Stormwater Utility FAQs

Do you have questions related to the Stormwater Utility fee, disputes/appeals, and/or the credit program? Get answers below.

General FAQs

Why did the County change to a Stormwater Utility?

A Stormwater Utility provides a fairer way to pay for the County’s stormwater management program, based on the amount of hard surfaces (impervious area) on a property and the usage of the storm system. A property’s impervious area is a better measure of how much stormwater runoff each property generates, as opposed to the property assessment.

Can you explain how a Stormwater Utility fee works?

Under a Stormwater Utility, a property’s impervious coverage is estimated using the County’s digital mapping system (GIS). The median impervious coverage for single-family detached properties in Arlington has been calculated to be 2,400 square feet. This is called an Equivalent Residential Unit (ERU) and is used as the billing unit. Properties will be charged based on how many ERUs are on the property. The County Board will adopt the annual ERU rate each year during the budget process. For Calendar Year 2024 (the first year the utility will be billed), the rate was set during fall 2023 at $258 for one ERU.

What are impervious areas?

Impervious areas are hard surfaces that significantly prevent water from seeping into the soil. Impervious surfaces include roofs, buildings, streets, parking areas, driveways, and any concrete, asphalt, or compacted gravel surface. 

How is the impervious area calculated for each property?

Outlines of the impervious area on a property are developed from aerial maps and geographic information system (GIS) data. A GIS technician manually reviews the imagery and outlines impervious areas as defined by County policies. That information is combined with GIS parcel data, resulting in an outline of impervious area on each parcel. The GIS software then calculates the impervious area on the parcel based on that outline. County GIS staff perform regular maintenance of the impervious area based on updated aerial imagery, building permits, and other sources.

Did the stormwater utility fee replace the sanitary district tax?

Yes, the stormwater utility fee replaced the sanitary district tax. Since 2008, Arlington’s stormwater program has been funded through a Sanitary District Tax, which is based on a property’s assessed value. The current stormwater fee is $0.017 per $100 of assessed value. However, a property’s assessed value doesn't correlate well to the amount of runoff a property generates. Beginning in 2024, the County changed to a Stormwater Utility fee based on the amount of impervious area on a property (hard surfaces like roofs and driveways that don’t let rain runoff soak into the ground). Customers will receive the first real estate bill with the Stormwater Utility fee in May 2024.

What does the stormwater funding pay for?

Arlington’s stormwater program through Dec. 31, 2023 was funded through a Sanitary District Tax based on a property’s assessed value. The final stormwater fee was set at $0.017 per $100 of assessed value. An average property had paid about $136 per year under the sanitary district tax. However, a property’s assessed value didn't correlate well to the amount of runoff a property generates.

Arlington’s stormwater programs are part of the Office of Sustainability and Environmental Management in the Department of Environmental Services including water quality regulations, planning, engineering, construction, stormwater infrastructure, and incentive and outreach programs. Learn more about the County’s stormwater management program.

The Virginia Department of Environmental Quality issues permits for the discharge of stormwater into waterways like Four Mile Run and the Potomac River. These permits, called municipal separate storm sewer system (MS4) permits, are good for five years. Arlington’s current MS4 permit (VPDES Permit No. VA 0088579) was issued on July 1, 2021.

The previous Sanitary District Tax and the current Stormwater Utility fee generate all of the funding to support these programs. The Stormwater Utility fee is calculated on a cost recovery basis – fees are set to generate the necessary revenue for the stormwater management program.

More information about the stormwater management program’s budget can be found here starting on page 805.

Do we expect the revenue to stay the same, or increase to help with upgrading the aging stormwater system?

Changing to a Stormwater Utility did not generate more funding for the stormwater program. However, based upon projected funding needs for stormwater projects in the Capital Improvement Plan (CIP), we do anticipate that over the next 10 years there will have to be rate increases to support the debt service on bonds issued to address the substantial upgrades to the stormwater system. The utility fee will be adjusted each year based upon generating sufficient funding to cover the budgeted expenditures, including debt service, operating and maintenance activities, utility administration overhead, and the capital program.

How does the County bill the Stormwater Utility?

