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Water Quality Fees, Credits & Incentives

3675196894 3b754df6e5Water Quality Fee and
Credits & Incentives

The Credits and Incentives program provides a coordinated and balanced framework of fees, incentives, and credits for the development community and non-residential property owners to encourage increased water quality management.



New Credits & Incentives Applicability Chart


Credits chart


Appeals for Correction, Exemption or Partial Exemption of Water Quality Fees



See the FAQ for the Water Quality Fee at the bottom of the page.   


Map of Impervious Areas: Zoom in to see your parcel's impervious area.  




Credits & Incentives

For information on the Current Credit Program (effective December 1, 2014) see the Credits & Incentive Manual or the Credits & Incentives section on the Resouce:RAIN page.  We are updating this site now so expect regular changes. 



The information below is referencing the credit program that is in effect until December 1, 2015.  



Water Quality Fees and Credits information through December 1st, 2015


Frequently Asked Questions

1. What is the Water Quality Fee?
a) Previously known as the Storm Water Fee, the Water Quality Fee (WQF) is a user fee and not a tax. It is defined in City code Sec. 31-302 as "a fee assessed to users and contributors of flow to the City's stormwater collection, impounding and transportation system."

2. Who is charged the Water Quality Fee?
a) All parcels within the City of Chattanooga containing any impervious surface are billed the WQF. The property owner is responsible to pay the WQF which is charged on the property tax bill.

3. How does Chattanooga define "impervious" surface?
a) According to City Code Section 31-302, "impervious" means not allowing the passage of water through the surface of the ground or ground covering or a substantial reduction in the capacity for water to pass through the surface of the ground or ground covering. The impervious area includes buildings, rooftops, driveways, parking lots, and sidewalks. Graveled surfaces are considered impervious and are billed at the same rate as paved surfaces.

4. Why use impervious surface as a measure to determine billing rates?
a) The impervious area method is used by the majority of storm water utility user fee programs across the United States. The measure of impervious surface is an indicator of water quality on the watershed scale.

5. Why charge the water quality fee?
a) In compliance with the Tennessee Water Quality Control Act of 1977 and in compliance with the provisions of the Federal Clean Water Act of 1972 as amended by the Water Quality Act of 1987, the Tennessee Department of Environment and Conservation (TDEC) requires that the City of Chattanooga implement a storm water management program. It is the intent of the City of Chattanooga that the costs of operation, maintenance, and improvement of the City stormwater system are borne by the users of the system in relation to their contributions of water quality to the system. A storm water user fee is authorized under TCA 68-221-1107.

6. Why is stormwater a problem?
a) The runoff of stormwater in developed areas can carry pollutants such as oil, grease, bacteria, heavy metals, and increased sediment loads to our local creeks and streams. In addition, the temperature and volume of runoff are both increased from developed sites. These pollutants damage the very waters that Chattanooga uses for recreation and drinking water supplies.

7. How was the fee calculated prior to 2009?
a) The previous fee was determined by a property's land use. The rate structure methodology was based on the estimated amount of impervious area for each property and the presumed quality of that runoff based upon its zoning classification. The annual rate for residential properties of one or two units having a lot area of ≤10,000 ft2 was $24 and for >10,000 ft2 it was $36. The rate for all other properties was determined by multiplying the lot area in square feet by the following rates:
• Multi-Family Residential = $0.00576
• Industrial = $0.0072
• Commercial = $0.00816
• Institutional = $0.0048
• Transportation, communication, & utility = $0.00672
• Recreational = $0.00048
• Agricultural = $0.000384
• Vacant = $0.000192

8. How is the fee calculated since 2009?
a) The current Water Quality Fee is based on measured impervious surface. The method determines actual impervious surface from high-quality aerial photography and color infrared imaging. In 2008, the impervious area of a random sampling of 396 single-family and two-family residential properties was measured; the average residential impervious area was determined to be 3,200 ft2. This area is referred to as an Equivalent Residential Unit (ERU) and is the base for all other billing rates. ERUs are only charged as whole integers using conventional arithmetic rounding. One ERU is billed $115.20 per year. All single-family and two-family properties, as well as condominium units, are charged 1 ERU per year. All other properties having impervious area are billed for the actual amount of impervious area measured on their site.

