The City of Seattle Department of Transportation requires a Shoring and Excavation Permit if a project meets the following criteria:
- excavation or construction adjacent to the street right-of-way deeper than three feet; and
- any excavation where the plane extending from the bottom of an excavation at 100% (45 degree) slope crosses the property/street right-of-way line.
This permit is required whether or not the street right-of-way is improved or even open to traffic. The purpose is to protect the stability of the street right-of-way and facilities within and/or near the street right-of-way.
In cases where there is an associated Department of Planning and Development (DPD) Construction Permit, SDOT does not issue a separate Shoring & Excavation Permit. However, when excavation on private property meets the criteria stated above, the plans for excavation or shoring must be reviewed and approved by the SDOT's Street Use Section before DPD will issue a Construction Permit.