Connections for the STEM Classroom

Freshwater Security in a Changing World

Bopi Biddanda, Professor, Annis Water Resources Institute

With inset by Nicole Horne, Graduate Student, Annis Water Resources Institute

Water underpins every aspect of our lives.  We rely on freshwater for drinking, growing crops, production of energy, industrial goods, livestock and fish, transportation, health, recreation and waste disposal.  Affecting every aspect of our society and economy, water is a key determinant of our quality of life.  Although there is more than 1 billion km3 of water on Earth, and water is arguably a renewable resource, freshwater comprises only a tiny fraction (<1%) of the global water pool.  Various national and global reports during the last decade point out that the gap between the availability of water and the human need for it will widen greatly during the rest of this century.  Climate change-induced shifts in the hydrological cycle and increasing consumption of water by a growing human population of 7 billion with higher per capita thirst for water would drive such changes.  As agricultural, industrial and domestic use of water increases, and contamination of our natural waters continues, both the quantity of water and quality of water are becoming critical issues affecting our food security and well-being.  At the present time, water use is growing twice as fast as human population.  Today, one in six people do not have access to safe drinking water, and the UN estimates that as much as three quarters of people will be living in countries or regions where water is scarce by mid-century.

With the human appropriation of water already over 50%, pressures on water resources are likely to worsen as we shift toward more meat-based diets, and other challenges emerge (Postel, 1999).  For example, the world’s water is increasingly becoming degraded in quality by anthropogenic contaminants, raising the cost of treatment and threatening human and ecosystem health (Palaniappan et al. 2010).  Furthermore, the mere physical availability of freshwater resources does not guarantee that a safe, affordable water supply is available to all (See Inset about rural Ghana below).  For example, arsenic contamination of ground water, as a result of natural geological factors, continues to be a major public health problem in South Asia, Africa, and in several Latin American countries where four million people regularly consume arsenic contaminated water (Castro de Esparza, 2006).  Of still greater concern to global water supplies is microbial and toxics contamination of drinking water posing a threat to health and welfare - even in some communities of developed countries (Palmateer et al. 1999).

The global crisis of insufficient water supply and poor water quality directly affects basic human health and socioeconomic development.  Over 1 billion people live in areas of severe physical water scarcity.  At least 780 million people do not have access to clean drinking water, some 2.5 billion people lack access to safe sanitation systems, and 2-5 million people—mainly children—die as a result of preventable water-related diseases every year (The World’s Water, 2015).  The main contributor to this vicious cycle of disease and poverty is open defecation.  High levels of poverty, malnutrition, and high levels of deaths among children under the age of five co-occur in countries of Asia, Africa and Latin America where open defecation is widely practiced.  In addition, lack of in-house private toilets makes young girls and women susceptible to violence, impeding their pursuit of an education and economic advancement.  Currently, India is No. 1 in open defecation.  But even modern cities like San Francisco where >7,000 residents are homeless, face this problem.  The UN has issued an urgent call for ending open defecation across the globe by 2025 (WHO & UNICEF, 2014). 


INSET: Case Study of Acquiring Safe Drinking Water in Coastal Ghana

Nicole Horne, Graduate Student, Annis Water Resources Institute

The Atekyedo village, located in coastal Ghana in Africa is one amongst thousands of villages in the world where the quality of water has been severely compromised (Figures 1 and 2).  In the summer of 2013, AWRI graduate student, Nicole Horne, performed field research in this village studying the efficacy of inexpensive biosand filtration.  Biosand filtration is a simple biophysical filtration method for providing point-of-use drinking water (CAWST, 2012).  The system works through a combination of physical filtration through graded sand and by the biological activity of the biofilm – together resulting in filtrate that is free of contaminants.  Typically, each biosand filter can provide up to 60-100 liters of filtered drinking water per day, based on a pause-period in between water charges of 1-4 hours (Hydraid Manual, 2011; CAWST, 2012).  Biosand filters are in operation all over the world for providing clean water in developing countries in kitchens, hospitals, and schools.  Atekyedo is a village where incidence of malaria is high and waterborne diseases is common, as a result of poor infrastructure, land use, and sanitation.


