Harvested rainwater can be used in many outdoor and indoor applications. The outdoor uses for rainwater include washing cars, gardening, and watering your lawn. Because rainwater does not contain chlorine or chloramine like city-treated water does, it is more beneficial to use this water for these applications than tap water. Unlike indoor applications, outdoor rainwater applications do not require water to be disinfected to use safely. Indoor uses for rainwater include toilet flushing, washing laundry, bathing, household cleaning, and drinking. Note that, before it can be used indoors, water must be disinfected and further treated before it is safe to use. If you only use rainwater to flush your toilets, it does not need to be treated. However, other uses, especially drinking, require thorough treatment.