For many millennia humans have been shaped by their environment and the vagaries of the climate. Aquatic ecosystems have largely resisted, and have been resilient to, these climate forces. People have increasingly impacted water catchments – using technologies that range from fish traps to drainage systems to inter-basin transfers. The impact of intensive industry can be detected back several thousand years and the great acceleration attests to the recent rapid exploitation of freshwater ecosystems testing our safe operating space. So it should be of no surprise that the freshwater ecosystems we study today are not in the same state they were 250 years ago. While environmentalists and ecologists have warned of the risks to biodiversity for more than half a century, we tend to attribute the cause of the declines we monitor today to recent factors, rather than the legacy effects of historic events. Yet, the force degrading our ecosystems is the sum of the impacts of the past, as well as those of the present. Past changes continue to impact systems, not least in that they have pre-disposed ecosystems and species to catastrophic declines. Rehabilitation of wetlands and rivers is unachievable if we only address proximal causes. How can we promise restoration when it is increasingly clear it is beyond our collective reach? Rather than seeking ways to save everything, the ‘crisis science’ now faces the challenge of deciding which parts of our ecological heritage will persist in the Anthropocene, and what our novel ecosystems will look like in the future.