The San Antonio Water System, or SAWS, describes its own rate system as more complex than your average water systems.
And if the utility has its way, the system later this year will get a bit more complex – for a simple reason.
While San Antonians have been very good at conserving water – we have dropped per capita use from 225 gallons a day in 1982 to 140 gallons today – we could do even better.
So SAWS has developed a plan to encourage us to do just that.
It’s not just about charging more for people who use more water.
SAWS already does that.
It’s about doing it in a smarter way.
Currently SAWS has four residential rate tiers.
Each time you shower, flush or soak your lawn into a higher tier, your per-gallon rate goes up.
But 60 percent of households are in the lowest tier.
So more than half the residential customers don’t save much by saving water.
Under the proposed plan, which should go to City Council for approval later this year, there will be eight tiers.
This will double the number of customer bills that are within an easy shot of meaningful savings on their water bills by modestly reducing their usage.
For users at the highest end, those savings could be substantial.
The possibility of getting San Antonians to use less water is reason enough to approve the plan or a close version of it.
But it has another advantage: It tracks the economics of producing the city’s water supply.
With most things we buy, we benefit from what is called the economies of scale.
The more a company produces, the less each item costs.
So that helps explain why you save money by buying the jumbo size.
But water is different – especially here in San Antonio.
Our primary source of water, and until relatively recently our only source, is amazingly cheap.
Sitting on the downhill edge of the vast Edwards Aquifer, our treatment costs are almost non-existent.
We deliver water virtually the same way George Brackenridge did when he responded to cholera epidemics that repeatedly occurred from drinking water out of the river more than a century ago.
Brackenridge sank wells such as the one across the River Walk from the Hilton Palacio del Rio Hotel.
The water, under pressure because its underground path flows downhill from the Hill Country, shoots up into storage tanks.
The only treatment SAWS gives it is to inject a little chlorine into it to kill harmful micro-organisms.
But as the city grew, farmers to the west and spring flow interests to the east won sympathy from the Legislature with their concern that thirsty San Antonio would dry up their wells and springs.
And the Sierra Club in the 1990s won a federal lawsuit on behalf of critters at the Gulf Coast whose well-being depends on sufficient fresh water from rivers that rely on springs gushing from the Edwards.
As a result, San Antonio is now required to develop new, vastly more expensive sources of water to supplement our aquifer water.
Water from a planned desalination plant in southern Bexar County will cost even more - $1,200 an acre foot according to SAWS estimates. An acre-foot is 326,000 gallons.
The recent $3.4 billion Vista Ridge contract to buy water from Burleson county 120 miles away will cost even more: an estimated $2,200 per acre foot.
It is the most expensive SAWS water project to date.
It’s not the people in small, one-bathroom houses on 40-foot lots in the barrios that are making us buy that water.
Nor is it people who have xeriscaped their yards and installed low-flow toilets.
A rate structure that charges these folks for the cheap water and high-level users for the expensive water makes sense on both economical and ecological grounds.
It is, in short, both fair and smart.