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Stormwater Multi-residential Charge


Mississauga has a growing number of multi-residential buildings. As the size, shape and style of each building is unique, every property will have a different amount of hard surface area such as roof tops and parking lots. This is why each property is assessed individually and the charge, calculated based on the hard surface area, is applied to the whole property.

How Will it Work?

Each multi-residential property in the city will receive a stormwater assessment. The calculation for the stormwater charge is the same for all properties. Charges are calculated by multiplying the stormwater rate by the number of stormwater billing units assessed for that property. The stormwater rate is subject to approval by Council and will be reviewed each year as part of the City’s annual business planning and budget process.

The number of billing units is calculated by dividing the total hard surface area (m2) individually measured on each multi-residential property by the area of a single stormwater billing unit. The area of a single billing unit is 267m2 representing the average hard surface area found on a single detached residential property in Mississauga.

Learn more about how charges are calculated.

Billing of the stormwater charge will begin in 2016. The total annual stormwater charge for a property will be divided into a daily rate and added to the most appropriate Region of Peel water bill associated with each property. Each bill will show the stormwater charge for the number of days that have passed since the last bill. Bills will be sent on the same schedule as they are today. As the number of days billed may vary from bill to bill, and charges are accrued daily, you may see varying stormwater charge amounts on each bill.

Estimate your Charge

The estimator tool gives you an estimate of your property's annual stormwater charge and an estimated daily charge based on your address.

Billing Information for Condominiums

A parcel of land jointly owned and operated by the members of a condominium corporation will receive one assessment on a water bill addressed to the corporation. The condominium corporation board, its property manager or other designate will determine the division of the charge amongst owners (e.g. according to your condominium declaration) and administer its collection and payment.

In rare cases, residential units were established as separate properties from the common elements, when the condominium was set up. In these cases, each unit will be assessed and receive a stormwater charge on a water bill addressed to the property owner. Property that is jointly owned such as private roads and clubhouses will be assessed separately and will receive a separate stormwater charge on a water bill addressed to the corporation.

Wherever possible, the stormwater charge will be added to an existing water bill for the corporation. A new bill will be created for property owners or corporations without an existing water bill.

Stormwater Credit Program For Multi-residential Properties

There are many stormwater management technologies and best management practices that can be used on a multi-residential property to reduce the impact of stormwater runoff from the property. The City will provide credits for multi-residential properties that have best management practices in place. Credits will be awarded in these four categories: peak flow reduction; runoff volume reduction; water quality treatment; and pollution prevention. Credits will be valid for up to five years and eligible for renewal, provided terms and conditions are met. The City’s Stormwater Credit Program Policy outlines the program framework.

For more information or to attend an information session about the credit program please send us an email at
Next steps to apply  →

Report an Error in your Stormwater Assessment

Assessments are created by staff using technical mapping software along with aerial images to digitally measure hard surface areas. Property owners may report an error in their stormwater assessment, such as mis-measurement of hard surface area or the categorization of a single residential home as non-residential. Staff may review and adjust existing digital measurements. Site visits are not part of the review process. Assessments will not be reviewed based on the ratio of hard surface area to total property area, soil types or individual stormwater measures like disconnected downspouts.

You may request a review of your assessment online or use the request for review form.

Please note, the most current assessment for the property will apply and a review may not result in a lower charge.

Learn More

For more information call 3-1-1 or 905-615-4311 outside city limits. Monday to Friday from 7 a.m. to 7 p.m.