I have previously written about the Victorian Government’s push to make us more sustainable including by only washing our hair once a week, click here for more information and my earlier blog piece is here.
Now, according to ABC Online, the Victorian Government is not practising what it preaches, when it comes to saving water and electricity. Apparently:
New figures show the Department of Sustainability and Environment (DSE) used 13 per cent more water and six and a half per cent more electricity over the past year.
The Nationals says the DSE’s annual report also shows it has overspent its budget by $500,000 a day over the past three years.
The Nationals Leader, Peter Ryan, says the Government should be leading by example.
“There is no justification for this, the Government talks the talk about saving water, saving energy, and I think it’s got to walk the walk, it’s got to comply with what it’s urging other Victorians to do,” he said.
“And as for over spending the budget, well, like the rest of us, they have got to live within their budgets.”
I wonder how other state governments compare?
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
The whole purpose of the campaigns to encourage the public into token water saving activities is to mask the extraordinary incompetence of water management authorities and their political masters.
Catchments are still being managed for maximum water quality even though all water goes through a full treatment process anyway. So we have this absurd focus on expensive recycling of sewerage when a very marginal lowering of catchment water quality can more than double catchment water yield. And at a fraction of the cost. Overly forested catchments produce the lowest water yield. Thinning those forests can maintain and often improve total biodiversity value while increasing yield.
The Brisbane catchments, for example, are 900,000ha of which 450,000ha is woody vegetation. (See http://www.slats.nrm.qld.gov.au/)Roughly half of this is woody weeds and regrowth while the other half is neglected, overstocked regrowth remnant. So both types will benefit from commercial or non-commercial thinning but most remnant is former Satanic Forest where such activities are prohibited.
The work of the CRC for Catchment Hydrology (see http://www.catchment.crc.org.au/) shows that yield is mostly a function of rainfall and retained leaf area index. The gain from a modest thin in this 900mm-1000mm rainfall zone is 0.25 of a megalitre per hectare or 125,000 megalitres over the entire catchment.
This water would travel almost the full length of the river system, delivering additional ecological benefits, before enabling additional retail sales of $125 million per annum. And as the system is already operating in profit with high fixed costs and low marginal costs, it would amount to an annual benefit of $250 per hectare of forest. Commercial thins pay for themselves while most non-commercial ones are justified by the improved growth and quality of the retained stems.
So we have a fully self funding solution that would enable a 50% increase in water supply to the existing infrastructure. And we haven’t even begun to talk about reducing the 250,000 megalitres of annual evaporation from the surface of the dams. Instead, we have one eyed tightarses imposing restrictions on the basis that the more the public sacrifices the more they think the spivs are doing their job.
Looks like a similar story for Perth, according to Warwick Hughes
http://www.warwickhughes.com/blog/
Ian – re SE Qld – we’ve cleared practically anything you could plough or graze. What’s the definition of a national park – anything on a mountain or with unproductive soils/wetland.
Where exactly are you saying these vast forest resources are – Jimna ?
Frankly I would have thought looking out the window that Wivenhoe’s problem was simply a lack of rainfall.
And how does the water travel the full length of the river system when we intend to pump it out at Mt Crosby.
OK – we can argue but need to test it – need two model runs with 100 years met data – with and without the Mott thinning method. The question is will modified forest management get you out of bad rainfall spots. The dam will store extra in good times – but how it interact with evaporation long term.
Won’t the LAI of the surrounding trees just take up the extra soil water from the thinning anyway – do we definitively know without clearfelling it to pasture?
The usual lazy response again, Phil. Look up the url I supplied above http://www.nrm.qld.gov.au/slats and find “Landcover Change in Qld 1999-2001” and see Table 13 Woody Vegetation change by landcover by catchment, and check Brisbane (18) South Pine (112) and Stanley (114) catchments and go to columns 3 and 12 showing total area and % woody vegetation cover for each.
It has been raining in these catchments but the excess competition between stems leaves a soil water deficit that must first be filled before runoff takes place.
