In a recent interview critical of the current government’s handling of the sewage crisis, Leader of the Liberal Democrats (and candidate for Prime Minister) Ed Davey said that Britain’s chalk streams are ‘really, really precious’ and ‘the equivalent of the Amazon for the UK, they’re so important environmentally.’ But what, exactly, do chalk streams do that’s so vital?

Chalk streams are some of the most unique and valuable freshwater ecosystems in the world, characterized by their crystal-clear waters, stable temperatures, and rich biodiversity. They are globally rare, with approximately 85% of the world’s chalk streams located in England, primarily in the southeast and southwest regions. This rarity underscores their ecological value and the urgent need for their conservation. These streams are fed by groundwater from chalk aquifers, which function as natural filtration systems. The water emerging from these aquifers is crystal clear, mineral-rich, and maintains a stable temperature throughout the year, fostering diverse ecosystems.