A Texas Sized Water Balloon

Admit it, water is a problem. Forecast to be the cause of many future wars, there are places (and times) that have more than plenty of it, and others that don't have enough. And people will pay, or fight, or even die, for water, which gives life after all.

What is the appropriate scale to think about this problem? It's not that there isn't plenty of water out there. But there are plenty of places that don't seem to have enough.

So consider how to get the plenty of rainwater, that the planet has, to the plenty of water-needy places, that the planet has elsewhere.

Today we use the mountains themselves as storage devices, locking gazillions of acre-feet behind outflow-blocking concrete dams.

In the future we could use the sea itself for water storage, with man-made materials keeping out salt and storm, deep underwater below the waves. We merely await progress in materials science and oceanic public works engineering to solve the tank and transport problems at scale.

Rainwater capture on a grand scale would solve the desert cities' water supply problem: capture the outflow of freshwater rivers especially during the periods of huge winter flows, storing a season's flow in underwater expanding storage facilities, perhaps in giant underwater water balloons, held down at the bottom of the sea and pumped in and out along continental-scale pipelines. Such systems could water

• the entire Middle East from the Nile average outflows of 3.5Mcfs;

• the Southwestern US megalopolis from the Oregon Coast Range rivers Klamath and Smith, even the Columbia;

• summertime India and Bangladesh with the captured, saved, treated, monsoon flows of the Ganges and Brahmaputra.

No wars need be fought over water, nor farmers or desert dwellers lose livelihood or even comfort due to its lack, if we could just build suitable, seasonal, underwater storage systems.

Can we make some practical progress on this? You can imagine, it would indeed change the world toward being a garden paradise!

So I've thought about it a bit, and here are my technical suggestions.

• How to start small. The capture systems can be separated from the storage. So one could indeed start small, without the underwater storage facility, and just do in-season pumping. Put an experimental grate under the winter-flow-levels of a river like the Smith or the Klamath, a few miles inland from the outflow to the sea. Run a pipe to a pump, and a pipeline to an aqueduct system (we have these in California in the Central Valley from far north to far south), and the aqueducts back to pump-back systems to max out existing storage behind dams in existing reservoirs. That alone might solve a lot of the California drought issues, adding 50kcfs for a third of the year, say, to the current supplies.

• If mountain storage is insufficient, then work on undersea storage.

• If the flow levels aren't enough, capture more from more and larger rivers, or use deeper and larger inlets, pump capacities, pipelines.

• Fund a scholarship, fund research grants! for materials science and engineering in support of undersea freshwater storage and transport. If this class of solution has a non-zero chance of success, it should get a non-zero fraction of the world's R&D support, in order to maximize the possibility of success.

• Someone else had a piece of this idea, years after I first had it in the 1990's. He was very determined, and took 16' x 100' water balloons in a many-links sausage filled at a Washington state freshwater river and towed them by a tugboat to Southern California. Choo choo! Somehow the scale is too small. Pi*R^2*H*N = pi x (16/2)^2 x 100 * 10 = ~200k cubic feet of water, which sounds like a lot of toilet flushes in the desert. On the other hand, a barely-comfortably-kayakable river pushes out 500cubic feet per SECOND, so that fellow's experiment amounts to taking 400 seconds or under 7 minutes from a small river and spending the cost in diesel for a high-friction tugboat ride all the way to California just to deliver it from its source in Washington. I salute his determination!

• Others have had another piece of this idea and proposed towing icebergs from Antarctica to South Africa (2021), or California (1940's) or Chile (1800's, the breweries wanted the ice for refrigeration not water, and they actually did tow icebergs for that purpose according to Bloomberg).

• Generally speaking, liquid transport makes more sense via pipes than packets, whether those are ocean-going tugboat-pulled water sausage trains, or giant packetbergs of water ice. You more easily imagine a continuously pumped, river-sized flow going down a 10' or 20' pipe all year long, but those kinds of volumes seem harder to achieve in practical trucking or rail or tugboat transport. Of course there is some balance point of equivalence, but my plumber's intuition certainly leaves me leaning toward pumps and pipes. The world's oil pipelines and the San Francisco water pipeline from Hetch Hetchy reservoir, etc. show that other visionaries have agreed and found practical success.

