Dam bursts on Lake Union, temporarily lowering the lake by nearly nine feet, on March 13, 1914.

  • By David B. Williams
  • Posted 12/07/2016
  • HistoryLink.org Essay 20222
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On March 13, 1914, high water in Lake Union leads to the failure of the Fremont Dam at the lake's western outlet. The lake drops 8.5 feet in 24 hours, which results in washed-out bridges, the loss of many docks, and houseboats dangling above the water. The Army Corps of Engineers quickly repairs the dam and little long-term damage is done. This is the fourth and final time that one of the dams on the route of the Lake Washington Ship Canal, the series of linked waterways being constructed between Puget Sound and Lake Washington, has failed to hold back water as it was supposed to.

Dam Bursts

One of the challenges of building a dam is the possibility of failure. The structure can fail due to natural causes, such as earthquakes, landslides, or a swollen reservoir caused by high rainfall or significant snow melt; material causes, such as poorly poured concrete or inferior subsurface; or nefarious human causes, such as dynamite or ramming the structure with a large object. In Seattle, this engineering challenge has played out most vividly in the Lake Washington Ship Canal and Hiram M. Chittenden Locks.

Substantially completed in 1916 and officially dedicated the following year, the canal and locks consist of a pair of locks and an overflow dam in Ballard and artificial waterways, known as cuts or canals, between Lake Washington and Lake Union and between Lake Union and Salmon Bay. The term "ship canal" typically refers to the entire route from salt water to freshwater; the modern connectors are known as the Montlake Cut and Fremont Cut, though some also refer to them as canals.

Throughout the history of the ship canal, dams (not including several cofferdams that were built as temporary structures) have been built in four locations: the narrows in Ballard separating Salmon Bay and Shilshole Bay, the west side of Lake Union, and two on the isthmus between Union Bay in Lake Washington and Portage Bay in Lake Union. All but the first location, where the present overflow dam and locks are located, experienced dam failure. Dam bursts happened twice naturally at the west side of Lake Union site and two others, one at each end of the connection between Portage Bay and Union Bay, were caused by dynamite.


The first dam burst occurred on January 22, 1899, before construction began on the government-funded project that finally created today's ship canal, but long after private efforts had made smaller connections between the lakes. Newspaper articles noted that dynamite had been used to blow out a wing and gate at the dam that separated Union Bay and Portage Bay. A dam and locks had been built in 1884 and 1885 at the west end of a narrow cut, which was about wide enough for a small boat and was where State Route 520 was later built. When the dam was dynamited, excess water escaped from Lake Washington into Lake Union and caused the smaller lake to rise about two and a half feet above its normal level. Fortunately, little damage occurred.

Curiously, blame for the explosion was placed on farmers in the White River Valley. Prior to 1916, when the ship canal rearranged the region's hydrography, winter was typically the time when Lake Washington was at its highest level, as much as seven feet higher than the summer low. For most of the year, Lake Washington drained out at its southern end in Renton through the Black River, which flowed for about three miles into the White River to form the Duwamish River. When the lake was high, however, it flooded the Black River and caused wide-spread flooding in the White-Duwamish River valley. For decades, farmers in the valley had sought to lower Lake Washington so that it would no longer flow out through the Black River. No one, however, was ever prosecuted for the explosion at the dam in Seattle.

(In 1906, however, farmers did impact the flooding problem. During a huge flood on the White River, the river -- with some help from locals -- changed its path to flow into Tacoma's Commencement Bay. That left only the Green River, which formerly had joined the White somewhat before the Black did, to join the Black and form the Duwamish. Completion of the ship canal led to the death of the Black River, because Lake Washington's level dropped below the outlet to the Black. The outlet of the Lake Washington is now through the locks in Ballard.)

Rain and Rats

Four years after the 1899 dynamite-caused burst, the dam on the west side of Lake Union failed at 6 a.m. on October 7, 1903. This time the cause was natural: Heavy rain had helped create a hole on the side of the dam that let water into what was known as the Government Canal, which had been built in 1901 and was a predecessor of the modern Fremont Cut.

"As soon as the hole appeared in the one side of the dam the earth began to melt away and in a few minutes the whole sheer had been cut out as cleanly as with a knife. Then the north embankment went, too, and the roar of the swollen flood could be heard a long distance" ("Lake Union Dam Gives Way ...").

"In a short time the street-car and wagon bridge across the canal on Fremont Avenue was in danger. Pile supports hung loose at the lower end and two large boom logs that had come down lay against the bridge supports with a tremendous force of water bearing them down" ("Floodgates and Dam ...," 2).

So much water escaped that it tripled the width of the canal between Lake Union and Salmon Bay, which was pleasing to some. "The water was digging the canal, digging it deep and wide, and Fremont was glad. Notwithstanding that a calamity was upon them eminent citizens were rejoicing" ("Floodgates and Dam ...," 1). Many people had long wanted a wide canal and the flood was finally doing what man had not yet accomplished. By the next day, the Army Corps of Engineers had built a temporary dam. No one was hurt, though traffic on bridges across the Government Canal was interrupted.

