Non-Residential Stormwater Charge

Non-residential properties are those that cannot be classified as residential or condominium, and typically include commercial and industrial uses, as well as residential properties with more than four dwelling units. Mixed-use properties, such as properties with both residential and commercial use, are also considered non-residential for stormwater billing purposes.

Examples of non-residential properties

  • Commercial properties
  • Industrial properties
  • Parking lots
  • Mixed-use properties
  • Vacant lots
  • Row homes
  • Condominium

Stormwater Charge Explained

Non-residential stormwater charges are based on a combination of the Gross Area and Impervious Area of the property. Gross Area is the total area within the legal bounds of the property, less any public right of ways. Impervious Area is any area where the surface coverage restricts water absorption, such as roofs or pavement. Each area type incurs a charge (“Gross Area charge” and “Impervious Area charge”), billed in 500 square foot units; the property’s monthly stormwater charge is the sum of the Gross Area charge and the Impervious Area charge.

For properties with multiple water accounts, the monthly stormwater charge is divided equally among all accounts. Each water account on a property is also billed a Billing & Collection charge as part of the monthly stormwater charge.

See Example Property section below for a detailed stormwater charge calculation example.

How we measure area

Gross Area and Impervious Area measurements are determined using mapping software, aerial images of the property and digital property records.

Gross Area is the total area of the property
Impervious Area includes parking lots, roofs, and roads

Credits

Non-Residential properties that manage stormwater on-site may be eligible for stormwater credits, which can reduce the property’s monthly stormwater charge.

Learn more about Stormwater Credits →

Minimum Charge

Non-Residential properties whose combined gross and impervious area charges fall below a certain amount are subject to a minimum monthly stormwater charge. A property’s monthly stormwater charge cannot be reduced below the minimum charge. The current minimum charge is $16.33 per month.

Example Property

We’ll use the characteristics of an example property to walk through the calculations that make up the property’s stormwater charge.

459 Example Street

70,142 sqft

Gross Area

1,000 sqft

Gross Area Credits

36,736 sqft

Impervious Area

1,000 sqft

Impervious Area Credits

Step 1


Gross Area

Start with the property’s total gross area and factor in any credits that have been applied in order to determine the gross area charge.

Process

Gross Area Charge

$100.08

Calculate Gross Area Charge

70,142 sqft Gross Area

– 1000 sqft Gross Area Credits


69,142 sqft Modified Gross Area

500 sqft Round Up to Next 500


69,500 sqft Billable Gross Area

500 sqft Divide by 500 sqft


139 Billing Units

$0.72 Unit Charge


$100.08 Final Gross Area Charge

Step 2


Impervious Area

Use the property’s impervious area square footage and apply any applicable credits to determine the impervious area charge.

Process

Impervious Area Charge

$389.52

Calculate Impervious Area Charge

36,736 sqft Impervious Area

– 1000 sqft Impervious Area Credits


35,736 sqft Modified Impervious Area

500 sqft Round Up to Next 500


36,000 sqft Billable Impervious Area

500 sqft Divide by 500 sqft


72 Billing Units

$5.41 Unit Charge


$389.52 Final Impervious Area Charge

Step 3


Total Charge

Start with the property’s total gross area and factor in any credits that have been applied in order to determine the gross area charge.

Process

Impervious Area Charge

$491.90

Calculate Total Stormwater Charge

$100.08 Final Gross Area Charge

+ 389.52 Final Impervious Area Charge


$489.60 Gross + Impervious Charge

1 Divide by Accounts


$489.60 Subtotal

+ $2.30 Billing & Collections Charge


$491.90 Total Charge

Look up your stormwater charge

Search then click the address found for details.

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