Cities and experimentation are central to water sustainability
Bolstered by the SDGs framework, cities must open themselves up to becoming laboratories for urban water-policy reform.
The age of water that is simultaneously cheap, abundant and clean is coming to an end.
While most of the world’s major cities were built where they could access stable water sources, overconsumption and climate change have darkened the urban water future. Rising sea levels and more-intense storms threaten both flooding and the contamination of drinking water on an even shorter timescale than expected due to land subsidence from pumping out too much groundwater.
Two global agreements in the past year do offer new collective strategies for dealing with these looming problems. The Paris Agreement finalized at the “COP 21” negotiations last December seeks to prevent the worst impacts of climate change by established commitments from countries to reduce their individual carbon emissions. In addition, the United Nations’ Sustainable Development Goals (SDGs) are designed to guide international anti-poverty and sustainability efforts over the next decade and a half.
The SDGs include 17 goals and 169 specific targets that could substantially improve prospects for global sustainability. Goal 6, for instance, aims to “ensure availability and sustainable management of water and sanitation for all”. In this, it expands upon the previous iteration of the SDGs, the Millennium Development Goals (MDGs), which oversaw significant progress in drinking-water access globally. The notable difference on this issue between the MDGs and the SDGs is a new focus on moving toward sustainable water use even as a greater portion of the population gains access.
Urbanization is correlated with higher rates of water use per capita. As such, cities will be especially impacted by Goal 6 in addition to Goal 11, which explicitly calls for more-sustainable urban spaces. The SDGs came into effect this year.
At the moment, however, we are not on track to meet the water-related SDGs. Demand for water has grown at twice the rate of population growth for more than a century. If consumption continues at current rates, demand will be 40 percent greater than sustainable supply by 2030, the end date for the SDGs.
Cities can improve this gloomy picture, but it will require a concerted effort by civic leaders to make urban zones more sustainable. Here are four specific areas where cities could make a major contribution to achieving global water-sustainability goals.
Policy, regulations and pricing
Ultimately, urban water sustainability means using less water. One way for cities to do this is through local regulations and water-rate structure changes that encourage greater efficiency.
“Utilities must be given the ability to run pilot programmes for improving reuse efficiency with the understanding that some experimentation will be required to develop the next systems.”
Even if every place everywhere were able to meet the SDGs and the national commitments of the Paris Agreement, scientists expect us to pass the 2 degree Celsius global average temperature rise that is likely to produce severe impacts from climate change. It is highly probable that implementation of these accords will be uneven, so it is incumbent on cities to take especially aggressive steps toward sustainability — to do even more than their national governments are asking them to do.
To this end, cities should set their own consumption standards at levels significantly more stringent than those required nationally to meet the SDGs. Leadership here is possible. For example, the water utility in the U. S. capital, DC Water, has partnered with the Water Environment Federation to create a local green-infrastructure-certification programme that credentials green-infrastructure specialists working in the city.
Cities might also raise the requirements for water efficiency in all new developments. How they do this will vary by city — some may change their building codes, while others could create new requirements for developments that get public funding. The worldwide success of “LEED” certification suggests that voluntary award-based certifications can be effective tools for change, as well.
With respect to water rates, cities should set them to more accurately reflect the value of this resource and to encourage better use patterns. Water rates typically aim to cover fixed infrastructure costs and maintenance, and are rarely used to influence consumer behaviour. But utilities should be able to save money through conservation by reducing treatment costs, energy consumption and system wear, and lowering the risk of sewer overflows.
At the same time, water can be priced too low. In such situations, conservation measures would prevent a utility from being able to cover its high fixed costs. This is a problem caused entirely by policy decisions about rate design.
Across the world, water rates are set without much concern about influencing demand. An OECD international survey of utilities found that less than half of them raise the price of a unit of water along with the volume of consumption. And some cities still price water in decreasing block rates in which units become get cheaper the more one uses.
While pricing water closer to its actual value is probably essential to more sustainable use over the long term, there are a number of regionally specific challenges to implementing it. Consumption, for instance, must be accurately metered, which requires technical investments in meters and people or technology to check them. It also requires convincing citizens to pay for marginal costs, such as higher rates aimed only to discourage capricious use.
Even if cities were to take on a greater role in meeting the SDGs related to water sustainability through regulation and pricing changes, national standards would still be necessary to ensure quality and equity. Ideally, central governments should set these regulatory baselines and a shared set of sustainability goals while freeing up cities to exceed them substantially in whatever ways citizens will be most likely to accept.
Waste as resource
Cities also will become more water efficient by reusing water and harvesting resources from wastewater. Large cities have a unique opportunity in the scale of the waste they produce — in the case of New York City, for instance, over a billion gallons a day. Traditionally, this wastewater is cleaned and released to surface water (rivers, lakes and seas), and the removed solids eventually end up in landfills. This is both a missed opportunity and an environmental problem.
“Cities hold the keys to meeting the water-related SDGs, as they are a pressure point. If those living in cities can be made to see water security as a shared civic responsibility, they will be more likely to take on the experimental task of urban water-policy reform.”