Examples of Water Quality Fee charges
• Single-family residential property having 2,000 ft2 of impervious area is billed for 1 ERU/yr.
• Two-family residential property having 6,000 ft2 of impervious area is billed for 1 ERU/yr.
• A billing parcel considered a condominium having 10,000 ft2 of impervious area is billed for 1 ERU/yr.
• A multi-family residential complex (i.e., apartments) having 150,000 ft2 of impervious area:
o 150,000 ft2 / 3,200 ft2 = 46.875 ERUs (rounds up to 47 ERUs)
o 47 ERUs x $115.20 = $5,414.40 per year
• A commercial property (e.g., gas station or restaurant) having 36,500 ft2 of impervious area:
o 36,500 ft2 / 3,200 ft2 = 11.406 ERUs (rounds down to 11 ERUs)
o 11 ERUs x $115.20 = $1,267.20 per year
• An HOA-owned community parcel having 10,000 ft2 of impervious area:
o 10,000 ft2 / 3,200 ft2 = 3.125 ERUs (rounds down to 3 ERUs)
o 3 ERUs x $115.20 = $345.60 per year
• An institutional facility (e.g., church or school) having 98,000 ft2 of impervious area:
o 98,000 ft2 / 3,200 ft2 = 30.625 ERUs (rounds up to 31 ERUs)
o 31 ERUs x $115.20 = $3,571.20 per year

9. Are there any exemptions?
a) TCA 68-221-1107 provides an exemption for users that do not discharge - directly or indirectly - into a municipally owned stormwater system. If a property is in the drainage area of any City owned stormwater infrastructure (culvert, pipe, ditch, etc.), then that property is not eligible for an exemption.

10. Can I appeal the fee?
a) The City does have an appeal process for those properties that feel that they have been incorrectly billed or have had their impervious area measured incorrectly. Appeals forms can be found on the Water Quality Fee homepage and submitted to the Water Quality Program for review.

11. Are there any discounts available?
a) Yes. Upon submitting an application with supporting documents, multi-family and non-residential users may qualify to receive up to a 70% reduction in their WQF. The fee discount is provided for properties that reduce their stormwater runoff through engineered controls that infiltrate, evapotranspirate, or capture and use stormwater to prevent it from leaving the site as surface runoff. The City refers to this as Stay-On-Volume (SOV). Please see the City's Credit & Incentive Manual for more information.

12. What are the services that are provided with the Water Quality Fee?
In 1996, the Tennessee Department of Environment and Conservation (TDEC) issued the City of Chattanooga a National Pollutant Discharge Elimination System (NPDES) permit containing more than 131 requirements such as, but not limited to the following: 1) detailed mapping and maintenance of the stormwater system, 2) implementation of an illicit discharge detection and elimination program, 3) industrial facilities inspection and monitoring, 4) construction activities permitting and inspection, 5) municipal facilities monitoring, 6) stormwater runoff and stream sampling, 7) stormwater infrastructure maintenance, and 8) public education. The WQF is used to directly meet this mandated programs. In addition to the NPDES permit requirements, in 2006, TDEC issued the City a new federally mandated, unfunded requirement known as Total Maximum Daily Loads (TMDLs). TMDLs require the City to conduct enhanced stream sampling and develop new programs to reduce stream habitat alteration and pathogen and sedimentation loadings of our streams. In addition to regulatory requirements, stormwater drainage system maintenance and flood management services were increased to include flood mapping and drainage system upgrades. Advanced programs launched by the City include, stream assessment and restoration projects, stormwater infrastructure retrofitting, and sanitary sewer discharge detection and elimination.

13. How does the fee benefit me?
The fee will be used to reduce and prevent pollution, provide guidance for construction and industrial activities, and control flooding through constructing, cleaning and maintaining stormwater infrastructures (i.e., roadways, inlets, pipes, ditches, and detention facilities).

a) For Single and Two-Family Residential Parcels
Each single or two-family residential property is equals to one residential unit (1 ERU). The Water Quality fee for these residential properties is $115.20 per year.
b) For Multi-Family Residential (Condos)
Each Condo unit will be assigned 1 ERU. The Water Quality fee for these residential properties is $115.20 per year.
c) For Multi-Family Residential (Apartments) and Non-Residential Parcels
Step 1: Assume an impervious area of 100,000 sq. ft.
Step 2: Divide 100,000 sq. ft. by 3,200 sq. ft. (1 ERU) = 31.25 ERUs
Step 3: Round down (or up) using standard mathematical rounding = 31 ERUs
Step 4: Multiply 31 by $115.20 = $3,571.20




Mailing Address

1250 Market Street, Suite 2100

Chattanooga, TN 37402

Attn: Water Quality Fee


       Back to Water Quality Home

To preserve and enhance the quality of the physical environment and infrastructure through prompt, cost effective and courteous delivery of services which protect the health, safety and welfare of citizens.

Justin Holland, Administrator
1250 Market Street
Chattanooga TN 37402 (map)
(423) 643-6311



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