Walgett, Brewarrina, Bourke, Wilcannia and Menindee Lakes

Yaama Ngunna Baaka Corroboree
Tour 2019, Wilcannia.
Photo by - Mark Merritt,
courtesy of Earthling Studios P/L

I attended the Yaama Ngunna Baaka Corroboree Festival, from 28 September to 2 October, in western NSW. This was by bus from Sydney to Walgett, Brewarrina, Bourke, Wilcannia and Menindee Lakes, then train from Dubbo to Sydney. Mat Ward produced a detailed blog of the trip, there is the Water for the Rivers Facebook Page,
so I will just provide a few reflections of my own.

Sometimes you see a photo, and think: that is not real: it was staged: they added the smoke and colored lights.  Well
Mark Merritt's photo of the Corroboree at Wilcannia looks too magical to be real, but I am one of those dots around the circle: that is what it looked like. Leaving early, crossing the old lift bridge over the river to the campsite, I looked back and the moon had risen directly over the ring, the smoke hung low.

While I have written about the problems of telecommunications, and e-learning in regional Australia, this was an academic exercise conducted at a distance. There were two buses, two trucks for supplies, and a convoy of cars. It is rare for me to travel long distances with a large party, and at times voices were raised. But mostly it all worked out.

One highlight were the Brewarrina Fish Traps (Baiame’s Ngunnhu), with a tour by staff from the Brewarrina Aboriginal Cultural Museum. The fist traps may be the oldest existing human made structure.

 Save Our Rivers by
Bruce Shillingsworth 2019.

You may have missed this year's tour, but the Save Our Rivers Tshirt is still available.

Update: 

Indigenous community say they've lost their culture to water mismanagement, by Aneeta Bhole SBS, 18 October 2019

Yaama Ngunna Baaka Corroboree Festival 2019

Got my tent, and sleeping bag, ready for the Yaama Ngunna Baaka Corroboree Festival, with local Aboriginal organisations at Walgett, Brewarrina, Bourke, Wilcannia and Menindee Lakes, 28 Sep to 2 Oct 2019. There are a few seats left on the buses: book now.

While I have written about the problems of telecommunications, and e-learning in regional Australia, I am now going to go out and experience it first hand. 

"Each dance group will perform in each township at the corroboree that will begin at dusk:

Betina Bysouth (Menindee / Bendigo)
Barkindji (Wilcannia)
Budjiti (Enngonia)
Kamilaroi (Walgett)
Mungundi (Moree)
Murrawari (Goodooga)
Ngemba (Brewarrina)
Wankamurra (Bourke)
Wakagetti (Brewarrina)
Wiradjuri (Trangie)

Also Aboriginal dance groups ...

Garul Giyalu Rock Mob (Katoomba)
Yama Guroo (Sydney)
Koomurri (Sydney)
Tal-Kin-Jeri (Adelaide)
Mujamundu (Quilpie)
Group (Darwin)"

"In Walgett, Brewarrina and Bourke, the Mothers Milk Bank will involve their musicians as part of their Ruby Hunter project ... In Wilcannia and Menindee the duo JOCEAN from Shell Harbour will perform ... The Murray Lower Darling Rivers Indigenous Nations will lead these programs  ...

Eva Cannan will lead small ethical foraging bush trips and any food collected will contribute to evening meals. ... In Walgett she will be joined with Elder Camellia Bonney  ...

The Indigenous Energy Australia stall will provide information about their leading initiatives...."

Yaama Ngunna Baaka Corroboree Festival Bus Tour 2019

Bubble shower adapter to save water

CSIRO are promoting the New Zealand made Oxijet ‘low flow’ shower adapter from company Felton. This screws in between the water pipe and the shower head, injecting tiny air bubbles to bunk up the water. To the person showering it appears they are getting more water than they actually are, thus proving a shower with less water. I have had a device of this sort from Australian company E-Co  in my shower since 2005 and it works very well, the effect being of showering in effervescent water. There was also the Oxygenics shower head., seems to operate on the same principle as the E-Co and CSIRO units. CSIRO previously announced a device in 2007. That CSIRO announcement appeared to be worked very similar to that of a maker of a bubble shower already on the market.

