May All Thirsts Be Quenched Everywhere

Season’s Greetings

+

 The Very Best of Wishes

For Extreme Delight and Joy

To Become Routine

For You and Yours

In Twenty-Thirteen!

263 Rivers on Land and 1 River in the Air!

Rivers are the oldest source of freshwater for humans, most ecosystems and most living species.
River Basins
A river basin is the land area from where water drains to feed rivers. The 263 river basins of significant rivers are fed by 45.3% of the land surface area of Earth. The 26 major river basins are shown in the graphic.

26 Largest river basins on Earth
Cartographer - Delphine Digout, UNEP/GRID-Arendal

Arid Areas
The most arid areas are those that do not have enough water i.e. are areas that are not in river basins: Southern California in The US, Western and Central Australia, The Mediterranean sections of Europe, North Africa and others are the  most arid areas on Earth.
The Missing but Largest River of all

Rainfed Agricuture
Source - fao.org

When land areas that serve as river basins are compared with those where rainfed agriculture is predominant, it becomes apparent that much of the water fed into rivers is water delivered by rain.
In a manner of visualization, rain too can be seen as a river in the air or atmosphere.
As is to be expected, the river in the air differs from the rivers that are on the surface of land:
- The river in the air is mobile and is subject to the movements of air streams (that carry the water in this river) in the atmosphere. Land based rivers are, over short periods of time, fixed in space.
- The river in the air is the original river of fresh water that feeds a land-based rivers.
100% of the water in rivers on land is in liquid for, while only 2% of the water in the river in the air is in liquid form. 98% of the water in the air exists as water vapor.

It is this river in the air, that we must find a way to tap when we seek to extract water in the air we breathe.

The Most Water Loving Molecule in Nature: Hyaluronan

In some organisms 90% of their weight comes from the water that is in the organism. Human babies and kids have the most water (about 78%) which drops to 60-65% when they become adults. Adult women generally have less water than men do.

Human bodies and water

Source - ec.gc.ca

Every part of the human body is predominantly made up of freshwater.

Our physical body simply would not exist if freshwater did not exist.

We also would not exist for very long if we could not replenish the water lost by the human body. Continued availability of freshwater is absolutely necessary for humans and other life-forms to continue to exist.

But what keeps all this water together in the human body?

Hyaluronan

Source - vitanetonline.com

The "glue" keeping all this water in our bodies is a carbohydrate called Hyaluronan.

The average 154 lb. person has roughly 15 grams of hyaluronan occurring naturally and distributed over all parts of the human body.

Its consistent function in the human body is to bind with water and hold the water for use in individual cells of the human body.

Hyaluronan has a half-life of about 3-days in all organs of the body except in the skin where it's half-life is just about a day. As Hyaluronan decays more supplies are biologically synthesized in specialized areas of the human body,

Commercial Applications

Source - bueatyinthebag.com

Hyaluronan can be synthetically created and is the predominant ingredient in skin care products. As human skin ages, it looses its ability to hold large amounts of hyaluronan i.e. the skin is no longer as hydrated as young skin and shows wrinkles and feels drier when touched.

Now that we can commercially produce hyaluronan, can we use its water-loving (hydrophilic) properties to extract water vapor from the air we breathe?

Let Global Public Play With Science!

Source - Financial Times Newspaper
dated 16 Nov 2012

A note I wrote was published in the Financial Times Newspaper on 16 November 2012. 

The contents of this note essentially describe the approach that is applicable to producing the progress we desire on every one of our most intransigent challenges in the twenty-first century.

This is also a key element of the approach being used to create the means to extract water vapor from the air we breathe.


The note can be accessed online at http://www.ft.com/intl/cms/s/0/750f8a06-2e8d-11e2-9b98-00144feabdc0.html#axzz2CPXvG8qL

Urbanization = Use Clean Water to Remove Dirty Water!

