On May 27, 1907, the Jackson Street regrade begins in Seattle. Though less ambitious than the city's Denny Hill regrades, the Jackson Street project is the largest single hill ever cut down in Seattle, encompassing nearly six miles of streets comprising approximately 56 city blocks. The hill stretches south from Washington to Lane streets and east from 6th Avenue S to 12th Avenue S (today part of the Chinatown-International District), and it is washed away with high-pressure water hoses. Its dirt is channeled to nearby tidelands, where it rebuilds an area from King to Atlantic streets between 4th and 8th avenues S. The project will be substantially completed in December 1909, though ancillary and cleanup work will continue into 1910.
Can Do
The success of the initial Denny Hill regrades and other, smaller projects in Seattle in the early twentieth century encouraged civic boosters to take on the regrade of a large hill located just southeast of the city's downtown core. The hill on and near Jackson Street between 6th and 12th avenues S was proving to be an impediment to the burgeoning growth of Rainier Valley to the southeast, and residents of the valley complained of having to traverse its harsh street grades – in places as much as 19 percent – to and from their jobs in downtown Seattle. But the hill also caused an economic problem. It was still the era of the horse and wagon, and steeper hills required more horses to haul the same weight than what was needed on a gentle slope or none at all. In turn, this increased shipping costs as much as five-fold on Seattle's steepest streets. In a can-do era when confidence in reshaping the city was high, Seattleites turned their eye to regrading the hill, and the project became known as the Jackson Street regrade.
The job was feasible. The hill was primarily compact dirt instead of solid rock, making it relatively easy to blast away. The idea quickly gained traction, and in October 1905 the requisite petition from property owners in the affected area was submitted to the Seattle City Council. "It will be the largest quantity of dirt moved in any (single) regrade ever attempted in the city," wrote The Seattle Times, and it was a monumental task indeed. Nearly six miles of streets and approximately 56 square blocks were impacted, but in opposite ways; 29 blocks would be regraded, while 27 would be filled with dirt from the regrade. The filled area would build up the low-lying tideland flats south and west of the hill and bring it level with the regraded area. The hill to be cut stretched south from Washington to Lane Street and reached east from 6th almost to 12th Avenue S. The land to be filled ran east from 4th Avenue S at King Steet, reaching east just past 6th and King Street before expanding southeast before the work ended just north of Atlantic Street between 4th and 8th avenues S.
In February 1906, the city council passed an ordinance authorizing the project. Many thought that it would soon begin, but the start was repeatedly delayed. The problem was that part of the work involved private land, and it was necessary for the city to take legal action to condemn many of these properties. Proceedings dragged on well into the autumn of 1906, and it was the following January before the city finally solicited bids for the project. The Lewis Construction Company, doing business as Lewis & Wiley, was the sole bidder.
Following the Grade
Work began on May 27, 1907, when two hydraulic hoses, commonly referred to as giants, began blasting away at the hill at its base at 8th Avenue S and Lane Street. The giants were fed by water from the Beacon Hill Reservoir, which was supplemented with water pumped from Lake Washington. In 1908, a new pump was installed at the foot of Connecticut Street that drew salt water from Elliott Bay. Wooden pipes made from fir trees delivered water to the worksite, where workers stationed in pits directed the water onto the hill. When all the pumps were in operation, six hoses fed up to 25 million gallons of water to the job site each day. The dislodged dirt and rock were directed by a pipe connected to a flume that sent the slurry south to the tidal flats below the hill to be used for fill.
The first part of the regrade knocked out the southern and western sides of the hill, and by the beginning of 1908 considerable progress had been made. The work slowly moved east, following the increasing grade of the hill. In September 1908, the project passed the halfway point. By this time the southern and western part of the hill was almost gone, while Seattle Boulevard (now Airport Way S) had been raised 30 feet at 6th Avenue S. In October, streetcars began operation along newly graded Weller Street.
Work steadily continued into 1909 and was about 70 percent complete when it abruptly stopped shortly after the first of the year. A dispute had arisen over the amount of assessment fees charged to private property owners, which was far higher than what they had agreed to when they signed the petition approving the regrade. In November 1908, the state supreme court ruled that the assessment was invalid. Many property owners, feeling they had been tricked by the city, were no longer inclined to pay anything. The city had in part relied on assessment revenues to fund the job, and a large contract deficit loomed. Lewis & Wiley abandoned the project for nearly a month, until enough property owners cooled off and agreed to pay what they had originally agreed to more than three years earlier.
Work resumed on February 8, moving east along the crest and eastern flank of the hill near Jackson Street between 9th and 12th avenues S. The hill was at its highest at Jackson and King and 9th and 10th avenues S, and it was there that the deepest cuts were made. To illustrate, at 6th Avenue S and Jackson Street a relatively modest 11-and-a-half feet of soil was removed, while at 9th and Jackson the cut measured 85 feet. (At least one cut on private property near 10th Avenue S and Jackson Street reached 100 feet.) The grade on Jackson Street was reduced from a high of 17 percent to 5 percent, and other nearby streets enjoyed a similar leveling.
The Jackson Street regrade was largely completed in December 1909 when sluicing operations ended. Approximately 3.35 million cubic yards of dirt were moved, and the final contract price was $455,226 – about $15.2 million in 2024. On the western edge of the regrade site, which had been complete for more than a year, construction was briskly underway. Farther east a muddy mess remained, with some streets incomplete and others still blocked from the regrade work, resulting in arduous traffic jams and plenty of complaints. Work to finish the streets and clear some slides continued through the winter, until Lewis & Wiley provided its final estimate to the city on February 28, 1910, and formally reported that the project was complete.
