EcoRadio

Category: Water

The world’s fresh water supplies are almost fully exploited.Almost al, 97 per cent, of the world’s water is salt. Of the fresh water in the world, two thirds is locked up as ice and snow (the cryosphere – to you and me, kid!). Globally, three quarters of the water that is used is used by agriculture. India, China and the United States, use more fresh water than is available. The water level in those nation’s aquifers is falling as a result.The current food crisis has come about largely as a result as the shortfall in available water begins to impact on the cost of irrigation. 

  • Snowy River revival ‘ a complete failure ”

    Alliance vice-chairwoman Louise Crisp says parts of the river are running out of time.

    “Basically the river has possibly only 18 months before some of the upper section will die,” she said.

    “It’s been a complete failure as far as what the community expected.

    “None of the legislated target flows are binding and neither are the environmental objectives.”

    Ms Crisp says the Snowy’s annual natural flow sits at 4 per cent below the Jindabyne Dam, but the agreed target for June 2009 was 15 per cent.

    The Alliance has been advised it has little chance of suing the three governments for failing to live up to their promises.

    ‘NSW responsible’

     

    Craig Ingram is the independent member for the Victorian seat of Gippsland East and a former member of the Snowy River Alliance.

    On his election to parliament in 1999, the Victorian Labor Party gave him an undertaking that it would work to have an environmental flow of 28 per cent returned to the Snowy, and Mr Ingram’s resulting support helped them take office.

    He blames the New South Wales Government for the Snowy River stalemate.

    “New South Wales under the agreements and under the legislation is the responsible government, if I can use that term very loosely,” he said.

    “They have systematically failed to deliver on the intent, the spirit and what the community thought they were getting when they signed up to the agreement.

    “One of the disappointing things is that we really haven’t had the level of support from the New South Wales Opposition that we should have had to hold the New South Wales Government to account.

    “And basically they’ve been missing in action on this.”

    He said the other governments should probably have taken action against New South Wales.

    “I think it’s probably time they actually investigate their legal avenues to ensure that the money that’s been contributed by the other stake-holding governments delivers the environmental outcomes that the community expects,” he said.

    “If New South Wales isn’t prepared to do it, then the other governments should force them to do it.”

  • Trend towards El Niño strengthens

    From The Land
    The signs of a developing El Niño have strengthened during the past fortnight, according to the Bureau of Meteorology.

    It says the key indicators for this forecast are a drop in the Southern Oscillation Index (SOI) to around -10, further warming of the Pacific and a strong decrease in the strength of the Trade Winds.

    And the Bureau says many computer models remain firm in their predictions of an El Niño event in 2009.

    This puts the odds of an El Niño at above 50 per cent, which is more than double the normal risk of an event.

    However, the Bureau says it is still possible, though increasingly less likely, that the recent trends may stall without El Niño thresholds being reached.

    El Niño events are usually (but not always) associated with below normal rainfall in the second half of the year across large parts of southern and inland eastern Australia.

    Another adverse sign for southeastern Australian rainfall is the recent trend to positive values in the Indian Ocean Dipole (IOD), as measured by the Dipole Mode Index (DMI).

  • Murray beyond saving says Young

    From the ABC

    A water scientist has told a parliamentary committee in South Australia that parts of the Murray-Darling should be allowed to die to save other parts of the river system.

    Professor Mike Young says the best way forward would be to have water flows for the environment controlled by a trust rather than the government.

    He says if it does not rain, parts of the river in South Australia which are dying should be let go to ensure the survival of other parts, although he says it would be a horrible decision.

    “It’s not to me about just closing off part of the lower lakes,” he said.

    “It’s about looking at every backwater, every wetland, every forest throughout the system from top to bottom and having a very careful discussion about which bits we invest in keeping going and which bits we are prepared to let go if it doesn’t rain.”

    Professor Young says, if a temporary weir is built at Wellington on the lower Murray to help safeguard water needs for Adelaide, it may not be able to be removed within three years as planned.

    He says a flood the size of one in 1956 would be needed to flush the system, fill up the lower lakes and enable the weir’s removal.

    “The environmental impact statements that are being prepared at the moment all assume that this problem is going to be solved in three years’ time because there’ll be enough water in the system to enable us to remove the weir,” he said.

    “If we remain in the dry regime, and we’ve just had forecasts for another dry winter, I can’t see how we can get the water back in the system in sufficient volumes that we could take out the weir.”

  • Feds invest in water efficiency

     “Today’s announcement starts to get the balance back into some semblance of equilibrium. It gives farmers some confidence to invest in water-saving measures on-farm and across regions.

     “Today’s funding commitment comes on the back of the $300 million for on-farm water efficiency programs under the May Federal Budget – a program the NFF pressed hard for.

    “Combined, this type of investment provides irrigators and their communities with a choice between selling back their water entitlements or co-investing with government in water-saving technologies on farm – or, indeed, a combination of both.

    “To date, irrigators have only really had the sale of their water as a sole option.

