The City of Boise sewer is the system of over 1000 miles of pipes that transport used water from homes and businesses to the city’s water renewal facilities. The Public Works Department designs, maintains and repairs Boise’s sewer system, ensuring reliability to keep our city clean and safe.


Sewer Fees

Residential and commercial buildings must connect to the sewer system. Fees paid to the city for connection to the sewer system generally consist of two major components, connection fees and assessment fees. These fees purchase capacity in the city’s water renewal and sewer systems and recover the cost of public water renewal infrastructure. The cost to complete the physical connection from the building to the edge of the right of way is not included in this connection fee.

Connection Fees

All new and expanding water renewal customers are required to pay a connection fee to connect their property to the city’s water renewal system. Connection fees are usually a one-time payment comprised of two parts: trunk fees and treatment fees. Your connection fee reserves space in the city’s water renewal system for cleaning used water.

  • Trunk fee – Pays for the pipelines that carry used water from the property to the city’s water renewal facilities.
  • Treatment fee – Pays for capacity at the city’s water renewal facilities based on the amount of water used by the property and the cost to clean that water.

For questions about connection fees, please contact sewer rating or call 208-608-7150.

Assessment Fees

Assessment fees are a one-time payment to the city for construction of a sewer pipe in the roadway plus the service line to the edge of the right-of-way. Assessment fees are usually only required for properties that have never been developed or have never connected to the sewer system. This fee is based on the average cost to construct pipes and manholes, restore pavement and process permits, designs, surveys and inspections of the project.

Not all properties will need to pay an assessment fee because they may already have an existing sewer line built up to the right of way ready for connection. If you are building on an existing lot which is being split, building on a previously undeveloped lot or connecting an existing building to sanitary sewer, the assessment component of the connection fees will likely be required.

Notice of Connection Fee Adjustments

The City of Boise Water Renewal utility is updating rates and fees to reflect the current cost of sewer and water renewal treatment infrastructure. Connection fee adjustments begin October 1, 2024, with phasing to full cost of service over the next three years and regular updates thereafter. These connection fee changes, outlined below, will affect development costs for residential dwelling units and commercial facilities that are new or are increasing water usage.

watch Recorded Presentation

Upcoming Engagement Opportunities

  • Attend the public hearing to hear about sewer fee increases and make public comments on July 16 at 6:00 p.m.

If you are building on undeveloped land, please contact sewer rating or call (208) 608-7150 for more information.

Residential and Commercial Connection Fee Changes

Residential connection fees apply to new or expanding single family homes, multi-family units and accessory dwelling units. Commercial connection fees apply to new commercial development or expansion of existing commercial facilities. Changes to residential and commercial connection fees will go into effect on October 1, 2024, the first day of fiscal year 2025 (FY2025).

Changes to connection fees beginning October 1, 2024:

  • Residential and commercial connection fees will be adjusted to reflect the current cost of service. Connection fees were last updated in 2014 and require updating to reflect the current cost of sewer and water renewal treatment infrastructure.
  • Residential connection fees will be based on square footage of the home, replacing the previous categories based on dwelling types. Fees based on square footage will be more aligned to the amount of water that is used in each home compared to the previous categories.
  • Residential trunk connection fees will be set by the number of units per acre for all dwelling types. Previously, single-family trunk fees were assessed per-unit and multi-family trunk fees were set by number of units per acre.

View the proposed FEE changes here

Sewer Extensions

Sanitary sewers are constructed in conjunction with Ada County Highway District (ACHD) projects, based on the needs of the property owner, or if there is evidence of significant septic system problems. City approval is based on the number of residents signing a petition agreeing to pay fees and connect, the cost and length of the sewer extension and is subject to funds being available. Contact Sewer Extensions or call (208) 608-7150 for more information.


Contact Information


For information on design requirements, please call (208) 608-7150.

Connection Fees or Extensions

For information on connection fees and / or extensions, please call (208) 608-7150.

Sewer Odor Complaints

For complaints related to sewer odor, line back-ups or construction related issues, please report online or call (208) 608-7200.

Report Online

Report Issue

For sewer back-ups, line breaks or construction issues, call (208) 608-7200.

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