SUPADIVERTA - syphonic rainwater diverter

Frequently Asked Questions

Q. Does fitting a rainhead or diverter into a downpipe create a potential for blockages?
A. SUPADIVERTA will not block.

• The SUPADIVERTA inlet is free flowing with no `dead ends' and the downpipe's flow continues unrestricted through the SUPADIVERTA during periods when diversion may not be required.
• SUPADIVERTA does not have a chamber within a chamber or other potential flow restrictors.
• The SUPADIVERTA internal rainhead has a high yield filter set at a 50 degree angle and IS NOT mounted across the downpipe's continuum flow to storm-water.
• The outlets are separated from the downpipe's continuance and the SUPADIVERTA internal flow path is larger than the downpipe's internal profile.

Rainheads and other downpipe diverters block when...

• Debris in unfiltered water blocks an outlet, hose/pipework or a passage that is smaller than the downpipe's internal profile.
• The diverter restricts the downpipe's continuum flow by reducing the downpipes internal area.
• Low velocity flow of unfiltered water through hoses or pipework will often cause an obstruction within the hose or pipework.
• A rainhead or filter creates a barrier across the downpipe's continuum passage. Such filters may be fitted either internal or external to the diverter and are often a separate fitting to the diverter. (A blocked filter MUST NEVER block the passage of water to storm water.)

NOTE: If fitting a diverter to a downpipe presents an internal obstruction that will restrict flow; the installation may not be compliant with plumbing regulations. Plumbers with reasonable concerns about any product may not be wise to install them given their potential liability in the event of the installation causing property damage.
AQUATREK provides research and design information on this site to assist consumers make informed choices when comparing products.

Q. What is the main use of SUPADIVERTA?
A. SUPADIVERTA evolved from a project created to address house cracking - brick cracking issues but the cost savings, versatility and aesthetic benefits when used with rainwater tank installations has created the most interest.
Ground water recharge is another issue of immense importance. Some suburbs have as much as 90% covered, paved, concreted or tarred areas and the remaining permeable surfaces are the sole recharge points for the groundwater that exists under the total area. Groundwater is a fragile resource and a lot more research needs to be done in this field.

Q. How can a small head of water in a small hose push against the force of the water in the tank?
A. Once purged of air, water in the pipe and the tank becomes a solid mass and so reacts according to the laws of fluid mechanics. The head, being higher, has a pressure positive to the tank’s head and the tank’s head correspondingly is negative to the dynamic head. This means that the water in the pipe is `pushed’ at one end by the dynamic head and `pulled’ at the other end by the lower pressure. This also explains why the flow in the pipe has instant acceleration once syphonic conditions are established.

Q. We have a large tank in the backyard and a first flush diverter is fitted at the top of the wet system's vertical riser. We also installed rainhead at the top of the downpipe and were informed this would clean the water going to the tank. The plumbing and accessories, not including the pump and connections, cost nearly eight hundred dollars.
When we drain the first flush, the water is always clean and yet we recently had to dig up the buried pipework to remove a blockage that looked like congealed tar and grit. We cannot understand where the tar has come from. We have a tiled roof. Any ideas?
A. Wet systems retain water in the pipework and most plumbing regulations specify that the pipework must be drained after it stops raining. This is to remove trapped sediment and prevent the water stagnating. Sediment flushing however requires an adequate flushing velocity but this is not achieved by draining the pipework.
Still water has a settlement process and the water in the vertical riser would have settled after the last rainfall with the upper levels containing clean water. It is this water that would be flowing into your `First Flush’ diverter next time it rains if the pipework was not flushed.
The `tar’ is probably a combination of grit from the house roof and bacterial die off. Water trapped in a wet system’s pipework has minimal open surface area for ventilation and the combination of bird droppings, decayed vegative matter and other pollutants that are not flushed through due to the pipe’s low velocity allows micro organisms to flourish. This can make the water stagnant and bacterial die off occurs once the food supply is exhausted by the ever increasing bacteric populous.
If the rainhead has a contained fine mesh screen across the downpipe's flow path, the screen serves as an entrapment filter and nutrient rich bird droppings will be trapped by and later flushed through the mesh.
Replacing the troublesome wet system with SUPADIVERTAS will harvest more water and the internal .75mm divert filter combined with the optional first flush kit will provide cleaner water.

