The Dawson Dike: How the City Was Saved from Flooding

In the spring of 1898, before the dike existed, the Yukon River flooded the lower streets of Dawson City. The flat on which the city had been built — a natural river terrace at the confluence of the Klondike and Yukon rivers — was only a few metres above the river's normal level, and when the spring breakup sent a surge of ice and snowmelt downstream, the water rose to cover the lower sections of Front Street. Buildings flooded. Goods were lost. The residents who had not moved their property to higher ground in time found the lower floors of their establishments under water. This was not a surprise to anyone who had looked carefully at the geography of the site before building on it. The flat where Dawson City was established was an obvious flood risk — a low-lying river terrace that had clearly been inundated many times in its geological history, as evidenced by the silt deposits and the general flatness of the terrain. The decision to build there anyway was driven by the practical requirements of the rush: the flat was the closest available buildable land to the confluence, it was accessible by river, and there was no time to be careful about flood risk when thousands of people were arriving and needing buildings. The flooding that recurred with varying severity in subsequent springs was a persistent problem. The solution — a dike along the riverfront — was discussed for years and implemented in stages, with various improvements and extensions over time. The current dike system, maintained by the Yukon territorial government, protects the riverfront and lower sections of the city from the kind of flooding that was an annual risk in the early years. ## How the Breakup Works The spring breakup of the Yukon River ice is one of the most dramatic annual events in northern Canada, and understanding it helps explain why flooding in Dawson City is a recurring concern. Through the winter, the river freezes to a depth of several feet, and the ice forms a continuous cap from bank to bank over the river's entire navigable length. As temperatures rise in the spring, the ice begins to weaken and melt from above and below simultaneously. The breakup happens not as a gentle thaw but as a sudden, violent release. When the ice weakens enough and the water pressure from upstream becomes sufficient, the ice breaks into large sheets and slabs that are carried downstream by the current. At points where the river narrows or bends, the ice jams — piles up in great ridges that can stop the flow and cause the water level to rise rapidly behind the jam. The ice jams at Dawson City, where the Yukon River makes a turn and narrows slightly, were historically severe. The water level behind a jam could rise several metres in hours, and when the jam released — as it always eventually did, with a crack and roar audible throughout the town — the surge of water and ice that followed was violent enough to do significant damage. ## The Klondike Sweepstake The breakup of the river ice was so important to Dawson City's life that it became the subject of one of the oldest and most beloved community events in the Yukon: the Klondike Sweepstake. Residents buy tickets predicting the exact day, hour, and minute that the Yukon River ice will break up and the official marker — a tripod mounted on the ice — will move. The sweepstake has been running in some form since the early years of the rush, though its formal organization into the institution it is today developed over the following decades. It is one of the most purely northern events in Canada: a community betting pool on a natural phenomenon that has direct consequences for the community's safety and wellbeing. The person who predicts the breakup most accurately wins the accumulated pool of ticket sales. The sweepstake dates have shown remarkable consistency over the decades, clustering around late April and early May, with variations of several weeks in either direction depending on the year. Warm springs produce early breakups; cold springs delay them. Climate change has affected the average date, trending slightly earlier over the past several decades. ## The Dike in Practice The Dawson City dike is not an impressive piece of engineering by the standards of major flood control infrastructure. It is essentially a raised earthen berm along the river bank, reinforced and shaped to hold back the kind of flooding that the historical record suggested was the realistic maximum. It does not protect against all possible flooding — an extreme ice jam event could overtop it — but it manages the ordinary spring flood risk effectively. The maintenance of the dike is a regular responsibility of the territorial government's infrastructure program. The permafrost challenges that affect all Dawson City infrastructure affect the dike as well — ice-rich permafrost in the dike foundation can cause subsidence if it melts, and monitoring the dike's structural integrity is an ongoing requirement. The dike also has an effect on the visual character of the Dawson waterfront. The river, from the main streets of Dawson City, is seen over the crest of the dike rather than directly from the bank. This is not a problem in terms of the view — the Yukon River is visible and impressive from the waterfront — but it does create a slight sense of distance between the city and the river that would not exist if the dike were not there. ## Floods in Living Memory Despite the dike, Dawson City has experienced significant flooding in the past several decades. The flood of 1979 was particularly severe, causing damage to buildings and infrastructure throughout the lower sections of the town. More recent high-water events have also caused problems, sometimes requiring emergency response from the community and government. Each flood event adds to the community's knowledge of what the river can do and what the infrastructure needs to manage it. The residents of Dawson City have a relationship with the spring breakup that combines dread, fascination, and a kind of grudging respect for a natural process that the city has been living with for a hundred and thirty years. The [Dawson City Travel Guide](/guide/dawson-city-travel-guide) covers the seasonal rhythms of Dawson City, including the breakup and the Klondike Sweepstake. If you are visiting in the spring — particularly in late April or early May — the breakup is one of the events that defines the Yukon experience, and Dawson City is one of the best places to witness it. Bring waterproof footwear, watch the river carefully, and understand that you are watching something that the city has been watching anxiously every spring since 1897.