Kala Vairavamoorthy explains how systems thinking can help us tackle complex water problems and avoid unintended consequences.
I recently attended IWA’s Hydroinformatics conference in Bucharest and one word stood out: systems. The rise and spread of this word is thrilling, and long overdue.
As I have said for many years – water is a system of systems of systems. And to avoid risky and even fatal threats from unintended consequences, water professionals ignore systems thinking at our peril.
I should know. Years ago when I was a student, my mentor, Dr Jeremy Lumbers, explained that my role as an environmental engineer was to modify the physical world to improve human quality of life. For someone entering a profession that could promise neither riches nor fame, such a challenge excited the imagination. It conjured a future of diverting river currents, lifting aquifers to the surface, cleaning and pumping and distributing the source of life through endless miles of pipes to ensure the healthy growth of countless families and firms. I could envision the honour and satisfaction of serving the public good.
But against this outlook, Dr Lumbers raised uncomfortable questions. Why might new piped domestic supply bring more infection than the ‘primitive’ distributed water collection it sought to replace? Can’t we build irrigation canals and dams without attracting parasites or ruining arable land? Must public wells and fountains introduce disease vectors?
I wasn’t alone in being vexed by such questions. All too often, until we reflected on the UN International Drinking Water and Sanitation Decade, many ‘water-focused’ global institutions, funders, governments and educators missed the corresponding waste disposal and treatment component of the ‘sanitation’ process. Moreover, they missed the equally vital ecological context, from which water came and to which it must return.
Even today, most elected officials – attuned to culture and constituent priorities – proudly boast of new taps, reservoirs or desalination plants. Rare is the ribbon-cutting ceremony for new latrines or anaerobic digesters. Both are needed, but true political leadership recognises that water and sanitation are necessary adjuncts, linked in a symbiotic relationship. Building one without the other, we belatedly found, not only fails to improve human well-being. It may endanger it by introducing new disease vectors into a community where it had never existed.
Looking back, it became clear that our self-image of water provision wasn’t so much bad as it was myopic and incomplete. Our imaginations had been constrained, in short, by linear thinking.
Linear thinking is the traditional way we solve problems. We apply logic, use past data and seek to improve on existing solutions. There’s nothing inherently wrong with that, but it can prove dangerously simplistic. In 1920, the critic H L Mencken knew that “there is always a well-known solution to every human problem – neat, plausible, and wrong.”
Now apply that simplistic thinking to our urbanised, industrialised, and globalised world, heating up while racing to meet the needs of 8 billion people linked by the ‘wicked problem’ of water. Wicked doesn’t mean evil, just confounding, because of incomplete, contradictory, and changing dynamics that are slippery to grasp and prevent a single path out. Worse, water is inextricably linked to other wicked problems such as climate change, natural disasters, hunger, pandemics, and poverty.
The response isn’t to shrug in despair or frustration. It is to shift our decision-making framework.
Rather than a narrow, A-to-B, top-down linear approach that addresses each need in isolation, we can learn and develop broader and more complex systems thinking. We can recognise water and sanitation as a system of systems of systems. We can adopt competitive and collaborative strategies and models that avoid uniformity and help us tame this wicked problem.
What we can’t do is maintain the status quo. In a summary of our sector’s key priorities – to save water, slash emissions, enhance sanitation, and prevent disease – we see how the old ‘well-known solutions’ have already wrought painful and even deadly unintended consequences.
The converse of conservation
To cope with increasingly scarce and volatile resources, thirsty utilities often seek to maximise limited supply by encouraging families and firms to use less. Some apply rations, restrictions, and rate increases. Others offer highly efficient toilets, drip irrigation or appliances, and encourage greywater recycling. Such tools sound obvious, but each can backfire in unexpected ways.
For starters, water efficient technologies may not always translate to less demand – the ‘rebound effect’. Water saving showerheads can lead to longer showers. Improved irrigation techniques that purport to save water often result in increased water demand and less groundwater recharge.
When efficiency brings waste
Even ecologically benevolent interventions to save water can exacerbate social inequality. The painful sticks of rations and tariff increases often fall hardest on low income families who use less because of financial constraints, and lack funds to invest up front in more efficient fixtures. Meanwhile, landlords have little to no incentive to act on behalf of bill-paying renters. Conversely, according to the World Bank, economic subsidies are typically captured by the affluent. Hence the poor end up paying more for water than the better-off – especially after rates rise.
