First Flush Water Diverters improve rainwater quality and safety, help extend the life of pumps (used to distribute rainwater for use in and around the home) and internal appliances that draw upon rainwater (such as laundry, toilets, hot water systems and dishwashers), and reduce tank/cistern maintenance.

First Flush Diverters from Rain Harvesting are simple to install, operate automatically to help prevent pollution of tank water, and are available in a number of different sizes to suit specific requirements.

Types of First Flush Water Diverters (or 'Roof Washers'):
Downspout Diverter
Post, Wall or Stand Mounted First Flush Diverter
In-Ground First Flush Diverter

How do they work?

When it rains, water slowly builds up in the roof guttering system before it exits through the downspout. The first flush of water from the roof can contain amounts of bacteria from decomposed insects, skinks, bird and animal droppings and concentrated tannic acid. It may also contain sediments, water borne heavy metals and chemical residues, all of which are undesirable elements to have in a water storage system.

Instead of flowing to the water tank, these pollutants are diverted with the initial flow of water into the chamber of the water diverter. The water diverters from Rain Harvesting utilise a dependable ball and seat system - a simple automatic system that does not rely on mechanical parts or manual intervention.

As the water level in the diverter chamber rises the ball floats, and once the chamber if full, the ball rests on a seat inside the diverter chamber preventing any further water entering the diverter. The subsequent flow of water is then automatically directed along the pipe system to the tank/cistern.

For a Water Diverter to work effectively, the contaminated water in the chamber must be sealed off. This prevents the water passing to the storage tank and ensure the water does not "syphon" off the contaminated water in the chamber. The simplest and surest way to do this is with a floating ball and seat.

A slow release valve ensures the chamber empties itself after rain and resets automatically. The diverted water need not be wasted water because the drain pipe from the diverter chamber can be fitted to a standard drip irrigation system.

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Downspout Diverters

Simple and effective first flush devices, they are installed at the downspout and used when there are a small number of downspouts supplying water to the tank/cistern.

It is preferable to fit the longest length chamber as possible to ensure better quality water. Install from the roof gutter and after the rain head, to within 6" above the ground to allow easy access to the end cap.

Downspout Diverters should be installed at each downspout that supplies water to the tank/cistern.

 

The diverters are supplied in kit form and come with everything needed to complete installation - just add the length of PVC pipe required to form the diverter chamber.



Water Diverters work best when a gutter downspout rain head is installed upstream of the diverter. Fitted at the downspout either directly on the underside of the roof gutter or to a wall, the Leaf Eater or Leaf Beater rain heads, also from Rain Harvesting, are self cleaning devices that deflect leaves and debris away from the flow of rainwater. Rain heads ensure the diverter chamber and Slow Release Control Valve do not block up as easily. They not only help Water Diverters operate more efficiently in preventing fine sediments and pollutants from entering the rainwater tank, they also ensure Water Diverters drain and reset automatically after rainfall, significantly reducing system maintenance.

Further information about First Flush Water Diverters, including a background document on improving rainwater quality - Water Quality First

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Post or Wall Mounted First Flush Diverters

Versatile units that divert larger volumes and in many cases one unit is sufficient. Can be mounted on a wall or post, to hold larger volumes and can be adapted to suit a wide range of applications and will manage single or multiple pipes coming from the roof.  The benefit of one larger unit is that it can be easier to maintain than a series of smaller diverters installed at each downspout.


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In-Ground First Flush Diverters

Buried and out of site, an In-Ground Diverter is perfect for sloping allotments. On a site with a minimum 5^o slope, an In-Ground Diverter allows a 'wet' system to be converted to a 'dry' system.

After rainfall when an In-Ground Diverter is installed, not only will the diverter chamber empty, the water held in underground pipes will also drain out through the diverter, converting it to a 'dry' system.


For more information about In-Ground Diverters, download our document on "Harvesting Rainwater - A Safe, Sustainable Water Source"

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