In 1950, with world population around 2.5 billion, there were just two cities (London and New York) classified as mega-cities because their population was more than 8 million each. In 2008, with the world population at over 6 billion, over 3 billion people lived in mega-cities distributed around the globe.
Migration to cities - Urbanization

Source - wikipedia.org

More than half the world's people live in cities today.
Meeting the concentrated water needs of these large numbers of people has led to the rise of urban institutions whose sole focus has been the supply and delivery of fresh water and of urban institutions responsible for removal of dirty water.
Clean water removes dirty water

Dirty and Clean Water
Source - trashwater.org

City dwellers use water differently than people living in rural areas.
In rural settings dirty water is left alone to either seep into the ground or evaporate into the air. Sometimes. to avoid it being a health hazard, dirt is added to the dirty water to absorb the dirty water and cover up its location.
In urban settings, however, the usual practice is to not allow dirty water to seep into the ground or evaporate into the air.
In urban areas, clean water is used to get rid of dirty water.
This increases the per-capita water requirements of city dwellers over people living in rural areas.
The most pronounced use of this practice is in the bathroom where water contaminated with human waste is flushed away by clean water.
Importance of Residential Water Consumption

Source - westbasin.org

Urban water is typically used for residential, industrial, commercial, and public purposes. In addition, minor amounts of water are used in urban settings for other purposes like fire-fighting, line-cleaning, and to make up system losses.
The largest amount of water is used in residences. For example, 66% of the total water, supplied by the Metropolitan Water District of Southern California, is used in residences of the approximately 15 million people living along the Southern California coast from Oxnard to San Diego.
This is 66% of an estimated 195 gallons per-capita per day. (source - paper titled "Determinants of Urban Water use" by W. Michael Hanemann).
It is estimated that over two-thirds of the residential supply (66% of 195 gallons per-capita per day) is clean water being piped in solely for the purpose of getting rid of dirty water!
Is there an innovation in clean water supply (like extracting water available in the local air) or in flushing away dirty water (like using composting toilets) - innovations that do not require the capital-expensive and costly-to-maintain water supply and waste extraction piping systems (both susceptible to leaks) of today?

How does Water exist in Air?

Water molecules in the air exist like sand, salt and sugar molecules exist in a salt-sand-sugar mixture. The compound H2O is free and stands alone like a component in a physical mixture not as a component in a chemical mixture
A mechanical Mixture

Each component stands apart
Source - tojojoling.blogspot.com

Each piece stands apart
Source - cookteen.com

In a mechanical mixture, each component exists separately from every other component.
In a mechanical mixture, each component can be separated from all other components through a process akin to separating all the pasta or the red candy.
Air is a mechanical mixture of elements and compounds
Elements in the air include:

Gas	Ratio compared to Dry Air (%)		Chemical Symbol
	By volume	By weight
Oxygen	20.95	23.20	O2
Nitrogen	78.09	75.47	N2
Hydrogen	0.00005	~ 0	H2
Argon	0.933	1.28	Ar
Neon	0.0018	0.0012	Ne
Helium	0.0005	0.00007	He
Krypton	0.0001	0.0003	Kr
Xenon	9 10-6	0.00004	Xe

Source - http://www.engineeringtoolbox.com/air-composition-d_212.html
Compounds in the air include:
Water, Carbon Dioxide, Sulfur dioxide, Methane, Nitrous oxide, Ozone, Nitrogen dioxide, Iodine, Carbon monoxide and Ammonia
Water exists in the air in 2 forms
The water in air exists in two states: about 2% exists in liquid form while the remaining approx 98% exists in liquid form.
The task of extracting water from the air is mostly a task of extracting the vapor form of water from the air.

Wish Freshwater Scarcity was as Simple as the Fiscal Cliff !

The US Fiscal cliff and Global Freshwater Scarcity are quite similar but it is the differences that matter and push for a very similar remedy for both.
The US Fiscal Cliff

The US Fiscal Cliff
Source - healthreformexplained.com

The US faces a Fiscal Cliff on January 1, 2013 when a mix of spending cuts and tax increases go into effect unless a deal is reached between politicians in Washington DC by end of day December 31, 2012 - a little over 8 weeks from today.
The Freshwater Cliff, of course has two possible outcomes once the end of the 'ramp' is reached:
- Either gravity will take over and the US will drop down into whatever is at the bottom of the cliff and a number of unpleasant results will be felt
- or, the target on the other side will be hit and nothing with too extreme negative impacts will result.
The Global Freshwater Cliff