Utilities must be encouraged to move away from “linear” treatment systems into increasingly circular ones that encourage various forms of reuse. Some of the technology for wastewater reuse already is available. For example, solids removed from wastewater can be captured, sold and used as biogas to offset a treatment plant’s own energy use. This is being done by Chicago’s Metropolitan Water Reclamation District.
The practices that would make the biggest difference require serious effort by municipalities for implementation and change. It would be better, for example, not to purify water to drinking-water standards simply for use in toilets, industry and irrigation, or for cooling.
Making widespread reuse a reality also requires building expensive parallel piping and treatment systems. For instance, while we know that phosphorus, a limited resource, can be recaptured from waste to make fertilizer, it remains unclear whether this is economically feasible on a large scale.
At the moment, cutting-edge reuse schemes have shown up mainly where scarcity is a problem. Tel Aviv reuses 100 percent of its wastewater as irrigation. But real urban leadership must materialize in places where acute scarcity hasn’t yet forced the issue. Utilities must be given the ability to run pilot programmes for improving reuse efficiency with the understanding that some experimentation will be required to develop the next systems.
Some of the best opportunities for implementing reuse technology may be in the developing world, where heavy centralized infrastructure has yet to be built. Urban density creates waste density, and this larger scale holds the potential for making cost-effective waste-reuse schemes more possible.
Cities increasingly need to take a “systems” approach to water, seeing themselves as an influential node within the larger dynamics of a shared watershed that goes far beyond the city limits.
The goal should be to move away from heavy, expensive, centralized infrastructure and toward more diffuse “soft” infrastructure. This may include pricing changes and relying more on ecosystem services — for instance, protecting natural spaces that provide “services” such as water retention and natural filtering. It also means regulating consumption and replacing heavy infrastructure with physically diffuse methods of distribution and sanitation.
Most likely, centralized treatment always will be necessary. But cities can make such set-ups last longer and work better by making water that arrives at a plant easier to treat or by keeping it out of the treatment system entirely. Even so, systems could be expanded in increasingly modular ways that would allow for more dynamic management as conditions change, including as the impacts of climate change become clearer. Cities that share a watershed need to see themselves as connected parts of a larger water system and manage the resource accordingly.
This sort of change is difficult and would seem to require coordination that is out of the question when urbanization is fast and organic. Take, for example, Karachi, Pakistan, one of the world’s most water-stressed cities. The centralized system meets only half the need for the city’s 24 million inhabitants, and the population is steadily growing at 5 percent a year. Water provided by the centralized system is intermittent and frequently stolen by a “water mafia” that fills tankers from municipal pipes and then resells the water.
Meanwhile, a secondary private water-delivery system using now-pervasive smartphones has begun to provide an alternative to the centralized system. The way this is unfolding is not especially admirable, and it raises serious questions about equity and access for the poor. But it also hints at the possibility of better alternative provision models more tightly tied to consumer demand and less dependent on building (and defending) heavy, centralized infrastructure.
Build an ethos
Ultimately, cities that lead on water sustainability must convince residents that it is worth investing in. The timescale of climate change is slow, and responding to it effectively requires leaders who are willing to sink political capital into changes that they know will not return benefits while they are in office.
The improvements discussed above are potentially expensive, as well. Mayors must build institutions that support integrated urban water management and make it a compelling public achievement.
Rotterdam in the Netherlands currently leads the way by making water sustainability a basic principle in civic design and a very visible part of its governance choices. The Dutch have a long history of dealing with an overabundance of water in their cities, portions of which are below sea level. The city’s chief resilience officer is tasked with implementing a long-term climate adaptation strategy that aims to create a city with public spaces, industry and infrastructure that are prepared for significant climate impacts.
Now we need similar efforts by other cities. Indeed, without such effort even by those that don’t face immediate existential threats from climate change, it is doubtful that we will meet the water and urban sustainability aspects of the SDGs globally.
Novel experiments in waste recovery and high environmental standards must be made a matter of civic pride. For example, Windhoek, Namibia, has become a model for this kind of conversion. The city recycles 35 percent of its wastewater into potable drinking water and has insulated itself against the stress of persistent drought and a population that has doubled in the past 20 years. Initially sceptical citizens have come to see water recycling as a point of civic pride that has allowed the city to push its water-security efforts even further.
Political will remains the biggest obstacle to changes in urban water policy, both regulatory and technological. But cities hold the keys to meeting the water-related SDGs, as they are a pressure point. If those living in cities can be made to see water security as a shared civic responsibility rather than an entitlement that “someone else” takes care of, they will be more likely to take on the experimental task of urban water-policy reform.
At World Water Week in Stockholm this year, leading development experts were clear-eyed about these challenges. But as Henk Ovink, the Dutch special envoy for international water affairs, pleaded, “We must be ambitious and not wait for perfection to try new things.” If we require sure success before acting to meet the SDGs, civic leaders are unlikely to risk attempting it at all. Cities must open themselves up to becoming laboratories for sustainable development practices and lead the effort to build a resilient and increasingly resource stable environment.
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