Q. We have a tank and the downpipe is diverted to the tank's meshed inlet. If we fitted a Supadiverta, do we have to divert flow through a bottom inlet?
A. No. As detailed in Slash Installation Costs, flow can be directed to the tank's meshed inlet from the nearest downpipe provided the Supadiverta outlets and fittings are higher than the top of the meshed inlet. Flow rates for each 25mm polypipe will be a maximum of just over 20 litres per minute; more than adequate for most rain events but considerably slower than a syphonic flow rate.

Supadiverta is proving most popular for diverting from additional downpipes and for replacing `wet systems' at very low cost. If your tank has only one outlet, consider fitting a 25mm barbed x 25mm threaded BSPM T fitting to the outlet or other similar fitting as best advised by your plumber.

Q. Will the flow of water through a bottom inlet stir up the sediment on the bottom of the tank?
A. Observations over a two year period have shown that inflow through a tank's bottom inlet rapidly dissipates with no visible evidence of sediment turbulence, however, water entering through a tank's top meshed inlet has amazing penetrative properties and can create significant turbulence.
Additionally, water diverted from the SUPADIVERTA will be cleaner with smaller and fewer foreign particles than water diverted to a tank by other conventional methods. A reduced food source, particularly nutrient rich bird droppings, reduces sedimentation by restricting microorganism growth and hastening their die-off. If the sediment layer was high enough to be disturbed by the inflow, AQUATREK would suggest it was time to clean the tank! It is recommended that heavily sludged tanks be cleaned prior to fitting Supadiverta.
If a simple DIY Vortex Induced Sediment Separation filter (parts available from our online store) is also used with SUPADIVERTA, tank sludge will be minimal.
Ideally, tanks should have a bottom outlet that is used to drain the tank during cleaning and another outlet fitted with an internal hose and float to draw the cleanest water from just under the surface. Many tanks are optioned with a draw off outlet fitted 100 - 200mm above the tank’s base and syphonic fed inlets should ideally be located at a similar height.
The University Of Warwick (UK) has a brief, easy to read research report dealing with the rainwater tank settlement (self cleaning) process, first flush diverters and the pros and cons of various filters. A recommendation in the report is to introduce water to the bottom of the tank while water removal should be from the top, the reversal of normal practice.

Q. We live in Melbourne and in a few years a desalination plant and the north-south pipeline will end restrictions. We earn good money and water bills are of no concern. Why should we buy a SUPADIVERTA?
A. Many cities have committed to the desalination solution but such plants are power hungry water factories which produce an expensive product.
The fact that there are many households who can afford increased costs and who have little commitment to water conservation is a strong argument for a user pay system.
The north-south pipeline is to supply Melbourne with a percentage of the water saved from the `food bowl’ modernisation project. The food bowl’s Murray-Goulburn basin is a region of decreasing rainfall, consequently future rainfall patterns could effect the long term viability of the pipelines intended use. There is also well founded community scepticism regarding the accuracy of supply targets. It is doubtful that all restrictions will be lifted after both of these major projects are commissioned.
SUPADIVERTA would serve you well by supplying gravity fed drip hoses to provide additional watering to gardens during times of light rainfall. This would save time and target needy areas.
A walk around the property may identify problem areas that would benefit from redistributed rainwater and reading the house cracking and trees pages is recommended.


Q. I was told that the government will end up taxing everyone who has applied for a rainwater tank rebate. The farmers get taxed if they have a dam, so why should l have a tank?
A. Vehement protest erupted across Australia on January 14, 2007 after the Herald Sun published the article

OUTCRY OVER TAX ON RAIN

The article, which was picked up by numerous media outlets, was based on a leaked email written by the CEO of the National Water Commission, Ken Matthews. The article stated the email had been confirmed by the National Water Commission as accurate.
The email allegedly said in part; “Legally, all water in Australia is vested in governments” and referred to “issuing of specific entitlements” and “A residential household version could include a licensing arrangement and taxes for those wanting to collect more than a set amount”.
Outrage erupted from the public and both sides of politics. South Australian premier, Mike Rann, typified opinion by saying the suggestion of a rainwater tax was ridiculous and “It’s about the dopiest idea l have heard during the silly season”.
Ken Matthews later claimed the story was wrong and the email referred to by the Herald Sun did not use the word “tax” at any point.
The Sydney Water web site reassures its customers with the statement: “Sydney Water will not charge you now, or in the future, for the use of your rainwater tank” and similar reassurances continue to be given by other water boards and leading political figures.
It is unfortunate the rumour has perpetuated to urban myth status and has undoubtedly influenced some householders to either not claim their rebate or purchase a tank(s).

