Chicago reversed its river in 1900 to divert sewage from Lake Michigan; 126 years later, it flows backwards

To combat outbreaks of disease linked to polluted drinking water, Chicago undertook an extraordinary engineering project to reverse its river's flow.

This initiative, aimed at diverting sewage from Lake Michigan, successfully bolstered public health over the decades.

Despite facing legal struggles from neighboring Missouri and other states, the new river connection has inadvertently introduced fresh ecological challenges that could disrupt local ecosystems.