Agricultural Water Tower Domes

In July, 2000, my girlfriend Stacie and I went to Houston, Texas for the annual conference of the World Future Society. While there, we drove across part of Texas to visit the city of Austin, and noticed a huge preponderance of water towers all across the state...hundreds of them, just in the small area we passed through. The area of Texas that we were in was also extremely flat. We drove hundreds of miles and it pretty much remained flat the entire time. The water towers there are used for storage, irrigation, and to generate water pressure for the plumbing systems of the surrounding communities.

The other thing we noticed was that, like in California, and most other places, the irrigation water was being sprayed onto open cropland, where it could promptly evaoporate and blow away. In very real terms, this is roughly equivalent to spraying a garden hose onto a hot rock or sidewalk. Try it sometime and watch what happens to the water.

This is something that has bothered/annoyed me for a number of years. We keep hearing about the need to conserve water, and the droughts that California and other western states constantly go through, yet if you go for a drive into the agricultural regions, you'll find farmers spraying millions of gallons of water onto hot rock every day, letting it evaoprate and blow away, then complaining that there's not enough water. This is daft, to put it politely.

I've studied fabric-structure architecture, such as you see in park pavilions, sports arenas, and the like, and for years I'd been trying to think of ways to enclose the agricultural fields in some sort of lightweight, transparent vapor-barrier structure, so as to retain that precious water. It seems to me that one could reduce water consumption by a large amount, perhaps as much as 80-90% by employing such a method.

Seeing the water towers in Texas really made it click. I suddenly envisioned a complete system that could be manufactured offsite, delivered by airship, and erected in an area in about a day. This system would have an inflated dome made of a tough, clear material, such as Tefzel, which could act as a vapor barrier, protection against the elements and pests, and also function as a gigantic greenhouse. It would have an atmospheric condenser at the top of the tower, to draw water vapor out of the air and keep the tower filled without needing to drill wells or pump water out of the local water table. The runoff from any rain that hit the dome could also be collected at the perimeter, and drawn up into the tower for storage.

The top of the tower would also house solar power panels and windmills to generate all local power needs, as well as perhaps selling excess power back into the electrical grid, and could even have an observation deck for local sightseeing, weather observation, housing, etc.

I've also noticed in driving and flying around the country that some farms use irrigation equipment that goes around in a giant circle. So they are already using the circular field design depicted here, but they aren't retaining any moisture from their waterings, so they have to keep pumping it from somewhere. They also arrange these circular fields in a square-based grid pattern, like a tic-tac-toe game, rather than in a closest-packing arrangement, which utilizes the space more efficiently, and leaves less land wasted. You can see some other closest-packing arrangements here. In the two top-level views shown here, note the difference in wasted space. Even if you were to push the domes right up to the edges of each other (which you might not want to do if you want to have access roads between them), the non-closest-packing arrangement has obvious waste areas, which to a farmer equals lost cropland, and lost profits.

And here's a view of how I envision a cluster of these agri-domes appearing from the air:

The renderings on this page were made with Bryce 3D.

It appears Frei Otto had the same idea, and even came up with a great solution for large span coverings. The use of anticlastic (saddle-shaped) curves allows the membrane to undulate across a large area, and also provides for rainwater collection points in all of the depressions in the membrane.

These pictures come from the book:

"the work of frei otto"
MOMA
Glaeser, Ludwig
1972
LOC Num:  NA 1088.O78 G55