Q. I have cleaned my tank of sediment (it took hours) but now want to sanitise it. What do you suggest?
A. There are businesses that inexpensively clean tanks and hire firms may one day stock tank cleaning equipment.
Your local pool shop would be the best place to seek the advice you require.
Use SUPADIVERTA to extend tank cleaning intervals and make cleaning easier.

Q. I have pine needles in my gutters; will they get stuck in the filter?
A. This is possible but AQUATREK is conducting tests and has not encountered problems to date. The designed back flushing should remedy the situation and an internal inspection of the SUPADIVERTA a couple of times a year is recommended.
Pine needles can make water acidic and should, if possible, be prevented from entering gutters. Acidic water can damage pipes, pumps and fittings. Leaves and other debris can also alter rainwater PH levels.
A new technology surface tension guttering system can be viewed at: www.leafsafeguttering.com.au
The system utilises the existing guttering (which is lowered to install), is highly desirable in fire prone areas, attractively designed, well priced and is one of our favourite products.

Q. My tank is connected to the toilet and the inside of the cistern has become dirty. Why is this and how can I fix the problem?
A. If you do not have a suitable leaf/debris diverter and first flush system in place before your rainwater reaches the tank, your tank’s meshed inlet will receive all the debris and contaminated water coming from the roof! NOT GOOD!!!
Note that even when using leaf and first flush diverters, the water entering the tank will, in most instances, still contain contaminants.
Ideally, the `draw off’ valve should be 100 - 200mm above the bottom of the tank.
Fitting a SUPADIVERTA and installing a suitable filter from the pump will provide cleaner water to the cistern. A simple DIY Vortex Extraction filter available from Aquatrek for just a few dollars can also be fitted between the Supadiverta and the tank as a third stage filter.
It is recommended that tanks are cleaned prior to fitting SUPADIVERTA.

Q. We have a 5000 litre tank serviced by a `wet system’ from one downpipe and sediment build up in the pipework has been an ongoing problem. There are no filtering devices fitted and the tank never fills. We would like to fit SUPADIVERTAS to two downpipes to harvest more water. Would we have to run two hoses to two (tank) inlets and would the hoses, being smaller than PVC pipe, block easier? What flow rates could we expect? The tank is 15 metres from the house.

A. As a minimum, connect vertical 19mm polypipes to both SUPADIVERTA'S second priority outlets, then join to a single 25mm horizontal polypipe connected to the tank's bottom inlet/outlet. It is hard to estimate flow rates without seeing the lay of the property and location of downpipes but with this plumbing, a 1.5 metre head should generate a syphonic flow rate of 29 litres per minute (1740 lt/hr).
Note that the third outlets would still be available for other uses or they could feed into a second 25mm polypipe and connect to the tank. This is advisable in higher rain intensity areas. If possible, retro-fit the tank with a larger gate valve that will accept a 40 mm PVC fitting. This will allow the use of low pressure 40 mm PVC pipe for very high flow rates during storm events.
Self cleansing velocity for horizontal 19mm and 25mm polypipe equates to flow rates of about 11 and 18 litres per minute respectively. For 40mm PVC pipe, it is 46 litres per minute.

Q. What is Supadiverta made of?
A. SUPADIVERTA is made from U.V. resistant A.S.A.; a tough recyclable plastic that has superior resistance to outdoor exposure and ageing.

Q. I have seen a clear SUPADIVERTA demonstrated at an expo. Are clear models available for purchase?
A. AQUATREK will be moulding more clear models but due to the necessity to retain clarity, these will not be UV stabilised. As such, they are not of merchantable quality and will not be offered for sale. Many customers do however, for a variety of reasons, use clear vinyl tubing for the vertical drops.