Fig 1a

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Figure 1 Atekyedo village, located on outskirts of Winneba, Ghana, Africa. (a) Satellite view of Ayensu River & Atekyedo village; (b) Ayensu River, the main water source for the village


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Figure 2 (a) Student Nicole Horne, sampling a stagnant rain pool for microbial contamination analysis; (b) Children returning to Atekyedo village fetching raw water from the rain pool.


At the time of this study, there was no access to tap or piped water.  As such, villagers ‘fetched’ raw water from two extremely turbid sources, the Ayensu River and/or a pool of stagnant water left from a combination of rain and river water.  Both sources of water were sampled for fecal coliform and Escherichia coli analysis and found to contain very high levels of these organisms  - at levels above that considered safe by UN’s World Health Organization (Figure 2). 


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Figure 3 (a) Sampling a common water collection area of the Ayensu River; (b) Biosand filter in use in an Atekyedo home, filtering river water (Blue taller unit: Biosand filter; shorter orange tub: Filtered water storage).


Although, several US made Hydraid® biosand filters had previously been installed and maintained for 2-3 years prior to this 2013 field study, and several people showed gratitude for the filter and expressed how much it had improved their health, the flow rates of the biosand filters had decreased significantly, due to high turbidity of the source water (Figure 3).  The observed high turbidity was most likely due to the fact that over the past 30 years, the Ayensu River basin has undergone great transformation, as a result of significant land use activity including agriculture, urban development, grazing, mining, random waste disposal, water extraction, deforestation for fuel wood, abundant use of chemical fertilizers, and overall land degradation (Ayivor and Gordon, 2012). 


Due to efforts by the newly developed non-governmental organization, International Sustainability Health, Education, & Water (ISHEW), piped treated water has been restored to Atekyedo in early 2015, and their biosand filters will be reinstalled in different villages that are still in need of clean water!  Point of use water treatment technology continues to have a bright future.  The number of biosand filters originally developed by Dr. David Manz that are installed has increased from about half-million in 2010 to now over one million in more than 100 countries.  The utility of the biosand filter has been greatly enhanced, by adapting it for removal of arsenic (Ngai, 2006), and scaling it up to community level water treatment plants (  Many global humanitarian agencies such as International Aid of West Michigan, USAID, and UN-Water, are implementing biosand filtration units around the world, to help meet the Millennium Development Goal target for drinking water and the drinking water target of 88% coverage (WHO & UNICEF, 2014).

As the world’s population increases, its water is under pressure from numerous sources such as, pollution, over-use, changing lifestyles and production of food, energy and goods that require water.  Thus water is part of the powerful Water-Food-Energy nexus mix.  In 2010, Secretary Hillary Clinton told the State Department: “The water crisis is a health crisis, it’s a farming crisis, it’s a climate crisis, and increasingly, it is a political crisis.  And therefore, we must have an equally comprehensive response” – and asked for an Intelligence Community Assessment (ICA) of Global Water Security.  The ICA assessed seven major African and Eurasian river basins and concluded: “During the next 10 years, many countries important to the United States will experience water problems….  Between now and 2040, fresh water availability will not keep up with demand without more effective management of water resources.  Water problems will hinder the ability of key countries to produce food and generate energy, posing a risk to global food markets and hobbling economic growth.  As a result of demographic and economic development pressures, North Africa, the Middle East, and South Asia will face major challenges coping with water problems” (ICA, 2012). 

The World’s Water (2014), chronicles water-related conflicts over our long history, and concludes that more and more modern day conflicts have their roots in the need for water and over control of this vital resource.  According to Jan Eliasson, Deputy Secretary of the UN, the lack of access to water can fuel conflict and even threaten peace and stability: Water can drive both cooperation and conflict (Eliasson, 2015).  More than 90% of people live in countries that share river and lake basins, and about 150 nations share at least one trans-boundary river basin.  Because the water cycle is global, the availability, use and security of water readily cross local, state, national and even continental boundaries.  Degraded access to water resources increases the risk of social unrest, political instability, intensified refugee flows and even armed conflicts.  Ongoing civil wars in Syria and Iraq are examples of situations wherein water scarcity, drought, and the resulting economic and population dislocations may have contributed to political unravelling.  It is not an exaggeration to posit that world peace may increasingly depend on our use of water as a source of cooperation, rather than as a source of conflict.  Good water governance will be key to the future of humanity.

