City Council Agenda Report
September 1, 2026
TO: Honorable City Council
FROM: Jesus M. Gomez, City Manager
BY: Albert Mendoza, P.E., Director of Public Services/City Engineer Jacqueline Koontz, P.E., Senior Civil Engineer
Fabian Lucarelli, EIT, Assistant Engineer
Patricia Santana, Assistant Engineer
SUBJECT: ACCEPTANCE OF THE 2025 SEWER MASTER PLAN
Background:
The City’s sewer system serves the area consisting of all lands within its corporate boundaries (9.35 square miles) and provides sewer collection service to a population of approximately 98,100. The existing sewer collection system is comprised of approximately 163 miles (860,640 linear feet) of mostly gravity sewers of varying diameter; 2,480 sewer manholes; 26 sewer siphons; and three sewage lift stations.
The previous 2014 Sanitary Sewer Master Plan (SMP) was completed and accepted by City Council in 2015. SMP’s are intended to be used to provide guidance and recommendations for improvements to system operations and maintenance; timely system improvements to ensure uninterrupted and compliant services; identify and recommend future system capital improvements; and account for future private development and associated system demands.
Due to the length of time since the 2014 SMP was completed, and the condition of the existing data, staff determined it was best to prepare a new 2025 SMP instead of performing an update.
Public Services Utilities staff sought qualified and experienced engineering consulting firms to prepare the 2025 SMP.
In April 2024, the City awarded a professional services agreement to Psomas to prepare the 2025 SMP. The scope of work included but was not limited to:
Task 1 - Project Management and Meetings
Task 2 - Review Existing Plans, Policies and Procedures
City Council September 1, 2026
Acceptance of the 2025 Sewer Master Plan Page No. 2
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Task 3 - GAP Analysis, Plan and Standards and Procedures Update or Development Task 4 - Flow Monitoring/Develop and Calibrate Sewer System Hydraulic Model Task 5 - Review Overflow Emergency Response Plan
Task 6 - Draft and Final Updated SMP
These SMP tasks were to achieve the following goals:
•Collect and review of all data significant to and thorough completion of the SMP and sewer hydraulic model. Coordination with relevant agencies such as Los Angeles County Department of Public Works and Los Angeles County Sanitation District to acquire all data
•Submit a Technical Memorandum to identify and provide rationale for flow monitoring locations throughout the City
•Develop key system data to be used in the development of Sewer Impact Fees •Provide a preliminary and final 2025 SMP that identifies deficiencies in the system and includes a prioritized 10-year plan (2025 – 2030/35) of all recommended alternatives for improvement of sewer facilities, cost estimates, and estimated project durations •Develop a new sewer hydraulic model to identify peak flow factors and flow patterns, assess capacity constraints, and potential limitations for future development •Conduct site investigations, as needed, to confirm information from existing reports and records
Once completed, staff reviewed and determined that the Plan provides a comprehensive evaluation of the City’s sewer collection system, identifies capital improvements necessary to maintain reliable service and mitigate or prevent sewer system overflows, and establishes a framework for future planning.
Additionally, the system mapping data generated by this Plan will be uploaded and utilized for the citywide Geographic Information System (GIS) system, allowing for timely and accurate access to information which will facilitate and coordinate both future capital improvement projects as well as private developments.
Fiscal Impact:
N/A
Citizens Advised:
N/A
City Council September 1, 2026
Acceptance of the 2025 Sewer Master Plan Page No. 3
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Strategic Plan 2023 Implementation:
The recommended action will further the City’s Strategic Plan Goal 2: Work in Partnership with Our Community to Achieve Safe and Livable Neighborhoods, Objective 1, Reinvest in existing and aging infrastructure.
Recommended Action:
Staff recommend City Council accept the 2025 Sewer Master Plan prepared by Psomas as complete.
Attachments:
Link to the Plan: https://link.norwalkca.gov/1zu