Browse Forums Building A New House 1 Oct 03, 2008 6:09 pm I thought I might share some of the hassles I have been experiencing over the rainwater tank.
Due to recent changes in legislation it is now compulsory for all new houses in South-East Queensland to have a rainwater tank plumbed in to their toilet and washing machine. The amendment to the Queensland Building Code Pt 25, (http://www.dip.qld.gov.au/docs/temp/mp4_2_water_savings_targets.pdf), which commenced on May 1 for all development applications after January 1 this year, requires that all new houses in reticulated town water areas of SEQ must achieve water savings targets of 70kL per year from an alternate water source. The recommended method for achieving this is a minimum 5000 litre tank installed to receive rainfall from at least 100 sq metres of roof, with appropriate ancillary equipment such as leaf beater, first flush device, backflow prevention, mosquito prevention and related plumbing. The builder's quote for all of this, in a Colorbond Slimline version on an engineered concrete slab was $7320. Gulp! Lot of money for rainwater! Still, methinks, if it's gotta be done, it's gotta be done. Then the sales rep informs me that because the tank has to be topped up from mains water from time to time to make sure the toilets will continue to flush during periods of low rainfall, the tank is effectively considered a part of the mains water supply and cannot be used for activities such as hosing gardens, washing cars and topping up pools during periods of water restrictions (http://www.ourbrisbane.com/lifestyle/gardening/water-restrictions-brisbane). So let me get this right...? I have to spend $7320 on a water tank and I still can't wash the car? OK, I really don't mind doing my bit for all kinds of environmental purposes, including water conservation, but deep down I'm seething at the injustice. What do I do? Splash out for another tank? We had trouble finding a place to put this one... Coincidentally a couple of weeks later I'm at a local festival featuring worm farms, permaculture and the like, when I spot a rainwater tank display and get chatting to the reps about something called an Onga Waterswitch (http://www.creativepumps.com.au/work/a_brand/onga/water_switch/onga_water_switch.htm). Aha, I think, problem solved! Wait 'til the builder hears about this one! So first thing Monday I'm emailing them about this wonder device that allows you to switch neatly between mains water use and tank use, so you never need to fear infringing water regulations again. Whatever it costs, it has to be less than putting in a second tank! In the meantime, I'm online, researching it, gathering evidence for the idea that it can be used to get around water restrictions. I find a council fact sheet (http://www.moretonbay.qld.gov.au/uploadedFiles/common/forms/building-plumbing/Rainwater-Tank-Installation-Guidelines.pdf) that outlines the three ways you can ensure back-up to the toilets - a trickle feed top-up, which adds a small amount of mains water whenever the level drops below a certain point, an automatic switching device, such as I discovered, or a manually switched supply line. I also find a Brisbane City Council site ( http://www.brisbane.qld.gov.au/BCC:BASE::pc=PC_2712 ) that implies that only the trickle feed top-up system restricts use. But no, the builder is not convinced. So, journalist that I am, I'm on the phone to the local Moreton Regional Council plumbing division to hear it from the horse's mouth. No it can't be done, they say. You can install a water switch as a top-up mechanism, but you'll still be subject to water restrictions. But, but, but...I say...and point them to the Brisbane City Council site. Well, they say, this is all pretty new to us. Leave it with us and we'll ring you back. A day later, the call comes. Yes, we've checked with the Water Commission. You can do it, provided the external tap is located between the tank and the pump (not downstream as it would draw from mains supply, and not upstream as it would suck air from the tank). Woo-hoo! I'm feeling like I'm on a win here. Now to find out how much the switch will cost... Question: Please provide upgrade price for Onga Waterswitch in lieu of top-up system. Answer: As per your contract, the following is standard: Onga SMH45 pump. Question: Yes, I can read the contract, but as the switch is sold separately, or can be purchased as a kit, it's not clear if it is provided. Answer: The switch is included with the pump. It is one unit. Question: OK, great. (Mumble, mumble...it took 17 days to get to this point, but at least it's good news that it's all included). Please confirm that the Ausbuild-supplied system can be used for water restriction purposes. Answer: Ausbuild is getting conflicting information from the council. So it is up to you to comply with your local council regulations and water restrictions. Question: Yes, I understand that. Please confirm that the Switch will be fitted with the garden tap/s installed between the pump and the switch, as required by council. No reply. Grrrrrrrrrrrrr............ Anybody else going through this? Visit my blog: http://www.jeanetez.blogspot.com/ Re: Rainwater Tanks ... To Top Up, or Not? 2Oct 03, 2008 8:46 pm Good work Jeanete.