The Freshwater "Gap"
Source - World Economic Forum

While the fiscal cliff has either an acceptable or an unacceptable 'end', the Freshwater Cliff has NO END - the Freshwater Cliff only gets worse with time i.e. it has only a worsening prognosis. 
In the graph, the Freshwater Cliff is the dark area that continues to grow with time i.e. unlike the Fiscal Cliff, there is no target that can be defined like it can in the case of the fiscal cliff.
This essentially means that the "drop" from the freshwater cliff will continue forever till an effective remedy is found.
Representative impacts of the continuing increase in the "freshwater gap" include a combination of:
- more geographical areas experiencing shortages (droughts) and/or overwhelming supplies (floods)
- droughts and floods of greater severity measured in terms of their negative impacts
- greater uncertainty in freshwater supplies in more areas

The challenge, thus, from both the Fiscal Cliff and the Freshwater Cliff is the same: Find a remedy that ends the "fall off the cliff" quickly and with the least negative impact on life and livelihoods

Freshwater Security: A Community or a Global Issue?

The only way I got my mother to stop using the phrase "Finish your food. There are starving children in .....(you can fill in the blank with the name of your favorite nation)" was by gathering the courage to say "Why don't we send the food to them?" Of course, such a delivery never took place but this conversation clearly showed me that human communities are in some ways totally independent from other human settlements.
Super-storm Sandy's early legacy

Super storm Sandy turns lights off
Source - news.yahoo.com

When the storm hit, power and services were lost in many areas of New York. Today, nearly a week later, Lower Manhattan and Staten Island are like world's apart even though they are just 10 miles, as a crow flies, from each other.
Electric power and many other services are fully operational in Lower Manhattan but not yet available for many Staten Island communities.
To residents of Staten Island without electricity, Lower Manhattan is today a world away.
Rich and poor nations share borders

Asuper wealthy country inext to a not-so welthy nation
Source - churchworldservice.org

This feeling of being a world apart, when you are really only next door, also separates countries e.g. The wealthy US shares a border with the developing nation of Mexico.
As we are well aware, rivers cross country boundaries and a truckload of case law and agreements specify how much water each country can draw from these rivers.
This inter-dependency with freshwater is one ordained by nature
Freshwater is both a Global and a Local Issue
If New York figures out a way to be freshwater secure, it does not imply that Miami cannot also be freshwater secure. However, if New York industries starts spewing excessive amounts of carbon in the atmosphere, it can impact the climate in Miami, which in turn could alter rainfall patterns for Miami. Freshwater inter-dependency, if any, for New York and Miami is the result of them being interconnected by the Earth's atmosphere. What one does to its atmosphere can and is felt by the other. Thus, freshwater security is typically a local issue if the atmosphere cooperates. When it does not, freshwater can become a regional and even a global issue.

Why Sea Water Needs Cleaning!

Seawater is 97.5% of the total water on Earth. In times of drought and other thirst, humans have tried to cleanup seawater to turn it into freshwater. But so far we do not know how to transform seawater into freshwater economically and without severely impacting the environment.
Seawater has a composition much like the human body

Seawater composition
Source - earth.usc.edu

Recognizing that our ancestors originally lived in the sea, it is not surprising to find that the proportion of minerals and salts in human tissue is very similar to that in seawater.
Of course, the exact proportion varies around a similar mean proportion for individual seawater and human tissues.
Human bodies require the salt they contain.
Human bodies loose salt easily
Sweating, crying and urinating are some of the ways in which the human body looses salts. We must replace this lost salt but we cannot intake an excessive amount of extra salt. The excessive salt is bad for the cells that make up our bodies and organs like our kidneys.
What happens when we ingest more salt than we need?
Water moves out of cells to dilute the salt content to a normal acceptable level. This movement dehydrates cells and impairs their normal functioning. Seizures, unconsciousness and brain damage are some of the results of extreme dehydration or prolonged dehydration. Excessive intake of seawater is, thus, a life threatening issue for the human body.
Salt content of Freshwater
USGS has categorized different waters, based on their salt content in parts-per-million (ppm), as follows:

• Fresh water - Less than 1,000 ppm
• Slightly saline water - From 1,000 ppm to 3,000 ppm
• Moderately saline water - From 3,000 ppm to 10,000 ppm
• Highly saline water - From 10,000 ppm to 35,000 ppm
• Ocean water - about 35,000 ppm

To avoid intake of excessive amount of salts, we must, therefore, clean up seawater (i.e. lower the salts it contains) before it is safe for human consumption. The process of lowering salinity or amount of salts in seawater is known as desalinization.

