which are typically older) over the next 40 years. As the COSMUD proceeds with the program, fire flow availability in these areas will improve. For new development areas, fire flow availability is evaluated to confirm sizing of recommended future system improvements for new developments. As development plans in future areas are refined, infrastructure is expected to change and the COSMUD should require project proponents to size infrastructure to meet all design criteria presented in Chapter 5.

8.4.2.2 Near-Term (2030) System Evaluation Results
Figure 8-7 presents available fire flow compared to adjacent land use at each tested hydrant location and along future development pipelines while meeting recommended criteria. Results presented on Figure 8-7 are representative of the system’s capacity and do not represent available flow from a specific hydrant.

Typically, fire flows exceeding 1,500 gpm are met by multiple hydrants.

As shown on Figure 8-7, with Priority 1 and 2 improvements, most existing tested locations meet or exceed the recommended fire flow criteria for that location, and a few locations meet at least 75 percent of the criteria. As the COSMUD implements Priority 3 improvements, the number of locations that were found to meet at least 75 percent of the criteria will further improve. All tested locations within future development areas meet the required fire flow.

In South Stockton, the long dead-end pipeline along South Harland Road does not meet the recommended fire flow. This pipeline is currently a 12-inch diameter pipeline, and the COSMUD is planning on replacing portions of this pipeline with 16-inch diameter pipelines. Even with these improvements, available fire flows still are not significantly improved. Further upsizing of this pipeline is not recommended as this would result in poor water quality in this area. As development within this area continues, potentially after 2040, the COSMUD should consider looping pipelines in this future development area to improve hydraulic capacity EXHIBIT 1
1795
and therefore fire flow. No additional infrastructure is recommended at this time to improve fire flow, aside from the previously recommended rehabilitation and replacement plan (Priorities 1 through 3).

8.4.2.3 Future (2040) System Evaluation Results
Figure 8-8 presents available fire flow compared to adjacent land use at each tested hydrant location and along future development pipelines while meeting recommended criteria. Results presented on Figure 8-8 are representative of the system’s capacity and do not represent available flow from a specific hydrant.

Typically, fire flows exceeding 1,500 gpm are met by multiple hydrants.

As shown on Figure 8-8, results are similar to near-term (2030) and most existing tested locations meet or exceed the recommended fire flow criteria for that location, and a few locations meet at least 75 percent of the criteria. As the COSMUD implements Priority 3 improvements, the number of locations that were found to meet at least 75 percent of the criteria will further improve. All tested locations within future development areas meet the required fire flow.

In South Stockton, the long dead-end pipeline along South Harland Road continues to not meet the recommended fire flow. As development within this area continues, potentially after 2040, the COSMUD should consider looping pipelines in this future development area to improve hydraulic capacity and therefore fire flow. No additional infrastructure is recommended at this time to improve fire flow, aside from the previously recommended rehabilitation and replacement plan (Priorities 1 through 3).

EXHIBIT 1
1796
")
")
")
TU
Q3
§¨¦5
¬«99
SAN J

O AQU IN RIVER

D R M A R T I N L U T H E R K I N G J R

B L V D

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
24"
Weston Ranch
16"
Stockton
East Water
District
Well SSS3
Well SSS9
Well SSS10
")
")
")
")
")
")
") ")
")
")
TU
TU
Q3
Q3
§¨¦5
¬«99
14 Mile
Slough
Northwest

SAN JOAQUIN RIVER

CALAVERAS RIVER
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
16"
12"
24"
16"
30"
16"
12"
36"
18"
24"
16"
18"
16"
18"
16"
16"
12"
16"
12"
16"
12"
16"
12"
42"
12"
16" 16"
18" 18"
16"
16"
16"
16"
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #10R
Figure 8-7
Near-Term (2030) System
Maximum Day Demand
Fire Flow Results
City of Stockton
Water Master Plan Update
Available flow is ≥100% of criteria
Available flow is ≥75% but <100% of criteria
Available flow is ≥50% but <75% of criteria
Available flow is <50% of criteria
Q3 Water Treatment Plant
TU Reservoir & Pump Station
") Well (Active)
COSMUD Water Service Boundary
Pipelines
Existing
Existing System Improvements
Near-Term (2030) Improvements
Future Development Pipelines
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_7_FFResults_NTSys.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes:

1. Delta Water Treatment Plant pump station discharge pressure was set to 58 psi and Stockton East Water District
pump station discharge pressure was set to 58 psi. Active wells were turned on as needed, based on local pressure.

