Let's start with Pacific Institute's report. It says we could save 3.4 million AF by installing drip irrigation. At $1,000 AF, that would cost something like $9 billion.
The governor has demanded a 20% reduction in urban water use. Currently, all urban water use is about 9 million AF, so a goal of 1.8 million AF is being set.
So far, most everybody agrees with these numbers. But how much is it going to cost to realize those 1.8 MAF of water savings? No reasonable person can argue that those savings are going to come from taking a shower with a friend. The savings are going to have to come from changing the use of water in the house, and that means mechanical changes.
Here are what I judge as typical costs, not counting installation, for making those changes. These are rough estimates after reviewing prices at Lowe's, Home Depot, Sears and Best Buy.
The state says that there are 12,100,000 households in California today. If every household made the changes suggested above in order to reach the 20% saving the governor is requiring, the cost would be something like $60 billion!
|Low flush toilets||2 @ $385 each||$770|
|Low flow shower heads||2 @ $ 15 each||$30|
|Water saving dishwasher||$1,000|
|Water saving washer||$1,200|
You can slice, dice and quarrel with these numbers just about any way you wish and the answer will still make drip irrigation look like the bargain of a life time!
By the way, on an acre-foot basis, drip irrigation has an initial cost of about $2,600/AF while urban conservation costs about $33,000/AF. (The good news is that both numbers are one time costs as opposed to desal which costs $2,000 to $3,000/AF every year.)
[JWT's] Bottom Line: No matter how you slice it, urban conservation achieved by expenditure of money is a really bad deal.
Addendum: The LA Times reports that drip may not reduce overall water use (plants absorb more, less "waste" means less groundwater recharge), something I pointed out 4 months ago -- after it was pointed out to me, of course :)