All charges will be based on the square footage of actual impervious surface (hard area) on a **Benefitted Property**, which will be determined by the use of digitized mapping data. "Impervious surface" means any area that does not readily absorb water, such as buildings, decks, patios, driveways, and other covered areas.

**A.** The formula for calculating the Annual Drainage Utility Charge of a Benefitted Property involves the multiplication of the following two factors:

**a.** The Square Footage of the actual Impervious Surface on your property, and

**b.** The Rate (per square foot) applicable to your type of property.

**B.** All Benefitted Properties are classified by City Drainage Utility Ordinance into two categories:

**a. Residential**, or

**b.** **Non-Residential**

**C. **An applicable **Rate **(per sq. ft. of Impervious Surface) is then applied to the square footage of your classified property, depending on the following:

**a.** If your Benefitted Property is defined as **Residential **-- the applicable rate will be determined by the type of drainage system serving your property:

i. If your property is served by a Curb & Gutter Drainage System – the Rate will be: $0.032 per sq. ft of Impervious Surface

ii. If your property is served by an Open Ditch Drainage System – the rate will be: $0.026 per sq. ft. of Impervious Surface.

**b.** If your Benefitted Property is defined as **Non-Residential**—the rate applicable to your property will be $0.032 per sq. ft., regardless of the type of drainage system serving your property.

**c.** For billing purposes, your annual Drainage Utility Charge will then be divided by the number of billing cycles pertinent to your property -- either monthly (divided by 12) if your Drainage Utility Charge will be billed on your water bill, or quarterly (divided by 4), if you are not billed for water by the City .

**D.** ILLUSTRATED EXAMPLES:

**a.** Type of Property:** Residential, Single Family**

Drainage System serving the Property: **Curb & Gutter**

Applicable Rate per sq. ft. of Impervious Surface: **$0.032**

Total area of Impervious Surface: 1,500 sq. ft

Total Annual Drainage Utility Charge = (1,500 sq. ft. x $0.032) = $48.00

Portion of Drainage Utility Charge billed Monthly = ($48.00 / 12) = $4.00

**b. **Type of Property: **Residential, Single Family**

Drainage System serving the Property: **Open Ditch**

Applicable Rate per sq. ft. of Impervious Surface: **$0.026**

Total area of Impervious Surface: 1,500 Sq. Ft

Total Annual Drainage Utility Charge = (1,500 sq. ft. x $0.026) = $39.00

Portion of Drainage Utility Charge billed Monthly = ($39.00 / 12) = $3.25

**c.** Type of Property: **Non-Residential**

Drainage System serving the Property: **N/A**

Applicable Rate per sq. ft. of Impervious Surface: **$0.032**

Total area of Impervious Surface: 15,000 sq. ft

Total **Annual** Drainage Utility Charge = (15,000 sq. ft. x $0.032) = $480.00

Portion of Drainage Utility Charge billed Monthly = ($480.00 / 12) = $40.00