Wind and Water on US Eastern Shoreline this weekend

How High Winds got named Hurricanes!

How we classify Hurricanes based on wind speed!

Source - en.ryan.ru
Copyright Ria Novosti 2010

Freshwater Shortage OR Crisis?

Whenever we talk and hear about freshwater and the future, our most frequently used phrase is 'freshwater crisis.' Less frequently used phrases include 'freshwater shortage' and 'freshwater thirst.'

The American Heritage Dictionary

Source - 123rf.com

This dictionary defines a 'crisis' as:

• a 'turning point' or 
• a 'crucial or decisive point or situation.'

It also calls a crisis 

• "an unstable condition in political, international and economic affairs in which an abrupt or decisive change is impending' and 
• 'a sudden change in the course of an acute disease either towards improvement or deterioration' and 
• 'the point in a story or drama at which hostile forces are in the most tense state of opposition.'

Crisis is about RISK and not about a BAD outcome

From the above descriptions, a crisis exists when a situation exhibits the following characteristics:

• An unstable state of affairs
• A decisive change is pending



Source - forbes.com

• Distinct possibility of a highly undesirable or a highly desirable outcome

Under these criteria, a crisis is not necessarily bad. 

The outcome of a crisis can also be a positive and good one.

The difference between calling the future situation with freshwater a 'crisis' and not a 'shortage' only implies that:

• Freshwater in the future is a situation characterized by a certain level of risk and uncertainty
• A necessarily 'bad' result is NOT being foretold

Depending on the risk and uncertainty, some will predict a 'freshwater crisis' while others will accept it as a 'freshwater shortage'

Sound & Music Generated by Freshwater

We all are very familiar with freshwater's role in generating electricity, changing weather, growing food and improving health. But few of us are aware of how our ancestors used water to make sounds and music.
Playing a glass partially full of water

Source - invigorate.royalsociety.org

We have all tried this in our home one time or another. Fill a glass partially full of water and wet its rim and rub one finger along the rim.

Source - exploresound.org

The speed with which we move changes the sound that is produced. The sound produced also changes depending upon the amount of empty volume in the glass.
Lining up a few glasses with varying amount of water in them, creates a musical organ.
Water Driven Pipe Instrument - The Hydraulis

hydraulis circa 1,000 BC
Source - en.wikipedia.org

Water Organ
Source - en.wikipedia.org

With water supplied from some higher point above the instrument, air is introduced in the water stream that is turning a musical cylinder quite like in today's music boxes. 
As the air produces pulses in the water stream, the stream changes the rotation of the musical cylinder to produce changes in sounds - changes that together produced music as early as 3rd century BC.
The Hydraulophone

A Hydraulophone
Source - en.wikipedia.org

Blocking the flow of water can also be done with the fingers somewhat like the plucking of guitar strings. When a stream of water is stopped by a finger it changes the sound the instrument makes.
In the hydraulophone, water is also sometimes used to make the sound

Water, a most abundant substance on the planet, also has a vast abundance of uses.

Water + Gravity = Tools to Tell Time

The sundial and water clocks are probably the oldest instruments whose function was to tell time. As long-ago as 4,000 BC, we were using gravity and water to measure time.
Inflow Timekeepers - The ghati

A Coconut Shell with a hole
Source - sciencephoto.com

These timekeepers measure time by how long it takes for water to fill a container.
In India, the standard water clock was a 'ghati' that measured time in 24 minute intervals - 60 of which together made up a 21st century 24-hour day.
The ghati was half a coconut shell with a hole drilled to just the right size in it. When floated in a tank of water, the shell would slowly take on water till it sank.
The size of the hole and the coconut half-shell were such that it took 24 minutes for the shell to sink.
The ghati was in use for over 5,000 years all over the ancient world.
Outflow Timekeepers - The Klepsydra

A Klepsydra
Source - depthome.brooklyn.cuny.edu

These time keepers measure time by long it takes for water to empty a container of fixed volume.
The jar at the higher elevation is filled to a fixed height. Water flows out of the hole at the bottom into another jar.
The klepsydra was made in the conical shape (a wide top and a narrow bottom) so that it would also be used to measure the passage of time. The conical shape ensured that the pressure at the bottom of the jar (that pushed out the water) remained constant as the water level dropped - A greater amount of water would flow out when the jar was filled, so that the surface level of the water in the jar would drop at a steady rate.

