First flush

When rain falls on a roof or a surface, it washes away all the dust, dirt, and debris that may have collected on it. These pollutants can be harmful and reduce the quality of water that is collected in rainwater harvesting systems.

The first flush is a device that helps to improve the quality of the collected rainwater by diverting the first few gallons of water that run off the roof through a pipe that leads it away from the storage tank. This way, the dirty water that carries dust, dirt, and other pollutants is not collected and stored in the rainwater harvesting tank.

The first flush device works by trapping the first portion of water that comes off the roof or surface in a chamber, where it is left to settle. The water in the chamber is then released and diverted away from the storage tank, allowing only the cleaner water to be collected in the tank as the rain continues to fall. This ensures that the harvested water is of good quality and can be used for various purposes such as watering plants, washing cars, or even for human consumption.

So, in summary, the first flush is a device that helps to improve the quality of collected rainwater by diverting the first few gallons that may contain dirt and pollutants away from the storage tank, ensuring that only clean water is collected and stored.