The Stormwater Utility fee is included on property owners’ twice annual real estate tax bill as a separate line item. Real estate taxes are due June 15 and Oct. 5 of each year.

If property owners have a mortgage on their property, the property tax bill will continue to be sent to their mortgage company. The mortgage company will pay the fee from the escrow account.

How was the utility decided?

After a public hearing held March 2023, the County Board approved a resolution on April 22, 2023, stating its intent to adopt a Stormwater Utility. Another public hearing was before the Board on Dec. 16, 2023, and the Board officially adopted the utility, ordinances, and set the Calendar Year 2024 utility rate at $258 per Equivalent Residential Unit (equal to 2,400 square feet of impervious area). There was an extensive engagement process leading up to and following the resolution vote in April 2023.

Are there any other municipalities that charge a Stormwater Utility fee?

Yes, stormwater fee-based programs are promoted by the Environmental Protection Agency (EPA) and authorized by the Commonwealth of Virginia as a way of providing dedicated funding for water resources and stormwater management. Stormwater fee-based programs have been used since 1974, and there are currently over 1,500 stormwater fee-based programs in the country. In the surrounding area, D.C., Prince George's County, the Cities of Alexandria, Falls Church, Manassas, Fairfax, and Manassas Park all have Stormwater Utility fees in place.

What if all the runoff from my home and driveway stays in my yard and does not run off into the storm system?

Everyone will pay a stormwater utility fee based on the amount of impervious area on their property because all property owners benefit from a properly maintained and operated stormwater management system.  Some key benefits include reduced flooding; reduced property damage; protection of critical infrastructure (such as electrical, communications, drinking water, wastewater); safe transportation for residents; improved quality of life; cleaner streams; restored water habitat; and compliance with Federal and State regulations for water quality improvements.

Stormwater is an issue that extends far beyond one immediate residence or business and a robust stormwater management program provides benefits to the overall community in which you live, work, and play.

Customer FAQs

What is the cost impact to homeowners?

For an average homeowner, the Calendar Year 2023 sanitary district tax of $0.017 per $100 of assessed valuation equates to $136 per year for a median single-family home valued at $798,500. Under a Stormwater Utility, 86% of single-family (attached and detached) homeowners will be charged 1 ERU or less. The equivalent Stormwater Utility fee rate for Calendar Year 2024 for one ERU is $258 per year.

Learn more about the rate structure for single-family attached and detached homes.

How are decks handled under the Stormwater Utility?

Decks are counted as impervious area if they have a patio or other hard surface underneath.

I have a gravel driveway. Does that count as impervious area?

Gravel driveways are considered impermeable surfaces due to the compaction required for them to be usable and because they prevent infiltration, which results in stormwater flowing off these surfaces at a higher rate than pervious surfaces. The County is following a nationally accepted standard by classifying gravel as impervious. In Virginia, the Department of Environmental Quality publishes the Virginia Stormwater Management Handbook, which defines impervious as, “a surface composed of any material that significantly impedes or prevents natural infiltration of water into soil.”

I have a permeable driveway or patio. How are these types of surfaces handled?

Permeable and impermeable surfaces are not distinguishable on the GIS maps, so all paved surfaces are counted in the total impervious area for the property. Credits will be available for permeable driveways and parking lots.

My property has a swimming pool. Does that count as impervious area?

A swimming pool is considered an impervious surface because it is a structure that does not allow water to seep through its walls or bottom. This means that when it rains, the water will stay on the surface of the pool rather than seeping into the ground like other pervious surfaces.

How is the Stormwater Utility assessed on condos?

For multi-family properties, including condos, the utility fee is billed a flat fee of 0.18 ERU per unit.

For commercial renters: Does our landlord pay this bill, or does each business pay a portion?

The stormwater utility fee is included on the real estate statement; therefore, it goes to the owner of the property. Visit this link for more information:

I noticed that high-rise commercial properties pay less. Why would that be?

Under the sanitary district tax, properties with a high assessed value paid a higher stormwater tax, even if they had less impervious area on their lot. That is because there is no correlation between real estate assessment and the amount of runoff from the property. In Arlington, commercial properties with a high property value are typically high-rise buildings with multiple stories (a more efficient use of the impervious footprint), so they pay less under the Stormwater Utility than under a sanitary district tax.