Demographic changes, unsustainable economic practices and rapid urbanization coupled with ongoing climate change are already affecting both the availability and quality of water for us all.  For example, the eastern basin of the Aral Sea dried up completely during August 2014 for the first time in 600 years, and California is experiencing an unprecedented 4th year of drought.  According to the February 14th edition of the Wall Street Journal, “more than 1700 wells have run dry, and emergency drinking water and shower stations have been now delivered to California’s rural Central Valley.  Global circulation models that make use of tree ring thickness as proxies of past droughts over the last millennium, project that future “megadroughts” in the American West will be worse than ever: more intense and more prolonged” (Underwood, 2015).

Many poorly governed nations of the world – even ones endowed with fairly good river flow and rainfall – are facing a severe water crisis.  Pakistan’s minister for Water and Energy, Khawaja Muhammad Asif is quoted in the February 13, 2015 issue of the New York Times as saying, “A combination of global climate change, local waste, and mismanagement have led to an alarmingly rapid depletion of the nation’s water supply.  Under the present situation, in the next 6-7 years, Pakistan can become a water-starved country”.  Indeed, a 2013 report of the Asian Development Bank described Pakistan as one of the most “Water-stressed” countries in the world – with water availability <100 liters per person per day.  Current per capita use in the US is >300 liters per day, and in the water-starved nations of Haiti, Mozambique, Rwanda, Ethiopia and Uganda, it is ~15 liters per day.  Peter Gleick of the Pacific Institute estimates that the minimum water requirement for meeting the basic daily needs of a human being is 50 liters (Gleick, 1996).  According to Arshad Abbasi, a water and energy expert with the Sustainable Development Policy Institute in Islamabad, “the biggest looming crisis is governance, not water – which could make the country unlivable in the next few years” – when the population of Pakistan is expected to top 200 million.

A recent article subtitled “Water Security” reports on how just a 2-year drought has triggered alarms in Brazil’s largest metropolis, Sao Paulo – where water reservoirs were down to <15% capacity in February 2015 (Escobar, 2015).  Here too, inadequate planning and poor crisis response seem to have exacerbated a situation already under water stress.  Driven by a persistent high pressure atmospheric anomaly, the normally southward drift of moisture from the Amazon and resulting rainfall have been absent over southeast Brazil, home to ~85 million people.  Such a prolonged multi-year anomaly is likely to be another extreme event related to ongoing climate change.  Closer to home, we had the month-long shut down of water to the city of Toledo in Ohio last summer due to the emergence of harmful cyanobacterial blooms in Lake Erie – whose proximal cause is excess runoff of fertilizers from agriculture in the watershed.  And there is the currently ongoing several months-long crisis over the perceived poor water quality of tap water in the city of Flint following the switch from Lake Huron to Flint River – the latter an industry-contaminated water body that has undergone significant restoration in recent years.

Water will be at the center of our lives and livelihoods for as long as we can imagine. Therefore, there is an urgent need to develop a new paradigm in the way we think about water and value it as a resource – one that recognizes the fact that water is at the center of changing climate, through droughts, floods and more extreme weather.  Forecasts by the Royal Academy of Engineering (RAE) suggest a “perfect storm” scenario where by 2030, the world will need to produce 50% more food and energy while using 30% more water – all while mitigating any adverse effects of climate change (RAE, 2010).  Indeed, the future adequacy of freshwater resources is extremely difficult to assess, owing to a complex and rapidly changing geography of water use across the world, even as climate change is regionally altering traditional precipitation patterns.  Just as demand for freshwater soars, supplies are becoming unpredictable.  The growing global demand on freshwater resources demonstrates the need to link rigorous scientific research with improved water management, resulting in sustainable freshwater resources.  The challenge is huge because a multitude of factors contribute to water security – many of which lie outside the water realm.