Air cooled wok to reduce water use

CSIRO has developed an air cooled wok for commercial kitchens to reduce water use. Usually water is used to cool the wok. This saves about 5,000 litres of water a day, per stove. The unit has a heat shield around the burner and an air gap, reducing transfer of heat to the stove top and removing the need for water cooling. While the units are described as "waterless" they still use some water, but have features such as a timer to automatically turn off the water so the operator can't leave it running. An example is the Luus Waterless Wok range.

CSIRO Food Sciences, supported by Sydney Water, has developed an air-cooled wok burner with a user-activated spout, which not only reduces water consumption by 90% but also halves gas consumption. It is understood that Sydney Water is working to make the design commercially available. All models commercially available at present are of the conventional water-cooled type. ...

From: Switch on Gas - Revised Work Plan for 2007 to 2007/08, Report No: 2006/11, DRAFT DISCUSSION PAPER, EQUIPMENT ENERGY EFFICIENCY GAS PROGRAMME, E3 Gas Secretariat, Australian Greenhouse Office, October 2006

Low cost water filters for developing nations

Stuart Forsyth talked about Abundant Water at the Engineers Without Borders Canberra meeting in Canberra on Thursday. AbundantWater.org is a non-profit organisation developing a system using low cost clay pot water filters for developing nations.

The water filters are made from local clay mixed with organic material to make pots using traditional local craft techniques. When fired, the organic material burns away leaving fine pores in the clay which filer out bacteria.

The filters are claimed to have been developed by materials scientist Mr Tony Flynn of the Australian National University. There is a step-by-step guide (PDF 169k) to making the filters.

However, while Mr. Flynn may have researched how to make an effective filter, it is too much to claim to have invented the clay pot filter. Potters have known since the discovery of fired clay, that if you mix some organic material with the clay you end up with a porous pot.

The key to the Abundant Water project seems to be to transfer the technology to the local communities. The local existing potting techniques can be used and local staff employed.

While Abundant Water appears to be a worthwhile project by sincere people the way the project is promoted could be improved. In this case the presenter told a stories about family planning and corruption, which was inappropriate and insulting to people in developing nations.

One part of the talk claimed that Abundant Water used a tertiary model of technology transfer, with a partnership between the first world educator and the third world learner. However, it was still assumed that the people of the first world are needed to teach and the people in the developing nation are doing the learning.

The talk also diverted into a factually incorrect analogy to open source. The claim was made that Open Office.com started out as a European open source project. This is not correct: OpenOffice.com started as a closed source product: StarOffice. This product was purchased by Sun Microsystems and only then became an open source project.

The Abundant Water approach to development seems to be for trained engineers and other professionals from developed nations to go to developing nations to tell them what to do. This is a slow and expensive process. In the Internet age it would seem more efficient and effective to put the information and education online, so that those already in these nations could apply the technology. This could be done by providing a mobile phone compatible training course. Engineers and other professionals can be educated in place in developing nations in place. As an example of this, staff at the ANU and CSIRO work online with students in Indonesia.

Another problem with Abundant Water seems to be its charity business model. It is assumed that all the funding for the work will come from donations from the first world and be directed to projects in the third world. This may well perpetuate the poverty such projects are supposed to be working against. Abundant Water should look at business models which will make the project self supporting and allow the project to expand without donations.

Atlas of the Global Water Cycle

An Atlas of the Global Water Cycle by Wee Ho Lim and Michael L. Roderick is available free online from ANU ePress. This has maps of estimated rainfall, evaporation and runoff for the 20th century and predictions for the 21st century. There are maps for the globe and more detailed ones for Australia.

