It’s a well-established fact that forests and water are deeply connected. For decades, paired-watershed experiments have shown that when we lose forests, the total amount of water flowing through our rivers tends to rise. But a critical question has remained unanswered: does this extra water come from previous reserves, or is it simply “new” rain that the land is failing to hold? Is forest loss causing our watersheds to lose their internal integrity and leak like a sifter? Our recent study at the University of BC analyzed 657 watersheds across the globe. By using a tool called the Young Water Fraction, we found that forest loss significantly accelerates how fast precipitation travels through a landscape. We estimate that for every 1% of forest lost, the “young water” in our streams increases by about 0.17%. Crucially, our research reveals that… the way we arrange forest patches can either aggravate or mitigate this leakage.