Pro Rata Share Assessment Rate and Credit Changes

 

 

Effective July 1, 2023, the countywide Stormwater Pro Rata Share Assessment rate will change from $25,482.89 to $26,713.59 per increase in impervious acre; the maximum water quality credit will increase from 61.5% to 61.7%; and the maximum water quantity credit will decrease from 38.5% to 38.3%.

 

These revenues, collected during the development process and combined countywide, pay for the drainage infrastructure that is required to reduce harm to receiving waters in Fairfax County, the Potomac River, and the Chesapeake Bay. They also stop the deterioration of the current drainage systems and flood damage.

 

The county determines the Pro Rata Share assessment for an individual development project as a proportion of the total estimated cost of the drainage improvement program. The assessment is based on the stormwater impact of the project measured by its increase in impervious cover discounted by any applicable credit for on-site stormwater management facilities and best management practices provided as part of the new construction.

 

Once collected, the assessment fees will be allocated to the Fairfax County Department of Public Works and Environmental Services for the program. Learn more about typical community improvement projects supported by funding from the Pro Rata Assessment fee and other funding sources by visiting the Stormwater Management page.

 

For more information on Pro Rata Share Assessment, refer to Public Facilities Manual (PFM) § 6-0600.

 

If you have any questions, please contact the Customer Experience Team at 703‑222-0801, TTY 711.