Water, a most abundant substance on the planet, also has a vast abundance of uses.

Freshwater and Radio Waves = A Security Tool!

We depend on adequate supplies of freshwater for our food, energy, health and every other artificial creation of ours. Now, with advances in science and technology, freshwater is also key to our security needs.
Full Body scanners at Airports

Image from Full Body Scanners
Source - en.wikipedia.org

Full Body Scanner Equipment
Source - au.ibtimes.com

Transportation authouroties around the world have adopted a tool, the full body scanner, to ensure that no travelers take board prohibited items on board aircraft, trains and other mass transportation vehicles.
There are many technologies used to create images that can reveal prohibited items.
Terahertz Radiation

Terahertz radiation band
Source - teranova-ist.org

Light with wavelength between 300GHz and 10THz is known as Terahertz Radiation.
This radiation exists naturally and falls between infrared and microwave radiation.
A characteristic quality of Terahertz radiation is its ability to penetrate clothing and the human body but only to a very limited extend - freshwater just below the human skin stops and absorbs particular terahertz radiation
Absorption by Freshwater 

Terahertz Radiation absorbed by water vapor
Source - en.wikipedia.org

One form of body scanner works by firing radio waves of Terahertz length onto the human body and capturing the pattern of reflected and absorbed waves.
This pattern creates a body image of the kind full body scanners create to identify the existence of banned items.
As most metals do not absorb terahertz radiation, their existence can be confirmed in the pattern and the image. As most banned items are made of metals, the pattern can identify items hidden in clothing that could be one of the items banned from being transported on planes and trains.
Commercial Use of Terahertz Radiation

A Custom Clothing Machine
Source - digitalstyledigest.com

The first commercial application of freshwater-based body scanners is a set of machines that have been deployed in some specialty clothing stores.
These machines create an exact outline, in 3-D of the human body so that fitting clothes, for each of our individual body contours, can be found or manufactured.
These machines fire radio waves in the Terahertz range and catch the returning waves to build a true 3-D outline of a body.

Can terahertz radiation be used to locate new sources of freshwater?

Perspective & Predictability Define Scarcity!

Source - cartoonstock.com

"One person's junk is another person's fortune" goes the old adage.
The difference between "junk" and "antique" is predominantly one of perspective.
Perspective is, of course, itself influenced by many factors that vary widely because these factors are very individual and extremely personal in nature.
It's much the same condition with safe drinking water:
- Those that have enough cannot see how they could ever do with less 
- Those that don't have enough seem to find a way to survive with what they can get
Of course those that can only get less than the necessary minimum suffer ill heath and other debilitating impacts.
Is piped water available 365/24/7 the definition of no scarcity?

Bathroom plumbing
Source - avivimprovements.wordpress.com

In the middle of the twentieth century, piped water was the norm not the exception for most of humanity.
Now, at the beginning of the twenty-first century, a large part of humanity does not get piped water 365/24/7 although all permanent houses have the necessary plumbing in place - for these house dwellers, supply of water may be intermittent or only available for a few hours a week on a unpredictable schedule.
Using the definition of 365/24/7 piped water supply, a large part of humanity already is experiencing scarcity with more people joining this group daily.
Perspective is ruled by Existing Circumstances

Esher's Waterfall
Source - en.wikipedia.org

Esher's depiction of a waterfall is a great example of perspective. Only people who happen to be in the left tower and in the big house on the left, are the ones who experience the waterfall.
The former see water dropping from where they are, while the latter see water falling to where they are.
For everyone else, water is simply moving at the same level as, of course, water cannot rise against gravity.
When asked if receiving freshwater 365/24/7 is necessary, most people who don't have 365/24/7 water supply do not label regular continuous unavailability a problem. From their perspective, they can live with much less than 365/24/7 piped water supply. 
The opposite is true for those that are used to having water run out of a tap when they turn the tap on. For them scarcity has arrived, if there is no water, even for a few seconds, running out of any tap.
Unpredictability creates scarcity

