The warnings signs were visible, for those who wanted to see them.

Five years ago, the World Economic Forum asked its members to rank the calamities that posed the greatest threat to society. That year, in the middle of the Ebola outbreak in West Africa and while SARS-CoV-2 was still only circulating among bats, respondents deemed the spread of infectious disease the number two risk in terms of impact. The citizens of 2020, who have endured lockdowns, job losses, travel restrictions, and the deaths of friends and family during the pandemic, would surely agree. In retrospect they might even lift infectious disease to the top spot.

What was the top-ranked risk in that survey of five years ago? Water crises.

Water crises, in many ways, are not like a pandemic, an event with a single, triggering cause. They are more diffuse and multi-faceted, and an individual crisis is usually constrained, not reverberating globally. But like the pandemic, water crises stem from environmental neglect and failures of leadership, and the repercussions of both are becoming more apparent every year.

2020 was no different.

Manmade systems were tested by supercharged weather and lax oversight. Water levels behind the Three Gorges Dam were the highest since the dam began impounding water in 2003. Operators were said to be on “wartime footing” to manage the inundation from a severe rainy season in southern China that caused an estimated $32 billion in flood damages.

The Three Gorges held, but structures elsewhere could not withstand mounting pressures. In Uzbekistan, the Sardoba Dam, completed just three years earlier, collapsed in May following days of rain. More than 100,000 people were evacuated. That same month in Michigan, two dams upstream of Midland failed during heavy rains. Soils were already saturated in the state, whose coasts were also besieged by record-high levels in lakes Huron and Michigan.

Shifts in water availability affected commercial infrastructure, too. In Panama, managers of the Panama Canal considered a range of water-supply projects to keep the vital shipping route viable during extended drought. To raise funds, the authority introduced new fees in February that apply to large ships using the locks in the waterway that connects the Atlantic and Pacific oceans. Farther south, record-low water levels in the Parana River in Argentina resulted in ships running aground and cargo restrictions that limited soybean exports.

Not all was gloom, though. Water use in the American West continued its downward trend as conservation policies in the drying region paid off. A coalition of governments, businesses, tribes, and green groups pushed forward with tearing down four dams on the Klamath River of California and Oregon, in what will become the world’s largest dam removal. Lead service lines in Flint have nearly all been replaced. And the government of Denmark, though a small producer, set a 2050 timetable for ending oil and gas production from its North Sea fields.

Then there was the pandemic, which not only exposed the cracks in public health systems. It also laid bare the intimate bond between water, sanitation, hygiene, and health. Ensuring that households had adequate water during a health emergency was suddenly a top priority for municipal and national leaders. The governor of Michigan ordered all homes without water service to be reconnected, while the president of Ghana said the central government would cover the water bills of all residents for the months of April, May, and June.

All years impose their discomforts. This year, in truth, stood out. Not just for the trials of the last 12 months. But as evidence of the tests yet to come. Environmental challenges of water, climate, and health are real and growing — visible for those who want to see them.