Stormwater FAQs

Why do we need to spend more for stormwater?
Walla Walla County stormwater has been regulated under a National Pollutant Discharge Elimination System (NPDES) Phase II Permit since 2007.  This permit requires the County to take new measures to improve the quality of the stormwater that discharges to creeks, rivers, and groundwater.  State and Federal penalties for non-compliance can exceed $10,000 per day.

How does the County currently pay for its stormwater services?
Money from the County Road Fund is currently the primary source of funding for stormwater management. Approximately $340,000 from the County Road Fund is used every year for operation and maintenance of the County’s stormwater system; this level of County Road Fund funding is ongoing. Revenue from the County’s stormwater utility fee is used to pay for the expanded stormwater management requirements mandated by the Department of Ecology and the EPA. In recent years, Walla Walla County has received several small grants from the Department of Ecology to help start its stormwater management program, but there is no sustained or long-term funding available from the State or Federal Government.

Who pays for Stormwater?
All developed property within unincorporated Walla Walla County pays the stormwater utilty fee.

How is the Stormwater service charge collected?
The stormwater utility fee will be included as a separate item on property tax statements.  Those not receiving a property tax statement will receive a separate bill.

When did the Stormwater billing begin?
Walla Walla County started collecting the stormwater utility fee in 2011.

How is the Stormwater Utility Fee set?
The Stormwater utility fee, just like water and sewer fees, is based upon the cost of services provided. Because this is not a tax, it is collected from all customers who receive service.

Single-family lots are charged a flat rate. Other properties are charged based on the amount of impervious area (rooftop, parking lot, concrete, asphalt) on the property.  Stormwater rates are based on an Equivalent Residential Unit (ERU) measurement, as defined by the average amount of impervious area on single-family residential lot in Walla Walla County.  1 ERU is equal to 5,000 square feet.

The Stormwater utility fee for businesses, industries, farms, apartment buildings and other non-single-family-residential land uses are calculated based on their impervious area as compared to the average single-family residential unit.  For example, if a commercial lot has four times more impervious area than the average residential lot, it is charged four times the single-family rate --  if a commercial property has 20,000 square feet of impervious area, the fee will be based on 20,000 square feet divided by 5,000 square feet/ERU which would equal 4 ERUs.

What is an Equivalent Residential Unit? (ERU)
An ERU is determined by the amount of impervious area on the average single family residential lot. The ERU for Walla Walla County is 5,000 square feet. All single family lots are treated as 1 ERU.

How much is the stormwater utility fee?
The stormwater service charge is $3/month per ERU, or $36/year for single-family residential lots.

What is impervious area?
Impervious area includes pavement and building areas such as driveways, parking areas, rooftops, patios, garages and out-buildings. The amount of impervious area on a property directly correlates to its contribution of runoff volume and pollution.  Impervious area impacts natural infiltration, creates more runoff, increases the rate of runoff and alters runoff patterns.

How is impervious area measured?
The County uses Geographical Information System (GIS) maps and aerial photographs to measure the total square footage of the impervious area on a lot.

How will we be able to see where our money is going, and what are the priorities?
The money collected through the stormwater service charge goes towards better stormwater management, and is restricted solely for stormwater management activities.  We are gradually seeing results in terms of better flood management, stormwater maintenance and regulatory compliance. The County’s Stormwater Management Program plan is posted on the Public Works website and is updated as needed.  The County is required to file annual reports with the Department of Ecology describing completed stormwater management activities, and the current annual report is posted on the Public Works website.

My property retains water and/or I live on a hill and have no drainage problem, why should I pay?
All property receives some benefit from the County’s stormwater management system and facilities. In some cases, a property benefits by having unimpaired access to streets. Other properties may benefit because the County’s stormwater management system and facilities collect runoff from streets and other private properties, which would otherwise drain onto it causing flooding and/or property damage. The approach being taken through this program recognizes that everyone contributes to the problem (runoff and pollution) and everyone will benefit from the solution (improved water quality, reduced flooding, unimpaired access to roads, etc.).  If your property truly has no impact to the County’s stormwater management system, you can apply for an exemption from the stormwater utility fee.

How much do I owe?
The Walla Walla County Treasurer's office does all the Stormwater billing for Walla Walla County. To get an accurate balance on your Stormwater bill, please contact the Treasurer's office at: (509) 524-2750.

Where can I go for more information?
Please contact Seth Walker, Stormwater Program Manager at (509) 524-2710.