If I am a senior and/or disabled property owner who will receive Real Estate Tax Relief (RETR) for Calendar Year 2024, or who receives a real property tax exemption as a Disabled Veteran or Surviving Spouse, do I need to apply for the stormwater fee relief?

No, you do not need to apply separately for the 100% stormwater fee relief; it will automatically be applied for residents who qualify and are receiving these real property tax deferrals and exemptions.

How does the Stormwater Utility fee affect non-profit and faith-based organizations?

Some organizations, such as faith-based organizations and non-profits, were exempt from paying the old sanitary district tax. By State Code, they are no longer exempt under the Stormwater Utility. Starting in 2024, the fee for these organizations depends on the amount of impervious area (i.e., number of ERUs) on their property. The adopted rate of one ERU is $258/year.

Does the fee apply to the County itself? Are County properties included in the GIS survey and publicly accessible?

County properties are exempt from paying this fee because the County holds a municipal separate storm sewer system (MS4) permit. The fees do not apply to every organization. A small number of property types are waived by Virginia law, such as public rights-of-way and properties covered by their own MS4 permit. With a Stormwater Utility, most properties, including untaxed properties, are charged the fee, which ensures that all properties that contribute to stormwater impacts are paying their fair share towards the stormwater management program.

Disputes and Appeals FAQs

What are the acceptable reasons for disputing my Stormwater Utility fee?

The acceptable reasons for filing a dispute application are as follows:

(1) an error was made regarding the square footage of impervious area

(2) an error was made regarding the number of units for Multi-Family (MF) property

(3) an error regarding customer class

(4) fee for property should be waived based on Section 26-120 of County Code

(5) an approved credit was incorrectly applied

When can I file a dispute application?

Disputes may only be submitted within 45 days of the bill issuance.

Where do I submit a dispute application?

Dispute submissions must be filed through the

“Report a Problem”

tool on the County website.

When is the deadline for disputes to be filed by?

The deadline is June 30 for the bill due on June 15 and Oct. 20 for the bill due Oct. 5.

What do I need to include in my dispute application?

The property owner should submit any photos, aerial images, GIS imagery, or appropriate supporting documentation that supports their dispute. The County may require an inspection to assist in making a decision. Denial of access for such inspection may result in denial of the property owner’s dispute.

When will I find out if my dispute was approved?

There is a 45-calendar day timeline for a dispute decision. If more information is needed by the County to make a decision, the 45-days will begin once all requested information has been received by the County. If the information requested is not provided to the County within 10-calendar days of the original request, the dispute will be considered withdrawn.

What are the acceptable reasons for an appeal to my dispute denial?

The acceptable reasons for an appeal to a dispute application must relate to the impervious area calculation or the customer class. The property owner may appeal a dispute decision to the Department of Environmental Services Budget and Finance Division Chief for further determination.

Where do I submit an appeal to my dispute application?

Appeal submissions must be filed through the “Report a Problem” tool on the County website.

What if I don’t agree with the decision on my Stormwater Bill appeal?

The decision on a Stormwater Bill Appeal made by the Department of Environmental Services Budget and Finance Division Chief is a final decision from which the property owner may then appeal to the Circuit Court of Arlington, Virginia.

Fee Estimator and Rate Structure FAQs

What is the Fee Estimator?

The Fee Estimator is a tool that lets property owners see the estimated impervious cover and number of ERUs on their property. Learn more and view the tool at

How do I use the Fee Esimator tool?

View the Fee Estimator map at this link.

Search by Address:   
1. Enter an address. 
2. There may be two or more results:
  • Arlington Geocoder:  Address Location
  • Property Fee Data:  Estimated Annual Fee
Click on a Parcel:
A pop up will appear displaying the estimated Stormwater Utility fee information.  If there is more than one record for the parcel, use the address drop down in the pop up to select the desired address.  Or click on the Next to scroll through the associated records.  
Turn Layers On and Off:   
Select the Layers tab to view the available layers.  The layers can be turned on or off.
To zoom to the full extent of the map, click on  

Zoom to Full Extent:  

To interactively pan around the map, click on:   

What is an Equivalent Residential Unit (ERU)?

