Stormwater charge

If you’re a property owner in Mississauga, a stormwater charge appears on your Region of Peel water bill. The Region bills for the charge on behalf of the City. The money collected from this charge is used exclusively to meet the increasing demand and investment for stormwater management, including planning and operations, new capital construction and improvements.

What you see on your water bill

Your annual stormwater charge is divided into a daily rate. Each bill will show the stormwater charge for the number of days that have passed since your last bill, so it may vary from bill to bill.

How the charge is calculated

Charges are calculated based on the amount of hard surface on your property. A stormwater assessment is updated based on the most recent aerial imagery.

Billing units and the annual rate

A billing unit represents the average hard surface area on a single detached residential property. To calculate the charge, the number of billing units is multiplied by the annual rate per unit.

The annual rate is reviewed and approved by Council every year as part of the City’s annual business plan and budget process.

Learn more about the Stormwater Budget.

Residential homes include single detached, semi-detached, freehold townhomes and row houses.

Each property falls into one of five tiers based on the rooftop area, which is used as a predictor of the total hard surface area on the residential property.

Estimated annual fees proposed for 2021

Size tier Property type Rooftop area in square meters 2021 Estimated fees per year 2022 Estimated fees per year 2022 Increase 
Smallest Freehold townhomes and row houses 26.7 to 99 $55.20 $56.70 $1.50
Small Semi-detached homes, linked homes, small single detached homes 99.1 to 151 $77.28 $79.38 $2.10
Medium Medium single detached homes 151.1 to 194 $110.40 $113.40 $3
Large Large single detached homes 194.1 to 242 $132.48 $136.08 $3.60
Largest Very large single detached homes 242.1 and above $187.68 $192.78 $5.10

Why rooftop area is used to calculate hard surface

The City completed an extensive study measuring all the hard surfaces on a sample of residential properties: rooftops, driveways, patios, and any other hard surfaces.

The City found that rooftop area is a reliable predictor of the total hard surface area on a residential property even though driveways and other hard surface areas may vary in size from home to home.

Stormwater charge subsidy

Low-income seniors and persons with disabilities may be eligible for a subsidy to help pay their stormwater charge.

If you qualify for tax assistance for residents, you’ll automatically qualify for a stormwater charge subsidy.

For residential buildings with multiple units, such as apartment buildings or condominiums, or commercial or industrial buildings, the stormwater charge is calculated based on the hard surface area of the entire area.

The total hard surface is divided by a single billing unit (267 square metres) and then multiplied by the current stormwater rate.


Buildings owned and operated by a condominium corporation will receive one assessment. The condominium board or the property manager will determine how the charge is divided among all of the individual unit owners. The board or the property owner will be responsible for the administration and collection of payments.

Stormwater credit for non-residential and multi-residential properties

Non-residential and multi-residential properties that have implemented stormwater management best practices can apply for a credit from the City.

Estimate your charge

You can use the stormwater charge estimator to see what the daily and annual charge may be for your property. The estimator also shows an aerial image of the area used to estimate your charge.

Estimate stormwater charge

Report an error in your assessment

If you feel that the stormwater charge assessment on your property is incorrect, you can request a review of your stormwater assessment.


For more information, please email or call 311 (905-615-4311 outside City limits).