If you need to use first-flush diverters and/or leaf catchers, install them once you first install your tanks. This might be much, MUCH easier, and cheaper, than retrofitting them later. Even when you do not need to put in these, allow enough vertical space between your gutter outlets and tank inlets to install them later just in case you modify your mind!
– If you are concerned about adverse health effects from bacteria and traffic-generated pollution that might be present in your rainwater, consider installing rainwater filters in your kitchen taps. (I personally would want a filter if we lived in a high-traffic area, but since we don’t, we don’t use a filter.)
– You can install the tanks yourself, following the manufacturer’s guidelines, but you will need to hire a licensed plumber to plumb the water to your own home and to ensure that the mechanism for switching between mains water and rainwater conforms to health regulations.
– Sustainable Gardening Australia has published a shoppers’ guide to rainwater tanks here. This discusses the professionals and cons of tanks made of assorted materials.
– You have to a pressure pump connected between one of your tanks and the house to provide adequate water pressure for showers, etc. This pump will automatically switch on every time you activate a tap. The pump will not be very noisy, but you’ll hear it. I found this slightly annoying for the primary few days, but I soon got used to it. For those who think this noise will bother you, take this into consideration whenever you decide where to locate your pump. The up side is that you’ll know if anyone has accidentally left a tap dripping – you will hear the pump cutting in and out at times when nobody is using water.
– When deciding what size tank to buy, check that you’ve suitable access to get the tank from the street to wherever you want to put it. If access is a problem, you might decide to change the placement of the tank, buy a distinct shape/size tank, or hire a crane to lift the tank over whatever is blocking access. Crane hire is expensive, but a big tank plus crane hire might be lower than the cost of achieving similar storage capacity using smaller tanks. (I had to hire a crane to move my 23,000L tank into my back yard.)
– It’s a good idea to have a stop cock as the very first fitting attached to every tank. That way, if you happen to need to change a tap (taps do break) or hose, you can turn off the stop cock and never lose any water.
– Lately there may be an unlimited range of tank sizes and styles available, so you may probably be able to find tanks that suit whatever space you will have. If you are aiming at collecting and storing large quantities of rainwater, the most affordable option is still the normal round tall-ish type of tank if you have space for one of these somewhere in your yard. For reference, with the kind of poly tanks I used, a 5,000L tank has a diameter of 1.85m (inlet height 2.05m), a 10,000L tank has a diameter of 2.59m (inlet height 2.16m), a 25,000L tank has a diameter of 3.73m (inlet height 2.40m), and a 46,400L one has a diameter of 4.60m (inlet height 2.95m).
that rather more to be water self-sufficient than it does to, for example, have a tank plumbed to just the toilet, or to install a tank and pump for garden usage. Regardless that a full-scale system will cost more initially, will probably be more cost-effective, and it’ll “pay for itself” more quickly (partly due to the various associated savings mentioned later in this post).
Admittedly, house blocks are getting smaller and houses are getting bigger, but there is often some way around a perceived lack of space for water tanks. There may not be much space adjacent to your downpipes, but you’ll be able to perhaps install small slimline (or even ultra-slim) tanks along your wall as collect-and-feed tanks and have a large storage tank in the back corner of the yard. (Connect the bases of all the tanks together and the water will level out and automatically fill the storage tank.) Slimline tanks might be fairly useless as water storage tanks, but they can collect and transfer enormous quantities of water to a large storage tank.
Since rainwater tanks are expensive, in case you are thinking of investing in a single (or more), it can be a good suggestion to “get it right” from the outset and maximize the advantages of creating that investment…rather than going through the identical learning curve I went through!
Mistake No. 1: My biggest mistake was to put in a 5,000L tank to use for watering my garden. Actually, an awful lot of individuals try this, even those, like me, who live within the kind of climate that has loads of rain in winter (so we needn’t water the garden then) but has next to no rain in summer. So what happens? The tank fills up quickly in the beginning of winter and, for the remainder of winter, all further rain just runs down the stormwater drain. Then, when summer arrives and the garden needs regular watering, the tank runs dry after watering the garden for a few weeks, then the tank sits empty for the remainder of summer.
Assuming you are paying somewhere between $1 and $2 per 1,000L for mains water, that tank will prevent about $10 per year….and the tank cost what? $1,000? Rather a poor investment I would say, and never quite a lot of benefit to the environment either. But…rainwater tanks can be an excellent idea. You just must do it right!