Even a city’s unified and fair water saving efforts can drive up water loss. Lower demand on the consumer side of meters can increase pressure – and amplify leakage rates – across the network.
Clean water conservation also complicates dirty water disposal and treatment. Highly efficient showers, sinks, appliances and greywater diversions can in aggregate dramatically reduce flows into municipal sewers. The result intensifies odour complaints, increases potential clogging from sedimentation, and generates more hydrogen sulphide that accelerates corrosion. Ultimately, efficiency denies a wastewater treatment plant of its dilutive solvent, prolonging detention times, concentrating older influent, and resulting in potentially septic conditions.
Lower energy, higher emissions
We know rising greenhouse gases (GHG) worsen the climate chaos that impact water systems. Less appreciated is how water systems emit GHGs – and how well-meaning efforts to mitigate these emissions can backfire. A vigorous commitment to a cleaner sector has led water professionals to focus on local and direct or ‘Scope 1’ emissions.
Our drive to reduce carbon dioxide throughout utility operations, while laudable, has an unintended and negative consequence. A plant may shift towards ‘energy efficient’ and ‘low-carbon’ tactics that require, for example, less aeration in the nitrification and denitrification process. In doing so, it may well generate far more nitrous oxide, a gas 300 times more potent than carbon dioxide.
So our sector’s question is whether to pursue strategies that achieve net-zero energy, or net-zero emissions. Paradoxically, if the water sector can source green electrons – and thus reduce ‘Scope 2’ emissions from the electricity it purchases – it could adopt more energy intensive processes yet still reduce overall emissions for a net gain.
Cleaner toilets, filthier aquifers
One enduring mark of human progress has been our graduation from open defecation to outhouses to, ultimately, flush toilets. Yet even here, the simple picture can get complicated.
In 2014, India launched ‘Swachh Bharat’ – a five-year nationwide campaign to stop open defecation by building 100 million toilets. The mission set out to prevent the spread of untreated faecal matter in the environment, disease vectors, and psychosocial stress among women and children.
Unfortunately, the project spiked demand because of excessive flushing, and wrought more contamination of wells in densely populated, ‘toilet-equipped’ areas than those where open defecation continues unchecked. Why? On-site sanitation technologies funnelled high volumes of new wastewater into unlined pits until contaminants leached into groundwater, a resource on which most of the country’s population depends.
By contrast, open defecation remained widely distributed and used little or no water. Exposed on the surface to air, sunlight and heat, the faecal matter dried and desiccated fast, leaving only a fraction of the bacterial load to percolate into the soil.
Pick your poison
To combat waterborne disease and diarrhoeal outbreaks that elevated child and infant mortality rates, Bangladesh took action. With UNICEF and the World Bank, it launched a large-scale, decades-long collaboration to drill and pump an estimated 8.6 million tube-wells. The massive local water infrastructure investments succeeded in moving 94% of rural Bangladeshis from stagnant, parasite-infected surface water to tap groundwater that was, supposedly, protected.
Only it wasn’t. Many aquifers turned out to hold unacceptably high levels of naturally occurring arsenic. Countless infants, children, and adults alike faced a new carcinogenic waterborne affliction.
This grim discovery in turn triggered a nationwide arsenic mitigation campaign. Heralded by international health officials, the new life-saving effort urged families to abandon shallow backyard tube wells and switch to distant arsenic-free sources of water. Sadly, this latest solution to a problem (caused by an earlier solution to a problem) caused yet another negative health complication as the collected water was not stored properly and became prone to contamination. Also, as these wells were distant, the time spent in collection increased fifteen-fold and so many resorted to surface water sources that were microbiologically contaminated. The outcome was an increase in diarrhoeal disease by 20%, spiking rates of child and infant mortality with no corresponding gains in adult life expectancy.
Envisioning water systems through the eyes of birds
The above litany should not discourage action, cause analysis paralysis, or lead us to assume that all well-intentioned efforts might make matters worse.
On the contrary, the water sector must, if anything, increase the pace and scope of our interventions. But to lower risks of unintended consequences, young and seasoned water professionals alike must step out of our comfort zone and learn to see water and sanitation through fresh perspectives. That is, we must grasp water through systems thinking, integrating decisions from three ‘bird’s-eye views’.