Nit picking again, Mt Crosby is ALMOST the full length of the non-tidal river. And after Mt Crosby the river flow is substantially boosted by urban stormwater. It is the upper reaches that are still bone dry when they would not be under pre-settlement fire regimes or with regrowth thinning.
And your 100 year test requirement has a powerful stench of obfuscation about it. Why dont you just look up the URL for the crc for catchment hydrology like you were invited to do above. It represents the life work of current head of CSIRO Land & Water, Rob Vertessy and numerous others. If you do so without an ideological paper bag over your head you may discover that by removing half the trees you remove half the leaves as well. And the remaining trees will take 10-20 years to reach the same over stocked condition. A win for the forest, a win for the wildlife, a win for the rivers and a win for the urban punters.
Ian Mott
Ian, your post was very interesting concerning water use and conservation,particularly the comments about water quality and evaporation.
One of the main problems with water use in Australia particularly in the MDB is that it is so absurdly cheap. I think the going rate at the moment for temp water is down to $50/ML in some parts, and up to $150/ml in others.There is therefore no incentive whatsever for consumers/ irrigators to conserve, and if all the turkey nest dams lose half their volume over summer from evaporation (on average 1.8m in depth), it is cheap and easy to just turn the pumps on, and take more out of the river systems.
The true price should be nearer $1000/ML as suggested by various water scientists & economists, like Peter Cullen et al. Sure it is going to rise over time now that the market mechanisms are getting better and the availbilty is getting less.
Most approaches to minimising evaporation need the price to be nearer $250/ml and higher, for it to be cost effective, (assuming of course that they do work and not all do so). I recently did a Business Plan/financial Model for an approach that does work, is not affected by high winds and will last 50 years, but it aint worthdoing if the price of water is only $50. And therein lies the problem.
Ian – you are the leader in lazy responses by not addressing my previous comments on SLATS data previous thread. You need to do better than just quoting raw stats – what sort of basal areas and on what slopes. Tell me it’s forest timber?
Also I don’t intend to scan CRC’s entire web site because you’re too lazy to supply the url for the paper either.
The 100 year run is standard hindcast stuff – no obfsucation at all – you need to do a river model run and work out what happens long term.
Anyway your response is totally rude – if you’re too thick to understand reasonable ecophysiological comment when you see it no wonder your side is losing the debate.
So lift your game mate.
P.S. and oh – thinning is now removing half the trees is it?
Thanks, Malcolm. There is only one problem with you and Cullen’s desired $1000 per megalitre price of water. That is that neither of you, or any Australian consumers for that matter, are willing to pay for the produce grown in a $1000/ml value chain.
Blind freddy could foretell that urban Australia will simply take the cheaper imported product that has been grown with subsidised water and only partial cost recovery. Our farmers will go out of business while urban Australia looks the other way and engages in some sort of hideous tokenism.
But truth to tell, this so called under valued water is only a product of substandard costing methodology. It leaves numerous public benefits uncosted so the irrigator appears to be the only beneficiary and hence, is getting water at below cost. This is exacerbated by the complete isolation of the most efficient (cheap) water supplies from the farming community so general perceptions of price are only influenced by the least efficient storages.
A good example is Wivenhoe Dam in Brisbane. A major portion of its capital cost was to supply two million megalitres of flood mitigation capacity to Brisbane city. This facility is only used every 8 years or so. This cost element is not a product of water use but, rather, of water that is temporarily parked on adjacent farmland and then dumped in the weeks following a flood. There is no mechanism to pass on this part of the capital cost to the flood prone property owners and CBD businesses that get the benefit.
Only a very small portion of total storage is sold to downstream farmers. Seasonal (4 yearly) surpluses are dumped, often prior to the wet season to make room for more water. But the nearby Atkinson dam, which is small and shallow but only 12km away, and downhill, doesn’t get a drop of this dumped water.
So we get feasibility studies on pumping waste water (but not the more abundant storm water) uphill from Brisbane yet there is no investigation of the changes to the cost structure that would result from diverted dumping and increased sales from enhanced water yield.
