With the help of these reliable First Flush devices, the first rainwater that flows from your rooftop, which usually contains the grit, gravel, dirt, debris, and other things stuck up there, is diverted to a chamber that slowly releases the dirty water over time. This effectively prevents that water from ever getting into your tanks. The capacity of the device can be infinitely variable as determined by the chamber length and diameter. This allows you to adapt it to suit the amount of water you want to divert when it starts to rain. These first flush devices require regularly cleaning to ensure that the dirty water empties and it’s ready for the next rainfall that comes along.