Tuesday, July 10, 2007

Saving water is counter intuitive

Toilet Sink LidThere are plenty of books, TV programs, and government information campaigns on how to save water. But the message does not seem to be effective. Recently I visited family friends who wanted to help the environment by saving water, so they installed a rainwater tank but found it did not help.

They had just finished showing me their very expensive tank, with electric pump when they opened the mail to find a letter from the water board. Their water consumption was above average and the authorities were threating to take action unless consumption was reduced. They said: "but we got a water tank, it cost thousands of dollars, why didn't it work?".

When I checked the tank I found it the pump had not yet been connected to the power and so could not be used for watering the garden. In any case this would only save a minimal amount of water, as most of the water was being used in the house and the tank was not connected to that. Even if the tank was connected, it could not save much water as there was a drought.

When I asked what water saving had been done, they explained that they had, as per regulations, been using a bucket to water the garden. Unfortunately they had been doing this very diligently and probably using as much water as if a hose had been used (using a bucket does not actually save water, just makes it harder to use a lot of water).

In the house they had asked the children to take shorter showers but that had little effect. When I asked if they had installed dual flush toilets they explained the rebate for this was much less than for a water tank and they were waiting to renovate. Similarly they had not installed low flow shower heads or tap aerators. The fact that these measures would be much simpler and cheaper (even without a rebate) than the water thank and save much more water, had not occurred to them.

These were not stupid people (both have PHDs) and this indicates the current water saving strategies by government are seriously flawed. The policies send two different messages: the water pricing policy sends the message that water is cheap (and therefore must be plentiful), but the water conservation policy says it is in short supply. The rebates on water saving devices favor some devices, such as water tanks, over others. This mixed message makes it hard for people to make good choices.

It would be more effective if the water saving target per household was aligned to the water pricing: if the household uses too much water it gets charged more. There would then be a clear incentive to save water and the household could sensibly budget for water saving devices.

The measures I suggested they take were, in order of ease, cost and effectiveness:
  1. Low Flow ShowerLow Flow Shower: I have the Australian made "Ecoshower Sapphire" shower head (from Queensland company E-Co Shower) in my bathroom. This only uses 6.8 litres a minute, but creates tiny bubbles of water so it looks and feels like more. The Oxygenics range of showerheads are claimed to work on a similar principle. CSIRO claim to have invented a better one, but it may be years before they are available. There are many other low flow showers.
  2. Water Saving AeratorWater Saving Aerator: E-Co Shower also sell a "Sink Hand Shower" which fits in place of a tap aerator. This is the same mechanism as used for the shower. This is expensive for an aerator (there are cheaper options), but might be worthwhile.
  3. Washing MachineWater Efficient Washing Machine: Front load washing machines tend to use less water than top loaders. For those who want a top loader, Fisher & Paykel make the AquaSmart, which claims to provide the water saving of a front loader in a top load model.
  4. Dual Flush Toilet:Dual Flush Toilet: Caroma's Smartflush toilets use 4.5/3 litre on their dual flush (typical dual flush toilets use 6l for a full flush). But they can't be installed in all situations. Otherwise you could just buy a standard dual flush tank which can be fitted in a few minutes (two pipes to connect).

    If you really want something to show you are saving the planet, you could get
    Caroma's Integrated Hand Basin. This has a handbasin built into the top of water cistern. When you push the button water flows through the spout allowing you to wash your hands. That water is then collected in the tank to flush the toilet. Caroma claim this meets plumbing standards. There is a similar "toilet sink lid" offered on Amazon, which is intended to be retrofitted to a cistern, but I do not know if it meets Australian regulations.
Another tip, which I was not game to tell them was to stop watering the garden. Those plants which were not capable of surviving could be replaced with others which would. They could also stop using a garbage grinder, which consumes water and wastes organic matter, and instead compost the scraps in the garden. This would improve the soil and allow it to retain more moisture.

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