Frequently Asked Questions

  1. What is storm water?
    Storm water is the water produced during precipitation events. In Memphis, storm water is typically produced during rain events but is also produced when snow and ice melt.

  2. Why is storm water such a problem?
    As rain falls on agricultural and undeveloped areas, it is either absorbed into the ground or it slowly runs off into streams, rivers, and other bodies of water. However, rooftops and paved areas prevent water from being absorbed and result in a faster runoff. These factors lead to flooding problems and other water quality and quantity issues.

  3. What is the City’s responsibility for storm water?
    In 1990, the United States Environmental Protection Agency issued new storm water regulations that require communities the size of Memphis to control water pollution caused by storm water runoff. The City is required to implement municipal storm water programs that will reduce storm water pollutant discharges to the “maximum extent practical.” The Tennessee Department of Environment and Conservation (TDEC), in accordance with the Clean Water Act, issued the City a NPDES (National Pollutant Discharge Elimination System) Permit to discharge storm water. In accordance with this permit, typically referred to as the Storm Water Permit, the City is required to implement measures to minimize the potential for contamination of storm water. In addition to the Storm Water Permit requirements, the City is responsible for conveying storm water within the City through drainage ways into natural waterways.

  4. What is the Storm water Enterprise Fund?
    Aging infrastructure, increased regulatory requirements, and flooding problems prompted the City to develop a Storm Water Enterprise Fund, established by Ordinance 5135 and effective as of May 2006. This fee provides funds to implement the Storm Water Permit, construct and maintain the storm water drainage system, and implement measures for flood control and protection while reducing the strain placed on the City’s General Fund. A storm water enterprise fund is the most fair and equitable funding source because it utilizes impervious area (see question #5) as a basis for a user charge. The current MLGW billing system is used to collect this fee.

  5. What is impervious area?
    Impervious area is a surface that does not allow water to migrate through it. Some examples of impervious area include areas such as concrete, asphalt, and rooftops. Highly compacted dirt and gravel can be considered impervious area.

  6. What is a SFU?
    A SFU (single family unit) is the amount of impervious area on the average single family home in Memphis. One SFU is equal to 3,147 square feet of impervious area. When the fee was implemented, the fee determination relied on the most recent digital data and aerial images from the City of Memphis.

  7. How is the storm water fee calculated?
    The storm water fee is based on the amount of impervious area (see question #5) a property has. The number of SFUs (see question #6) on a property is used to calculate the storm water fee.

  8. How is my residential storm water fee calculated?
    The storm water fee is calculated based on the number of SFUs assessed to the property. Residential properties have an SFU amount assigned to the type of residential property and that is multiplied by an SFU rate. As of July 2019, the current SFU rate is $5.25. Charges are typically the same every month and monthly billing is considered to be on a 30 day cycle.

    All single family homes are classified as small, average, or large homes with an associated SFU as shown below:

    Small 1,841 square feet or less = 0.58 SFU Monthly Fee $3.05
    Average 1,842-4,794 square feet = 1 SFU Monthly Fee $5.25
    Large 4,794 square feet or more = 1.52 SFU Monthly Fee $7.98

    Non-single family homes and associated SFUs are as shown below:

    Multifamily homes = 0.41 SFU Monthly Fee $2.15
    Town homes/Condominiums= 0.57 SFU Monthly Fee $2.99
    Mobile homes= 0.77 SFU Monthly Fee $4.04
    High-Rise Apartments= 0.13 SFU Monthly Fee $0.68

  9. Are their elderly/disabled or any other discounts for residential storm water properties?
    No. There are no credits available for residential properties.

  10. How is a nonresidential storm water fee calculated?
    Types of properties included in this category are developed commercial, industrial, governmental, institutional, or agricultural properties. The storm water fee is calculated based on the number of SFUs assessed to the property (and remember, an SFU is equivalent to 3,147 square feet of impervious area). The number of SFUs is multiplied by a SFU rate. As of July 2019, the current SFU rate is $5.25. As an example, the number of SFUs for a commercial property with 10,000 square feet of impervious area would be determined by dividing 10,000 square feet by 3,147. In this example, the number of SFUs would be 3.2 and when that is multiplied by the current SFU rate, $5.25, the 30 day charge would be $14.85.

  11. Are storm water fee credits available for nonresidential properties
    A credit adjustment policy is in place to provide incentives for businesses to install storm water management devices. Nonresidential property owners may apply for a credit toward their storm water fee by implementing measures that either reduce the volume or improve the quality of storm water discharged from their site. The specifications for these measures and the application procedure are provided in the City’s Storm Water Enterprise Fund Adjustment and Credit Manual.

  12. The storm water charge on my MLGW bill is higher/lower than months before. Why is that?
    If your usage (SFU) has not changed on your bill, and other services (like the mosquito fee) are higher, then your bill may have been pro-rated. MLGW strives to bill within a 30 day cycle but sometimes the bill is generated earlier or later than 30 days. Days less than 25 or greater than 35 will trigger the billing system to pro-rate with a calculation of base rate divided by 30 and multiplied by the days of service (example below).

    On the section of your bill detailing the storm water fee, you will see a ‘multiplier.’ If you divide that multiplier by 30, you will get your daily charge. $5.25 / 30= 0.175

    IF YOU ARE A RESIDENTIAL PROPERTY: Look at the bill date on your current bill and your last bill (NOT the days of service or the meter read date, which is used for MLGW fees). You will need to count the days between the two bills. IF YOU ARE A COMMERCIAL PROPERTY: On the same line as the storm water fee charge, find the days charged and count the number of days between the two dates. FOR BOTH RESIDENTIAL AND COMMERCIAL PROPERTIES: Take the daily fee and multiply it by the days of service (49 in this example). Round it to 2 decimals. 0.175 * 49 = 8.575 (rounded to 2 decimals = 8.57) Multiply that number by the units you are charged for (on the portion of your bill detailing the storm water charges, in this example it is 29.3). This is how MLGW’s system calculates the charge. 8.57 * 29.3 units = $251.10 You should call MLGW if you have more questions about their pro-rating system or the Storm Water Department at 901-636-4349 if you do not believe this explains why your bill is higher or lower than usual.

  13. What do I do if I think my storm water fee is incorrect or if I have additional questions?
    If you believe your storm water fee is incorrect, you can call the storm water office at 901-636-4349 to discuss. Please be prepared to provide us with the last 7 digits of your MLGW account number, your name, your address, and your call back number.


Fees & Billing

The City of Memphis Storm Water Program is required by our NPDES Permit to do many things. To meet the requirements of our permit, the City established the Storm Water Enterprise Fund. You may specifically reference Ordinances 5135, 5157, and 5650. The fee funds the ongoing maintenance and improvement of the storm water drainage system, the detection and monitoring of illicit discharges, construction site inspections, public awareness, the sampling of our waterways, and more.