Book excerpt: Rainwater is the purest form of water on earth and water is a cyclic resource that is continuously cycled in nature and can also be reused for various activities after it is cleaned. Don’t you agree then that harvesting rainwater is something that should be a popular practice? Ancient India was well ahead of time, and civilization as early as Indus Valley already had excellent rainwater harvesting system. But, as we progressed along with the rest of the world, we abandoned our traditional practices; and at present we are trying to reintroduce the ancient conservation techniques and integrate them with the new technology to address our water scarcity. Let’s Save The Rain not only talks about the traditional and modern rainwater harvesting systems, but it is a short introduction to this important water conservation technique. The concept, its uses, and its close relationship with the environment are beautifully elucidated with experiments, DIYs, and math calculations. This book is an easy read that explores the concepts and increase awareness about rainwater harvesting.