albeit life-limited ones. Further, conventional systems generally do not consider full cost accounting. The natural drainage system alternatives can also provide returns on investment by improving urban environments. The street edge alternatives street breaks most of the conventions of 150 years of standard American street design. Narrow, curved streets, open drainage swales, and an abundance of diverse plants and trees welcome pedestrians as well as diverse species. Adjacent residents maintain city infrastructure in the form of street "gardens" in front of their homes, visually integrating the neighborhood along the street. The natural drainage system united the community visually, environmentally, and socially. The 110th Cascades SEA (2002–2003) are a creek-like cascade of stair-stepped natural, seasonal pools that intercept, infiltrate, slow and filter over of stormwater draining through the project. Example projects Viable, daylighted streams exist only where neighbourhoods are intimately connected to restoration and stewardship values in their watersheds, since the health of an urban stream can not long survive carelessness or neglect. With impervious surfaces having replaced most of the natural ground cover in urban environments, habitat for wildlife is dramatically reduced compared to historic baselines. Hydrologic changes have resulted, and impervious waterways directly carry non-point pollution through urban creeks. One effective solution is to restore streams and riparian habitat. This improves the entire urban watershed, far beyond the riparian channel itself. Wild et al 2011 described the first known online map and database of urban river daylighting projects. Wild et al 2019 published geo-spatial database about all schemes. University of Waterloo documented a very similar list featuring many of the same stream daylighting projects around the globe. Switzerland Zürich The City of Zürich’s stream daylighting policy has long received the attention of researchers and is considered by some to be unique in the world. It had been adopted since 1986 and ensued in daylighting nearly 21 kilometers of Zürich’s buried streams thus far. The positive impact on the quality of water and biodiversity has been significant. There are also benefits for enhanced stormwater management, and even socio-cultural benefits such as, enhanced public realm and educational ones. Canada Vancouver, British Columbia In the 1880s there were over 50 wild salmon streams in Vancouver alone. However, as Vancouver grew, these streams were lost to urbanization. They were covered by roads, homes, and businesses. They were also lost when they were buried beneath sewers or culverts. The City of Vancouver and its