While other parts of California are bone dry, San Diego faces the opposite problem: too much water

[Zorro]

The $1-billion desalination plant coming online next month in Carlsbad will fit right in with years of careful planning and investment in water supply in San Diego County.

It will also worsen a peculiar San Diego problem amid a multiyear drought: an oversupply of water.

Unlike other parts of California, San Diego has 99% of the water needed for normal usage. But statewide conservation mandates have applied equally to areas that have plenty of water and those that don't, so the result here has been water piling up unused while local water agencies raise rates to make up for lost sales.

Carlsbad Mayor Matt Hall, a San Diego County Water Authority board member, said the situation is hard to explain to his constituents.

http://www.latimes.com/local/lanow/la-me-drought-watch-20151125-story.html

[progree]

1. So, why run the desalination plant (which is expensive to run)?

So I wondered. Answer:

Enter the desalination plant. The private venture kicked off a 30-day test period Nov. 9 and is expected to start producing water next month, enough to meet between 7% and 10% of the county's demand. Water officials agreed in 2012 to buy the water whether they need it or not, to make the plant financially feasible.

... Next year, the desalinated ocean water will cost San Diego water agencies at least $113.6 million — more than double the $45.2 million they would pay for the same amount of imported water, which remains available despite a statewide drought.

(The desalination plant is powered by electricity from the grid).