Many rain chain owners have chosen to incorporate their rain chains into water reclamation schemes - this practice is also known as "rainwater harvesting." These systems make rain chains much more valuable than just being simple decorative downspouts. Two popular ways of harvesting rainwater are rain barrels and rain gardens.
Rain barrels are a great way to store rainwater for later use around the house and garden. Rainwater is superior for plants and flowers compared to water from the tap, so it is popularly used amongst garderners who know. Since a rain barrel can draw a lot of attention to itself, it's also more aesthetically pleasing to have a rain chain feeding the barrel than a conventional gutter downspout.
In addition to the reasons already mentioned, rainwater harvesting is also an important way that we can all reduce storwater runoff. Stormwater runoff is a big problem in regards to pollution in urban settings. This type of pollution occurs because there is a high prevalence of impervious surfaces which make it so that rainwater doesn't soak into the ground where it falls. Instead it flows along these surfaces until it is channeled into drains. Along the way, the stormwater can pick up debris, chemicals, and many types of other pollutants where they ultimately get carried into lakes, rivers, streams, wetlands and coastal waters. This can be harmful to the local waterbodies we use for fishing, swimming, and drinking water.
When water is saved for use in the yard (such as in a rain barrel) or funneled into a rain garden, then water can soak back into the ground in a natural way, where it can be filtered by ground soil and vegetation. This allows these harmful toxins to be filtered out by the time they make their way back to inland and coastal water-bodies. Although the impact of one household reducing runoff can seem small, this is exactly where it must begin. And as a critical mass of people in an area engage in these types of practices, there can be a real impact on the improvement of water quality.