FIRST FLUSH & CONTINUOUS SEDIMENT EXTRACTION - Supadiverta - syphonic rainwater diverter

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Remove the sediment & dirty water before it enters your tank

First flush is the dirty water that is washed from the roof and gutters when it first rains, continuous sediment extraction is the removal of sediment throughout the entire rain event.

NOTE: Flush diverters are commonly used to capture this initial roof wash but many fixed volume first flush diverters have endemic problems including dripper blockages, small capture volumes and an inability to continuously capture sediment when full of water. This is not a problem with SUPADIVERTA!

AQUATREK has designed a simple and efficient first flush kit that fits below the Supadiverta middle (flush) outlet.

NOTE: If using the Supadiverta without the optional first flush kit, Aquatrek recommends connecting a vertical length of 19 mm or 25mm poly pipe or a 20 mm PVC pipe to the middle outlet. Fit a 90 degree elbow to the bottom of this pipe, join this  to a length of horizontal pipe and then fit an inline tap to the end so that the pipe can be manually drained. Do not fit the inline tap to the vertical pipe as sediment sitting on the inner turning mechanism will make the tap difficult to turn.         
This will be nowhere near as efficient as our first flush kit but it will capture some of the dirt and grit that would normally enter your tank.

Features and benefits include:

  • Neat and easy installation.
  • Designed for 100mm (104mm I.D.) PVC pipe which holds 8.5 litres per metre.
  • The flush chamber is not subject to the venturi effect that normally draws and recycles the captured flush unless a ball float is used to seal the flush chambers when full. Deleting the float allows most of the debris that passes through the 750 micron filter and falls to the reservoir floor to be diverted to flush throughout the entire rain event.                       
  • The supplied 19mm inline tap is manually opened to drain the flush chamber. The tap also allows the manual diversion of additional first flush during times of higher contaminant concentration after dry periods.
  • The inline tap also eliminates the small drip outlet common to other diverters. Small drip apertures frequently block, requiring manual extraction of collected flush debris and sediment. This messy and high maintenance regime is avoided with the Supadiverta flush kit.

Rainwater quality and retardation of sediment build up is substantially improved by the high yield 750 micron filter continuously diverting solid bird droppings and other debris throughout the entire rain event. Fitting the optional 100 mm first flush kit will give further substantial improvement.


  • Fit the inline tap to a horizontal section of 19mm polypipe to prevent sediment sitting on the tap’s internal turning mechanism.
  • The supplied air purge tube vents the flush chamber and must be fitted as per the supplied instructions.

Supadiverta First Flush Kit
One 25mm x 3/4” BSPM barbed director
One 300mm length of 4.5mm breather tube
One 100mm length of 25mm poly pipe
One 25 mm ratchet clamp
One top cap with 25mm inlet
(a lug on the underside locates the breather tube and clamp)
One x 4.5mm hose clamp
One bracketed bottom cap with 19mm outlet
One 19mm ratchet clamp
One 250mm length of 19mm poly pipe
(supplied in one length, the buyer cuts it to a size to suit)
One 19mm barbed elbow
One 19 mm inline tap

CUSTOMER TO SUPPLY: Required length of 100mm DWV pipe
For quality rainwater harvesting, gutters must be regularly cleared of leaves and debris.

Help the environment by diverting the bottom section of downpipe to a Rain Garden which filters the water before returning it to storm water.
Some States encourage homeowners to divert storm water to rubble pits and soak wells to recharge the ground water. Home owners need to be aware of local regulations.
NOTE: If diverting to a tank and the Supadiverta’s overflow has been height adjusted to substitute as the tank’s overflow, the Supadiverta may retain water in the internal reservoir when the tank is full. If the flush chamber is drained under these circumstances, it will refill when water backflows from the tank back into the reservoir.

To drain; close the tank’s infeed valve and drain off the first flush. The infeed valve can then be opened once the tank’s level has dropped below the level of the Supadiverta outlets.

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