The book is available for free in PDF format chapter by chapter, as one large PDF file or can be ordered as a paperback. The data files used can also be downloaded.

Unfortunately the PDF is difficult to read having been formatted for print publication, not for on-line viewing. The text is in multiple columns, making it difficult to read on screen and the maps are small and blurry. However, this is a useful publication.

An Atlas of the Global Water Cycle

Based on the IPCC AR4 Climate Models

Wee Ho Lim and Michael L. Roderick

ISBN 9781921536885 (Print version) $95.00 (GST inclusive)
ISBN 9781921536892 (Online)
Published July 2009

• Preliminary Pages
• 1 Introduction
  • 1.1 Rationale & Motivation
  • 1.2 Atlas Contents
• 2 Methods
  • 2.1 Models and Scenarios
  • 2.2 Definition of Regions
  • 2.3 Calculations
• 3 Results
  • 3.1 Maps and Tables
  • 3.2 Time Series Precipitation
  • 3.3 Global Hydrologic Summary
  • 3.4 Australian Hydrologic Summary
  • 3.5 The All-Model-Runs Average: Maps and Tables
  • Additional content: spreadsheets of data sets for Chapter 3 (Excel format)
• 4 Discussion
  • 4.1 Global Hydrologic Balances
  • 4.2 Australian Hydrologic Balances
• 5 Acknowledgments
• 6 References
• Appendix

- Whole Book (8.7 MB)

What do climate models predict for the rainfall where you live? What about evaporation or runoff? Should your local community consider constructing new dams or do the existing water storages appear adequate? What about the availability of water for irrigation farming? Do the predictions differ between different climate models or do all the models basically predict the same changes in water availability where you live?

These are all simple questions but it is surprisingly hard for an individual, whether they be a farmer, water resources engineer, teacher or interested citizen, to answer them. As researchers active in the field we could not answer the questions either. In fact, we had never seen a compilation of the rainfall, evaporation and runoff predictions made by all the different climate models.

The Atlas contains maps and tables that document model predictions contributed by international climate modelling groups to the 2007 4th Assessment Report of the Intergovernmental Panel on Climate Change. The predictions are made available here via the wonders of the internet and ongoing cooperation by the international climate modelling community who routinely archive their results.

The maps and tables in the Atlas document rainfall, evaporation and runoff estimates for the 20th century along with predictions of the same quantities at the end of the 21st century. Whatever your interest, we hope you find the Atlas as helpful as we do.

Waterless Video Urinal

The award for the most eye-catching product at the DesignBUILD 2009 exhibition would have to be Urimat's Waterless Video Urinal. This is a waterless urinal, much like others used to save water in public buildings but with a flat area at the top facing the user. This flat area can be used to fit a 7 inch, wide format video screen for advertising or information messages. This is one of the more imaginative forms of digital signage I have seen.

Modular Water Tanks

ModTank is a system of plastic water tanks which stack like children's building blocks. The tanks are 600 x 550 x 300mm, hold 77 litres each and cost about $60 each. This makes them about the same price per litre as other plastic water tanks. The tanks can be stacked as a wall, as a cube, or around corners. They can be stacked four (2050mm) high. One catch is that there are four connections for each tank, to allow water to flow to the adjacent tanks, making for a lot of places for potential leaks and the installation instructions look a little complex.

One advantage is that the couplings allow the tank to be flexible. One applicaiton is for carrying water in a ute, truck or trailer.

These tanks could have industrial and military application, where water is needed in remote locations. The tanks could form part of the protective wall of a military building. The tanks could be used in a building to form a thermal mass to keep it warm in winter and cool in summer. This would also provide some protection in a military application.

Point-of-Use Electric Water Heaters

Delving into the issue of how to avoid wasting cold water while waiting for the hot to arrive, I found there are small "Point of use" indoor electric water heaters. There are
tankless models and ones with tanks. The tank less models are rated by their flow (in litres or gallons per minute) and the ones with tanks by the tank capacity.

