Snohomish County Public Works Surface Water ManagementPoly perimeter points are surveyed in order to construct a polygonal drainage feature or a linear fence feature. This is done when aerial imagery is unsuitable for manual digitization of the polygonal feature.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/2b4ad21921e14b9584152f7fd557c868_0engSnohomish County Open Data PortalPublicPolyperimeter [Washington (State)--Snohomish County]Web servicesWashington (State)--Snohomish CountyWashington (State)Last Modified: 2022-11-09