State of Washington - Who Needs Construction Stormwater Permit coverage?
- Does your construction project disturb 1 or more acres of land through clearing, grading, excavating, or stockpiling of fill material? Remember to count the cumulative acreage of the entire project whether in a single or in a multiphase project. This applies even if you are responsible for only a small portion [less than one acre] of the larger project planned over time.
- Is there any possibility that stormwater could run off your site during construction and into surface waters or conveyance systems leading to surface waters of the state? In almost every case, the answer to this question is yes. However, if the topography and location of your site is such that there is no possibility that rainfall or snowmelt could leave the site or enter a waterway, you do not need permit coverage.
If you answered "yes" to both of these questions, your construction site needs a permit. Construction site operators must apply for a permit 60 days prior to discharging stormwater.
