If you are a contractor or geotechnical special inspector who will be conducting earthwork activity at a project with a grading season restriction or in an Environmentally Critical Area (ECA) during Seattle's wet season (Oct. 31-April 1), you will need to obtain a Grading Season Extension Letter from DPD to avoid a stop work order. This provision does not apply to grading in liquefaction-prone areas and abandoned landfill ECAs, unless the parcel contains another ECA.

To minimize soil erosion and slope stability issues, the Seattle Municipal Code requires that all grading in ECAs must be completed or stabilized by Oct. 31 of each year, unless it can be proven to DPD that no environmental harm or safety problems will result (SMC 25.09.060 G). Similarly, grading season restrictions applied to projects in non-ECA areas must be completed or stabilized by Oct. 31 of each year (SMC 22.804.160 A).

Overview of Grading Season Extension Requirements
For permits issued prior to Oct. 1:

• The geotechnical engineer must provide a schedule for completion of the grading work to DPD.
• If the grading completion schedule indicates that all of the grading will be completed and the site will be stabilized by Oct. 31, the geotechnical engineer must submit to DPD, by close of business on Oct. 31, a written statement that the grading was completed per the approved plans and the site was stabilized by the Oct. 31 deadline.
• If the schedule shows that the grading and site stabilization will continue past Oct. 31, a Grading Season Extension Application must be filed with DPD. We strongly encourage that this application be submitted as quickly as possible, but if the extension is not approved by Oct. 31, the contractor must stop any grading and stabilize the site immediately.

For permits issued between Oct. 1 to April 1:

• No grading work can start after Oct. 1 for projects subject to grading season restrictions unless the contractor submits, on or before the date of permit issuance, a schedule approved by the geotechnical engineer showing that the grading will be completed by Oct. 31. If the schedule shows that grading will be completed after Oct. 31, no grading work shall occur unless a Grading Season Extension Letter is obtained.
• For permits issued between Oct. 31 and April 1, no grading work shall occur between Oct. 31 and April 1 unless a Grading Season Extension Letter is obtained. We recommend that applications for grading season extension be submitted after building permit issuance. Applications for grading season extension may be submitted before the building permit is issued; however, the application will not be reviewed until the applicant notifies the DPD geotechnical reviewer that the permit has been issued.
• DPD’s Site Development Team may issue a stop work order on or after Nov. 1 to projects that are not in compliance with Director’s Rule 3-2002 (see box at top right).