
By Kathleen McSweeney

Earlier this year, the Arlington County Board voted to implement a new Stormwater Utility Tax that will become effective in May 2024. The new tax is based on the amount of hard surfaces on a property such as buildings, roofs, driveways, and patios—anything that prevents water from seeping into the ground and creates runoff. The additional funds raised will pay for the maintenance of over 200 miles of sewer pipes, increases to system capacity, restoration projects, management of flood plains, and other
needed improvements.
This new tax will replace the Sanitary District tax, which has been bundled within the County’s real estate taxes. The cost of this tax is $.017 for every $100 of assessed value. The new stormwater taxes will be listed separately on real estate tax bills after next May.
How can you tell what you may owe? The County used GIS-mapping to estimate that an average single-family home in Arlington has 2,400 square feet of impervious surface. This represents one ERU, or Equivalent Residential Unit, and there is a scaled system of billable units (see chart below) used to calculate the tax for each property. Initial estimates are that an ERU has a sample value of $230–250, though the rate will not be set until the County Board votes this Fall, and is dependent on the adopted budget.
Why is the County moving to this new tax structure? There have been additional demands on the stormwater system, and the County needs to raise additional revenue to pay for planned improvements, The shift to the Stormwater Utility tax is considered to be a fairer way to assess cost because it is based on the amount of impervious lot coverage, rather than a property’s value. The new fee is demand-based: the larger a property’s impervious surfaces, the more that property contributes to runoff and puts pressure on the system. There are some properties (places of worship, non-profits, and Federal buildings) that currently don’t pay the sanitary district tax. Those properties will likely be impacted by this new stormwater tax.
The County acknowledges that property owners will be paying more under this tax structure, but there is a way owners can qualify for credits. Between November 1, 2023 and January 15, 2024, property owners are able to reduce the tax amount by making specific improvements to their properties in 2023 that reduce runoff. Additional information on the credit program, a (not-very-user-friendly) fee estimator by property, and FAQs may be found on the County’s Stormwater Utility Implementation page (go to https://www.arlingtonva.us and search for stormwater utility).