The tank less ("instant") units have the advantage that they can heat water continuously, but require more power to do this than is available from a normal power point (they have to be specially wired). The units with tanks can be plugged into a normal power point, but only supply a limited about of water.

The units are designed to be used on their own, or placed at the end of a long line from a larger hot water system. For this purpose the smallest units (2 gallons, or about 8 Litres) would seem suitable. In my case the point of use hot water system would supply the first 4 Litres of hot water, at which point hot water would arrive from the main system and the unit's thermostat would cut out. The unit would not need to heat the remaining water arriving and would have its supply of hot water replenished. But it would use power keeping the 8 Litres of water hot, when the tap was not used for extended periods.

US Model point of use water heaters:

1. Point of use water heaters
2. water heater point of use tankless
3. water heater point of use with tank

ps: Some bloggers have suggested turning the thermostat down or hot water system off when not needed to save power. It should be noted that authorities in Australia require a minimum temperature of 60°C to inhibit the growth of legionella bacteria. Also some of the POU heaters are designed for use with one tap and cannot be plumbed to several, nor connected to a shower.

Electric Trace Heating For Domestic Hot Water Pipes?

My apartment shares a central gas boosted solar hot water system with the rest of the block at "City Edge" in Canberra's Inner North. This results in low hot water bills and minimal green house gas production, but wastes water. Perhaps I should install Electric Trace Heating, which would increase the energy use, but lower the water waste.

Water is heated by a large solar collector on the roof and when the sun is not shining by a large gas burner in the basement. The water is continuously pumped throughout the building, so it is hot when it gets to my apartment. But then there are several metres of pipe between where it arrives at the apartment and the taps. About 4 Litres of cold water has to come out of the internal plumbing before the hot water reaches the shower.

My efficient Australian made "Ecoshower" shower head uses only about 7.5 litres a minute, or 22.5 Litres for a three minute shower. So the cold water wasted is increasing the shower water consumption by 18%. In the kitchen this is a bigger problem with many litres of cold water going down the drain before the hot arrives.

By the way, as a subtle reminder to only have short showers, I have set the bathroom "tastic" heater to turn off after three minutes. So you see the light dim slightly to remind you you have been in too long. This is done using a motion sensor/timer, so the heater comes back on automatically when you step out of the shower.

As well as wasting water, the cold water is increasing my hot water bill. There is a meter on the hot water pipe and I am charged for a share of the building gas bill, according to how much water is used. So I am charged gas use for the cold water coming out of the pipe, before the hot water arrives. In my case this might be as much as 50% of the cost.

Electric Trace Heating (also known as Heat Tape and Pipe Heating Cable ) uses a fat flat electrical cable with a resistive element built in, which gets warm when current is put through it. A length of the cable is taped along the hot water pipe, between the normal hot water supply and the tap. Insulation is then wrapped around the pipe, and the cable plugged into an ordinary power point. A few watts of electricity is used to warm the pipe (about 14 Watts per metre). The cable is manufactured from a material which automatically regulates the temperature, so having its own built in thermostat and is designed for a set temperature.

I saw Thermon’s Warmtrace System on display at the 2006 Canberra Spring Home and Leisure Show , but haven't seen it mentioned elsewhere. Presumably the element only draws maximum power when the water in the pipe is cold, so it would not add much to the heating bill (or greenhouse effect).

Heat Tape seems to be common in the USA for preventing pipes from freezing. Amazon.com has Heat Tape for about $4 per meter. But note that the anti-freezing tape may heat to a lower temperature than that needed for domestic hot water. Also the USA uses a lower voltage than Australia and US tape can't be used in Australia. Also many of the tapes do not appear to be self regulating: they have a thermostat installed somewhere along the pipe, which would be less able to regulate the temperature.

