On April 23, 1936, construction crews place the last concrete slab of the seawall on Seattle's central waterfront. The wall will protect the fill placed behind it to create a level space on which to build a street and lay new railroad tracks that will be load and unload cargo and passengers from ships.The newly made land replaces an extensive web of piers and trestles on which buildings and railroads straddled the tide that flowed beneath them. The project is funded by the depression-era State Emergency Relief Fund, the city, and adjacent property owners, many of them railroads that had balked at paying for the improvements for decades before the relief funds reduced their portion of the cost. Upon its completion, the City will build Alaskan Way on the new land. Within a decade it will begin planning for the Alaskan Way Viaduct.
Waterfront Teetering on Pilings
Like many coastal cities, Seattle has transformed its shoreline from a sloping beach into a level terrace. Before being filled, the tidelands in Seattle extended to where Western Avenue lies today, around a tip of land about where King Street meets 1st Avenue, inland to the base of Beacon Hill, then around an arc to the mouth of the Duwamish River. A steep bluff jutted up from the beach from north of Piner's Point (today's Pioneer Square) to the Interbay area. The waterfront's only level land lay on Piner's Point, a small point of land extending into Elliott Bay.
The buildings and streets on the central waterfront (west of Western Avenue) perched on pilings in the water. The elevated district began with Henry Yesler's (1810-1892) wharf in 1852. According to J. Willis Sayre, a Seattle journalist and historian, "that wharf [Yesler’s] grew with the village; by the early ‘80s it was more than 900 feet long, a miniature town of shops, stores, and warehouses" (Sayre, 2).
Railroads, too, relied on piers, their tracks running on trestles above the water (where Alaskan Way is today). The elevated waterfront gave wagons, trucks and trains a level place to travel and people a place to work, but the tide continued to flow underneath these thoroughfares and buildings. The wooden pilings supporting the buildings and streets required constant upkeep as the untreated wood deteriorated and the pilings succumbed to teredos (Teredo navalis) and gribbles (Limnoria lignorum) -- marine organisms that chew through underwater wooden structures.
In the late nineteenth century, railroad builders constructed trestles from the mouth of the Duwamish River to Piner’s Point and then northward along the shore. In 1887, the Seattle City Council created Railroad Avenue. Kurt Armbruster explains in Orphan Road that competition for level ground adjacent to the waterfront on which to build railroads led the City to create Railroad Avenue so that it could offer a franchise to a local railroad, the Seattle, Lake Shore & Eastern. The Northern Pacific had the franchise rights to the shoreline along the central waterfront and its trestle blocked any other railroad from carrying cargo to ships on the waterfront. By creating Railroad Avenue and laying out its right-of-way, the city expanded the space on which the city could conduct its maritime business.
As the city grew, particularly after 1897, when Seattle became the primary supply depot for gold seekers on their way to the Klondike, so did the number of railroad lines. By the early twentieth century, nine sets of tracks ran along Railroad Avenue. The area between Western and Railroad avenues filled with buildings and streets, all constructed on pilings.
Makeshifts, Rats, and Refuse
A city built on maritime trade in lumber, coal, fish, and transcontinental railroad freight needed an effective waterfront infrastructure. A 1908 editorial in the Seattle Post-Intelligencer lamented, "There, and there alone, are the makeshifts of a pioneer era permitted to remain. Instead of permanent concrete docks there are temporary wharves on piling, rapidly crumbling under the ravages of the teredo" ("No Further Makeshifts"). The editors called on the City to build a seawall to meet the port’s needs.
In addition to structural issues, the elevated neighborhood also created health concerns. In October 1907, Leong Seng, who lived near the waterfront, died of bubonic plague. Fearing an epidemic, the city health department searched for the source of the outbreak and found it in the rats on the central waterfront.
When health officials inspected the area, they found repulsive conditions. Near First Avenue and Cherry Street, they found
"tons and tons of refuse from the chicken section" of a meat company under the planks ("Crighton Closes Business Houses"). Another report noted, “Between Railroad and Western Avenues there is a vast amount of rotting timbers, planks, boxes, and all kinds of garbage, the waste of commission houses, restaurants, and markets. Within this district are broken sewers and cesspools. One cesspool in particular is ... filled with the most horrible filth that it is possible to imagine" ("Report of the Health and Sanitation Committee").