2. The available flow at each junction is the maximum
flow available while maintaining 20 psi residual system pressure.

3. Approximate near-term (2030) development pipelines
are in areas where the pipe layout and sizing will be
determined by the developer at a later date.
24"
EXHIBIT 1
1797
TU
TU
")
")
")
Q3
§¨¦5
¬«99

SAN JOAQUINRIVER

D R M A R T I N L U T H E R K I N G J R

B L V D

C E N T E R S T

A U S T I N R D

E I G H T H S T

J A C K T O N E R D

F R E M O N T S T

F R E N C H C A M P R D

M A R I P O S A
R D

H O W A R D R D

S U T T E R S T S A N J O
A

Q U I N S T

M I N E R A V E

N E W C A S T L E R D

P O C K L N

N A V Y D R
E L D
O R A
D
O S T

H A R L A N R D
B S T

A I R P O
R
T
W
A Y

M A R I P O S A R D

K A I S E R R D
Weston Ranch
Stockton
East Water
District
Well SSS3
Well SSS9
Well SSS10
24"
16"
24"
16"
24"
16"
24"
12"
16"
1 12" 2"
24"
24"
16"
24"
16"
Mariposa
Lakes
TU
TU
TU
")
")
")
")
")
")
") ")
")
")
")
Q3
Q3
§¨¦5
¬«99

SANJOAQUIN RIVER

CALAVERAS RIVER
14 Mile
Slough
Northwest
E L D

O R A D O S T

L O W E R S A C R A
M
E
N
T
O
R
D

P E R S H I N G
A
V E
P A

C I F I C
A
V E

E L D O R A D O S T

A S H L E Y L N
W
E S T
L N

F R E M O N T S T

H A M M E R L N

S W A I N R D

M I N E R A V E

M A R C H L N
S
T A N

D R E W S D R
T
H
O
R
N
T O
N
R
D
C
H
E R O
K E E
R D

B R O O K S I D E R D

L I V E O A K R D

A L P I N E R D

W A T E R L O O
R D

E I G H T M I L E R D

E I G H T M I L E R D

A R M S T R O N G R D
H

O L T R D

H I L D R E T H L N

R I N D G E R D
Delta Water
Treatment
Plant
Stockton
East Water
District
Well #18
Well #19
Well #21
Well #27
Well #29
Well #03R
Well
#30 Well #31
Well #32
Well #33
Well #10R
16"
12"
8" 12"
8"
16"
12"
12"
12"
8"
16"
12"
12"
12"
12" 12"
24"
16"
12"
16"
12"
30"
16"
12"
18"
16"
18"
16"
36"
18"
24"
16"
16"
12"
16"
16"
12"
42"
18"
18"
18"
12"
16" 16"
18"
12"
16"
16"
16"
16"
16"
Northeast
36"
36"
Figure 8-8
Buildout (2040) System
Maximum Day Demand
Fire Flow Results
City of Stockton
Water Master Plan Update
Pipelines
Existing
Existing System Improvements
Near-Term (2030) Improvements
Future (2040) Improvements
Future Development Pipelines
Available flow is ≥100% of criteria
Available flow is ≥75% but <100% of criteria
Available flow is ≥50% but <75% of criteria
Available flow is <50% of criteria
Q3 Water Treatment Plant
TU Reservoir & Pump Station
") Well (Active)
COSMUD Water Service Boundary
WEST YOST - N:\Clients\129 Stockton\60-20-41 Stockton WMPU\GIS\MXD\Water Master Plan\F8_8_FFResults_BOSys.mxd - wjones - 1/26/2021 0 3,000 6,000
Scale in Feet
0 3,500 7,000
Scale in Feet
South Stockton
North Stockton
Notes: