The environmental impacts of certain public and private development proposals must be assessed by the City of Seattle per the State Environmental Policy Act (SEPA) and the Seattle SEPA Ordinance (Chapter 25.05, Seattle Municipal Code or SMC). In order for these assessments to be made, permit applicants whose projects meet the criteria listed below are required to prepare an Environmental Checklist.

For more information about this topic, check out the following CAMs:

  • CAM 208, When Environmental Review is Required in Seattle
  • Shoreline application/ J.A.R.P.A. (forms attached to CAM 209, Master Use Permit Application Requirements for Shoreline Permits)

Projects Subject to Environmental Review:

  • construction of more than 4 residential units in a Single Family, Lowrise Duplex/Triplex, Lowrise 1, Neighborhood Commercial, Commercial or Industrial zone
  • construction in a landslide-prone area, riparian corridor, wetland, or fish and wildlife conservation area of one residential unit in a Single Family zone (if it exceeds 9,000 square feet of development coverage) or for two or more residential units
  • construction of more than 6 units in a Lowrise 2 zone
  • construction of more than 8 units in a Lowrise 3 or Lowrise 4 zone
  • construction of more than 20 units in a Midrise, Highrise, Downtown or Seattle Cascade Mixed zone
  • construction of more than 4,000 square feet of non-residential space in a Single Family, Lowrise Duplex/Triplex, Lowrise 1, Lowrise 2, Lowrise 3, Lowrise 4, Neighborhood Commercial, Midrise, Highrise or Downtown zone
  • construction of more than 12,000 square feet of non-residential space in a Commercial, Industrial or Seattle Cascade Mixed zone
  • construction of a parking lot designed for more than 20 automobiles
  • landfills or excavations of more than 500 cubic yards
  • any grading within wetlands and their buffers or riparian corridor buffers
  • grading exceeding 25 cubic yards in the four environmentally critical areas listed in the SEPA Ordinance, Section 25.05.908 (landslide prone, riparian corridors, wetlands, and fish/wildlife habitat conservation areas)
  • grading exceeding 25 cubic yards in four major creek watersheds (Thorton, Pipers, Longfellow, Taylor)
  • any grading within 10 feet of the shoreline
  • short platting in environmentally critical areas
  • any construction in or over water if it requires other permits, unless it is a minor repair of an existing legal structure or development to the same configuration
  • most Seattle City Council land use decisions

For property use questions, refer to DPD Director's Rule (DR) 23-2000, State Environmental Policy Act (SEPA) Exemptions from Environmental Review Requirements When Establishing, Changing, or Expanding a Use.

For a complete listing of exempt and nonexempt projects, see SMC Chapter 25.05.