Can we propose an at least imaginably practical design today? Maybe not a texas-sized water balloon, but an enormous water balloon held deep in the ocean, intermittently fed by enormous seasonal flows and connected to a pumped pipeline to its target recipients. What might that look like?

• Here's a thought. Design a continuous-feed plastic production process to create a 20' wide strip of salt- and borer-resistant underwater reservoir wall, each edge formed as the female or male side of a zip-lock style, interlocking, water-tight joint design. Modularize this production process so that it is contained in a manufacturing plant on a ship or towable barge; you don't need onboard storage for the product, which can be drawn directly out of the side of the vessel into the water. Such a manufacturing barge could in principle produce thousands of feet, even many miles, of wall strip, with the ocean itself to hold them during handling and assembly.

• (Incidentally, isn't carbon capture-and-storage another of our generation's challenges? Aren't we as a world searching desperately at this moment in history for a place to sequester all the carbon being pumped into the atmosphere? A large, permanent, public work using a truly huge amount of carbon could answer some of the sequestration problem. An atmosphere to graphene process, for example, conceiveably satisfies both requirements, carbon capture and sequestration, and undersea reservoir wall material manufacture. Was it too wild-eyed to mention this thought? Forgive me, I'm susceptible to the occasional Big Idea. Obviously. So let this serve only as inspiration to future engineers, a bug in the ear, for those who in future might be able, that's all, that's plenty, that's more than enough.)

• Zipper machinery on boats or swimming drone robots could take two adjacent edges and zip them together or apart, thus producing wider and wider planks and sheets and ultimately giant cylinders by finally zipping the female of the last-manufactured leading edge to join the male of the first-manufactured trailing edge, closing the loop.

• Cutting, fitting, and joining methods, whether based on heat, solvents, or adhesives, would still be required to connect sheets at angles, to make corners, to make inlet and outlet connections for piping. If required to be done above water in dry conditions, such processes will have to build in these features before the product goes over the side. But it's not impossible to have an enormous flange joined to one or two strips temporarily held partly out of the water. Nor would it be impossible to cut straight, then glue over at 90 degrees, special corner edges, in a process done out of the water, since the ends can be pulled to the surface and pulled aboard and dried off for the joining. Exception: Patching holes in place would still have to be done underwater, but mechanical patches are also practical: a pair of discs joined across a small hole with a nut and bolt.

• Since freshwater is buoyant in saltwater, the storage balloon will naturally want to float, even protrude from sea level, proportionately. Experiments will likely prove a need for deep subsea restraints to keep them still, and keep them out of the stresses of stormy waves. Cables may need to be built in to the reservoir wall strips, or separately-made cable nets spread over the whole, or threaded through built in fasteners, in order to anchor an assembled balloon to the bottom of the sea. Anchors are another important subject, but I have no especial insight except the confidence that anchoring anything is possible.

• The marine-compatible materials questions relate to not only the reservoir wall material and its production (and recycling), but also to pipes and pumps which must survive the external salt environment, and the maintenance facilities that will be needed to keep watch over it and to fix whatever could go wrong. Don't forget the anchoring systems.

• Danger! Damage! Anchored signalling buoys might keep boats and submarines away, hopefully, but the primary principle seems to be that depth is safety. Even below the storm surge depth, things could still fall from above, perhaps mostly carcasses or garbage which a robot sweeper could pick up and dispose of in periodic passes. Sabotage and warfare, mines and submarines, are imaginable concerns, but of course everything is vulnerable during war, and this would be no exception. We don't want to discover our new favorite material is a favorite food for starfish. Yes there are many issues to resolve, does that mean it's not worth exploring -- and solving -- them one by one, when great benefits await?

Okay, enough said. Even though it's rather crazy, it's not quite entirely crazy, and I hope I have persuaded you at least that much in this short conceptual essay. If so it follows that our society SHOULD find a way to fund a few people to work on it so that if it pans out in the future, we all win big. Imagine peace in the Middle East; Indian farmers saved from drought; and the Eastern Sierra Nevada green again. That's how entrepreneurial societies win; they try a lot of stuff, in hopes a few things have big payoffs, which they tend to do. A few engineer-years or -decades would be a tiny investment to enable a huge payoff like a potential doubling of the California megalopolis.

So this is certainly worth a try. Contribute your special contribution! Encourage! Pass it on!

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