Rainwater tanks is still a new concept, especially in some modern urban areas where householders are very used to just turning on the tap to water their garden or fill their swimming pools. I remember when growing up, rainwater tanks, water issues and drought were very rarely talked about. I remember we'd use water for hosing down concrete paths and driveways. We'd pour as much water as we'd liked onto our lawns over summer and as kids we'd spray each other with the garden hose for hours. And of course all of this water came from our local water storages. These water storages were always full of water, as every winter it rained and filled them up. Then during the summer we'd do our best to try and empty them again but the levels never really seemed to get low. South eastern australia has now been in drought since 1997. As a consequence most of the water storages, lakes, dams and reservoirs are now perilously low. This winter in 2009 we have received average rainfall which is the first time since 2000. Unfortunately all this has done is slow the decline of melbourne's water storages which are now at an all time low of 29%.

Rainwater tanks is inappropriate, in which case there is a need for simple, inexpensive, on-site tests that can be used by the householder's onsite. On-site testing of water in remote areas offers the householders a quick, accurate and low cost option of testing their water for contamination at any time. On-site methods also allow people to access information, which affects their livelihood and quality of life. The on-site methods currently available include the colilert and colisure, which test for total coliforms and thermotolerant coliforms. These tests require an incubator for constant temperature incubation as well as refrigeration facilities to store the biochemicals (which can be purchased from suppliers). Also the incubators need to be checked often for their performance, all of which make regular testing not practical if not possible for householders. Therefore there is a need for a more simple method for routine water testing by householders. (1982) based on the detection of sulphate reducing bacteria (srb) in the water sample is a simple method.

The h2s method is a very user friendly method as the media can be prepared in any laboratory with minimum facilities at low cost and the chemicals, stored in bottles, can be stored in any household at room temperature for an indefinite period of time. The positive result (contamination) is indicated by a change in sample colour to black which can be identified by a layman. The major advantages are that it is inexpensive and does not require technical expertise or strict laboratory conditions to test the water. The h2s method was tested for its sensitivity compared to the standard laboratory methods for testing for thermotolerant coliforms in rainwater samples by pillai et al. Out of the 121 household tanks tested, every household was unaware of the quality of the rainwater and the majority of tanks were poorly maintained. The h2s method was found to indicate better sensitivity after 48 hours of incubation. Agreement between the h2s method and the standard coliform method is excellent.

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. 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 rain water 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).
Rainwater tanks is suitable for a variety of domestic and industrial uses, such as garden irrigation, toilet flushing and processing. Council does not recommend that it be used or consumed as drinking water without additional filtration. Prices of rainwater tanks vary according to size, make, installation, additional fittings and suppliers.