Despite the negative forecasts, there has been some significant progress.  For example, under the global mobilization behind the UN Millennium Development Goals, 2 billion people have benefitted from access to improved water resources.  However, a recent international assessment of UN’s Sustainable Development Goals has found its targets to be often vague, and argued that nations will struggle to achieve them unless the targets are better defined and quantified (Science, 2015).  Such open debate and reassessments of water security and sustainability issues is key to good and effective governance.  The good news is that water is now receiving more attention from everyone – but education and awareness continue are key to making progress (The World’s Water, 2014).  The Grand Rapids Art Museum has currently on display a dazzling tapestry of images by world-renowned aerial photographer Edward Burtynsky, representing waters’ critical roles in modern life and our increasingly strained relationship with Earth’s most valuable natural resource (  Recognizing the central role that water plays in human well-being, UN declared 2005-2015 as the “Water for Life Decade”, and celebrates the World Water Day on March 22nd every year – but events last throughout the year.  The theme for this year’s World Water Day 2015 is very timely: “Water and Sustainable Development”.  You too can join this watery celebration at 

Literature Sources:    

Ayivor, J. S., Gordon, C.  2012. Impact of land use on river systems in Ghana.  Institute for Environment and Sanitation Studies, University of Ghana, Legon, Accra, Ghana. West African Journal of Applied Ecology, 20 (3), 2012. p. 83-95. 

Burtynsky, E. 2015. Water. February 1 – April 26, 2015.  Grand Rapids Art Museum, Michigan (      

Castro de Esparza, M.L. 2006. The presence of Arsenic in drinking water in Latin America and its effect on public health. International Congress, Mexico City. p. 1-12.

Center for Affordable Water and Sanitation Technology (CAWST). January 2012. p. 4-10.

Eliasson, J. 2015. World View: The rising pressure of global water shortages. Nature, 517: 6.

Escobar, H. 2015. Water Security: Drought triggers alarms in Brazil’s biggest metropolis. Science, 347: 812.

Gleick, P. H. 1996. Basic water requirements for human activities: Meeting basic needs. Water International, 21: 83-92.                   

Hydraid® BioSand Water Filter: A product of Triple Quest, LLC. Cascade Engineering, Grand Rapids, MI. 2011.  p. 7.

Intelligence Community Assessment (ICA) 2012. Global Water Security. p. 30.

Manz, D. 2014. Water Information (

Ngai, T., Dangol, B., Murcott, S., Shrestha, S. 2006. Kanchan Arsenic Filter. MIT and ENPHO. Kathmandu, Nepal. p. 2-8.

Palaniappan, M., Gleick, P., Allen, L., Cohen, M., Christian-Smith, J., Smith, C., Ross, N. 2010. Clearing the Waters: A focus on water quality solutions. UNEP and Pacific Institute. p. 89.  

Palmateer, G., Manz, D., Jurkovic, A., McInnis, R., Unger, S., Kwan, K. K., Dutka, B. J. 1999. Toxicant and Parasite Challenge of Manz Intermittent Slow Sand Filter. Environmental Toxicology. 14: 217-225.     

Postel, S. 1999. Pillar of Sand: Can the irrigation miracle last? World Watch Institute. p. 303.

Royal Academy of Engineering (RAE) 2010. Global water security, An engineering perspective. p. 42.

Science 2015. Sustainable goals from UN under fire. Science, 347: 702-203.

The World’s Water 2014. Volume 8, Island Press.

Underwood, E. 2015. Models predict longer, deeper U.S. droughts. Science, 347: 707.

UNWater 2013. Water security and the global water agenda. UN-Water Analytical Brief. p. 39.

WHO & UNICEF 2014. Progress on drinking water and sanitation, Update.  p. 21.

Water Security

A 2013 infographic of the key elements of water security, and the centrality of water to achieving a larger sense of security, sustainability, development and human well-being. The working definition of Water Security proposed by UN-Water is: “The capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability”. UN-Water supports the inclusion of water security on the agenda of the UN Security Council and in the post-2015 development agenda as part of the Sustainable Development Goals. Source of  freely available online infographic at is: