This does seem rather short sighted thinking, but indicative of a debate where many seem to have forgotten that the economic and social health of these regions will depend on the health of the river (i.e.: the environment). After-all, if we reach a stage where there is little or no water reaching downstream farming communities and the lower lakes, it won't be just the environment that is negatively affected.
There is also a greater long term irony in this kind of thinking. As Prof Ross Garnaut said in his recent speech to the Academy of the Social Sciences on the need for action on climate change:
"If the mainstream science is broadly right, later in this century we will probably not be squabbling about whether a 37 per cent reduction in allocations to Murray-Darling irrigators is too much; but rather working hard to improve the chance of there being any water at all to allocate."
Not one drop indeed.