Rating: 7.8/10.
Too High and Too Steep: Reshaping Seattle’s Topography by David B. Williams
Book about the history of Seattle focusing on how humans have changed its natural landscape, eg by filling in the shoreline and tide flats, creating artificial islands, and leveling hills near the city center. The landscape has changed quite drastically since before European settlement, and how much of the area that we see today has been modified drastically to suit human needs.
Seattle geology is shaped by several features. First, its lakes were carved out by Ice Age glaciation, leaving many hills, so when traveling from east to west, it’s much steeper than traveling from north to south. Secondly, its deep harbor is due to being on a fault line, leaving the area prone to earthquakes. The post-glacial soil is prone to landslides, and the proximity to volcanoes, which have erupted several times recently, adds to the geological complexity.
Seattle was first settled around 1856 and grew quickly through the 1870s to 1890s. During this period, the original shoreline changed drastically as the tidal marsh was filled with sawdust and other materials, so that the present-day area south of Yesler Way has much flatter and softer soil than to the north of this street. In the 1870s, a large area of the Duwamish River tide flats was filled (again with sawdust and other industrial waste). The reclaimed land was used by marginal residents, then a railroad built on this land became essential for transport of coal from the east of Lake Washington. The network of roads and railways were initially as trestles over shallow water, but eventually an organized effort gathered to build a seawall and fill in the land properly around 1910; today, much of downtown Seattle is reclaimed land with a heightened risk of liquefaction during possible earthquakes.
Changes to the Lake Washington area: the Cedar River (near Renton) used to flow to the Black River and then the Duwamish, but in the 1910s, in response to flooding risks, it was dredged to flow directly into Lake Washington, causing many wetlands to disappear with various effects on the wildlife and ecosystem. A series of canals and locks were built to connect Lake Union and Lake Washington to Puget Sound, after which the east side of Lake Washington grew in importance.
The final part of this book is about the regrading (flattening) of Denny Hill, which was a prominent hill close to the city center. Since the area was initially settled near a moderately sized hill, the community gathered in an effort to flatten the inconveniently placed hill starting around 1910, using hydraulic technology from the gold rush. Much of it was done quickly, but it left many houses sitting on mounds above the ground level, which were slowly moved or demolished until the last one was finally removed in the 1940s.
