Cape Town, South Africa, a city of 4 million people, is just weeks away from becoming the world’s first major city to run entirely out of water — but of course, it won’t be the last. South Africa’s second-largest city after Johannesburg, Cape Town was not an obvious candidate for that dubious distinction. In 2014, its dams were flush with rainwater and its water-conservation strategy was award-winning. Then came the worst drought South Africa had seen in a century, lasting three whole years. Now, the Theewaterskloof Dam, the city’s main reservoir, is at just 13 percent of capacity. Climate change is obviously a factor in Cape Town’s water crisis, as South Africa faces a hotter and drier future, but it’s not the only one. Politics and misgovernment have played a role as well. Even as the city government enacted its aggressive and remarkably successful water-demand-management strategy over the past decade, the national government allocated too much water to agriculture and d...