The appearance of bubonic plague in Seattle jolted the city into action. For a port city, plague could be devastating. If an epidemic began, officials would quarantine the port, barring the exit of docked ships and the entrance of arriving ships until the disease was under control. In addition to their work to eradicate rats, including killing about 60,000 of them in 1908, city officials considered long-term solutions, including building a seawall so that the district could be filled and made more sanitary.
Debating the Seawall
A steep underwater slope just offshore posed difficulties for seawall construction on the central waterfront. At the western edge of Railroad Avenue (north of Madison Street), in many places the water measured 25 feet deep at low tide. High tides could rise as much as 12 additional feet.
The environmental consequences of filling the intertidal zone did not deter the engineers, but the project’s cost did. City engineers wanted to build a vertical concrete and steel wall. Ideally, it would have footings underground to prevent the fill behind it from pushing it outward. Unfortunately, this design was costly for such a tall structure.
A state law, which is still in place today but amended significantly, required that adjacent property owners pay a portion of the costs for any street improvements and also allowed them to block projects. The property owners on the waterfront objected strenuously and repeatedly to proposals presented by the city. Additionally, only one-half of the cost of a project could be assessed to the property owners and the city did not have the funds to pay for the remainder. The city looked at alternative ways to solve the problem, including building less expensive (and less effective) types of seawalls.
In 1909, city engineer R.H. Thomson (1856-1949), the city engineer who spearheaded the effort to level Denny Hill, proposed adding 200 acres of fill into the bay (which would have come from leveling more of Seattle's hills) to solve the problem. Thomson estimated the total cost at $17.5 million, but argued that selling the newly created lots at $5 per square foot would bring a $27.5 million profit to the city. It does not appear that the City or the public seriously considered the plan.
Unable to get agreement on and funding for a comprehensive solution, the City worked on the part of the waterfront that required a less expensive solution. South of Madison Street, where the water depth was shallower, the city built a seawall stretching to the Duwamish River in the 1910s. Meanwhile, north of Madison, the elevated streets required continual upkeep. The Department of Streets and Sewers repaired rotting planks as its budget allowed, but not quickly enough to prevent accidents. An ice truck fell through the road in June 1918. In 1923, a railroad trestle at Broad Street collapsed into the water. By 1933, Mayor John F. Dore (1881-1938) described Railroad Avenue as “a death trap” (Mayor John F. Dore).
Funding and Building the Seawall
The Great Depression solved the funding dilemma. In 1934, the State Emergency Relief Fund granted $396,000 to the seawall project. This reduced the cost to the City and the property owners, and provided a budget of about $1.4 million ($23.6 million in 2011 dollars). The adjacent private property owners paid nearly a third of the cost.
City of Seattle engineers designed a seawall that utilized steel sheet piling topped by a concrete wall and supported by a wooden relieving platform. The relieving platform is located 13 feet below street level, behind the seawall. The weight of the ground above it holds the relieving platform in place on top of pilings driven into the ground. Connected to the wall and anchored to the pilings, it counters the outward pressure of the fill that is resting on the sloping beach. Manson Construction & Engineering Company placed the relieving platform pilings into the ground behind the wall. Workers then recorded the location of each of the pilings relative to the adjacent pilings. Off-site, workers built pier caps, grids of 60-inch by 12-inch by 18-inch timbers, then floated them in to the seawall construction site at high tide and lowered them into place as the tide receded.
Workers drove steel sheet piling, large, corrugated sheets of metal, into the sea bottom then placed pre-cast concrete slabs, 18 inches thick, eight feet wide, and 20 feet long, on top of the metal and connected them to the relieving platforms with poured concrete.
Workers lifted the last section of concrete into place on April 23, 1936. To fill the void behind the wall and to create level ground on which to build a roadway and lay new railroad tracks, scows (barge-like boats) brought in 667 loads, about 250,000 cubic yards, of fill from the mouth of the Cedar River at Renton. This volume of fill is equivalent to a column of dirt and gravel more than 100 feet high on the CenturyLink football field.
Later that summer, Alaskan Way opened on the newly created land. The city named the street in recognition of Alaska's role in Seattle's economic development. The roadway quickly increased the popularity of the waterfront as a bypass route around downtown's crowded streets, to the frustration of maritime businesses and railroads that had to maneuver around the automobile traffic. Calls for an elevated roadway on the waterfront, which began in 1910, continued. Planning for the Alaskan Way Viaduct started in the mid-1940s.