Wivenhoe breaks even at a wholesale price of $120/ml and volume sales of 270,000ml per annum. Most costs of water supply are fixed overheads, not variable costs. So an additional catchment yield of 100,000ml per annum, sold cheaply to the hundreds of farmers who are lower than the dam level, would lower the break even price to $87.50 per megalitre.
Allocate one third of the cost structure to flood mitigation and spread the remaining costs over the expanded water sales and the unit break even point drops to $58 per megalitre.
And, of course, if the catchement is more efficient and more water is being sold then a greater portion of storage capacity can be utilised. This leaves an enhanced capacity to capture, store and sell on a spot market, the 1 in 8 flood events that are currently dumped. So this extra million megalitres spread over 8 years would average an extra 125,000 megalitres. So if only 2/3rds of this were sold and the other 3rd lost in evaporation then the additional 83,000 megalitres a year would drop the unit break even price down to $47 per megalitre. And this is before we cost the environmental flows that, in Brisbane and many other catchments, are actually in excess of natural flows for much of the year. And there are even more efficiencies to be gained so don’t get too close to Cullen’s $1000 buck megalitres just yet.
You are correct in your estimate of the current threshhold price of $250/ml for evaporation control. But what is not widely appreciated is that this would be additional water into a system that has already broken even. And in the case of urban water, the additional sale is at $970 to $1400 per megalitre. And this leaves a very healthy profit for just about every serious evaporation prevention technology. Basically, the market sector where evaporation prevention is most viable is, a)publicly run, and b)least likely to get it’s tiny collective, asynergistic brain around the opportunity before them. And even if they could get their head around it, they would probably stuff it up anyway.
Percent Wooded Vegetation from SLATS
Catchment Area – hectares 1988 Percent 2001 Percent
Brisbane 697,000 50.57% 49.00%
Stanley 154,000 61.24% 58.21%
South Pine 42,000 51.06% 47.56%
So the area of wooded vegetation in the Brisbane catchments has slightly decreased between 1988 and 2001. Wivenhoe opened in mid 1980s. South Pine doesn’t flow into Brisbane catchment.
Of course much of the remaining vegetation that is wooded is on steep terrain.
Will do the rainfall analysis next.
South Pine Dam forms part of Brisbane’s water supply catchment and is in a very similar veg condition to the Bris/Stanley. Nit picking again, Phil?
Total veg cover change is from 468,000ha in 1988 to 451,000 ha in 2001, for a total of 17,000ha or only 1.9% of the catchment over 13 years. The slight decline in vegetated area has little impact on the major (up to 50%) decline caused by compositional change (thickenning).
The extent of a silvicultural thin is dependent on the number of stems present. A very thick regeneration event after a hot fire can produce up to 40,000 seedlings per hectare which will begin competing with each other (and reducing catchment yield) in less than a year with stem diameter of only 4cm. A prudent thin on such a stand may involve removal of 90% of stems or more. A typical larger stand with 1000 stems/ha and diameter of 20cm should be thinned back to 200 stems/ha. Those remaining 200 should then be partially harvested (up to 50%) when they again fully occupy the site at about 45cm diameter. An intergrated grazing/forestry use would normally reduce the 1000 stems/ha back to 100 to maintain healthy pasture and tree growth. In most forests, however, there is not a uniform stem size so there would be a mosaic of stem densities representing 4 to 8 crop classes in the one forest. And the extent of removals will vary accordingly.
Ian – now that you’ve returned your baseball bat to the rack perhaps we might have a discussion. My intial comments weren’t an attack as much as reasonable questions.
Ian – I patiently answer the same questions on climate change furphies over and over again to new people (even not so new). Is it not reasonable people to ask questions – some people may argue but will listen and even be won over by a reasonable discussion.
I presumed you would say the remaining vegetation has thickened from lack of fire and/or lack of harvesting operations.
So for me the remaining issues are – how much area can we get at e.g. national parks, too steep etc. Is there an erosion risk.
