The National Forum   Donate   Your Account   On Line Opinion   Forum   Blogs   Polling   About   
The Forum - On Line Opinion's article discussion area



Syndicate
RSS/XML


RSS 2.0

Main Articles General

Sign In      Register

The Forum > Article Comments > The great water debacle > Comments

The great water debacle : Comments

By Ian Mott, published 21/8/2006

Kneejerk fixes to temporary water shortages could leave Queenslanders with an expensive legacy in a declining water market.

  1. Pages:
  2. 1
  3. Page 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. All
ericc-

Under Part 25 of the Queensland Development Code, the acceptable solution for rainwater tanks is a follows:

“(a) i. The rainwater tank has a minimum capacity specified by the local government; or
ii. where the local government has not specified a minimum capacity, a storage capacity of at least 3000 litres where used for external use only, or 5000 litres where used for external internal use.
(b) The rainwater tank must be installed in such a way that it receives the rainfall from a roof catchment area of at least 50 square meters.
(c) Where rainwater tank water is required to be used internally, it is connected to all toilet cisterns and to washing machine cold taps.”

http://www.lgp.qld.gov.au/docs/building_codes/queensland_development_code/referencedInLeg/QDC_Part25.pdf

QDC Newsflash dated 18 August 2006 states “The Australian Standards allow Councils to refuse to authorise cross connection between a rainwater supply and a town water supply. Where this is the case, it should be possible to plumb rainwater separately into the house.”

AS3500 is the Applied provisions of the Standard Plumbing and Drainage Regulation 2003. AS3500 provides the deemed to comply methods for plumbing of rainwater tanks. Where a person meets the requirements of AS3500 the Local Council may not refuse plumbing approval.

http://www.lgp.qld.gov.au/docs/corporate/publications/building_codes/newsflash/2006/NewsFlash241.pdf

The Newsflash also says “the Australian Standards do not prohibit the use of rainwater as drinking water.”

AS3500 provides acceptable solutions for plumbing a rainwater supply to the drinking water supply. AS3500 does not control the use of rainwater. Water collected from roofs for rainwater tanks is not owned by the State in Queensland. A person has the legal right to use rainwater for drinking water supply. The plumbing must comply with AS3500. Rainwater that is connected to the mains drinking water supply is drinking water for plumbing purposes. The owner of the rainwater – the householder – is responsible for its quality.

The Queensland Government would have householders believe that the State Government controls their rights to use rainwater. The State does not have this right. The State regulates construction, installation, plumbing and health aspects of rainwater tanks, but not the use.

Greg Cameron
Posted by GC, Monday, 21 August 2006 3:50:08 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
As I've indicated elsewhere, I think the author's costing assumptions are somewhat on the optimistic side. That aside the calculations appear to stack up in the case where

a) The roof is of median size (or greater),

b) household water usage is average,

c) all household water usage comes from the tank except when it is empty, and

d) the installation costs are as as low as they can be.

But what of the houses of less than median roof size? That makes the optimum tank size lower, but smaller tanks cost more per litre of storage, which pushes up the net cost of water.

The same is true if the household water usage is below average.

Some people will not want to drink or shower in rainwater, which again implies a lower optimum tank size, and higher net cost.

The costings calculation requires that the 13,500 litres consist of a single tank, because two tanks of half the size cost more than one tank. Tanks of that size are usually round, but in any case rectangular tanks cost more.

A typical 13,500 litre tank occupies 7 square metres of land. No everywhere has a 7 square metre patch of level land, so extra work may be required to build a suitable foundation. Again that increases the cost. It may also be impossible to man-handle such a tank into place because of obstacles, requiring the use of a crane. More cost.

Taking all those considerations into account, what proportion of households could really make economical use of a rainwater tank? What about the rest? Should they be condemned to install uneconomic water tanks, or live with perpetual water restrictions?

BTW, installing a large tank on my property appears to be impossible without demolishing the house and car port. There is no mobile crane available with sufficient reach.

Sylvia.
Posted by Sylvia Else, Monday, 21 August 2006 4:39:28 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
for those who may be depressed about water, as I was becomming. Can I suggest a thorough reading of this site

http://www.abc.net.au/news/newsitems/200608/s1720514.htm

I'm not saying Aussie is leaking in the same manner as Mexico, but suggesting the manner of thinking of the problem, so evident in Australia.

The suggestion to me was if we were consious of our use of this "right we have to water" perhaps problem solved?

I'm seventy five and remember well padlocks on tanks, children were barred from access, just in case. All water for personel use was in a shallow bowl early morning. The same water all that was available for 24hrs, the exception of course was for drinking, kept in a galvanised bucket. This in the mallee of WA.

When I consider my present use of water, I'm ashamed.
While I'm much more conscious than most I know, I feel as though I had lost some part of me? this site reminded me of the loss.

I never felt deprived all that time ago, I'm pleased to be reminded.

Maybe the thinking could also be applied to "history"
There could be a problem, what if everyone had the temerity to have their own history? Too radical of course, I'd fail any exam anyway, memory is so unreliable! This may also fail to recognise myths and fairytales can have histories, that ain't science?

Whew glad to get rid of all that

fluff
Posted by fluff4, Tuesday, 22 August 2006 1:00:04 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
FLUFF,
You are an inspiration to all, I laughed a couple of years ago when "new thinkers" came up with the "new" idea of rainwater tanks. It's like the Top 40 these days, if you bother to listen occasionally, you recognise some of the words, the "new thinkers" have used the 1960's songs, and put a different "beat" to them, so very creative. I hope to see more contributions from you on this and other subjects.
Regards, Shaun.
Posted by SHONGA, Tuesday, 22 August 2006 1:50:12 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
Thats a bit of a mixed bag, Sylvia. The stuff about the crane is fine but most of the tanks will be in new dwellings remember? So they can be put in first, under the slab if desired or just buried before the landscaping starts. In any event, they can be done when the machinery is already on site and for a fraction of the cost of a retrofit.

The other points about variations in cost due to roof size, use and tanks size are relevant but just barely. The modelling found that unit costs per KL varied only by about ten cents/KL. And the proportion that may or may not be used as drinking water is very minimal compared to the remainder of normal use.

And even in retrofits, empty tanks are very light. In fact, the biggest problem with empty tanks is with sudden gusts of wind that can shift them about.

And wrt one of your earlier posts, these costings also take into account the cost of buying mains water if the tank runs dry. This produces an average cost/KL of all water so the increased use of mains water when a smaller tank is used is reflected in the average cost to the household. I think this is a truer and fairer view of the real cost structure than the simple calculation of tank water alone. And as the prices of mains water increases in future to cover the excess capacity, this averaging of costs will really show up the folly of a less than optimum tank size.
Posted by Perseus, Tuesday, 22 August 2006 1:55:27 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
The proportion of Australian households that could make economic use of rainwater tanks is a minimum 75%. In the 2001 Census, occupied private dwellings in Australia were 5,327,309 separate houses (75.3%), 632,176 semi detached, row or terrace houses and townhouses (8.9%), 923,139 flats, units or apartments (13.1%) and 134,274 other dwellings (1.9%).

It is straightforward to calculate the cost effectiveness of rainwater tanks for people who do not live in separate houses. A cut-off point could be determined, if required.

Based on 175m roof area for a separate house, the actual yield from a 5KL system is around 75KL for the 80% of Australians who live within 50KM of the coast.

The incentive to maximise use of rainwater (which the householder owns) is to require reduced consumption of mains water (which the State owns). People actually drink 1% of purchased mains drinking water. Maximum yield of rainwater is when it is used for hot water, laundry, toilet flushing and limited outdoors. People can choose to use water saving devices if they don’t want to maximise rainwater use.

A simple solution to the problem of tank size (in existing houses where engineering solutions for large tanks may not be a viable option) is to have numerous small tanks linked in series. Since maximum yield is obtained by ensuring that water is collected from all downpipes, whereby 100% of the roof area is utilised for collection, 1KL tanks are a solution because they neatly beneath the eave of a dwelling and any number can be installed. Small tanks no more than 800mm wide do not impede movement. And with demand from 5.5 million separate houses, watch the rainwater tank industry develop innovative sizes, shapes and colours to meet consumer tastes.

The Victorian Government estimates that rainwater tanks in every house in Melbourne would yield 60,000 ML a year (toilet flushing and laundry cold water use only), cost less than $950 million and would be water bill neutral.
Source: Sustainable Water Strategy Central Region Appendix 2 page 144
http://www.dse.vic.gov.au/DSE/wcmn202.nsf/LinkView/427BD3FAB0838556CA25709F00148870DEE554DEB21669DBCA256FFE00103BF8

Greg Cameron
Posted by GC, Tuesday, 22 August 2006 3:00:57 PM
Find out more about this user Recommend this comment for deletion Return to top of page Return to Forum Main Page Copy comment URL to clipboard
  1. Pages:
  2. 1
  3. Page 2
  4. 3
  5. 4
  6. 5
  7. 6
  8. All

About Us :: Search :: Discuss :: Feedback :: Legals :: Privacy