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
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
- 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.
- So, 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.
- (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 for 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
- 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
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!