Sounds like you are pioneering with an ineducated builder and coincuil there - but keep at it - they will learn what ispossible eventually What you're doing is what I'd do as well. Re: Rainwater Tanks ... To Top Up, or Not? 3Oct 06, 2008 1:47 pm Hi Jeanete. Not really going through it as you say, but we've already had this same discussion with our builder before building. For NSW BASIX, in order to get the score we needed, we are doing the same, plumbing the rainwater tank to the toilets. In our case, we are installing the switch that changes over to mains water supply when the tank is below a certain level.
This goes on the line between the tank and the house. In our case, we can use the rainwater tank for whatever we want, so long as the tank nor taps are directly fed by mains. Greg Re: Rainwater Tanks ... To Top Up, or Not? 4Oct 06, 2008 1:54 pm Our builder told us that we would be getting a pump that automatically switched over to mains when the tank was too low ... instead we have the system where there is a float in the tank and it gets topped up by mains when needed.
Admittedly our 2000L tank is full at the moment and will probably remain full until well after Christmas (so wish we had another tank!), but it does mean that there is never more than about 1500L of rainwater in the tank - rest is filled from the mains. Re: Rainwater Tanks ... To Top Up, or Not? 5Oct 09, 2008 11:00 am Further to the above, I have had a detailed discussion with the builder, and have been left with the feeling that there is a very large grey area here that the state government and councils haven't adequately addressed.
The builder says they have adopted the water switch method because they believe it is better than the top up system and provides a clearer delineation between mains water and tank water use. Agreed. However, they don't accept that a correctly positioned garden tap offers peace of mind when it comes to using the tank water during periods of water restrictions. In their words, the additional expense to modify the plumbing configuration wouldn't provide a "get out of jail free card". They say even though the switch may be indicating that tank water is in use, the homeowner is not free to use the water at their own discretion. Rather, the key to avoiding a fine is to keep the objectives of the legislation in sight and ensure "responsible use" and "water savings" at all times. But who's to say what responsible use is? If the tank is full, is it responsible to use some water so that the next downpour has somewhere to be stored? Does the same still apply if the tank is three-quarters full? Can we draw the line at half full? Does responsible use mean you can hose the garden when the tank is full, but can't hose the path when it's only three-quarters full? And does it make any difference if your household is using well under the target of 140 litres per person per day? In the absence of guidelines, it would seem to be a matter of conscience, and being prepared to argue the toss with the council and the neighbours if challenged? Where's the peace of mind in that? Visit my blog: http://www.jeanetez.blogspot.com/ Re: Rainwater Tanks ... To Top Up, or Not? 6Oct 21, 2008 10:21 am Hi Jeanette,
From what I have discovered there are pumps available which as soon as your tank is empty, bypass the tank and the mains supply to your toilet or washing machine is reinstated until the next rainfall puts more water in the tank. These pumps are round about $1000 give or take. There is another system which has a float switch fitted inside your tank, a bit like the ballcock arrangement in your toilet cistern, when the water level falls in your rainwater tank it automatically allows the level to be topped up by your mains to a predetermined level. Apparently they are adjustable so you can maintain a minimum of just a couple of inches and take full advantage of any rainfall or let your tank fill three quarters full with mains. I doubt with this system you will be able to water your garden from this tank though, you will probably need to put in another tank/s for garden use. Realistically a 1000L tank won't last long any way(150 flushes?) I can fit 3x5000L in our yard, it's not really a lot of water either and economically I could buy a lot more water for the money the tanks will cost but it might make the difference between my garden surviving or not. Anyway that's my 2cents worth Tom Re: Rainwater Tanks ... To Top Up, or Not? 7Oct 27, 2009 8:08 pm Hi, THis may be a bit late to help, but there are other products on the market that allow you to have a mains switching device from rainwater to mainswater and enables you to have a seperate external tap that provides rainwater only. You cannot install a tap in between the pump and the switching device as it controls the pump. This is common with other systems. Be aware of installing tank top up systems as councils classify your rainwater to be part of the mains water system therefore cannot use the water during water restrictions. Insist that your builder installs a mains water switching device , not a tank top up system. Try the product called H2DUO Rainwater Automation Device, it provides the homeowner multiple options when it comes to rainwater use. The product is sold on its own enabling the user to purchase the right size pump for the job, making it cost effective solution compared to other brands. Regards Shane That was always going to be a challenge and a test of patience. Full marks to your mate. Did you discuss the wet area near the trampoline? 16 17287 DIY, Home Maintenance & Repair But if it is a ground level open pit, then it is not a charged system. No surprises there. The pipes have obviously been altered and there would be a reason for this.… 3 31230 |