The FNQ water strategy website link and RWT comments

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Notes from Shaun Hartley ARUP

The FNQ water strategy is publicly available here: http://www.nrw.qld.gov.au/water/regiona ... index.html
Note that it is still officially in draft format, as the Gov't has not released it yet.

In relation to the other items:
Rainwater tanks are indeed very expensive on a per litre basis - something like five times what we currently pay for mains-supplied water. Various studies have been carried out on RWTs and on a Cairns-wide basis they may yield averaged savings of 10% if they are fully utilised for flushing and irrigation. This is not going to save the world. On a single household basis, if used to their full potential, RWTs may offer savings of 50-60% on annual water usage for any particular house. For this to happen, the RWTs need to be plumbed into the irrigation system, toilets and possibly the laundry. If RWTs are used for garden irrigation only, then on a household level, savings of some 20-40% may be achievable in Cairns, based on typical usage levels. But people need to use them properly by using the water stored regularly and allowing the rain to top them up. Too often RWTs are used as 'savings accounts' for water (particularly in SEQ, but also here for cyclone season). Bearing in mind that most State legislation is based on the needs of SEQ, RWTs have their benefits 'statewide' purely on a demographic spread, but less so in the Wet Tropics on a community-wide level when our reservoirs get topped up reliably each year.

This is without any consideration of the embodied energy in rainwater tanks and the return period on a tank with a 10 year life expectancy and maintenance/running costs for the electric pump. With mains water so cheap, they are not actually financially viable (the rebate comes from our taxes!). The 'green eco paint' that has been applied to them does bring a feel good factor though!

On the underground storage option, this is certainly a concept with potential, but to be financially viable probably needs to be included at masterplanning stage. Retrofitting such a large scale system may be cost prohibitive. There are clearly issues with simply catching surface water runoff - not least the propensity for pollution and contaminants to clog the system (grease and oil from roads, litter, leaf debris, etc). The requirement to filter and clean up this water for its intended use is also costly and aside from the benefits of increased retention in the overall catchment one needs to be clear about the potential uses for stormwater trapped in this way and the locations in which it is stored (potentially leading to a need to pump the water to its destination - hence the need for masterplanning as opposed to retrofitting).

I note there's no mention of the aquifer in the Northern Beaches - without knowing the technicalities of ground water behaviour, I understand this is a particularly reliable source, which could perhaps be used on a community level.

My thoughts on the limited amount I know, not a professional opinion!