Sanitary Sewer and Stormwater Rates and Charges

Rates and Charges

Residential and commercial customers have different rates for sanitary sewer and stormwater but are charged the same rate for Portland Harbor. Commercial customers also receive additional charges that residential customers do not.

On July 1, 2022, sanitary sewer and stormwater rates increased for residential customers. The typical single-family sewer and stormwater monthly bill increased 3.14%, from $80.30 to $82.82. Sanitary sewer rates also increased for commercial users.

Residential Users

• Sanitary Sewer: $12.35 per 100 cubic feet of water use
• Stormwater*: $13.00 per 1,000 square feet of impervious area

Commercial Users

• Sanitary Sewer: $12.172 per 100 cubic feet of water use
• Stormwater*: $13.46 per 1,000 square feet of impervious area
• Special Meter Charge: $40
• Clean Water to Stormwater Drainage System: $1.20 per 100 cubic feet

Portland Harbor

• $0.12 per 100 cubic feet of water use
• $0.36 per 1,000 square feet of impervious area

*Stormwater rates consist of two separate charges, off-site and on-site. See the Stormwater Charges section on this page for more details

View the rate ordinance for more information on charges and rates. ENB-4.20 – Sewer and Drainage Rates and Charges, Exhibit A

Annual Rate Study

Environmental Services goes through a financial planning process every year to determine the sanitary sewer and stormwater rates required to fund operations for the upcoming fiscal year. The final step in the financial planning process is the Sewer and Stormwater System Rate Study.

View or download the complete Rate Study:

Calculating Sewer Volume

The City of Portland calculates residential single-family or multi-family sewer volume using actual water flow, class average flow, or winter average flow. The City calculates non-residential volume using actual water consumption. For residential customers, the City bills customers the winter average consumption or actual water consumption during those billing periods, whichever is less.

• Actual Water Consumption: The water consumption measured through your water meter. 
• Class Average: The average water consumption for a specific account class, such as residential single-family or residential multi-family. Class average is used when there is no water use history or when a winter average is unavailable. 
• Winter Average: The average water consumption between December 1 and April 30 for monthly billing cycles, or January 1 and April 30 for bi-monthly billing cycles. For residential accounts billed quarterly, the winter average is calculated on water readings taken between February 1 and April 30. Winter average volume is applied to residential accounts during billing periods outside the winter average period. Most water used indoors during this time of year enters the sewer system. Since much of the water used in warmer months waters lawns or gardens and doesn’t enter the sewer system, the winter average is the most efficient way of determining sewer volume. 

How to Calculate Your Winter Average

Divide the total winter average review period consumption by the total actual days of service in your review period (days between the billed meter readings in the winter average review period) and multiply by:

• Quarterly accounts: 90
• Bi-monthly accounts: 60
• Monthly and budget billing accounts: 30

Winter Average Example

Winter consumption ÷ days between readings x 90 days = winter average

12ccf ÷ 94 days x 90 days = 11ccf

Minimum Use Billing

Accounts billed 0 to 2 ccf during the winter average billing period will be assigned the following winter average based on billing frequency:

• Monthly billed account: Metered winter average water use of 0 ccf will be assigned 2 ccf minimum use average per billing period.
• Bi-monthly billed accounts: Metered winter average water use of 0 to 1 ccf will be assigned 5 ccf minimum use average per billing period.
• Quarterly billed accounts: Metered winter average water use of 0 to 2 ccf will be assigned 7 ccf minimum use average per billing period. Multi-family quarterly billed accounts will be assigned 5 ccf minimum use average per dwelling unit billing period.

Stormwater Charges

Stormwater charges pay the cost of managing both the quantity and quality of stormwater runoff from all properties within the City. Private properties with impervious surfaces within the City pay a stormwater fee. Stormwater charges include:

• On-site stormwater management charge: the cost to collect, convey and dispose of stormwater runoff from private property.
• Off-site stormwater management charge: the cost to collect, convey and dispose of stormwater runoff from public property like streets and sidewalks.

Stormwater Charges in Drainage Districts

Utility customers in the Multnomah County Drainage District only pay off-site stormwater management charges. Drainage districts help protect property from flooding by operating and maintaining stormwater and flood management systems for more than 1,200 acres of land along the Columbia Slough and the lower Columbia River. These systems include levees, pump stations, ditches, sloughs, streams, and culverts.

For more information about drainage districts, visit the Multnomah County Drainage District website.

Portland Harbor Superfund Charge

The Portland Harbor Superfund charge goes towards the clean-up of Portland Harbor.

Where Does Your Sanitary Sewer and Stormwater Rate Money Go?

Rates and charges are allocated towards various services that protect public health and our environment. For more information, visit the where your rate money goes page.

Water Bureau Rates and Charges

The Water Bureau is responsible for delivering water service to Portland residents and businesses. To learn more about the water portion of your bill, visit the water rates and charges page.