There are also some practical problems with the heat tape: you have to run it along the length of the pipes and so need to be able to get to them where they run through the walls. The tape needs to be carefully installed, following detailed procedures. Also there has to be a power point handy somewhere to plug the tape into.

So the questions I have are:

1. Is heat tape used for domestic hot water in Australia?
2. Is the saving in water worth the increase in energy use?
3. How much energy does the heat tape use in actual conditions?

Another option would be to install small electric water heaters near the taps. These would heat the first few litres of water.

Of course this all assumes that there is a reasonable charging system is used for the cost of the gas used for hot water. At present most of the bill I get is not for the cost of the gas used, but a fixed minimum charge. As a result there is little financial incentive to reduce energy use. It would be more cost effective to disconnect the solar and gas system and replace it with a conventional electric heater. This would be bad for the environment, but cheaper to run, as there would be no separate gas bill with its high minimum charge.

One interesting possibility would be to replace the complex pumping system and gas booster of the central solar system with the heat tape. At present water has to be continuously circulated with a pump to have hot water available. The pumps do not use much electricity, but when the sun is not shining, it is gas heated water which is being circulated. If the tape was installed on the pipes, that would remove the need for the pumps. It may also remove the need for the gas booster. Electricity is more expensive and less greenhouse friendly than gas, but this is only needed as a supplement and might make solar systems more practical.


See also:

• Heat Tape
• Home Energy Efficiency Books
  
• low flow showers

Solving the global sanitation crisis

"The Last Taboo" (Maggie Black and Ben Fawcett, Earthscan, 2008) tackles the little mentioned, but important problem of sanitation in the developing world. The authors point out that this problem was largely solved in western countries more than a hundred years ago with the flushing toilet, but that system is not economically or environmentally feasable for most of the world. They also point out that most attention and resources about water-related diseases go to providing clean water, when it is the failure to correctly dispose of human excrement which causes the problem.

The authors detail and critique several designs of low cost and water saving toilets (pour flush pit toilet, double vault composting toilet,VIP Toilet, sanplat) and the programs developed to supply them. They are critical of projects which do not plan for maintenance of the systems and do not involve local people. They also advocate looking first to low cost solutions, based on behavior, not technology. As an example in rural areas they advocate an approach where people are educated to use a designated piece of land away from housing and simply bury their waste (in a "cat scratch").

I have one quibble with the book. At one point they discuss the benefits of separating urine from feces. They point out that urine contains much of the nutrients of the waste, while being almost free of pathogens and suggest its separate collection for use on crops. But they then point out that toilets designed to collect the urine separately are difficult to make, especially for females.

However, they don't suggest an obvious and simple solution: provide a urinal for males. Urinals are simple to make and maintain.They need not be complex waterless urinals which have been designed to look like a flush unit (some also require to be refilled with Sealing Liquid).

A urinal cab be as simple as a designated patch of ground, or a funnel and pipe. Males in many cultures are happy to use them, as satirized in the novel "Clochemerle". A urinal would divert about half the urine at minimal cost. In a communal facility it could also greatly increase capacity.

How to fix a dishwasher using the Web

After several years of having to manually advance the dishwasher through the cycle, I thought it was time to fix it. The web turned out to be a useful resource to do this. Apart from the inconvenience, I was using more water having to use more water to rewash partly washed dishes. To find out how to fix just about anything, try typing into a search engine "how to fix a ...".

One danger is that how to instructions can get you to attempt repairs you should not really try. In this case the Dishwasher Troubleshooting Tool proved most useful. The symptom was " Dishwasher cycle does not complete" and the suggested checks were:

• Test the timer motor
• Test the thermostat
• Test the heating element

Unfortunately these are generic instructions not specific to a particular model. But after testing the timer motor and heating element, I tried the thermostat. There turned out to be a small press button on the thermostat. I pressed this and it stayed pressed. The dishwasher then worked. This seems to be an overload cutout, but was not mentioned in any of the instructions.

