COUNCIL WATER COMMITTEE
Groundwater Recharge Project
July 10, 2025
Agenda Item No. 25-0762
MUNICIPAL UTILITIES DEPARTMENT (MUD)
Department Description
Water Utility
• Treat & deliver high-quality drinking water to the community Wastewater Utility
• Collect, treat and recover wastewater for the greater Stockton area Stormwater Utility
• Collect & discharge surface runoff in City to rivers and local flood basins
CITY OF STOCKTON WATER SERVICE AREAS
MUD serves North and South Stockton
California Water Service Company serves Central Stockton
DRINKING WATER - SURFACE WATER SOURCES
San Joaquin and Mokelumne Rivers
Treated at City’s Delta Water Treatment Plant
Calaveras and Stanislaus Rivers
Treated at Stockton East Water District Water Treatment Plant
DRINKING WATER - GROUNDWATER SUPPLIES
Groundwater wells ensure continued water supply, quality, reliability, and drought resiliency for the City.
Used conjunctively with surface water supplies
North Stockton - 6 active wells
South Stockton - 3 active wells
GROUNDWATER RECHARGE BASINS
Project – Groundwater Recharge Basins
Location – Delta Water Treatment Plant
Project Cost - $11.4M
Project Completion – 2027
Facilities
3 Groundwater Recharge Ponds
Visitor information Center
Viewing area and a walking trail around 1 recharge pond
PROJECT BENEFITS
Supports and aligns with the Groundwater Sustainability Plan (GSP) Protects the City’s existing Delta Intake water right
Enables groundwater banking using water from alternative sources such as the Mokelumne River Provides up to 21,000 acre-feet of groundwater recharge annually Enhances drought resilience
Promotes public outreach and education
Offers multi-benefit use, including the creation of wildlife habitat
GRANTS
Integrated Regional Water Management Grant
$1,900,000
Design and Construction phase
Sustainable Groundwater Management Grant
$300,000
Design phase of the project
WaterSMART Water and Energy Efficiency Grant
$400,000
Design phase of the project
SITE PLAN
APPROVE ADDENDUM TO THE 2005 DWSP EIR
The City certified a Program Environmental Impact Report (EIR) for the Stockton Delta Water Supply Project (DWSP) in October 2005.
HELIX Environmental Planning, Inc. prepared an Addendum on behalf of the City of Stockton The addendum includes mitigation efforts the City must comply with before and during construction The addendum complies with California Public Resources Code (PRC) Section 21166 and CEQA Guidelines Sections 15152 and 15162.
Stockton City Council can approve the addendum without a public hearing.
CONSTRUCTION MANAGEMENT
Six proposals were received on May 29, 2025.
A committee of MUD staff reviewed and scored the proposals.
Procurement tabulated the final scores, incorporating points for cost and local preference.
Inferrera Construction Management, Inc. (ICM) was identified as the most qualified vendor.
The proposed fee schedule is estimated at $728,760.
An Intent to Award letter has been issued to ICM.
DESIGN CHANGES FROM ORIGINAL CONTRACT
Added connection and control facilities from the Woodbridge Irrigation District’s Pixley Pipeline.
Included new interconnections between recharge ponds to enhance operational flexibility.
Enhanced the functionality of the visitor center to create a more park-like atmosphere.
The visitor center will feature project information and serve as an educational destination for students and the public.
CONTRACT CHANGE ORDER
CONTRACT CHANGE ORDER… continued
CONTRACT CHANGE ORDER… continued
No.
Description
Total Cost
1 Cost Expended to develop electrical scope expansion Pixley pipeline and Landscape Scope $148,000.00
2 Pixley Pipeline
$1,332,000.00
3 Additional Dry Wells
$180,000.00
4 Pond Equalization Crossings
$230,000.00
5 Additional Fencing Cost
$225,000.00
6 Modifications to RW line: Added ARV & Vaults
$160,000.00
7 Increase in Electrical Scope
$1,921,000.00
8 Additional Increase in Engineering cost due to increased scope $363,000.00
9 SCADA Costs (Budget)
$50,000.00
10 Credits from Original Contract
$(943,390.00)
11 Cost for Bonds & Insurance & Fee
$239,955.00
Total
$3,914,565.00
CONTRACT CHANGE ORDER… continued
Original Contract
$ 11,438,248.00
Project functionality Expansion
$ 3,914,565.00
Visitor Center & Landscape
$ 1,800,000.00
New Contract Amount $ 17,152,813.00
RECOMMENDATION
Recommend the following to City Council:
Approve the addendum to the 2005 DWSP EIR
Awarding a contract to ICM as the construction manager
Approve a contract change order to Gateway Pacific