Women fetching water
Source - artwolfe.photoshelter.com

Those with and without continuously piped water agree on one thing: water availability must be predictable.
Once predictability is assured, scarcity disappears for most every individual wherever they may live and under whatever circumstances.
Take the case of people, mostly all of whom are women and girls, who make daily long difficult treks for drinking water.
In their minds, fetching necessary drinking water is just a necessary chore they must perform daily. That's just part of their life.
They don't even consider fetching water a burdensome chore. It is those with piped water that call fetching water an unnecessary and unfortunate chore.
What is the Absolute Minimum amount of freshwater for Humans?

Water Meter
Source - caes.uga.edu

Humans loose water when they breathe and when they perform virtually any movement. Even the process of being alive (not counting breathing, uses up water.
At a United Nations conference in 1977, it was decided that an average human being requires 3 liters (3.2 quarts) of water under average conditions i.e. an person living in an average climate and doing the things that people do on an average.
But, of course, there is no average human being or average climate or average life condition. And, the 3 liters do not include water needed for cooking and sanitation and human hygiene.
Adding up these numbers in a practical way, the minimum required freshwater per capita is 50 liters (13.2 gallons) per day, it was agreed, for maintaining a person's body water balance and ensuring acceptable healthiness.
Is 50 liters/day/person truly enough?
Yes, if we ask those 2+ billion who live on less than 50 liters per day!
No, if we ask those that live on more than ten times the 50 liters per day!

So what's should be the freshwater supply target per head per day?

Freshwater's Supply Chain is Unlike that of Any Other Resource!

Freshwater is a resource like no other. While differences between freshwater and other renewable and non-renewable resources are many, freshwater's supply chain makes freshwater a most unique natural and renewable resource. Nature delivers freshwater in ways it doesn't do for any other resource. 
Freshwater's Current 3-Source Supply Chain

Source - willoughby.nsw.gov.au

3 sources of freshwater exist for most human settlements. These are:
1. Rainwater that naturally falls on the settlement
2. Freshwater transported from near and far locations  to the settlement, and
3. Locally obtained water, usually from a combination of sources located at ground level (e.g. rivers and lakes) and below ground (e.g. wells that tap the local water table).
Some locations do not, of course, have all 3 sources available to them -  but most do, because this 3-source approach was seen as the most prudent and dependable one.
Threat's to the 3-Source Supply
All three sources can be threatened today in a variety of ways for human settlements in different locations:
1. Climate change has impacted the frequency, amount and location of rainfall.
2. The ability to bring water from remote locations is threatened by both dwindling resources at the remote location and the assertion of communities along the transportation route to the freshwater being transported.
3. Continued extraction of groundwater has lowered water table levels, in some cases to depths that are difficult to access.
Rainfall - Resource delivery on a near-regular schedule

Source - diswaterdrams.com

Other than freshwater, nature delivers no other natural resource on a fairly regular schedule to locations where the resource may also be ingeniously available in bulk. 
Delivery of freshwater as rain was probably of little value while humans were migrating all over the globe. Rainfall's value only became evident about 10,000 years ago, when humans chose to settle down in one place (and grow the food they needed) instead of moving around in search of food. Humans, in a sense, became dependent on rainfall at the start of the agricultural age.
Rainfall Dependency
Once reliant on rain to grow their food, humans became subject to the impacts of any change in rainfall delivery frequency, amount or location. And it is, in large part, this dependency that is shaping a crisis in freshwater supply - supply of rain is simply too undependable.
The one unique feature that defines freshwater delivery is today the one unique force behind freshwater scarcity and water security.

Freshwater Innovations Fuel Population Growth!

