Storm Sewer

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Residents enjoy healthy local waterways and flood prevention thanks to the City's Storm Sewer System. 

The storm sewer system moves rainfall and drainage away from streets, homes, and businesses through ditches and underground pipes to local rivers and streams and is part of the Surface Water Management (SWM) Program.  This system is separate from the City's Sanitary Sewer System.

The system is comprised of 250 miles of underground pipeline and 7,800 curbside storm drains.  The system also includes other features, such as water quality facilities, manholes, and outfalls.  The Public Works Department manages, inspects, and cleans the system on a citywide schedule. 
image of Jackson Bottom Wetland

Preventative measures established to protect surface water include grading and erosion control plan review and site measures. These measures are required to minimize sediment runoff from active construction sites with 500 square feet or more of soil disturbance. The City has adopted standards which require the placement of preventative measures throughout these active sites in order to meet compliance with state (DEQ) and federal (EPA) requirements. By minimizing runoff from active or inactive construction sites the City is ensuring that sediment is not displaced throughout the storm system and transported to our local streams and wetlands.


The storm sewer system was designed to aid in moving surface water off of public and private streets and property in order to prevent localized flooding from rainfall events. As mentioned above, the City has 250 miles of storm pipe, ditches, creeks and water quality facilities that are included in this system and must be maintained. The City manages and ensures that each conveyance component is functioning correctly through quarterly inspections of each public water quality facility and 25% of all private facilities annually. City crews also inspect and rate the condition of each public storm sewer pipe with specialized camera inspection equipment at least once every 8-years and will clean these same pipes once every four years. Additionally, crews actively remove debris from culverts, ditches, and streams to ensure the system is able to flow and function properly. Performing routine and scheduled maintenance throughout the Storm Sewer System is essential in order to prioritize line repairs and/or replacements.

Read more about our Surface Water Management Facilities Repair Projects


To help treat surface water before it enters our streams and rivers, the City has adopted standards which require the construction of water quality facilities. These facilities are designed to assist in the removal of pollutants from the surface water prior to entering the tributaries feeding our rivers. They are also required when additional amounts of new impervious surface (which aid in surface water run-off) are added due to new development. City inspectors routinely visit each public water quality facility quarterly throughout the City to ensure that each facility is able to function properly, remove invasive species and ensure that native plants survive.

Maintenance Responsibility

The City's storm sewer system consists of 250 miles of storm sewer public main lines distributed throughout the City that are actively being reviewed for repairs and cleaning to ensure functionality. Laterals extending from homes and private businesses connecting to the public storm sewer main lines are considered private utilities and are the homeowners responsibility to maintain.


Any storm lateral that crosses over more than one property line and has more than one connection to it is considered a public line that the City is required to maintain. These unique combinations do occur throughout the City and also requires the City to have an easement recorded for access with each affected property. These easements can be found on residential and commercial private properties, however they have been established to allow the City to have access to the public storm sewer lines for maintenance purposes. If you have an easement on your private property, please understand that at some point in time the City might need access to this utility to possibly inspect, clean or replace the underground storm line.

Utility Fee Information

For more information on the charges and fees associated with surface water management (storm sewers), visit our Utility Billing Fee Information page

Cost of Service

Read the Service Delivery Study for Sanitary Sewer and Surface Water Management (Storm Sewer) Systems, which summarizes the analyses, conclusions, and recommendations necessary to fund and maintain safe, reliable, and high quality sewer and surface water management services for Hillsboro customers.

Report an Issue

Report a sewer issue through our online form.