Saturday, February 28, 2015

Infrastructure and the Megadrought - Moving the Water

[A note from MeanMesa: As a visitor to this blog, please join me in a moment of relief and satisfaction after the FCC has established fundamental "net neutrality" policy today. After we've all become so accustomed to one defeat after another, this is nothing less than a "brightly lit" exception to the trend. Hat's off to our President for standing up for us]

Just a Wee Bit About
Hydraulic Ram Water Pumps
Bear with MeanMesa for a few paragraphs...

There are a lot of spots around the planet where the locals really need some way of providing water to villages and fields without relying on the availability of electricity to operate motorized pumps. Even when one finds himself in such a predicament, he may still be able to stand at the edge of that village or crop field and look down to see abundant water flowing along a stream or river far below him. However, centuries of human history have repeatedly suggested that just about all the possibilities of manually hauling that water up to where it is needed -- over any appreciable time -- is a "losing proposition."

Beginning sometime around the 1700's inventors in various European countries began developing the earliest versions of hydraulic ram pumps. So far these devices have become famous as small set ups which are suitable for watering gardens or providing water to homes on a very small scale. [Read more TRN26 - Hydraulic Ram Pumps, US Dept. Agriculture(pdf) 

As materials and machining capacities improved over the centuries, new designs for these hydraulic ram pumps improved along with them. Rather impressive design progress took place during the industrial revolution period before widespread rural electrification [i.e. REA in the US. Read more Rural Electrification Act - WIKI] programs distributed electrical power to operate motorized pumps.

Now, with plenty of electrical power available to operate irrigation and drinking water pumps the hydraulic ram idea has gradually become stranded as a "self-sustaining design" curiosity in the industrialized countries, but the "utility of the beast" continues to make such small pump systems very useful in facing the difficulties found in third world nations.

The photograph [left] shows a small capacity hydraulic ram pump fabricated in a small shop in Central America. For visitors interested in the process, theory and application MeanMesa suggests spending a few minutes with this video: 17 min. "How to make a hydraulic ram pump" - EMAS .

At least a passing understanding of the fundamentals involved in such a pumping system will be required when we get to the point of this post. For a quick introduction to the general principles of a hydraulic ram pump, this graphic may also help.

How a Hydraulic Ram Pump works. [Image courtesy of Green & Carter]
Anyone becoming fidgety can relax. Hydraulic ram pump "school" is officially completed.

Why Is This Important?
An old dreamer's plan to wet down
 NASA's approaching megadrought

The previous post at Short Current Essays was all about the latest NASA research which is predicting a long term [30-40 year duration] drought extending across most of the western United States and Canada beginning around 2050. [Read the post  here - Ignoring NASA, MeanMesa] This blog's visitors might find this highly unsettling conclusion rather alarming. That would be a very reasonable reaction in this case.

But what do tiny little hydraulic ram pumps have to do with this oncoming train wreck?

To answer this we can begin by considering the fundamental problem posed by such a drought, that is, the biggest and most immediate problem first.

There's no water.

An often overlooked aspect of the "drying out" phenomenon usually associated with global warming is that the total amount of fresh water on the planet doesn't change much. Yes, fresh water glaciers are melting in Greenland, and the ancient fresh water they previously held is, as a consequence, being mixed with salty ocean water, but on the land, the global warming problem isn't simply less water as much as it is less water where it used to be. There is no particularly convenient means to pick up the vast agricultural heart land of the US and go chasing off to where the precipitation has gone.

On the other hand, as America's farmers and ranchers watch a decades long drought gradually consuming their agricultural production capacity -- and their fortunes -- they might find themselves in a situation similar to the one described above. At least symbolically, they could stand at the edge of their dried out farmland and see massive amounts of fresh water still rushing headlong into the Pacific Ocean.

The "problem" associated with this observation of theirs is also similar to the one faced by the villager in Central America. There doesn't seem to be any way to move that fresh water from the point where it rushes into the ocean to their dried out farm or ranch.

The parameters are quite different. The Central American village will be fine if a hydraulic ram pump on the near by stream delivers a few hundred gallons of fresh water to the village and the near by fields daily. Happily, for them at least, the stream is only a few hundred yards down the hill from where the water is needed, and the pump's capacity will solve the problem.