An ERU is the billing unit for a Stormwater Utility. One ERU is the median impervious coverage for single-family detached properties in Arlington, which is estimated to be 2,400 square feet. A fee for one ERU will be established for the Stormwater Utility based on the adopted budget each year and properties would be charged based on how many ERUs are on the property. The utility fee rate of one ERU is $258/year in Calendar Year 2024.

Why are we using ERUs rather than simply charging a fee based on square feet of impervious area?

The ERU is considered the industry best practice for billing because it represents the typical impact of a single-family home's impervious area footprint and establishes a consistent billing measure across the residential and non-residential customer classes. Using a rate structure based on ERUs and residential tiering also reduces the cost and administrative burden of implementing the stormwater program.

What if some of the areas shown as impervious on my property are actually a permeable surface?

Learn more about the Stormwater Utility Credit Program, where property owners can receive reductions for some types of permeable surfaces and actions taken to reduce runoff on their property.

Will there be a way to dispute or appeal my stormwater utility fee or credit?

Any property owner may request an adjustment to their stormwater utility fee by submitting a dispute application on our website. This process will open in spring 2024 after the bill is mailed. A denial of a credit application is not subject to appeal.

If a single-family residential detached property has less than 2,400 sq ft, will it still be charged 1 ERU?

The proposed rate structure for single family-detached properties has several tiers, with the initial tier of 0.6 ERU for properties with less than 1,600 feet of impervious area. Tier 2 properties have between 1,600-3,600 square feet of impervious area are charged 1.0 ERU. Tier 3 properties are between 3,600 and 4,800 sq feet of impervious area are charged 1.7 ERU. Single family-detached properties with more than 4,800 square feet of impervious area are treated the same as Non-Residential properties, whereby they are charged per ERU.

See the table on this page for the proposed rate structure.

Why are some properties shown with 0 or TBD ERUs on the map?

The development of the Stormwater Utility is still underway. If a property is made up of multiple parcels, the ERU information is associated with the main parcel and the related parcels are shown with 0 ERUs. If we do not have information for a parcel yet, it is shown as TBD.

Credit Program FAQs

What types of credits are available?

Mandatory structural credits are for stormwater facilities installed as a requirement of a development project through the Land Disturbing Activity (LDA) permit. Property owners will get an automatic credit towards their Stormwater Utility fee if they complete their required facility inspection and certification on schedule and are in compliance.

Voluntary credits are available for actions taken by property owners to reduce runoff or stormwater pollution. 

Some credits are annual credits and the activity must be completed each year to receive that credit. Other credits, such as conservation landscaping, rain gardens, and permeable driveways or parking lots, are ongoing credits. These credits can be re-certified every other year once they are completed and approved the first time. 

Property owners can apply for Calendar Year 2024 credit activities completed during the application process between Nov. 1, 2024, and Jan. 15, 2025, for the Calendar Year 2025 billing period. The maximum credit available is 35%.

How do I apply for voluntary credit?

The County uses a one-stop online platform to track requests for various services. During the annual stormwater utility credit application period from Nov. 1 – Jan. 15, property owners will have the option to submit a “Stormwater Voluntary Credit Application” on this page:

For additional information about the credit program and what is required, visit and view our step-by-step instructions.

Do you accept paper applications?

No paper applications are available. All service request types for the stormwater utility fee are only available online. If you do not have access to a computer or internet, call 703-228-5577 to learn how to receive assistance on completing the online submission.

How do I apply for more than one stormwater utility credit?

Each voluntary credit action requires its own Stormwater Voluntary Credit Application. Multiple credits cannot be applied for on the same application. Get started with your application here.

How do I monitor the status of my voluntary credit application?

You can set up an account on our online service request platform. An account is not required to submit a voluntary credit application; however, it is highly recommended. With an account, you will receive updates on the status of your application, edit your submission if additional information is required, and receive the determination letter(s) related to your submission. If you have an account, you can go to “My Service Requests” to view your service request submission and the progress. See how to set up an account using our step-by-step instructions.

If I have a mandatory stormwater facility and I submitted my inspection report, do I get an automatic credit?

