Knowing Where Your Water Comes From

According to Data360.org, US residents use 575 liters of water PER DAY. However, people rarely ask themselves, “Where Does It All Come From?”

Last week I was sitting in a restaurant trying to explain what I’ve been doing at UCAN to a fairly educated (UCLA PHD candidate) friend of mine. As I picked up my water glass I claimed, “I’d bet half of these people don’t even know where their drinking water came from.” She said, “Well, um, I guess I’m in that half.” So I’m here to set the record straight on where we’re getting it from, who we’re getting it from and how much its costing us.

WHERE we get our water from-

Colorado River Water (61%)

According to San Diego Water Authority, Southern California receives up to 80 percent of its water from the Colorado River. San Diego Water Authority specifically buys its water from Metropolitan Water District in LA which owns and operates the Colorado River Aqueduct.

San Joaquin Delta (18%)

San Diego also has rights to water from the State Water Project. The State Water Project includes over 20 dams and reservoirs, a delta pumping plant and a 444 mile long aqueduct which carries water from the delta through the San Joaquin Valley to Southern California. Metropolitan Water District owns the system by which the water is carried so although San Diego has rights to the water they have to pay Met to transport it.

Local Sources (21%)

In addition to our own sources of surface water, ground water, recycled water, and conservation, San Diego Water Authority also has an agreement with Imperial Irrigation District (IID) which says, basically, that it will pay for their conservation costs if the water that is conserved will go to San Diego County. This agreement is called the Quantification Settlement Agreement (QSA).

So now you know WHERE the water comes from and how much of it comes from each source.

But, it is just as important to know WHO we are getting the water from-

Metropolitan Water District (62%)

            Met is our major water supplier as the control the Colorado River water and State Water Project water which San Diego uses.

Imperial Irrigation District (16%)

            As mentioned above IID provides us all the water which they conserve and we in turn pay for the conservation needs and technology, such as canal lining to prevent loss of water. So this percentage reflects water transferred and conserved through QSA efforts.

Local Sources (22%)

            This is water which we collect ourselves through our own ground water and surface water. This water also includes recycled water and water saved through conservation efforts.

Now for the million dollar question- How MUCH does each water source cost?

Since San Diego Water Authority collects all these water supplies from all our supplier the prices San Diego residents primarily see are from Water Authority. The following cost estimates are the Water Authority marginal cost estimates. They are taken from the Equinox Center and reflect the low end of the estimates.

            Imported Water- $875 per acre foot

            Surface Water- $400 per acre foot

            Ground Water- $375 per acre foot

            Conservation- $150 per acre foot

Desalination and Recycled Potable Water are not currently being used but are being developed. So we can see that what we are paying for imported water (the water which we buy from Met) is more than twice the other options.

For more information on where these facts came from see aquafornia.com and SWA 2009 Annual Report.