While we may never know with absolute certainty the answer to the question: "Which came first, the chicken or the egg?" we can be reasonably sure that human population grew and thrived because required amounts of freshwater became available necessary to sustain growing numbers of people.
Human Population Growth

Source - Adapted from Page 15, of book titled
"Pandora's Seed" authored by Spencer Wells

Approximately 200,000 years ago, our breed of human (aka Homo Sapiens) originated in Africa. Only 60,000 years ago Homo Sapiens started to grow in number.
Some 10,000 years ago, however, this rate of growth accelerated dramatically - Human population grew thousand-fold, from 1 million people to 1 billion people, in less than 10,000 years. 
Role of Freshwater

Source - Ommato LLC

When key water-related innovations are superimposed on to the population graph, it becomes clear how these innovations influenced growth in numbers of people. Key water-related innovations included:
- About 10,000 years ago, humans dug a well to capture water they saw disappearing into the ground
- Some 7,000 years ago, irrigation was born when humans figured out that water would, on its own accord, move from higher levels to lower levels
- About 5,000 years ago humans made the artificial lake when they built a dam to stop a river from flowing
- Approx 4,000 years ago humans began to raise water from lower levels to higher levels with the invention of a Shaduf. This was quickly followed with the Archimedes Screw and the Waterwheel all increasing the height to which water could be raised.
- Around 300 AD, 1900 years ago, the Romans built their gigantic aqueducts to bring water from many miles away to their cities.

Impact of Innovations
Each innovation had its incremental impact. But as is evident from the chart, the greatest impact on human population numbers came from the inventions that raised water to very high levels and that transported water over long distances.

What innovations lie in the wings or are possible today, that will bring abundance to safe drinking water in the 21st century?

Small Numbers and Water Sufficiency!

Small numbers, like everything else, when looked at without a framing context have no meaning at all and usually lead to the wrong conclusion. The oft-repeated statement "Only 2.5% of the water on Earth is freshwater" is factually correct considering the measurements and assumptions behind its quantification. But is it correct in implying that because 2.5% is a small number, it only represents a problem?
Lumps of Sugar

Source - blog.cytalk.com

If the question is: Are 2 lumps of sugar more than enough to feed all the ants in the world or would 600 lumps of sugar be adequate?

Source - twobitbard.weebly.com

The likely answer usually is: 600 lumps.
The primary reasoning behind this answer is the assumption that as 600 is more than 2, then 600 is likely to NOT be the wrong answer. And, as the convoluted logic goes, if it is less likely to be the wrong answer, then, of course, it is more likely to be right answer.

Source - clker.com

The other bits of assumption are what we know about how much sugar an ant requires and the actual size of each lump of sugar! And as we do not precisely know these bits of information, we go with the larger number i.e. 600 lumps while assuming the size of each sugar lump based on how large we think the spoon is. This spoon size is based on the spoons we usually use.
But what if each lump was 1kilometer long on each edge? And there were 150 Trillion ants in the world? Then too the larger number would be the answer, because the number is simply larger. Going with the larger number of 600 lumps is just safer because it is less likely to be wrong.
This logic applies also to freshwater supplies
Only 2.5% of the Earth's Water is Freshwater

Source - go.water.usgs.gov

What is the conclusion when we see the world's water (larger blue sphere) and freshwater in liquid form (smaller blue sphere), displayed relative to the size of the Earth? 
The 1st conclusion: We have very little water and even less liquid freshwater! (relative to the size of the Earth, of course)
The 2nd conclusion: We could quickly run out of freshwater! ... because see how little of it exists in comparison with the size of the Earth.
But what's our conclusion when we know the following:
The total amount of water on Earth is: 
- About 332,500,000 cubic miles (mi³) = 1,386,000,000 cubic kilometers (km³)
- The larger sphere is about 860 miles (about 1,385 kilometers) in diameter
The amount of Freshwater
If 2.5% of the total water is Freshwater, then the amount of freshwater is: 8,312,500 cubic miles (mi³) = 3,465,000 cubic kilometers (km³)
The size of these numbers makes it very difficult to reach a conclusion one way or another! Even conceptualizing how large (or small) a cubic mile is, is difficult for most of us.
The Takeaway
Small percentages do not necessarily imply insufficiency or sufficiency.
Much more analysis is required before we can judge if we are facing freshwater insufficiency or insecurity anytime in the near or far future.