Q. I would like a `veggie patch' to grow organic produce but there is limited space in the backyard. Using rainwater has appeal but l do not want a tank next to the house or the expense of a pump and electrical connections etc. How can SUPADIVERTA help me?
A. No dig gardens are very productive and are often made in areas not otherwise considered.
Dwarf fruit trees, including lemons, can be planted in suitable pots or barrels and even moved around if necessary. A fruit tree grafted to bear several varieties always fascinates younger visitors and some fruiting plants respond well to espaliering.
A sunny, rocky area could be ideal to grow strawberries.
Hydroponic systems are easy to cultivate, highly productive and require little room.
SUPADIVERTA allows you to site a tank away from the house and the SUPADIVERTA to tank connection need not be fixed (as detailed in the following question/answer)
You may also consider a HANDY TANK. These are low cost and easily disassembled when necessary. Many established backyards are inaccessible to rainwater tanks but the HANDY TANK comes in a flat pack.
By siting the tank on a high base, water can be gravity fed to drip hoses placed on a garden bed and SUPADIVERTA can be plumbed at a height that suits most applications.

Q. We want to run a hose to the pool but don’t want a permanent fixture. We also don’t want to be changing fittings before and after using the hose. We have connected the second outlet to drip hoses and have the third outlet plugged. How can we do this?
A. Firstly, buy a quality 18mm hose connector that has an internal stop (plunger) valve. 
Next, use Teflon tape on the supplied 19mm director’s threads, then fit the director into the SUPADIVERTA’S third outlet.
Fit a length of 19mm polypipe to the director and then fit the hose connector to the other end of the polypipe.
Provided the polypipe is vertical, the connector’s stop valve will prevent water from escaping. When you need to divert water to the pool, use a hose coupling to connect an 18mm hose or 19mm polypipe also fitted with a connector and use a coupling to join the two connectors.
Fitting an inline tap to the second outlet hose will allow you to divert all the water to the third outlet when needed. Fitting an inline tap to the third outlet's hose may also be a good idea.
NOTE: The absence of a 90 degree elbow joining the vertical drop and horizontal polypipe will prevent the polypipe priming. This can be remedied by fitting the horizontal hose with either a detachable or permanent 90 degree attachment.      Further details:- Gardens/Pools

Q. We live in Melbourne and our 7,200 litre tank is 6 metres from the house and fed by two downpipes, one plumbed along the wall and joining a second downpipe nearest the tank. A 90 mm PVC pipe is then diverted to the top of the tank. The tanks overflow goes to the lawn because paving alongside the house prevented the overflow being connected to storm water. There is also a brace that the pipe rests on halfway between the tank and the house. It is an embarrassing eyesore as is the overhead pipe and the downpipe running along the wall. Can two Supadivertas replace the pipe work and how can they connect to the tank as we do not want the paving disturbed? We only have one spare bottom outlet, would this be enough?
A. You will need a plumber to restore your two downpipes; he could also fit an extra couple of gate valves but check with the tank manufacturer first for warranty conditions. The plumbing described is not uncommon but may not be compliant; depending on the combined roof area harvested.  Running the overflow to your lawn is compliant in many areas; Canberra for example, provided it does not flow to adjoining properties. Homeowners need to check their local regulations. You need to select an unpaved area where the poly or low pressure pipe can be plumbed across, then run to the tank. Avoid dips and rises to prevent air locks and use 25 mm horizontal lines. If using two or more Supadivertas, use three gate valves for best results. If you are restricted to one spare gate valve, you can still connect several Supadivertas to a single 25 mm horizontal pipe. Supadiverta operates at its most efficient when the tank level is low and most of Melbourne’s rainfall is drizzle and showers with downpipes flowing at less than 4 litres per minute each. Connecting several Supadivertas to a single gate valve will harvest a lot of water during periods of light rainfall. For example, you should expect a syphonic flow rate of 25 litres per minute with only a 1 metre head (tank half full) over 13 metres, more than enough capacity to handle the combined flow from three or four downpipes during a typical Melbourne shower. 

Q. There are many references on your site to poly pipe barbed connectors, directors, barbed elbows, joiners, etc. How do I know what I am looking for and where do I purchase these various components?
A. All of the components can be browsed and are available for purchase online through out online store at very competitive prices, you can include them with the order for your SUPADIVERTA and we won't charge for postage or handling! These components are also readily available at most hardware or plumbing stores.

Q. Your website is very informative. I would like to print some or all of it out for later reference, but every attempt results in lost words or parts of the page.
A. Every page has a small printer icon in the top right hand corner just below the header, this will open a PDF with the page content formatted to print correctly. If you prefer you can download this file and print out the whole site.