Think about your local weather patterns and about what you’ll use the rainwater for. My 5,000L tank might need been sensible somewhere like Sydney, which has an affordable proportion of its rainfall in summer, but in locations with dry summers, buying a tank to water the garden is a waste of cash.
In case you have a lot of rain in winter, why not use the rainwater during winter while there’s plenty more coming to replace what you may have used? We all use water contained in the house all year round. In case your tank is plumbed to your home, it’ll in effect be emptied and refilled something like 5 times over the course of winter. This means that your investment in a 5,000L tank offers you something like 25,000L of water.
Mistake No. 2: My original tank was fed by just one downpipe. So, if we did happen to have a summer thunderstorm with a heavy downpour (this was 8 years ago so I do not remember if we did), 3/4 of the rain landing on my roof went down the stormwater drain instead of into my tank.
To maximise the quantity of water you possibly can collect, no matter what tank capacity you may have, ensure that every drop that lands in your roof goes to your tank(s). To do this you will almost definitely need multiple tank. However, in case you connect them together at their bases, they are going to function as one tank, filling and emptying in tandem. Which means your plumbing between the tank outlet and the house/garden need only be connected to one of many tanks.
Mistake No. 3: When i decided to make use of my rainwater in the house rather than the garden, I had no idea how much water I would wish in the house to last all summer without rain, or how much water could be available for collection (how much rain would land on my roof). I suppose I thought that it did not matter much if we ran wanting rainwater because we could always switch back to mains water until the following rain, so I just went with the idea that we wanted an even bigger tank, and that we would have liked to collect the water from all the downpipes. I bought a 9,000L tank and installed it at a special downpipe.
9,000L tank ( I had to move the fence and gate to suit this one in!)
I also bought a 1,000L modular tank to suit within the small space at the other side of the house, and redirected the opposite two downpipes into that tank.
1,000L collect-and-feed tank
We used that setup for a couple of years, and despite just being guesswork, that gave us roughly the best capacity in terms of getting enough rainwater to use for everything contained in the house all year round. (That is, 10,000L for 2 people in a dry-all-summer climate.) One year we did not run out of rainwater in any respect, and the opposite year we had to switch back to mains water for under a few weeks. In purely financial terms, that was probably the optimum capacity for us. However, during winter, rain fell faster than we used it, so we still had overflowing tanks for the last half of winter. I could not bear the considered all that good water going down the drain so I bought another tank – a 23,000L one this time – and installed it within the back corner of the yard, and just connected the base of it to the opposite tanks (no water from the roof runs into it directly).
23,000L tank used only for storage
The above setup has been in use for about 5 years now, and it seems to now be the precise total tank capacity given our roof area and local annual rainfall. Some years the tanks do not quite fill completely, and a few years there’s somewhat overflow going down the stormwater drain. Also, now that we now have water restrictions, it is vitally convenient to have more rainwater than we’d like for household use and to be able to use various it within the garden. Even so, if I’d known on the outset the optimum total capacity for us, I’d have designed the tank layout differently and bought different-sized tanks…a larger tank costs greater than a smaller one after all, but not all that rather more.
If you know how much rainwater falls on your roof in a median year and the way much water you employ for different purposes, you possibly can better plan how you’ll use the water and work out your optimum tank capacity. Do you just want enough rainwater to flush the toilet and wash the clothes, or enough to plumb it to all the house? (The plumbing modifications are simpler if it is plumbed to the house as an entire.) Will you be able to gather enough for the garden too? If you would like to make use of your rainwater just in the garden, what tank capacity will that you must see you thru the longest dry spell you are likely to have in your locality?
To find out how much water you possibly can collect you will need to know your local annual rainfall and the whole area of roof from which you collect rainwater (floor area + eaves + garage/patio/etc). For rainfalls within Australia, go to Climate Data Online and choose Rainfall – Monthly – your location. Multiply the roof area (square meters) by the average annual rainfall (mm). The result’s the variety of litres of rainwater you’ll be able to collect. In the event you prefer to use other units of rainfall or area, there’s a rainwater calculator you should use here.
