This data represents LiDAR-derived culverts (lines) for the Milwaukee Metropolitan Sewerage District (MMSD) in 2021. [3D culvert lines and points were generated from lidar bare earth DEM's and 2020 WROC 12 inch stereoimagery. During extraction a degree of user interpretation was necessary in determining culverts versus other similar cultural features. The Lidar base project DEM will be hydro flattened but not hydro-enforced which is typically used on water and flood modeling. To hydro enforce the DEM, we will collect culvert locations across the county. These culvert lines will then be draped to the Lidar point cloud, and the lowest elevation will be applied to the line. We will use the resulting 3D breakline to reclassify the ground points and cut the DEM, allowing water to flow through the culverts, rather than dam against the road bank. This is useful for hydro modeling and land conservation planning across the county.]