Over 180,000 people were evacuated from Oroville, California and surrounding areas Sunday evening when water began to severely erode the emergency spillway of a dam at Lake Oroville. As intermittent bursts of storms have soaked northern California in recent weeks the state seems set to break it’s five-year drought streak, although the increased precipitation has brought a host of new problems with it — particularly widespread flooding.

The problem at Lake Oroville, California’s second largest reservoir and home to the nation’s tallest dam, began Sunday evening when the earth beneath a concrete wall designated as an emergency spillway began to erode. State water officials had diverted water to the emergency spillway from the dam’s main spillway after it began to show signs of erosion following heavy rainstorms. The emergency spillway was intended to be the last, best defense against an overflowing lake and had never been used since the dam’s construction in 1964.

Shortly after water started to flow over the concrete wall a problem emerged as a large portion of earth downhill from the wall started to erode, threatening to breach the wall and release millions of gallons of water uncontrolled into the Sacramento River. The resulting floods in surrounding communities would be catastrophic, so officials immediately issued evacuation orders as soon as they noticed signs of erosion and began attempts to mitigate the impending disaster.

Highways branching out from Oroville were quickly choked with traffic, as a minefield of country roads mostly ended in uncrossable flooded sections. Hotels in the closest city to the north, Chico, were sold out by the end of the night Sunday. Sikh temples in the area opened their doors to as many evacuees as they could hold, while thousands are left stranded with no end to the crisis in sight.

In the day since the dam’s two spillways began to show signs of weakness, State officials have rushed to supplement the structural integrity of the ground that eroded. Helicopters are dropping sacks of rocks into a hole created by the water, while a gravel road is being build to the helipad so that trucks can begin to drive in and out, creating a slurry to solidify holes in the earth.

Chris Orrock, a spokesman for the Department of Water Resources said “You’re putting rocks in a hole. Then you’re putting slurry in to solidify it. When water comes down, it will hit that patch and roll off.” The physics aren’t exactly rocket science, children regularly test similar concepts in the form of painstakingly crafted sand castles breached by high tides — only here they play out on a much larger scale, with much more serious consequences.

John France, an engineering consultant with more than 30 years experience working on dams said “The large rocks will break up the flow of water a bit so it won’t have so much energy,” and “If the water has less energy, the underlying structure won’t erode as quickly.” Essentially, it’s a temporary fix that will mitigate the effects of the flow but won’t prevent it all together.

Additionally, a motion to intervene on licensing filed by environmental groups in 2005 clearly predicted precisely the sort of failures that took place over the weekend. The document claims that if the emergency spillway were used, erosion would take place and high voltage towers could be at risk. It says, in part, “Because the area downstream from the emergency spillway crest is an unlined hillside, significant erosion of the hillside would occur,” and “the spillway road and possibly high voltage transmission towers would be impacted.”

That appears to be exactly what happened, despite a response issued by the Department of Water Resources in 2008 with the dam’s final environmental impact report which found that the dam’s structures and emergency spillway were in “good condition”. As the crisis continues to unfold with no end in sight and the surrounding communities become home to over 180,000 internally displaced persons, it’s clear in hindsight how much easier it would have been to prevent this critical piece of infrastructure from failing than it will now be to properly repair it.

With a clear paper trail detailing the exact nature of the catastrophe over a decade before it actually happened and the astronomical potential costs, both financial and human, the Oroville dam should serve as a canary in the coal mine for our nation’s “crumbling infrastructure” as Senator Bernie Sanders frequently referred to it on the campaign trail. Images of clogged highways full of panicked residents desperately trying to evacuate ought to be burned into our minds, serving as poignant reminders of what ignored warnings can result in.

As threats of sea level rise intensify for low-lying coastal cities around the world and the relationship between climate change and extreme weather becomes more clear, the potential effects on our infrastructure are immense. The Oroville dam crisis will inevitably be followed by other, sometimes even more costly extreme weather events. Whether we choose to prepare or react is up to us, although the costs of waiting to react are already evident — especially as more storms are predicted to hit Oroville in the coming days, further pushing the limits of the already stressed spillways.