In response to statistics published in NSW Guidelines for Greywater Reuse in Sewered, Single Household Residential Premise (page 6), the typical in-house water usage for a household of three is 603L/day (bathroom 198L, laundry 131L, toilet 124L, taps, including kitchen, 140L), and outside usage (garden, pools, etc) is 223L/day. However, you might be able to get a more accurate idea of your usage by taking a look at your water bill, particularly when you have “wet” quarters where all your water usage is inside, and “dry” quarters where you also must water the garden regularly.
Perhaps you possibly can collect 80,000L, for example, over the course of a mean year, but remember that you are also using that rainwater throughout that point. To gather and use 80,000L in a year, you might only need a total tank capacity of, say, 20,000L. On the whole, to be able to effectively use any given amount of rainwater, locations that have reasonably regular rain during summer will need much less storage capacity than localities with long dry summers. (You will discover your local mean rainfall figures for each month of the year from the Climate Data Online site.)
Unfortunately, even with all the above figures at your fingertips, there continues to be a level of guesswork involved in deciding your optimum total tank capacity! It may additionally help to speak to other householders who have tanks in your area and see what works for them.
Mistake No. 4: After i connected the bases of all my tanks together in order that the water level in each tank levels out, I used 19mm hose between the tanks with the intention of allowing a reasonably quick water flow between tanks. However, the 1,000L modular tank came with an ordinary tap (about a 13mm internal bore I suppose). I should have replaced that tap with a bigger one, but I did not. I also used ordinary small-bore taps on the tank that all the others connect with. Water travels more slowly than you might think when gravity is leveling it out!
All of the tanks hook up with this one at its base.
Since the 1,000L tank receives rainwater from over half my roof area, it fills much quicker than the other tanks. This isn’t usually an issue, but during a very heavy downpour it fills and starts overflowing even when there’s still plenty of space in the other tanks just because the water doesn’t travel to the opposite tanks quickly enough.
When connecting multiple tanks together, ensure your taps and hoses all have an internal diameter of at the least 19mm to allow water levels to level out reasonably quickly. This may not be a difficulty if all your tanks are similar sizes and are fed by similar amounts of your roof area, but that’s not prone to be the case.
Mistake No. 5: The overflow spouts on my four tanks are usually not all level with each other. (This was not a “mistake” exactly – it was simply not possible to have all of them level.) Which means that one in every of my tanks reaches overflow point somewhat before the opposite tanks, so at that point I need to turn off its tap so that water from the other tanks doesn’t flow back and out the overflow spout of this lowest tank (so the opposite tanks can also fill completely).
Also, the overflow spout of my 23,000L storage tank is about 60cm higher than any other tank – it’s a taller tank and in addition on higher ground. That is the tank that has no direct input of water from the roof so, although the leveling out process can fill it up to a point, it obviously can’t fill up the top 60cm of the tank. Once all the opposite tanks are full, I need to show off the tap at its base and pump water to it from the other tanks to fill it completely (which also makes space for more rain in the other tanks). Fortunately, this isn’t particularly difficult. Since rainwater is automatically pumped to all my taps (by a pressure pump that kicks in automatically whenever I activate a tap), including those on the outside of the house, I just connect a rainwater hose to an outdoor house tap and poke the other end within the overflow spout of the 23,000L tank, and then turn on the outside house tap. The tap on the base of that tank remains closed until sometime next summer. When the opposite tanks are getting near being empty, I open the tap to allow the water to level out between all of the tanks again.
If possible, make the overflow spouts on all tanks level with each other to simplify management. If this is not possible, be certain you’ve taps at each tank (don’t connect the tanks along with hoses alone) – otherwise no tank will be capable of be filled further than the height of your lowest overflow spout.
Conversely, it makes no differences whether the bottoms of your tanks are level with each other or not. However, ensure that the pump that delivers your rainwater to the house and/or garden is connected to the tank that has the bottom base. That way all the water from your other tanks will end up within the tank you pump from (it will become relevant if you’re about to run out of water).
– If you would like to make use of first-flush diverters and/or leaf catchers, install them when you first install your tanks. This will likely be much, MUCH easier, and cheaper, than retrofitting them later. Even if you don’t want to put in these, allow enough vertical space between your gutter outlets and tank inlets to install them later just in case you modify your mind!
– If you are concerned about adverse health effects from bacteria and traffic-generated pollution that might be present in your rainwater, consider installing rainwater filters in your kitchen taps. (I personally would need a filter if we lived in a high-traffic area, but since we do not, we do not use a filter.)
