2. If we didnt have the dam systems that were set up for irrigation, the entire Murray-Darling would now be dry. This was certainly the case in other times even within white settlement. Its not the fault of the irrigators, its the lack of rain. The environment actually naturally dries up from time to time, and doesnt seem to suffer any long-term ill effects as a result (it happened for 000's of years before we put the dams in). If you find a 90yo from the Riverina, they will tell you that in the 1920's you could walk across the Murray (before the Hume Dame was built).

3. Irrigation water charges in NSW are made up of fixed rate and usage rate components. The fixed rate part is payable no matter what, and is designed to cover State Water's ongoing infrastructure costs. I dont have an issue with the concept (user-pays), but in exceptional times such as now there needs to be some kind of relief, even if its a deferral of the charges until the next year when a 100% allocation is able to be received (ie defer it until there is a least the production there to pay for it). Have a look at the State Water website (www.statewater.nsw.gov.au), and you will see that over time the fixed rate charge is coming down (a good thing, although it is still something like 50% of the total costs), and that the user-pays system has been developed to the extent that farmers completely cover the costs of water delivery for irrigation (and pick up some of the tab for what the "environment" gets too, though arguably this should be the taxpayer's area as its a "public" asset).

Instead of cotton wouldn't hemp be a more diverse crop to replenish the soil and produce over a hundred useful products including fiber and medicine?

I must confess that I dont know a lot about hemp production, its ideal growing conditions, or even by-products (apart from the obvious). I would certainly support investigation of alternative crops. My understanding is that attempts to commercialise he,p to date have been met with general government/community concerns over drug production and/or security. These would need to be addressed, although I also note that Tasmania manages to grow poppies for seed on a licence basis and quarantined farms, so no doubt a similar regime could apply to hemp. The other problem is one of market development and manufacturing process development, as well as consumer education and acceptance. You cant just say "lets grow something new" and expect it to work overnight. The rice and cotton industries have both steadily developed over many decades to get where they are now. But certainly worth examining the alternatives.

eftfnc, The primary reason it hasn't taken off in Australia is lack of markets and info on growing in our conditions. DPI trials have not be helpful from the info perspective. http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/74048/Low-THC-hemp-in-New-South-Wales-Primefact-211---final.pdf

From a marketing view, world sales of hemp in 2002 were $250 million compared with cotton at around $40 billion. The market liquidity is of great concern as a prospective grower. Canada's (where hemp is a "revolution") total hemp exports in 2005 were 124 tonnes valued at $188 000 ($1500/t). Australia exported 500 000 tonnes of cotton in 2005 for approx $1 billion ($2000/t).

Australian farmers will happily grow the most profitable crops. To my knowledge there just aren't any processors/buyers up and running here. No-one even getting expressions of interest from potential farmers.

Certainly the most promising hemp product is the chemicals (the legal ones) but at this stage they are not commercial on a large enough scale to drive an industry. The seed is often touted for its nutrition and oil content etc etc however yields in Canada suggest yields of 800kg/ha which could produce 200 litres of oil/ha. Compared to canola at 2t/ha or 800litres of oil/ha. Even cotton produces 3 tonnes of seed/ha for 600litres of oil. The big drawback for hemp is you have to choose: seed or fibre. For best fibre quality the crop is harvested prior to seed maturity.

Anyway thats all a bit technical, but as an irrigator (when water is available) I want to get the best return I can from the available resources without too much risk , and so investigate alternatives as best I can.