    “It is also recognition of the role regional Australia plays in underpinning agricultural production, which, in turn, is keeping the Australian economy afloat. It’s good news for producers, good news for environmental needs, supports regional communities by stimulating local employment and keeps farm production and the national economy ticking over.

    “This level of collaboration, which we have long argued is over-due in how Australian deals with drought and a changing climate, will enable farmers to produce more food and fibre with less water. This is a vital food security issue, both here at home and globally, in the face of a deepening world food shortage.

    “The funds announced today will implement modernisation plans developed by a number of infrastructure operators in NSW. The NFF hopes to see the remaining state priority projects, still awaiting the go ahead across the Murray-Darling Basin, triggered in the very near future.”

  • Atmospheric water generator

     

     

    Collecting water from the air has been a practice for some 2,000 years, in the form of “air wells” in Middle Eastern deserts, and later in Europe. Around the 1400s, we see water-collecting Dew Ponds, and later the Fog Fences, which have for hundreds of years have been used in Europe to collect clean water from the air. In the early 1970s, Melvin Littrell began producing water from the air with a system that did not need a compressor. Through this development, the creation of the first real Atmospheric Water Generator was produced. In 1990, Littrell patented the system’s technology as an AWG or atmospheric water generator.

    They are available in various sizes and styles, ranging from domestic systems that produce 32 oz. a day to all-electronic units producing 75 liters per day with compressors, and finally to commercial applications that can produce from 35,000 to 109,000 gallons of water each day.

    [edit] Principle of operation

    The principle of operation remains similar for most manufacturers except the WPG. The AWG is essentially a conventional dehumidifier that condenses water from air. A compressor circulates refrigerant through a coil or chiller array. A controlled-speed fan pushes air over the water reaction area and condenses the water. This water is then passed into a holding tank.

    The rate at which water can be produced depends on relative humidity and ambient air temperature and altitude. Relative humidity is the amount of water vapor present in the air at a given temperature at a given time. AWGs become more effective as relative humidity and air temperature increase. As a rule of thumb, AWGs do not work efficiently when the temperature falls below (35°F), the relative humidity drops below 40%, or at high altitudes (above 4000 feet). If the ambient air has passed through an air conditioner, much of the water vapor has already been removed. In the winter, with a heater on, most of the humidity is lost, leaving little for the AWG to produce.

    [edit] Optional AWG features

    AWG features vary depending on the manufacturer. In order to meet stringent FDA standards and NSF, most systems are coupled to one or more advanced filter systems (including an UV light chamber) before being stored in stainless-steel holding tanks. A list of optional features typically found in AWG systems would include:

    • An air filter to help prevent dirt from accumulating on the surface of the coil
    • An automatic level switch placed in the generator’s holding tank to shut the machine off when the tank is full
    • Hot and cold stainless-steel storage tanks that allow water to be served heated or chilled
    • The so-called “split system” is a two-part system. Designed by Prof. James D. Vagarasoto in 1991, the two-part system allows the user to place the generator in a location of high humidity and serve as a tabletop unit that dispenses hot or cold water. These systems eliminate the adverse effects of most older-style atmospheric water generators, as they heat the area where the generator is placed. In the summer, air conditioning system remove most of the humidity, so the conventional AWGs don’t work very well because they are humidity-driven.

     

  • Rain ensures critical water supply to Murray River

     

    Altogether, over the three-year period 2006-2009 only 5040GL has flowed into the river, one fifth the long-term three-year average of 26,700GL.

    The outlook for irrigation water for 2009-10 is grim.

    Mr Freeman said after nine dry years, the soil was now so dry that the long-standing relationship between rainfall and inflow into the rivers had broken down.

    “Even if you do get average rain, you get nothing like average run-off. In fact in most of the basin we have got no run-off from the rain.”

    He said although there had been some rain in the northern basin, “we haven’t got the run-off. We will get a small inflow into Menindee Lakes.”

    But Mr Freeman said the soil was now wet in the northern basin “and this most recent rain in the last few days is wetting up the southern basin to a point where it may respond and we might get run-off.”

    Mr Freeman was also optimistic about the Bureau of Meteorology’s forecast for average rain over winter, the wettest time of year for the Murray system. “The outlook for the next three months is better than we have had for the last few winters, without doubt.”

    Basin storages are now at 980GL, or 11 per cent of capacity, above the lowest year of 2007, but well below the average of 4670GL.

    “It is a pretty gloomy story,” Mr Freeman said.

    But he pointed out that there were some positives.

    The series of algal blooms that extended down the Murray River from Albury to Wentworth before Easter have dissipated, thanks to the lower temperature.

    “We have gotten through a terrible summer with minimal water, high temperatures and significant blue-green blooms without a major environmental disaster. I think that is good,” hesaid.

    Mr Freeman added that salinity was at an all-time low.

    “If you don’t irrigate, you don’t mobilise salt. People are talking about the water quality at Swan Hill — it is some of the best we have ever seen.”