Public Sanitary Sewer System

Sewer lid

The City of San Gabriel owns and operates over 72 miles of sewer and 1,300 manholes. The main sewer system is located below public streets and, in some cases, within easements that run along the back of private properties. Untreated wastewater is collected in the system and delivered to the trunk line system of the County Sanitation Districts (CSD). The CSD then treats and discharges the wastewater. The City's sewer collection system is operated under a state-issued permit and must comply with Federal and State water quality laws.

City of San Gabriel Sewer System GIS Map (2023)

Homeowners are responsible for the sewer line that runs from their house to the point where it connects with the main line.

If you have general questions about the City’s sewer system, please call the Public Works Engineering Division at (626) 308-2825.

Public observation is the most common way that the City is notified of blockages and spills. 

If you are reporting sewer spills and/or backups please call: 

Public Works Department (626) 308-2825 (Monday - Friday 8am - 5pm)

Police Dispatch (626) 308-2828 (After Business Hours)

Chris Diaz, Wastewater Lead (626) 308-2825 Ex. 6015  

Sewer Master Plan & Sanitary Sewer Management Plan (SSMP)


The City prepared a comprehensive study of the public sewer system in 2009. The study included an inventory of the pipes and manholes that make up the system, an evaluation of the sewer flows and capacity of the system, and an assessment of the condition of the system. Using the information collected, the study identified areas of the system that require improvement to increase capacity and to correct structural deficiencies. The study estimates that over $30 million in repairs are needed to the system. In addition, ongoing routine maintenance needs to be increased to ensure uninterrupted service and to protect public health and the environment from preventable sewer overflows. Staff are working on an updated sewer master plan.


With the approval of the first ever Sewer User Fee effective FY2014-15, the Public Works Department is now able to begin addressing these important capital improvement needs.

Download a copy of the current City of San Gabriel Sewer Master Plan below:

2009 Sewer Master Plan



The State Water Resources Control Board (SWRCB) adopted the Statewide General Waste Discharge Requirement (WDR) on May 2, 2006. The WDR established requirements for operating, maintaining and managing wastewater collection systems and applies to all public collection system agencies in California that own or operate collection systems. The WDR also requires each permitted agency to prepare a Sanitary Sewer Management Plan (SSMP) to document how the agency manages its wastewater collection system.

The SSMP was formally adopted by the San Gabriel City Council on October 20, 2009. The SSMP is due for a major update in 2014. The June 2014 interim updated version of the SSMP is available here:

City of San Gabriel 2018 SSMP - Updated