Start with the low-flying sparrow. Flitting about a few metres off the ground, our senses appreciate the details of each unique reservoir, pump, pipe, or tank. We see these components as part of an individual urban water system – clean water provision, wastewater treatment. The sparrow’s view is analogous to the veteran of certain IWA Specialist Groups: a global expert adding value through what she knows and does – water loss, membrane technology, sludge management – yet narrowly focused on close-up insights on the urban system.
With a wider wingspan, our range may expand into that of the albatross, recognisng the complexity, context and inter-dependence of utilities. Several of IWA’s programmes share the albatross’s vision. Water professionals in our Cities of the Future, Climate Smart Utilities, or Digital Water programmes embrace a broader perspective. They connect water utilities with other systems – public health, energy grids, carbon capture, resource recovery, ‘smart’ sensors, or machine learning.
Soaring higher on an updraft, our view shifts to that of an eagle. At this altitude, what we lose in sharp detail, we gain in system interconnectivity. We see the urban water system and related systems as part of an even larger and more complex basin, a hydro-ecological system to which each city belongs. As distilled under IWA’s Water-Wise Cities principles and Basin Action Agenda, this vision recognises how all the molecules that flow through urban pipes depend largely on water used for agriculture, industry, and the water flows needed for forest and landscape management.
What does this mean in practice, applied to the challenges above?
Systems thinking ensures that, for conservation, a sparrow’s close-up view of, say, physically efficient water use, is enriched by an albatross’s view of the impacts of low flows on the integrity of our sewers. The combined resulting watershed view reveals ways to get a wetter bang for each buck. A city’s $10 million spent on ‘cash for grass’ programmes or sprinkler timer rebates may conserve less than 5% of what it might gain from investing in agricultural water efficiency upstream.
It leads any approach to emissions beyond the sparrow’s immediate utility energy demand, to take into account the albatross’s network grid green energy potential and the eagle’s efforts to incentivise the watershed into a potential carbon sink.
For sanitation, it encourages a sparrow’s view of each flush to the albatross’s tracing faecal matter infiltration, and links these to an eagle’s perspective that basin-wide efforts to end open defecation would go beyond toilet inputs to ensure outcomes that protect groundwater.
In arsenic contamination in Bangladesh, systems analyses might lead an eagle’s view of both surface- and groundwater to inform a sparrow’s immediate focus on either embracing or (later) abandoning tube well technology, and explore an albatross’s view of slower but safer alternative systems for filtering water, increasing piped and pathogen-free water supply access households.
Above all, integrated ‘avian’ views drive home how water systems never exist in a vacuum, isolated from our own species. People are never merely passive consumers, recipients, or beneficiaries of water and sanitation. They are dynamic and essential stakeholders. Both as individuals or institutions, humans with agency respond to incentives. As IWA’s Basin Action Agenda reminds us, urban stakeholders want to secure water resources, protect water quality, and build resilience to extreme events. Proactively engaged and included in systems decision-making, their interests align with those of the water professional to ensure equitable and effective outcomes.
Systems thinking is never quick or easy. A paradigm shift in our approach to this wicked problem won’t happen on its own, or transform the water and sanitation sector overnight. But let us begin now. As retired mentors and young students alike, let us open our minds to explore alternative approaches. Expose our institutions to divergent views. Forge new linkages between disciplines so that our vexing decisions are informed by the behavioural psychologist, cultural anthropologist, resource economist and epidemiologist as they have been by the civil engineer or hydrogeologist.
Even as a student, I realised that water, left to its own devices, never moves in an orderly straight line. It is a fugitive and protean resource, ever moving and changing its form. As molecule, rivulet, or floodwater, water sinks down and diffuses out, evaporates up, and seeps through. It is an endless cycle of wonder, the ultimate complex system.
To work well with this magical resource, our thinking must follow its lead. •
Kala Vairavamoorthy is CEO of the International Water Association
See: Action Agenda for Basin-Connected Cities, https://iwa-network.org/projects/basin-action-agenda/
Principles for Water-Wise Cities, https://iwa-network.org/projects/water-wise-cities/
Climate Smart Utilities initiative, https://iwa-network.org/projects/climate-smart-water-utilities/
Digital Water Programme, https://iwa-network.org/programs/digital-water/