I asked about Jimna trying to ascertain where you were suggesting we harvest from – Brisbane Forest Park? Conondales – Jimna. Blackbutt area. Or ??
And when we take out the national parks, forest parks, reserves and steep terrain – what does that leave in area and what water yield – GIS land resources question.
We can get the rainfall data (should get) for say Kilcoy, Woodford, Peachester, Blackbutt, Jimna and Toogoolawah. We could do an interpolate coverage over the area for more fullsome calculations. Why – coz it’s been dry as a chip out there for some time IMHO and from driving through it.
And why a 100 hundred year run – to see how the forest thinning strategy sticks up at ameliorating dry spells and droughts over time. We can easily get 100 years rainfall data. Just as your beloved Catchment Hydrology CRC would have done – did do in various other areas.
I’m not sure that you’re suggesting so, but would find it very had to believe we could reduce evaporation on Wivenhoe and Somerset storages which have fishing, sailing and even power boats – even wave action on windy days i.e. they’re seriously big storages.
So the above calculations can be done back o’ envelope or more formally. Would have thought it was in forestry industry’s interests to get the calculations done and reported.
Mt Crosby comment wasn’t a “stop” comment. Just implying that the lower reaches IMHO need more flow which would be siphoned out at that point for consumptive use. But that’s OK.
So finally I’m simply trying to discuss if the drought is more important overall than any yield enhancement. Same thing with cloud seeding – worst time to it is in a drought, better in more average to wet years. Same issue may apply here but you have to model the consequent long term evaporation and storage. The whole issue is somewhat complex – I don’t think Aila will give you carte blanche without a few calcs. (probably not even then but that’s another debate!).
P.S. These questions will become more and more important for Australian water resource management – so we need to address them formally.
Ian’s suggestion of thinning may help a little (but it’s just playing at the edges really). If you look at big inflows they come from big events that totally overwhelm any soil moisture store, trees or no trees. For the last decade or so we have missed these big events (where have all the cyclones gone)?
Will climate change reduce runoff in SE Queensland? see recent article in Nature Vol 438 page 347. “Global pattern of trends in streamflow and water availability in a changing climate” Milly et al.
From this paper the prediction for SE Queensland looks like 9 percent less runoff in 2041-2060 vs (1900-1970). NB the figure in which the data is presented is quite small and SEQ even smaller so its a bit hard to read off.
While it appears that there could be reasonable errors associated the analyses I would say its better to have a systems analysis point of view (the best available but imperfect physics in general circulation models) rather than pulling a figure from one’s bum as the skeptics are inclined to do.
Richard – the CSIRO modelling seems to point to a consensus of a more negative overall water balance. We need better information on seasonality of flows and information on any changes in El Nino frequency. There also seems to be a longer term drying trend already apparent if you look at http://www.bom.gov.au/silo/products/cli_chg/
I suspect we both had our lances at the ready for a convenient windmill, Phil. Will cover your questions in order.
Thickenning can have many causes. Yes, lack of fire, lack of harvesting, but over harvesting and over thinning can do the same. As can over grazing and sometimes even a sequence of good seasons can have disadvantages.
How much area can we get at? That depends on how many sacred cows are considered more important than river health, soil health, forest health, biodiversity value, species stocking rates and water yield. DNRM have the systems to tell us the tenure, veg class, slope and whole lot more for every pixel in the catchments. Steep or other sensitive country need not be ruled out. We just need to recognise that methods must change for the circumstances. For example, a thinning on steep ground in early spring will present minimal risk of storm induced soil flows. And alternating bands of disturbance and undisturbance? along the contours have been shown to minimise erosion.
Where? If a stand of overly dense trees is degrading the soil microbial resources and diminishing stream health in Brisbane Forest Park or anywhere else then, on my reading of the EPA Act’s environmental duty of care, the person in charge has an obligation to take all reasonable and practicable steps to prevent that entirely foreseeable harm.