Of course, a replacement smaller countertop dishwasher, or a drawer unit would use less water and be more convenient for small loads. The Fisher Paykel Dual DishDrawer units look very attractive, with the ability to fill one drawer, while the other is washing. But as my unit is now working there is no point in replacing it.

ps: Another part of the dishwasher which may need replacing is the cutlery basket. There are some replacements ones sold, but these can be flimsy plastic. A better alternative might be a bit of the stainless steel security fly screen mesh used in windows. Offcuts are available from suppliers, such as Alucom in Canberra. Aluminum mesh is not suitable, as the harsh dishwasher detergent tends to dissolve it.

See also:

• Repair a Caroma Dual Flush toilet cistern outlet valve
• Dishwasher repair and installation kits on amazon.
  

Pressure Washer to Save Water?

Visiting a friend I tried out their new pressure washer to clean the balcony and tho cars. These units use an electric pump to spray high pressure water through a nozzle. We found the unit would work okay from a rainwater tank, without the need for a separate booster pump on the tank. This might be useful for people who want to save the cost of a pump on the rainwater tank, using the water by gravity for the garden, but occasionally want to use the water for washing a car, house or path.

The pressure pump uses about one third as much water as a mains pressure garden hose (5 versus 15 litres per minute) for much the same washing effect. But you need to be careful not to point the high pressure spray at anything delicate, especially people and pets. Also it will still use a lot more water than a bucket and brush. You still need a brush or a broom for some cleaning (such as getting down wasp nests from buildings).

See also:

• Pressure washer available on Amazon.com

The most complicated tap in Canberra

The public library I complained about in February seems to have fixed their water wasting urinal by installing an infrared movement detector which activates when someone is present. But another problem in the same toilet is the bizarrely complex hand basin tap. The sign on the tap reads: "To turn on tap pull lever out. Turn Level to the Left for hot. Turn lever to the right for cold.". The problem is that an elegant but difficult to use tap has been installed which is not suitable for a public facility. The library should replace the tap with one which is easy to use and remove the sign.

Donald Norman discussed the design of tap handles in his book "The Design of Everyday Things". The technical details may be complex, but the idea is simple: the tap handle should work the way the user of it expects.

In this case the tap handle looks like a round knob with a bar sticking out, much like the "Justyna" model depicted here. The usual way this would be expected to work is you turn it to get more water. Even when you read the instruction to "pull lever out", it is not clear what the lever is ( there is a thin round bar, which does not look like a lever).

It may be difficult for the library to retrofit two conventional taps in place of the mixer (they would have to drill another hole through the stone facing). A simpler option would be to install a conventional knob which you turn for cold water only. If the cold supply is at too low a temperature to be comfortable, then hot water could be automatically mixed or a small water heater installed.

ps: Better than the infrared flush urinal would be a waterless urinal, or a single flush per day system, as used in the six star rated Australian Ethical Investments building.

Saving water is counter intuitive

There 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 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 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. Water 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: 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.

Carbon Cops

ABC TV's new environment show "Carbon Cops" starts Tuesday June 26 at 8.00pm. It has a very similar format to SBS TV's "Ecohouse Challenge". Experts visit a typical family and conduct an energy and water use audit, then the family is set the task of reducing use.

These programs are useful for educating the community about enviornmental issues in an entertaining way. But they may give the wrong message: SBS's show first cut off water and power to the households and documented the suffering of the families. At the end they rewarded the families with low water and energy appliances to restore their lifestyle. But many people would not have lasted to the end of the show. The message many people would have got is that energy and water saving is not feasible, rather than seeing that only a small investment and a few changes were needed.

ps: To see how computers and the internet can save the planet, join the new ICT Environmental Sustainability Group.

