This winter, demand for water was so low that the San Diego County Water Authority temporarily idled a $160 million plant in San Marcos that it built less than a decade ago. Water agencies that went into debt building treatment plants still have to pay up, whether the plant is needed every day or not.
Over a decade ago, Southern California water officials rushed to build or expand treatment plants so they could keep up with the demand for drinkable water. That cost hundreds of millions of dollars.
Now demand for water has fallen dramatically. The treatment plants sit largely unused during parts of the year and officials are fighting over how to pay for some of them.
There are two kinds of water: treated water, which has been cleaned up for drinking; and raw water, which comes from a river or reservoir and is not yet fit for human consumption. Water treatment plants make the raw water drinkable.
In San Diego County alone, a dozen major treatment plants can produce up to 830 million gallons of drinking water each day.
Yet even when demand for water was highest – the dry summer months, usually – the county’s plants last year were treating only about 530 million gallons per day of water.