Does it take more water to grow organic veggies?

[DaveinOlyWA]

Shawn, those numbers are surprising to say the least. there is no doubt, huge regional variances.

also, the discussion was the amount of energy used to move the water. my contention is that gallon per gallon, the city uses much more power to move that gallon than farms.

go to vertically challenged places like New York, and i can imagine we are talking power squared or more

also, again this statistic does not really tell the story, especially in the context of this discussion. water used to irrigate the central valley in California where a significant percentage of the food grown is eaten by the population for 1500 miles in every direction on paper says that irrigation may have used a lot of water on a volume basis, but then that food is shipped to the cities where water is used on a much smaller basis by volume only, but the cost financially and to the environment is much much higher for its use.

also, the irrigation figures are not really indicative of anything. in Eastern Washington, they irrigate a TON of water, mostly because its very very porous and dry. water must be pumped in huge quantities because the soil is basically rocks and does not retain moisture. but like so what... there is a huge hydroelectric system that has to route the water so why not divert it to crops?

as it stands now, diversion dams are needed for flood control anyway. a diversion dam is a holding pond above the dam, after water is run thru the generators, its pumped back up to the top of the dam and stored again. this results in a power loss of like 20 to 1. iow, it takes 20 times more power to pump the water back up to the retention pond than what was generated when the water went thru.

but this has to be done to prevent downstream flooding or overflow of the dam. now, i am not familiar with the volumes run thru Bonneville and what is passed around in Califronia where water is much more precious, but its a huge amount which i am pretty sure is enough to skew the stats.

[fuzzy1]

U.S. Geological Survey Fact Sheet 2005-3051: Estimated Use of Water in the United States in 2000 ...
Irrigation: 34%
Thermoelectric: 48%

USGS: "Thermoelectric-power plants accounted for 48 percent of total withdrawals (195,000 million gallons per day [Mgal/d]) in 2000."

So, were does all this water disappear to? While a significant chunk of the irrigation water evaporates or slowly filters into aquifers, where does all that water used for Thermoelectric go?

And how high are they pumping that Thermoelectric water from its point of withdrawal?

[JamesBurke]

What is the proven health benefit to eating food soaked in pesticides and herbicides? The "soil" on those "farms" is dead inorganic clays and silts. Devoid of life except for the crop and the resistant pests that feeds on it.

The USDA organic standard allows or use to allow nicotine to be used as a pesticide and yes it's very nasty stuff as are many other plant extracts. What is more abused caffeine or nicotine?

Save the rain forests? Their are just as many species in Brazil's dry Forests but when these dry upland forests next are clearcut , slashed, and burned for a mono crop of soybeans (millions of acres) not a peep out of these activists. No reason that soybean crop can't be certified organic is there?

For me it more about not being dependent on a food source beyond local/regional control. Based on land that was not growing vegetation similar to the crops we might grow and sustained only through government subsidies and projects. California Central Valley and all its past and future tax gifts compete against those of us who have never had "Free" water projects built for them. Same applies to BLM and Natl forest grazing of cattle. We have to pay for our own land, build our own roads and fences and pay taxes, liability insurance, fair wages ect on our operations. Most of my family and neighbors have fallow land now and are employed in other lines of work. better stop before I get carried away.

[JamesBurke]

New York City water is gravity fed and minimally treated. It's not bad at all. Lakes and water works upstate and uphill. Seen on Modern Marvels I think or similar

[Celtic Blue]

Originally Posted by fuzzy1

So, were does all this water disappear to? While a significant chunk of the irrigation water evaporates or slowly filters into aquifers, where does all that water used for Thermoelectric go?

And how high are they pumping that Thermoelectric water from its point of withdrawal?

Good questions and ones I don't have the answers to. One can ask the same about domestic water use (e.g. showers, toilets.) In many cases water is going to be taken off and put back in some fashion. Other than evaporation losses in basins this is the case with either.

Thermoelectric does have major issues with the heat rejection into water sources. This is one of the global warming concerns that arises during droughts. You can only increase river water temps so much before other problems develop. At some point fossil fuel driven power plants have to shut down because of heat rejection limitations.

I have not tried working through balances on all this by hand, so I'm not sure where all the numbers come from. However, it appears that Dave is way too easily dismissing the many things that dwarf municipal water distribution.

Take irrigation for example, in many cases you still have to pump that water out of the ground, through a piping system, and to a sprinkler head with sufficient pressure to give a good spray pattern. I doubt these small pumps are as efficient as larger municipal pumps on average. And I doubt that the overall differential is less than half that of what a municipal system does. (And I can tell you from experience long ago that a poorly performing home well pump can cost you a fortune...stuck pressure switch in a place I had just moved into.)

I roughed out the numbers for the power my PRV wastes in dropping the municipal supply from 120 to 60 psig...even if I got it all back at 100% efficiency it's not much.

Now if you really want to save some money in town while reducing power use and save water that is lost to the atmosphere...reduce lawn irrigation.