First Flush Diverters

by Rain Harvesting

​​Georgia Water Tanks keeps the 3" and 4" Rain Harvesting wall-mounted first flush devices in stock in our Atlanta warehouse. 

HOWEVER, you should know that first flush devices, as popular as they are, are NO LONGER RECOMMENDED by the American Rainwater Catchment Systems Association (ARCSA). The rainwater prefilters such as the Leafeater rainhead, vortex filters, cascading filter, our hydraulic jump filter, have been found to be just as effective at improving water quality, without the need for monthly monitoring and cleaning.

Installing First Flush Devices

This from the manufacturer:

Where should I install my first flush diverter?

Your first flush diverter can be installed anywhere between your roof catchment area and your rainwater tank to isolate and capture the first “flush” of dirty water at the beginning of a rain event. You may choose to install smaller diverters to divert rainwater from each downpipe or you may choose to install larger diverters to divert rainwater from several downpipes.

We (Georgia Water Tanks) strongly recommend the ADDITION of a Leafeater rainhead, or other screening device UPSTREAM of the first flush device, IF you use one at all. This will significantly reduce the amount of debris that would otherwise collect in the first flush chamber. 

Georgia Water Tanks provided the rainwater treatment equipment for the recently commissioned Kendeda Building at Georgia Tech, which is 100% reliant on rainwater as the water source. As a commercial building, the water is treated and tested the same way any public water supply would. It does NOT have a first flush device. In testing the water quality, the operator found that the water IN THE CISTERN was CLEARER THAN THE MUNICIPAL WATER,  even before treatment!

At this point, the only time that Georgia Water Tanks would only recommend a first flush device is for a rainwater-to-potable project for single-family homes. On those projects, the water treatment is typically not as powerful as that for commercial buildings (40K UV instead of 186). Plus, any owner of a rainwater->potable system is going to have to learn more about how they operate. So keeping an eye on the first flush device would be more likely.

Contact Us

3731 Northcrest Rd, Suite 28, Atlanta GA 30340             404-991-0404          rdhanson@georgiawatertanks.com​