The farmers and ranchers in the western US, however, have a similar problem only on a gigantic scale. To mitigate the drought problem they are facing, a water supply must deliver millions of tons of fresh water daily; the "little stream" is going to have to be a massive river; and, that river isn't going to be a few hundred yards away -- it's going to be hundreds or thousands of miles away. Worse, while the villagers' ram pump only needs to elevate the stream water a hundred feet or so, most of the farms and ranches in the middle of the megadrought impact zone will be thousands of feet higher than the nearest river.

And, we already know, there are really a lot of those farms and ranches, and they are, well, remarkably thirsty.

Let's Do Some Dreaming
Engineers think of this as "concept design."

A good first step is to become comfortable with thinking big. The little Central American, home made, hydraulic ram pump is a good idea, but it is little more than a "point of departure." We will have to "scale up," and by "up" we mean "way up."

Happily, we have plenty of really massive, "scaled up" examples of aqueduct-type water transportation systems from the ancient past. and we can add to the impressive scale of those artifacts because we will also enjoy all the benefits of modern manufacturing and construction technology. The ancient Romans did it -- so did the Egyptians, Aztecs, Asians and Greeks. Each of these ancient civilizations moved water from where it was available to where it was needed, and they built the edifices required with horses, oxen and men with copper chisels.

Perhaps the greatest issue in our modern challenge will be building what we need while parasitic, vampire-like oligarchs are simultaneously sucking the blood from our culture's carotid arteries, dramatically insisting that we don't need it and trying to pocket our construction budget. Unhappily, in this case some of the very people whose lives will be decimated by the megadrought will not only believe this pitch from the deniers but become its most ardent supporters before they become its most tragic victims.

So, what does this "dream" look like? 

What are the "down sides?"

How much will it cost?

How long will it take to build something like this?

2012: The giant "arks" This megadrought is NOT a movie.  [YouTube]
In the apocalyptic movie, "2012," a huge portion of the existing wealth of the planet was allocated to the construction of giant ships in China. The "seats" on those ships cost a billion dollars -- the price for surviving the catastrophe.

It was a good investment because there wasn't going to be much planet left after "the big one." However, unlike this fictional movie, the megadrought, while serious, is not a "planet killer," and there is no justification for measures as drastic as the ones portrayed in the film. More realistically, this plan is a quite well reasoned, cost effective response. It would be reasonably affordable and, in fact, a pretty good bargain, considering the damage the megadrought will inflict otherwise.

The range of "other options" looks a "little slim."

Looking at the "Dream"

To "flesh out" this dream, let's select an example water source. We can use the Columbia River. Happily, we can already begin to think of the design -- at least in concept.

"Irrigated Relief" Pipeways for the Megadrought Zone
Concept Plan - Long Distance Water Delivery [MeanMesa]
The Columbia River flow into the North Pacific averages 190,000 cubic feet per second. [If you're curious, 1 cubic foot per second amounts to 448 gallons per minute.] This plan calls for the installation of a very large hydraulic ram pump in the River as it approaches the Pacific. The fresh water introduced into the pump system would have, otherwise, entered the ocean and become salt water a few miles down stream. 

Let's estimate the pump's intake flow at around 5% of that of the entire River, or roughly 10,000 cubic feet per second. We can conservatively [arbitrarily] estimate the efficiency of a ram pump of this scale at around 20% which means that around 2,000 cubic feet [roughly 800,000 gpm] of River water could be pumped to a higher elevation each second. So, how high could this water be pumped?

[image - USDA]
Normally, a ram pump's output ["delivered head"] depends on the height of the supply water source which is driving the pump. However, in the case of a fast moving river the "force" ["supplying head"] will be significantly increased because of the inertia of the river water pressing into the valve box.

To keep our discussion moving, let's say that the river installation pump can deliver water to a height of 1,500 feet above the river surface at around the flow rate mentioned above. If the delivery pipe were then allowed to drop 100 feet into the valve box of the second ram pump, that pump would deliver 20% of the water reaching it [400 cubic feet per second] to an elevation 1,500 feet higher.

