Stormwater and rainwater both originate from precipitation, but they differ in how they are collected and what they contain. Rainwater refers to water that falls directly from the sky and is typically collected from clean surfaces, such as rooftops, before it comes into contact with the ground. Because it hasn’t yet touched other surfaces, rainwater is generally cleaner and easier to treat for reuse.
Stormwater, on the other hand, is rainwater that has already flowed over surfaces like roads, sidewalks, parking lots, and landscapes. As it travels, stormwater picks up pollutants such as oil, chemicals, sediments, and debris, which can affect its quality. This makes stormwater more complex to manage and often requires more treatment before it can be reused safely.