– You may install the tanks yourself, following the manufacturer’s guidelines, but you’ll need to rent a licensed plumber to plumb the water to your house and to make sure that the mechanism for switching between mains water and rainwater conforms to health regulations.
– Sustainable Gardening Australia has published a shoppers’ guide to rainwater tanks here. This discusses the pros and cons of tanks made of assorted materials.
– You will need a pressure pump connected between considered one of your tanks and the house to provide adequate water pressure for showers, etc. This pump will automatically switch on every time you turn on a tap. The pump won’t be very noisy, but you will hear it. I found this a bit annoying for the first few days, but I soon got used to it. If you think this noise will bother you, take this into consideration when you decide where to locate your pump. The up side is that you will know if anyone has accidentally left a tap dripping – you will hear the pump cutting in and out at times when nobody is using water.
– When deciding what size tank to buy, check that you have suitable access to get the tank from the street to wherever you want to put it. If access is an issue, you might decide to change the situation of the tank, buy a special shape/size tank, or hire a crane to lift the tank over whatever is blocking access. Crane hire is expensive, but a large tank plus crane hire may be lower than the cost of achieving similar storage capacity using smaller tanks. (I had to rent a crane to move my 23,000L tank into my back yard.)
– It is a good idea to have a stop cock because the very first fitting attached to each tank. That way, for those who need to vary a tap (taps do break) or hose, you may turn off the stop cock and never lose any water.
– Nowadays there may be an unlimited range of tank sizes and styles available, so you will probably be capable of finding tanks that suit whatever space you may have. If you are aiming at collecting and storing large quantities of rainwater, the most cost effective option is still the traditional round tall-ish type of tank you probably have space for one of these somewhere in your yard. For reference, with the type of poly tanks I used, a 5,000L tank has a diameter of 1.85m (inlet height 2.05m), a 10,000L tank has a diameter of 2.59m (inlet height 2.16m), a 25,000L tank has a diameter of 3.73m (inlet height 2.40m), and a 46,400L one has a diameter of 4.60m (inlet height 2.95m).
Pros and cons of running a house on rainwater…
Buying tanks, pump, fittings, etc., involves quite high initial costs, and mains water is still incredibly cheap. If expected savings on your water bills are your main motivator and also you calculate how many years it will take to your rainwater system to “pay for itself”, you will probably decide to follow mains water. (Even when you employ no mains water at all, you may still need to pay the sewerage and water supply charge.) It is just when you are taking into account the other savings associated with rainwater use that it becomes reasonably financially attractive.
The big potential saving – or so I’m told – is that your hot water system will last thrice as long if you employ rainwater rather than mains water, and your washing machine will also last much longer. (I’ve not been using rainwater long enough to have proved that for myself.) Not needing to replace those devices will go a good distance towards paying off your rainwater system.
There are also various smaller savings which take effect immediately. You may must halve the quantity of shampoo and laundry powder you employ to avoid being swamped in bubbles. You won’t need to use fancy cleaners to remove mineral deposits out of your shower (because there will not be any). You’ll use hand lotions and moisturizers much lower than usual because rainwater doesn’t dry your skin the way mains water additives do. One delightful surprise for me was that the dry cracking heels that I suffered from for years stopped being a problem. I did not actually notice the problem going away (human nature being what it is!), but the year we needed to revert to using mains water for a few weeks I suddenly started having this problem again (until it rained and we could shower in rainwater again).
On the down side, you may probably need to wash your toilet a bit more often because rainwater does not contain chlorine. Also, if you’re washing greasy dishes you might need a bit more detergent than usual to cut through that grease.
Possibly the principle inconvenience of using rainwater is that you just need electricity for your pump to operate. If there’s a power failure, you will not get any water out of your taps. After all you’ll be able to always switch over to mains water until the power comes back on, or collect a jug of water directly from a tank.
Quite other than the many environmental benefits of using rainwater within the house, and regardless of whether it saves you money or not, I just really like using rainwater. It tastes nice, it doesn’t smell of chlorine, it leaves hair soft and silky, and hot rainwater showers feel pretty good too. Besides, it strikes me as absurd to depend on public utilities to treat and deliver water to me when loads of perfectly good water lands on my roof. It’s much more absurd that our urban areas have concurrent water supply problems and stormwater disposal problems – wouldn’t rainwater tanks neatly solve both problems?