VZ asks:
You say that low flush toilets are not that useful, but what about all the other usage of water in the household (shower, dishwasher, laundry…)? Does that water also get filtered in the same way (and hence it doesn’t matter if you use less of it) or that’s a different system and it makes sense to use less? Well, it makes sense to use less anyway (financially), since that’s the ways incentives are setup, but just wondering about the environmental benefits.
First of all, it makes sense to use less water if you have a water meter and the cost of additional water ($) is not worth the benefit (happiness).
But, second, the entire concept of charging for water use needs to be put into the context of the water system, i.e., will water that goes down the toilet and drains be available, after treatment, in the environment (or as recycled water returned to customers for landscape irrigation or for drinking)? If that’s true, then “efficiency” in terms of less water per shower, flush or wash will not really translate into any saved water.
Third, the real target for water savings should be outdoor use — mostly landscaping — since that water tends to evaporate and/or sink into the ground, from where it cannot be reused.
That’s why I think that outdoor watering should attract a higher charge (scarcity) or ban (shortage). Water budgets, by the same logic, do not make sense if they “lock in” a certain allowance of water for landscaping. That’s why they are a bad idea in water-scarce areas and a waste of time in water-abundant areas.
Bottom Line: Flushed water does not disappear, worthless. It has value because it can be used again.
Flushed water only has value if someone else is willing to use it. Few people want to drink someone else’s “sewage”.
Except that for example the folks in New Orleans drink a lot of water that was others sewage up river. As the article points out urban irrigation is a good use. But conversely using less water means less energy use in pumping the water to the house and in the sewer system.
“since that water tends to evaporate and/or sink into the ground, from where it cannot be reused.”
Or you could get more holistic and point out that one person’s wasted water sinking in the ground is another’s recharged aquifer or that someone’s evaporated golf course water in Phoenix ultimately falls as percipitation in New Mexico and feeds Texas’s Rio Grande River. Given weather and wind patterns it is a little difficult to insist that ANY California water is ‘wasted’ in a global sense.
Where there is waste is misallocations of water that has been artificially contained via dams and which can only supply so many farms via aquaducts and irrigation ditches/canals or alternately households and factories via pumps and pip. Having decided in decades past to invest in the infrastructure necessary to collect, control, distribute and treat that water and in the process drowning any number of river canyons it is incumbant on us to cycle the water as many times as possible. And certainly from that perspective any water that only goes through one cycle and is used to grow cotton in a fricking desert is ‘wasted’. But only in a technocratic and humano-centric sense.
Water is not like petroleum, it doesn’t get used up by chemical transformation in quite the same ways, at worst it can experience net transfers of location to places it never was. But as an example given the massive pumping of the aquifer under California’s Central Valley it is a little perverse to claim that what recharge it gets from agricultural water being ‘wasted’ ‘sinking’ into the ground is in fact a total waste that precludes reuse. There is reuse, just not by the agency of man (and perhaps not in the timely fashion engineers might fancy).