Economics of Rainwater Tanks in Australia

A report on "The economics of rainwater tanks and alternative water supply options" suggests tanks could delay the need for water desalination plants, particular when the energy costs of such plants are considered. The report was prepared by economics consultants, Marsden Jacob Associates for the Australian Conservation Foundation, Environment Victoria and the Nature Conservation Council of NSW.

One shock in store for house holders is that water from a rainwater tank costs at least $2.15 per kilolitre and possibly much more, taking into account the cost of the tank. But then the bigger shock will be that water from desalination plants costs around this as well. State politicians seem reluctant to tell voters that water is going to have to at least double in cost in the next few years.

The only flaw I can find from a quick skim of the report is that demand management measures are not given more weight. The report points out that saving water is cheaper than water tanks or desalination plants, but does not seem to go on to quantify this. This confusion seems to extend to the general community, where people are considering thousands of dollars on water tanks, before they have spent hundreds on a dual flush toilet and low flow shower.

The full text of the report is available online, but it is a large (1Mbyte) PDF document. The issue is an important one and the authors should take the trouble to produce an easier to access version of the document. They could at provide the Executive Summary in a separate PDF file, which would take a few mouse clicks to produce, or better still as a web page, which would take a few minutes work.

Here is the Table of Contents of the report:

Executive Summary 4
1. Introduction 8
2. The relative cost of rainwater tanks 9
2.1. Rainwater Tank yields 9
2.2. Cost of rainwater tanks 11
2.2.1. .Rainwater tank costs 12
2.3. Cost of alternative water sources 12
2.3.1. .Case Studies: Sydney and SEQ 14
2.3.2. .Summary 15
2.4. Other potential impacts 16
2.4.1. .Water mains 16
2.4.2. .Stormwater systems 17
3. Adding environmental costs to levelised costs 19
3.1. The cost of carbon 20
4. Deferring alternative water sources with rainwater tanks 22
5. Cost of rolling out rainwater tanks 31
6. References 33

Some excerpts from the Executive Summary:

Marsden Jacob Associates (MJA) has been commissioned by the Nature Conservation Council of NSW, Environment Victoria and the Australian Conservation Foundation to conduct research into the impact of a targeted rainwater tank roll-out in Sydney, Melbourne and South East Queensland (SEQ).

For individual property owners, the cost effectiveness of rainwater tanks is typically determined by comparing the cost of installing and operating a rainwater tank against savings from household water bills plus the impact of garden water restrictions. However, considering the benefits only from the perspective of the property owner does not recognise the broader cost savings to the community such as deferred water infrastructure, savings to stormwater infrastructure, and environmental externalities such as the cost of greenhouse gas emissions.

The present study compares the yield and levelised cost (i.e. the cost per kilolitre supplied) of various long term water source options in Sydney, Melbourne and SEQ against the potential yield and cost of rainwater tanks. Previous research by MJA for the National Water Commission indicates that both the yield and the cost of tanks varies significantly based on individual household variables - in particular the size of the roof collection area. This study compares the cost of rainwater tanks with other water infrastructure such as dams and desalination plants. Levelised cost (the cost per kilolitre of water supplied) is a factor of water yield from a particular technology and the cost of supplying it. Yield from a 5 kilolitre tank for a small (50m2 ) and large (200m2) roof collection area was shown to vary from around 47 kL to 105 kL in Sydney, 24 kL to 86 kL in Melbourne and 41 kL to 99 kL per year in Brisbane (airport sites only).

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In addition, the key findings of this report include:

rainwater tanks will be widely installed in new housing developments due to regulations imposed by both the Queensland and NSW governments. While new dwellings can be designed to be 'rainwater tank-friendly', a growing proportion of future dwellings are expected to be in high density unit blocks which are mostly unsuitable for rainwater tanks (although the majority of new dwellings since 2001 have been detached 'rainwater tank-friendly' dwellings). However there is also significant potential for take-up of rainwater tanks in existing dwellings. The majority of existing dwellings, particularly in SEQ, are detached houses, making them suitable in theory for rainwater tanks. Many may not accommodate a tank due to limited land area or plumbing constraints. There are currently around 1.1 million houses potentially suitable for rainwater tanks (i.e. detached and semi-detached houses)1 in Sydney and 0.9 million in SEQ.