The other 80% of the water delivered to the second pump would be "waste" discharge. Of course, it wouldn't actually be "waste." That discharge could form a small stream or fill a reservoir 1,500 feet higher than the river surface.

Now we can begin to see a "picture" of this design. Although all of this might seem somewhat complicated and expensive, we need to remember that:

1.  No external power is being consumed at any stage of the process, and,
2. Hydraulic ram pumps have only two "moving parts" which can wear out or need maintenance.

Numerous "strings" of these sequential pump sets can be constructed where water is available and routed to deliver water where it is needed in the drought zone. All along the route very significant volumes of "waste" water is discharged at usable elevations which can then be gravity routed to farm land or towns.

The volume of water required to off set the drought conditions described in the NASA report will be immense. Further, a plan to specifically transport water to this or that exclusive destination, while it might be somewhat attractive, doesn't address the megadrought problem. To do that, the western section of the US will have to be "irrigated into relief." A bit of "good planning" directs this relief to general areas which can use it, but this idea goes even further in its scope.

With several sets of massive ram pumps scattered along existing rivers the megadrought area will not only be receiving fresh water deliveries to the target locations, but soon there will be new lakes, new reservoirs and new rivers scattered all around through it as a result of these ram pump "waste" discharges.

How "Big" is "Big?"
We're not talking about "just a little water." 

MeanMesa has prepared a sketch showing an estimated size of pump installation located directly in the River.

A Large Hydraulic Ram Pump in the Columbia River
Concept Plan - Very Large Hydraulic Ram Pump, Columbia River [MeanMesa]
Although the project's scale may seem extremely large, its complexity would be refreshingly simple, its maintenance requirements very low and its operation costs very economical. The example's concrete "foot print" submerged in the Columbia River bed would be very large in this case, but these dimensions could be scaled to fit various sized rivers. The larger the pump, the more water is delivered.

To fully mitigate the megadrought's impact on the western US a good number of similar installations of varying sizes would be required. The target destinations where the pumped water was finally delivered would, naturally, become a political issue for Congressional funding debates, but the pipeline rights of way should be fairly easy because the pipes would carry only fresh water.

In the current political and economic climate the valve set fabrication might very likely be out sourced to low labor cost locations such as China or Korea, but the remainder of the design and construction work would create good domestic jobs which could not be out sourced.

Simply glancing at the summary of cost on an engineer's estimate might be rather shocking, but when the figure is compared to the value of the drought region's "damage mitigated" by the project, this might start looking much more attractive very quickly.

Environmental Impact of the Project

When considered in the "big picture," this kind of project is unquestionably "sacrificing" some parts of extremely valuable, existing rivers in exchange for preserving some very valuable arable land which would be lost otherwise. In the example the water being extracted from the Columbia River would be destined to become [agriculturally unusable] ocean water a few miles downstream from the ram pump, but other cases may present a more complicated balancing act.

At a certain point -- hopefully before the western states have been destroyed by drought -- we, as a society, must make a "majority decision" about whether or not mitigating the megadrought justifies the conversion of existing river water to irrigation and drinking water supplies for the affected region. In terms of avoiding the megadrought's straight cash loss the project looks attractive, but in terms of environmental impact we may have to take a "second look," perhaps on a case by case basis.

Interestingly, a Columbia River salmon captured in the pump's inflow structure could conceivably survive the entire journey to the water's destination, or, more likely, simply wind up swimming along in one of the fresh water "waste" streams or reservoirs. One of the environmental questions this poses would deal with the prospect of creating new salmon fisheries in places where there had not even been lakes or rivers before the project.

Although the hydraulic ram pumps have no rotating impellers, such a complicated "voyage" might still get pretty bumpy for a confused fish.

Let's Call the Design Engineers
If only we had a Congress...

Of course there are plenty of design questions remaining on the table -- this post was only intended to provide a "kick start" to one approach for solving this problem. Hopefully, this post also offers a little positive relief for visitors who are feeling the winter doldrums being further aggravated by something like NASA's chillingly dismal report.

This is no time to be thinking that "there is simply nothing we can do..."

MeanMesa wishes he were just a bit younger. This project looks like it would be great fun!

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