Impervious Area Billing Details

Impervious Area Calculator
Please select one; Residential Customer Other A "Residential customer" is defined as a person(s) living in a single-family dwelling (row, detached, semi-detached or condo unit) used for domestic purposes that is served by a separate service line that is individually metered.
IAB Details   Current Adjusted Impervious Sq Ft 0 Calculated ERUs 0 0 Cost Per ERU $ 21.86 $21.86 (Current FY 2024) $21.23 (Approved FY 2025) $24.23 (Approved FY 2026) RiverSmart Rewards Monthly Impervious Cost $ 0.00 $ 0.00	Impervious Area Changes Adjustments Structure Length Width Total Sq Ft Garage or Shed Pool Driveway Patio Walkway Other Add Subtract Clear Values Total Impervious Adjustments

The Clean Rivers Impervious Area Charge (CRIAC) separates from the sewer rate the cost of a massive construction project to reduce combined sewer overflows into local waterways. This charge, first appeared on DC Water bills in May, 2009, is based on the impact that water runoff has on the District's sewer system. The actual charge is calculated based on the amount of impervious area on the property. Impervious areas are man-made surfaces that cannot be easily penetrated by water such as rooftops, paved driveways, patios, and parking lots.

Frequently Asked Questions

The impervious surface area billing program is an investment in reducing pollution in the Anacostia and Potomac rivers and Rock Creek. The charge applies to all lots, parcels, properties and private streets in the District.

You can view the Impervious Surface FAQ

How is the amount of my charge determined?

The charge is based upon an Equivalent Residential Unit (ERU). An ERU is defined as the amount of impervious surface area measured in square feet based on a statistical median for a single family residential property. Initially, all residential customers will be assessed one (1) ERU. All non-residential customers shall be assessed ERUs based upon the total amount of impervious surface on each lot. This total amount of impervious surface will be converted into ERUs.

The Clean Rivers Impervious Area Charge for all residential properties is based on one (1) equivalent residential unit, or ERU.

If You Have Questions or Comments