We can only exclude national parks etc from this duty of care if we impose an article of faith that assumes that public tenure is, by its nature, pristine. It is not, and cannot be so in a changing climate. It is certainly not the case with all the former State (Satanic) Forests that are being handed over to parks.
The rainfall data must be daily falls (over a century is fine) rather than monthly because the key to the analysis is to determine the extent of the depletion in the soil moisture profile at the start of each rainfall event. It would need a range of assumed full moisture profiles for a range of soil types and slopes. But the preliminary work I have done in this area has indicated that the highest rainfall years are not the best for ecological or economic values. A lot of the big floods are wasted, being more than the available storage volume. It did show that actual yields are much higher than those that have been modelled on average rainfall data. This is because one is able to identify those events where a heavy fall lands on an already full moisture profile and also identify those, like our recent ones, where heavy falls have landed on very depleted profiles.
The whole point of the interventions is to adjust the stock of trees in a way that ensures that soil moisture is retained for a longer period between rainfall events. Young Eucs are recognised the world over for their unrivalled capacity to pump the ground dry, and fast. It is the classic Australian adaption, to make maximum use of water while it is there and then shut down and wait for the next fall. The problem with this is that this shortens the period in which soil microbes can do their fertility enhancing stuff. And this contributes to our low fertility soils but also impaires the growth of other species, especially ground cover and understorey species and their dependent browsers(biodiversity) that do not compete for water as well as the Eucs.
Richard is part right in stating that the big inflows come with the big rainfall events but the most contributive creek flows are not the floods. The most valuable flows, especially in the upper parts of the catchments, are the small flushes that come in late Autumn and early Summer. These are the ones that circulate the water in the pools and prevent temperature layering and oxygen depletion. And in storage terms they are also the most efficient because they occur when they are most needed. No part of these flows must be dumped like flood flows. They have minimal evaporation loss from extended storage and they substantially reduce the decision risk of the water managers. And it is these that are missing from overstocked forest catchments.
So instead of two rainfall events at, say, two weeks apart that are entirely absorbed by depleted soil, a thinned forest’s soil may still have some of it’s moisture (and live microbes)left when the next fall comes and the creek will get a drink too. And so it goes up the entire range of rainfall events and intervals. We turn no-flow into minimum flow, minimum flow into mild flow and mild flow into good flow.
And, yes, with climate change it is already a fact that todays stocking rate will be too high for tomorrows weather. We can sit back and watch as the forest adjusts by itself in a debilitating struggle for survival that exacerbates wildlife risk parameters. Or we can do what prudent land managers have always done in dry times, that is, adjust the stocking rate to fit the circumstances so the herds of trees and wildlife are healthy enough to make good use of the good times.
Oh, and Richard, if we are lacking the big inflow events then it would seem that we have no real choice but to improve the yield from the less spectacular ones.
Ian, to produce much from thinning you would really have to have a very big program of individual tree treatment. Within 1-4 years foliage cover re-equilibrates with removing say half the stems, although tree basal area and stem number can take much longer to recover.
With the figures quoted and an assumption that half the area would be suitable for thinning then you get 50000-100000 ha to be re-thinned each year, probably equivalent to the entire Australian forestry sector, who is going to pay?. Very hot fires over much of the catchment each year might help and so would permanant clearing with a bit of overgrazing thrown in for good measure, but in reality I suggest that this is unlikely to occurr due to green pressure and the inability of governments to admit to mistakes. I suspect the water users will pay more and use less, Brisbane a tropical looking city will become drab and savanah like wilh brown lawns and less tourism.
Re Phil and CSIRO analysis, I am quite skeptical of the last generation of models (no ozone hole I believe, Northwest WA projections sharply different from current rainfall / evaporation trends) and perhaps the results given a bit of spin for the politicians. The next generation of model asessments from up to 20 or so models are starting to be published prior to the Fifth Assessment Report. These new generation models should be better but most still do not have a fully interactive biosphere coded in, let alone running the biosphere and all the other bits correctly, regional trends may still not be accurate especially given GCM grid cell size relative to most east coast catchments. The question is can we advance the science faster than the problem evolves, I suspect not, so the future will remain somewhat uncertain and this alone should be reason to respond rather than do nothing.
