It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Friday, October 15, 2010

San Antonio and Water|Start Petition

This year's Blog Action Day is about "clean water for everyone", and that's easily within the realm of topics covered here. There's a lot of concern about clean water in remote, undeveloped areas, and I certainly support that, but I don't have much to add.

Where I do have a little bit of knowledge is on the sustainability question.

The right way to look at the sustainability of a particular conurbation is to consider the size of its hinterland. Places like Las Vegas and Phoenix, located on some of the most arid ground in the western hemisphere, survive as far as water supply is concerned, on a combination of nonsustainable ground water and on expensive water importation systems. The latter appear to be tapped out; see John Fleck's stories on the other Colorado River.

The other one? Yes, we Austinites love to confuse visitors by pointing to the main river in our turf, the Colorado River, without explaining that it has nothing to do with the one that flows out of, well, Colorado. This will cause varying amounts of headscratching from people, based on their knowledge of southwestern geography, peaking with people at a middling level. (Sophisticates will say "surely not the SAME Colorado", usually without saying what it isn't the same as; naifs will simply nod sagely. Folks in the middle can get mightily confused.)

The history and geography of Texas are dominated by its long, peculiarly narrow watersheds. Cat scratch geography.

In Texas, particularly the earliest settled parts, the rivers don't form tree shapes like in the rest of the world, but rather a series of trenches. The double lines above show water management zones which are closely connected to watersheds, and to the long, narrow southeast-to-northwest oriented subcommunities that formed the traditional Texas fabric.

While El Paso partakes of the bizarre water politics of the arid southwest, the rest of Texas is in a peculiar intermediate zone of its own, separate from the arid southwest or the damp southeast. (The panhandle towns of Lubbock and Amarillo are also somewhat exceptional. They have a massive ancient aquifer that they are depleting for agriculture, the Ogallala which is the same one that sustains Kansas, but push doesn't come to shove there yet for a while.)

Though there are many stories about the wilderness in the north and west of Texas, and many stunning images too, it is the central, southern and eastern parts that matter. This part of Texas has a population comparable to that of many important countries, for instance, Australia, or all of Scandinavia. Of course, as is well known, it is the world capital of the petroleum industry, still providing significant production as well as refinery, engineering and management. And, lacking in natural beauty but not in money or warmth, it is particularly heavily landscaped and thirsty.

Nevertheless, much of Texas' prosperity has been based in its burgeoning population, a process which continues through good times and bad. Its present population of nearly 25 million is expected to double by 2050. Which means that for purposes of water planning, demands are ever-increasing.

Now, as the map shows, the hinterland of Texas cities is naturally on a narrow strip organized southeast-to-southwest. (There is a natural ordering to these basins much as there is with Canadian provinces. Fortunately, the four great cities occupy separate basins, in the usual sequence from northeast to southwest these are Dallas/Fort Worth on the Trinity, Houston on the San Jacinto, Austin on the Colorado, and San Antonio at the confluence of the San Antonio River and the Medina. Essentially unclaimed are the Brazos which goes through Waco and the Guadalupe whose largest town is Victoria. Of course, the water supply decreases as you move southwest toward the desert. Still, Houston, being at the bottom of the river, has less water problems than Dallas/Fort Worth. Dallas, indeed, is sufficiently squeezed that there is talk of tapping the Ogallala; because of antiquated laws there are no limitations on what can be drawn form a well. All it would take is for the city of Dallas to own a single property on the aquifer to do its own massive draw-down!

San Antonio is the worst off of the major Texas cities because of its arid location and relatively small upstream watershed. The water limitations of San Antonio are hitting now. San Antonio also has some cultural weaknesses; the relatively less wealthy and largely Hispanic population is not popular in the rest of Texas.

As a Montrealer I have great sympathy for San Antonio. We share not only a certain eccentricity and cross-cultural ferment. We also share in being underrepresented in the world's awareness given the actual cultural and historical significance. San Antonio is the 7th largest city in the US, with 1.4 million in the city limits (Montreal has 1.6 million) and 28th largest metro area (2.1 million, compare Montreal 3.6 million). And as Montreal has been a crucial point of contact between French and English speaking cultures, so San Antonio is the real gateway between America and Mexico.

Of course the last thing Montreal needs is more water!

The Katrina episode has firmly convinced me that some cities are more important than others, as sources of culture and human growth. While I wish no ill to the people of Phoenix or Las Vegas, I would feel little sadness if their cities were to decay and vanish the way Detroit is doing. San Antonio, on the other hand, is a city for the ages.

The Texan ambivalence to the place is tempered of course by the fact that the centerpiece of downtown San Antonio is the Alamo.

So, if the ground water is depleted, if the watershed is inadequate, if two million San Antonians will live on, where does the water come from?

It turns out (surprise!) that Texans are mightily protective of their water rights. Shipping water between zones leads to enormous social stresses, even though our situation is not comparably severe to Arizona's or Nevada's. I have heard people talk about this in tones that have sufficient hostility as to make me think they carry tinges of the old blood feuds between Texans and Mexicans. Here's an article to give you the flavor. San Antonio is being driven toward a coastal desalination plant, even though water in Texas at large is not scarce. So this brings back the question of the size of the hinterland.

