Each neighborhood in Seattle constitutes a population of humans that uses resources and generates waste products. One resource which falls on and drains out of each neighborhood is water. This flux of a valuable resource suggests that one way to envision a sustainable neigborhood is to examine it from the perspective of its watershed(s). As an example, let us study the neighborhoods surrounding Greenlake and Ravenna/Cowen creek in the northern part of Seattle.
- City of Seattle Greenlake page
- " Geologists say the Vashon Glacial Ice Sheet, which also formed Puget Sound and other area lakes, formed Green Lake 50,000 years ago. Dredgings of Green Lake have produced volcanic ash from an eruption of Glacier Peak that occurred about 6,700 years ago.
The lake was included in the Olmsted Brothers? comprehensive parks plan, and was given to the City by the State of Washington in 1905. Green Lake underwent a series of changes over the next 15 years- it was diked, dredged and filled until it shrunk by nearly 100 acres! The last fill deposited in Green Lake was from the excavation of Aurora Avenue.
In more recent times, Green Lake has suffered from stagnation and pollution problems, as well as algae blooms. Milfoil and swimmers itch (caused by parasites from waterfowl) are still a consideration for those who swim in the lake." - kepeter UW Lecturer Greenlake site
- " Greenlake formed 10,000-15,000 years ago during the glacial retreat that carved out the entire Puget trough and also formed Lake Washington. The lake is estimated to have been 35-45 feet deep initialy. As forests returned around the lake, the lake bottom gradually filled with sediment formed from dead vegetation, perhaps losing half its depth by the time Seattle was established. At the turn of the century the lake was surrounded by old growth conifers, with alder and willow along the shore. The lake was developed as a park, between 1911-1915. To build the park, was a challenge, because roads and homes had already closely encroached on the lake's perimeter. So, to create "park space", the lake's water level was lowered 7 feet and its outlet to Ravenna Creek was cut off. In 1936 Duck island was created as a bird refuge of native willows and cottonwood. The island is used by waterfowl and roosting hawks and eagles. A 3 mile trail encircles the lake, which has an average depth now of only 13 feet. Greenlake has great bird watching year round with lots of waterfowl in the winter and migratory birds in spring and fall. Over 160 species of birds have been recorded here. Resident ducks, grebes and coots can be observed nesting in the summer. Bald Eagles and Osprey frequent the lake."
Land use zones in the city of Seattle. Blue = commercial/industrial, purple and red = commercial, orange and yellow = mixed commercial/residential, pale yellow = single family residential.
Image credit: City of Seattle, DCLU