Of the 5,866 lots in Roy, 2,393 touch a mapped landslide hazard area, 1,415 an erosion hazard area, 1,078 a flood area and 2,339 an inventoried wetland, on Pierce County's maps.
A mapped hazard area means the county may ask for a study or a buffer before building; it does not mean the land is unsafe.
The share of each lot inside each area is on its report.
Questions
How much of Roy is in a landslide area?
2,393 of Roy's 5,866 lots touch a mapped landslide hazard area.
What does a hazard area mean for building?
The county can ask for a geotechnical study, a flood elevation or a wetland buffer before it permits building. Search an address to see how much of that lot is affected.
From the Pierce County Assessor-Treasurer, the county's zoning, sewer, hazard and growth-area maps, and the Tacoma-Pierce County Health Department. Records as of November 7, 2026.