This is a critical factor in achieving good quality water. First flush water diverters prevent the first, most contaminated rainwater from entering the tank.

The recommended volume to be diverted is based on an assessment of (1) roof area, and (2) a pollution factor (between 0.5L to 2L of water per m2 of roof area).

The volume, type of downpipe system, and site characteristics will determine the type of water diverter required.

Water diverters with a variable volume chamber are better than “fixed volume” diverters, because they can be customised to the specific requirements of each site.

For best results with a “wet” system, the volume held in the pipes should be added to the roof diversion quantity.

Downpipe Water Diverters are simple and effective first flush devices requiring minimal maintenance.

They are installed at the gutter downpipe or via a T-junction to a new or existing system of 90mm or 100mm diameter PVC downpipes, and are supplied in kit form. Add the appropriate length of pipe based on the quantity of water you wish to divert. To calculate the length of the diverter chamber, consider as a guide that each metre of 90mm PVC pipe holds approximately 7.5L of water. It is preferable to fit the longest length chamber possible, from the roof gutter to within 150mm above the ground (to allow easy access to the end cap), to ensure a better quality water.

Downpipe Diverters should be installed at each downpipe that supplies water to the tank system and are ideal diverters for use with under eaves tanks.

Buried and out of site, an In-Ground Water Diverter is perfect for sloping allotments. On a site with a minimum 5° slope, an In- Ground Diverter allows a “wet” system to be converted into a “dry” system.

Many systems are “wet” because the size of buildings and the placement of tanks away from the buildings mean that there are long runs of pipe underground leading to a riser at the tank. Because the pipes are underground and below the entry point to the tank, even during periods without rainfall, water remains in the pipes. After rainfall when an In-Ground Diverter is installed, not only will the diverter chamber empty, the water held in these underground pipes will also drain out through the diverter. This converts it to a “dry” system and saves water because less water must be diverted in a “dry” system.

In-Ground Diverters also come in kit form - add the appropriate length of 300mm pipe based on the quantity of water you wish to divert.