Richard was referring to some consensus work in a CSIRO report – url is:
http://www.longpaddock.qld.gov.au/ClimateChanges/pub/index.html
There is some experimental work by others that suggests an interaction between stratospheric ozone depletion and greenhouse gases causing circulation changes in southern hemisphere – circumpolar vortex speedup. Shows Qld coastal drying trends up.
Until we have new info I guess all we have is the CSIRO report. I think even CSIRO would acknowledge that rainfall and hydrological cycle needs much more work.
Interesting, Richard, where did you get the 1-4 years recovery in leaf area index (LAI)? That may be the case in wet, closed forest types but in the dry schlerophyll forests that make up most of these catchments the recovery would be much slower. This is especially the case with cell grazed woodland. It seems you have over simplified the situation. An 8 to 10 year rotation would be more likely and not all of this would be of a charcter and scale of conventional commercial forestry operations. Much of the material would be smaller than post, pile or chip grade and could be done with spray, needle injection (a la Bill Keruish’s injector)and, of course, with fire mosaics. In the USA there is also a humungus front mounted slasher that can cut and munch 6 inch Alder in one pass.
In the national parks estate it is primarily understorey clutter, of a character and scale that actually favours feral predators, that is the main problem.
And Phil, there is a lot more out there than “all we have is the CSIRO report”.
DNRM has a very useful little Fact Sheet “Planning your farm dam” W24 July 2003 see http://www.nrm.qld.gov.au/ that shows water yield (number of hectares needed for 1 megalitre of runoff) for various rainfall, veg cover and soil types. It is for only 3 of every 4 years (the dryer ones) and is useful as a general guide only. For Dayboro, (RF 1100mm)it suggests 0.45 megalitres/ha in heavily timbered country and 0.91 megalitres/ha on grassland and crops. So a thinning water dividend of 50% of the difference, or 0.23 megalitres/ha, in the 3 of 4 dry years, is well within the possible range for these catchments.
Ian – was only addressing the climate change question of Richard (for now).
Ian, I would suggest that we kill most large trees by stem injection and leave the young stuff, this way one could increase the carbon stock if regrowth is faster than decay of standing dead (which is pretty slow), so a bit more water and a probable increase in carbon stocks a win-win. Re rate of regrowth as you say depends where you are could be 8 years in dryer areas but still a big area to cover & largely in hills where machinery may not be useful/wanted because of erosion, and no orderly plantation rows. I rember my father thinning on a cyprus pine block for better timber production and this seemed to take a lot of effort just for a amall area due to density of small trees.
The Government and or Sunwater should be better placed to analyse scenarios such as you propose. Naturally Sunwater etc probably spend more on advertising than on monitoring (trees, grass, rainfall, runoff, evapotranspiration) so therefore the hydrological inpacts over time of say a 50% thinning (of leaf cover) remain uncertain despite CRC hydrology, its little better then guesses based on largely empirical equations.
The question of thinning and regrowth rates on hydrology needs further investigation. I think I remember a conference paper where someone up in QDPI forestry(?) at Gympie(?) was doing some work on pine plantations and hydrology (measurement not modelling) but do not know if they had a thinning event.
A further post on the issue of trees in catchments, I was talking with someone from Sydney water board and they said the the former grassed areas around Sydney dams (old grazing land I guess) are now filling up with woody vegetation, perhaps this is lowering the catchement efficiency.
For Perth fire scars on grasstrees indicate a decline of fires from 1.6/decade to 0.6/decade in the last 100-150 years from memory, so increasing forest density is an issue along with declining rainfall. There is possibly an interaction here to really reduce inflow.
May I suggest that some of these posts are placed under the water heading its getting difficult to folow this thread
Hi Richard,
You may suggest, but I don’t move stuff around at the blog – that is I don’t move comments on a thread. cheers,
your all wankas