Construction Site Runoff (Control Measure 4)

Erosion and Sediment Control for Construction Sites

Please view our Erosion and Sediment Control Permitting Flowcharts to better understand what types of permitting and action may be needed for your planned project.

In July 2011 the Benton County Erosion and Sediment Control (ESC) Program was implemented. In March 2023, our stormwater quality requirements for development and re-development were modified to remain in compliance with Benton County’s DEQ National Pollutant Discharge Elimination System (NPDES) Phase II MS4 permit.

How do I know if I need a permit?

Benton County Code requirements and other supporting documents should be reviewed and adhered to by any person or business creating a total ground disturbance of one quarter acre (¼ acre = 10,890 square feet) or more, or one quarter acre or more of impervious surface. For ground-disturbing activities or impervious surface creation above these thresholds, a State and County permit may be required. The worksheets linked above can be used to calculate your site disturbance area and impervious surface to determine what types of permits you will need.

What are the definitions of 'ground-disturbing activity' and 'impervious surface?'

"Ground-disturbing activity" is defined by the Benton County Development Code as an activity that exposes, works or redistributes soil, including but not limited to excavating, filling, stockpiling, grading, grubbing, or clearing to bare earth.

An "impervious surface" is defined by the Benton County Development Code as “a surface that prevents or impedes stormwater from infiltrating the soil, and includes but is not limited to such elements as roads, driveways, parking lots, walks, patios, and roofs. Compacted gravel, asphalt and concrete surfaces are all considered impervious.”

Please note that any construction project may require erosion and sediment control BMPs, at the discretion of the county engineer depending on specific soils, slope, and other important erosion and sediment control factors.

Other information for applicants

Your application will require several documents. Please see the ODOT Erosion Control Manual for suggested practices, or find the appropriate ODOT Details & Standards for ESC.

1. Benton County ESC Permit Application

2. Disturbed Area Worksheet

3. Impervious Area Worksheet

4. ESC Checklist for Applicants

Our Example Site Plan and Site Plan Checklist will assist you with creating your ESC Plan.

If your project will create more than 1/4 acre of impervious surface, please visit our Post-Construction Site Runoff Control Page to download a SWM permit application.