A high water level in Lake Union may have been the primary reason for the dam failure but Joseph (John) M. Clapp (1866-1937) of the Corps looked to another villain. He told a reporter, "From the number of dead rats that I have found since the washout, I believe that they were responsible for the leak, to large extent" ("Lake Union Dam Gives Way ...").

Dynamite Again

Dynamite was used again on October 26, 1910, to blow out a dam between Lake Washington and Lake Union. This time the dam was at the eastern end of the Montlake Portage at the site of a new canal, which workers had started to excavate in 1909 and completed in the summer 1910. Known as Erickson's cut, it had been dug by contractor Charles J. Erickson (1852-1937) and was considered to be the first step in the process of creating the Lake Washington Ship Canal.

Erickson's cut was not originally supposed to be deep enough to hold water year-round; it was designed to have water in it only when Lake Washington was approaching its high, winter level. In this situation, water was supposed to flow out of the lake through the cut into Lake Union. The goal was to keep Lake Washington at a level where it didn't flood into the Black River.

Although this sounded like a good idea, Corps officials changed their minds and decided that it would be more practical to excavate a deeper cut that would allow Lake Washington to drop to the level of Lake Union after the full ship canal was completed. Until then, a gate system would be installed to control water flow, allowing enough in prevent flooding down the Black River, but not so much that Lake Washington's water level dropped further.

Not everyone liked the idea of lowering Lake Washington. A group of waterfront property owners on the east side of the lake, led by William L. Bilger (1862-1941), sued the state, King County, and Erickson to stop the contractor. The owners' lawyers argued that the new lake level would damage their properties and "that no provision has been made for paying such damages" (Bilger v. State, 459). The suit eventually led to an injunction imposed on October 22, 1910, which prevented Erickson from opening the gates and allowing water into his cut.

The injunction, however, did not apply to the United States government, so Captain Arthur Williams of the Corps ordered Erickson's foreman, Robert A. Carlson, to dynamite the embankment and let water into the cut, which he did at 4 p.m. on October 26. Judge John R. Mitchell (1861-1939), who had issued the earlier injunction, immediately issued a new injunction that included the U.S. government, and all work stopped on the project. Mitchell also held Erickson and Carlson in contempt of court, which led to years of legal wrangling that ultimately reached the U.S. Supreme Court. The justices ruled that Williams had not had the authority to order Carlson to blow up the embankment, but by this time -- May 1914 -- the question was moot as another contractor had further excavated Erickson's cut and developed it into the modern canal.

Final Dam Burst

The final burst -- due again to high water -- occurred on March 13, 1914, and led to the lowering of Lake Union by 8.5 feet in 24 hours. The flood waters released in the outburst when the Fremont Dam gave way washed out the Fremont Bridge, wrecked Northern Pacific train trestles, and took out several docks. Worse off were Lake Union's houseboat residents, whose homes were left tilted at odd angles after the water drained out. The Seattle Times interviewed C. M. Britton and William McCauslin, who lived in a houseboat on the east side of the lake. The lowered lake left them perched "almost perpendicular" to the lakebed, and they also "were having considerable trouble in cooking their dinner on the kitchen range, as the food would only brown on one side" ("Lowering of Lake Water ...," 9). Fortunately, the flood did not damage the locks that were then under construction.

Crews built a temporary dam to stop the flow, followed by a full replacement about a month after the original dam broke. With the outflow stopped, the Lake Union's water returned to its normal level, righting the tilted houseboats. The Fremont Bridge was quickly rebuilt. The east half was open to wagon and pedestrian travel by April 1, although the west side didn't reopen for another month or so. It was this rebuilt bridge that was replaced in 1917 with a new one (still in use a century later) spanning the newly opened ship canal.


"Lake Union Portage Dam Blown Out," The Seattle Times, January 28, 1899, p. 5; "Lake Are Still Rising," Ibid., January 29, 1899 p. 9; "Waters of Lake Christen Canal for First Time," Ibid., October 27, 1910, pp. 1,13; "Lake Dam Goes Out and Flood Wrecks Bridge," Ibid., March 13, 1914, pp. 1, 2; "Lowering of Lake Water Menaces N.P.," Ibid., March 15, 1914, pp. 5, 9; "Fremont Bridge Put in Operation Again," Ibid., April 1, 1914, p. 11; "Flood Threatens Fremont," Seattle Post-Intelligencer, January 28, 1899, p. 3; "Floodgates and Dam Carried Away," Seattle Post-Intelligencer, October 7, 1903, pp. 1-2; "Canal Enjoined; Advocates Not at All Worried," Seattle Post-Intelligence, October 23, 1910, p. 2; "Lake Union Dam Gives Way and Government Canal is a Raging Flood," Seattle Star, October 7, 1903, p. 5; William L. Bilger v. The State of Washington, 63 Wash. 457, 116 P. 19 (1911); David B. Williams, Jennifer Ott, and the staff of History Link, Waterway: The Story of Seattle's Locks and Ship Canal (Seattle: HistoryLink, 2017).

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