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Water sources could potentially be deferred by more than the indicated time if demand management initiatives reduce future demand, or may be deferred by less than the time indicated due to other factors such as the need for emergency water supplies or specific regional growth requirements. The deferral of water sources will be cost effective only to the extent that rainwater tanks are less expensive than alternative water sources ..

Similar results would be expected for Melbourne depending on the growth in the number of dwellings and the impact of demand management initiatives. Additional demand management initiatives could potentially defer the need for water infrastructure even further. ...

research indicates that rainwater tanks are more than five times as energy efficient as desalination plants per kilolitre of water produced (rainwater tanks requiring around 1 MWh/ML compared with a typical desalination plant requirement of 5 MWh/ML); ...

See also my:

• Home and Leisure Technology for Environmental Efficiency
• Water and energy saving products

Self Watering Pots

My smart apartment balcony is a harsh environment for plants. The Canberra sun can dry out plants quickly. One way around this is to use a self watering pot. These have a water reservoir in the bottom.

The pots are usually made of plastic and do not look as good as more natural materials. So I fitted the self watering pots into glazed ceramic ones. The air gap between the ceramic and plastic pots provides some insulation, reducing the heat in summer.

One plastic pot did not fit, so I cut the top off with a small saw. The pot then fitted, but did not quite come up to the top of the ceramic pot and there was a gap between the two. So cut a piece out of the off-cut top of the plastic pot to make an adjustable sleeve. This I inserted into the top of the pot to cover the gap to the ceramic one. The springy plastic held it firmly in place until the soil was added to cover it.

Keep in mind that some plants do not benefit from the constant water supplied from the pot and may need to be left dry some times. Also the water could harbor mosquitoes other pests in some areas.

Folding Bicycle in Echohouse

The first episode of SBS's Eco House Challenge TV show went reasonably well. The idea is that two families try to get along with limited water, energy, rubbish removal and no private cars.

In the first episode we are introduced to the two families and watch their worry as the water and electricity are disconnected from their homes. The families are given a kit of portable alternative energy and water gadgets to help them get along. In later episodes the houses will be provided with low energy and water saving devices to make them more livable.

One of the gadgets provided was a small folding bicycle. I am a folding bicycle enthusiast. These can be used on their own for short trips, or combined with a car or public transport. You can put the bicycle in the boot of a small car, or take it on a bus, train or aircraft. This makes it much easier to minimize car use.

The EchoHouse challenge is useful is showing how dependent we are on energy and supplied water. But those who watch the first episode my get the idea that energy saving results in a drastic drop in the comfort of life. In fact with the right investment a home can be very livable while using minim of energy and water. Hopefully that message will come through in later episodes.

See also my:

• Water and energy saving products
• Folding bicycles
  

Ecohouse Challenge Update

SBS TV have released more details of their "Ecohouse Challenge". It starts Wednesdays, 7.30pm from April 11. Two families try to along with limited water, energy, rubbish removal and no private cars. There is also a viewer competition.

The idea of the show might sound trivial to committed environmentalists, but is a good way to get people interested. The prizes look suitably green: Electrolux appliances, Air-Cell insulation, Solectair Heat Transfer System, Solahart hot water systems, SunPower photoelectric solar panels and a Toyota Prius hybrid car.

The Solectair Heat Transfer System is an interesting new Australian invention. Instead of a heater, ducts in a house are connected to fans which draw hot air from the roof cavity to warm the house in winter. This is similar in concept to the system in the new green office building in Canberra, but on a domestic scale.

See also my:

• Smart Apartment for Environmental Efficiency
• Energy and Water Saving Products