Can the utility be used to "reward" or incentivize private property owners to plant trees or take action to reduce runoff from the property?

A credit program is required for any jurisdiction that creates a Stormwater Utility in Virginia.  The credit program is a way to say "thank you" for doing certain environmentally friendly activities, such as installing a permeable driveways, rain gardens, planting trees, native plantings, etc.  Because the total amount of the stormwater fee is relatively low for most property owners compared to the costs of stormwater projects, the credit has a relatively long return on investment.  

Since the Stormwater Utility credits reduce the amount of fees collected which funds the program, Stormwater Utility credits are usually a relatively modest reduction for individual properties (typically credit programs comprise under 1% of utility fee revenues).  If stormwater credits were increased, that could result in an increase to Stormwater Utility fees so the appropriate amount of revenue is still generated to sufficiently fund debt service, all programs and projects.

Are there credits for existing trees or native plant landscaping?

Credits are available for new tree planting or new native plant landscaping. The credit activities were selected to try to manage the complexity and administration of the credit program. Providing credits for existing trees and native plant landscaping would be more complex as property owners may not have documentation from before the credit program was developed. In addition, issues such as plant species or condition of the native landscaping or trees might need to be taken into account. There could also be many people potentially claiming these credits, which could affect the overall rate for the utility. The credit program was developed as part of an extensive engagement process for the stormwater utility and included benchmarking with credit programs for other jurisdictions' stormwater utilities.

Credit Program Volunteer Events FAQs

Do I have to volunteer 30 hours during one event?

No, you may spread the 30 hours across multiple events. Be sure to document the event details, including location, date, and hours spent, using the stormwater utility volunteer form. Additionally, you must provide photographs.

Is it a requirement for volunteers involved in invasive removal or stream cleanup on a particular property to be affiliated with the organization that owns the property?

No, it is not mandatory for all volunteers to belong to the organization that owns the property.  However, volunteers do need to obtain permission from the property owner. It is strongly advised to keep a record of the email correspondence pertaining to the authorization granted for work on the property.

How do I document volunteer activity?

Please use the County provided stormwater utility volunteer activity form available on the stormwater utility website. You must bring a copy of your volunteer activity form with you to the event to receive proper documentation. Additionally, you must take before and after photos at the event. Please refer to the credit manual for documentation details for each activity type.

Do volunteers have to earn hours at a County-led event?

No, participation is not required to be at a County-led event. You may organize your own invasive removal on private property or non-County Park land. Please send an email to and with the location and information about your activity.

The County’s Remove Invasive Plants program organizes multiple invasive removal events every month.  If you participate in one of these events, you must bring a copy of the stormwater utility volunteer activity form to the event to receive proper documentation.

Do groups need County pre-approval to hold a stream cleanup or invasive removal event?

If you are organizing a stream cleanup or invasive removal on private property or non-County park land, please send an email to and with the location and information about your activity. 

How can I take part in the Adopt-A-Street program?

Individuals or groups may "adopt" a specific section of road committing to maintaining the street, curb, and storm drain free from trash and debris for a total of 30 hours. You must take before and after photos for proper documentation. Please refer to the Step-by-Step instructions for help.

How can I earn credit for participating in a storm drain marking event?

You may earn credit by contacting County staff to schedule your event. They will provide materials, training, and the event location. You must track the marked storm drains on the provided map and retain email exchanges with County staff for documentation. Then, record volunteer hours on the sign-in sheet, including participant names and date, and take a photo of the event. Upon completion, return any leftover materials and the map to County staff. Lastly, you must submit your volunteer sign-in sheet, a copy of the map, and the event photo to complete your voluntary stormwater credit application.

Are there any events hosted by Arlington’s Park services that will qualify for stormwater utility credit?

Arlington County’s Park Services regularly hosts events, such as Invasive Plant removal, which qualifies for stormwater utility credit! Please note that this credit is not applicable for individual homeowners.

Can I receive stormwater utility credit for the detention system installed in my property?

Unfortunately, detention systems are not eligible for voluntary stormwater utility credit. These systems were mandated as part of the developer’s permit requirements, making them non-voluntary. As a result, including them for credit would incur additional costs for homeowners which would far exceed the potential credit savings.