Mercer Island is a small city and because of its restriction to the island, it will never be a large city. However, in the 12 years that I have lived here, there have been huge changes to the physical structure of the downtown, with highrise buildings replacing one- and two-story structures. The watercourse that runs through downtown is the most polluted on the Island. Yet, I do not see any plan to mitigate stormwater runoff from downtown.
It is much easier to plan for and implement stormwater flow reduction before buildings are built rather than try to retrofit years later. In European cities and in American cities, green solutions to stormwater runoff and pollution are much cheaper to build than alternative gray structures.
With much downtown construction yet to come, Mercer Island should require green stormwater solutions for all new buildings in the downtown area and any place large buildings are constructed on the Island, including our schools.
Urban forests help reduce stormwater runoff, yet our tree ordinances only apply to trees in critical areas. Large trees provide more ecological services (per Seattle Times http://seattletimes.com/html/localnews/2019878659_oldtrees11m.html) than small trees, yet we allow them to be cut down by homeowners without restriction, except in critical areas.
I want to see Mercer Island better plan for our urban forest and stormwater runoff. There is a good article on case studies of how other cities, albeit much larger, are planning for urban forests and managing stormwater at: www.americanforests.org/our-programs/urbanforests.