To make matters more complicated, the demographics of Texas is swinging away from the good ol boy politics (that has been embodied by Republicans for the last two generations). Eventually the Democrats will prevail, and the influence of San Antonio (and other hipsanic communities) will increase dramatically. I don't see anybody saying this, but the time will come when water may actually be shipped to SA from the Brazos or even the Sabine. It's nothing near as absurd as happens further west.

It's also worth noting that this isn't about drinking water. It's about lawns!

And this brings me to the local vs global. It applies in water as in so many other things. Collectively, there is abundance globally. But political energies appear to be about protecting localities and nations. All the talk about the benefits of trade seem to count for nothing as far as collective resources go. Canada has enough untapped (ahem) water to supply US and Mexican agriculture forever. Yet the topic is a tremendous hot button in Canada.

I wonder why we are so bad at thinking as a global community.



Steve Bloom said...

IMHO the Canadian attitude is perfectly understandable given that under present circumstances so much of the water would simply be wasted. I expect that attitude would change if things ever got to the point where food production began to fail due to lack of adequate water.

Chris Pella said...

Canada's water supply is because it's mostly visible, especially in the Shield. I'd be pretty pissed off to think that some our lakes and rivers are being sacrificed to make golf courses in Nevada.

Chris Pella said...

I mean to say deceptively large...

Steve Bloom said...

IIRC discussion about tapping Canadian water has focused on the Rockies and West Coast, not on the Shield region.

Michael Tobis said...

No, it's huge by arid zone standards. Make no mistake about that.

I agree that a lot of water is wasted. I agree that water shouldn't be shipped large distances if it can be avoided, especially uphill as happens in California.

But I think that as the world gets smaller collective resources should be shared, not hoarded. I think we should get more global.

Most everybody besides me thinks we should get more local. I remain unconvinced.

David B. Benson said...

Not all other rivers form tree shapes.

The Nile

The Volga for most of its length.

Even, to a great extent The Mekong

Michael Tobis said...

What's striking about Texas geography is a bunch of these in parallel paths.

Kooiti MASUDA said...

It is interesting: China plans to move water of the south to the north and the direction is the opposite in the North American continent. These are cases of geoengineering in a sense not limited to mitigation of climate change. As we recognize limits of energy resources as well, plans of social engineering to move people in the opposite direction seems to be relatively more feasible (though obviously difficult).

Chris Pella said...

A snippet from the the Canadian Water atlas, which is online:

Availability of water: Canada's overall water supply is generous by any standard, but water is often not plentiful where it is needed most. Ninety percent of Canadians live in a narrow band along the extreme southern edge of the country. On the other hand, 60% of the water supply is found to the north of this settlement band. Not only is it north, but also most of the water supply also flows north, going away from the zone of population. Even within the settled area, most of the population is concentrated in relatively small areas. This concentration of people puts high and competing demands on some local water supplies. There are also problems of moderate to severe seasonal water shortages in many parts of Canada. In 1999, 26% of all Canadian municipalities having water distribution systems reported they had had problems with water availability during part of the preceding five years.

If you want to move water from northern Canada this will mean gigantic diversion projects with huge ecological effects... It isn't going to come from the Prairies, where large swathes are already under irrigation, and where water is needed for agriculture. Perhaps you plan on towing the ice bergs calving from Greenland as the glaciers melt?

Pangolin said...

We've proven in California that you can have large reductions in per-capita water use and still take showers and have a lawn.

Of course that means that we don't cover every square foot of landscape outside our homes and businesses with lawn. There are many attractive alternatives if people would bother to investigate them.

David B. Benson said...

Xeriscape your yard.

But close to the ocean, that includes San Antonio, seriously consider desalination as the Australians are taken up doing. One tonne (cubic meter) of fresh water costs about one dollar plus transportation. Horizontal transportation has but small costs; vertical transportation (pumping) is again about one dollar for each 400 meters of elevation.

For domestic use (except lawn watering) this $1--2 cost per tonne isn't out of the question.

These are ideal applications for wind and solar as the intermittency doesn't matter.

DavidP said...

Local plants that don't need watering are a win. During 8 years of drought in South East Australia, my (never watered) local groundcovers and grasses kept gently self-seeding into the (battered despite greywater use) lawn. I like it.

Transporting water is expensive. Shipping water from Australia's Ord river scheme to Perth would use more energy than modern desalinating in Perth. I don't like desal - emit lots of CO2 to aleiviate the effects of excess atmospheric CO2, but you have to be very careful on the energy budget for transporting water. Being expensive capital plant, managers want desal plants to run 24*7, not be intermittent - otherwise the capital costs are higher.

Upstream, irrigation system efficiencies can be improved enormously - metering the water and billing by volume used is a good start and remarkably unusual.

Michael Tobis said...

As you can gather, I am new to the dry zone, so thanks for any advice at either the personal or infrastructure level. Water behaves very differently in aggregate depending on whether there is a runoff surplus or not. It's a sharp line, and Texas straddles it. I think that people who haven't spent time on both sides of the line don't have a clear intuition for it.

John Mashey said...

A worthy topic, thanks.