Description: This data shows the sewerage subbasins in Pierce County Sewer Service area. A sewerage basin represents the existing and planned areas from which wastewater is collected and sent to specific wastewater treatment plants. Sewerage basins are often confused with watersheds or drainage basins. Because most sewer pipelines are designed for gravity flow, a sewerage basin is primarily defined by the topography of the watershed or drainage basin where it is located. Please read metadata for additional information (https://matterhorn.piercecountywa.gov/GISmetadata/pdbsewr_subbasins_cartographic.html). Any use or data download constitutes acceptance of the Terms of Use (https://matterhorn.piercecountywa.gov/Disclaimer/PierceCountyGISDataTermsofUse.pdf).