Rainwater Tanks

Rainwater Tanks are a product which are quite often associated with rural and country areas but over the last few years rainwater tanks have become more common in urban areas. This can be attributed not only to changing climates but also changing opinions as home owners use rainwater tanks as an accessory to make their homes greener.

The big question for many home owners though is how to go about it. Adding rainwater tanks to a new home is easy but for most existing houses it can be more difficult as when most were built, a rainwater tank was never a consideration.

For new houses underground rainwater tanks are a great option as they are much easier and cost effective to incorporate into the build right from the start. The other great advantages of underground rainwater tanks are that they are out of the way, saving above ground space but even more importantly they can easily harvest all of the rain water that a roof can collect. This is one of the most important attributes of efficient rainwater tanks, and that is the ability to harvest rain water from as much of the roof area as possible.

As far as existing housing goes, quite often the solution is not quite as simple. Above ground rainwater tanks may be a better option. These consist of poly (polyethylene), concrete, steel, fibreglass and even in some areas, timber rainwater tanks. The biggest problem with above ground rainwater tanks is it can be difficult to harvest large quantities of rain water as many typical installations only take advantage of the rain water delivered from a single downpipe.

As a result this type of installation may not harvest very much rain water at all and as such may give the impression that above ground rainwater tanks are much less efficient than underground rainwater tanks. I discovered this one day while talking to a neighbour. I knew he had a rainwater tank installed in his backyard and asked if he was happy with it. He said that he wasn’t as we don’t get enough rain to fill it. So above ground rainwater tanks do have reputation of not harvesting very much rain water.

In reality though, above ground rainwater tanks can be very efficient. I was able to design and make my own simple diverter that now allows me to harvest rain water from more of my roof area. This diverter has allowed me to significantly increase the amount of rain water that my rainwater tank can harvest. In fact this diverter has also allowed me to develop a complete rain water harvesting system that can now harvest rainwater from 100% of my roof area which includes two verandas and a garage. I have the equivalent of three poly rainwater tanks that are serviced by a total of ten downpipes. I can harvest at least 75,000 litres (19,800 USGal) of precious rain water per year from an average rainfall of just 300mm (12inches).

All up my poly rainwater tanks, complete with 3 pumps and plumbing, cost me less than 4,500 AUD (3,600 USD) to purchase and set up. My rainwater tanks have been positioned so they are inconspicuous and all of the plumbing (except for the plumbing to the tank inlets) is hidden and self contained.

So in comparison to underground rainwater tanks my complete above ground rain water harvesting system was much less expensive to install, is inconspicuous and most importantly can harvest rain water from all of my roof area.

If you’d like to find out how I went about designing and installing my complete rainwater harvesting system it’s all in my new eBook How to Harvest MORE Rainwater.

It includes how to make your own simple diverter to direct more rain water to you rainwater tanks, how to modify your diverter so that you can adapt it for other uses as well. It also includes how to make your own inexpensive rain barrels, rain barrel diverter and how to make the most of the rain water from the overflow of your rainwater tank.