178 of the 227 lots in South Prairie (78%) are zoned for houses inside an urban growth area. On those lots, Washington's HB 1337 requires the city or county to allow at least two accessory dwelling units (ADUs). Another 0 lots are outside the urban growth area, where Pierce County's own ADU rules decide.
7 of the 227 lots in South Prairie (3%) have septic records on file with the Tacoma-Pierce County Health Department. 0 lots are inside a Pierce County sewer service area, and 0 are within 300 feet of a county sewer main.
Of the 227 lots in South Prairie, 0 touch a mapped landslide hazard area, 0 an erosion hazard area, 43 a flood area and 1 an inventoried wetland, on Pierce County's maps.
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 October 2, 2026.
How these numbers are worked out · Guides