Roma e l'acqua: proposte didattiche

Roma e l'acqua hanno un rapporto naturalmente intimo. Il biondo Tevere, gli acquedotti, le fontane maestose e i semplici "nasoni" sono la continua testimonianza di questo filo diretto che lega la città e i romani all'acqua.
Queste proposte didattiche aiutano a capire meglio questa relazione e insegnano a conoscere meglio l'acqua, fonte di vita.

Il materiale presente nel sito della Casa dell'architettura è la parte elaborata dall'Ordine di Roma all'interno di un progetto di educazione ambientale in seguito al Protocollo d'Intesa tra il MIUR Ministero dell'Istruzione, dell'Università e della ricerca (attuale Ministero dell'Istruzione), il CNAPPC (Consiglio Nazionale degli Architetti Paesaggisti Pianificatori) e gli Ordini Professionali delle provincie di Fermo, Napoli, Roma, Sciacca, Treviso e Varese.

Casa dell'architettura - proposte didattiche - acqua

Water demand will 'outstrip supply by 40% within 20 years' due to climate change and population growth

Water demand in many countries will exceed supply by 40 per cent within 20 years due to the combined threat of climate change and population growth, scientists have warned.
A new way of thinking about water is needed as looming shortages threaten communities, agriculture and industry, experts said.
In the next two decades, a third of humanity will have only half the water required to meet basic needs, said researchers.

Agriculture, which soaks up 71 per cent of water supplies, is also likely to suffer, affecting food production.

Filling the global water gap by supply measures alone would cost an estimated £124billion per year, a meeting in Canada was told.
But this could be cut to between £31billion and £37billion by an approach which both raised supply and lowered demand, according to leading water economist Dr Margaret Catley-Carlson.


Read more: www.dailymail.co.uk

Water, wisdom and Wasmo: a learning journey

Old women are contributing their lifelong savings: can there be any bigger proof of community participation?

by ANIL K GUPTA

I recently met a number of village community leaders and innovators who had achieved remarkable results in collaboration with the Water and Sanitation Management Organisation in Gujarat in dealing with the problems of drinking water and sanitation.

If through transparency, honesty and self-critical attitude, public officials can achieve so much in this programme, then lessons need to be learned so that other programmes can also benefit from similar processes. It is a pity that NREGA funds cannot be transferred to Wasmo for implementation: we could have avoided so much corruption and misuse and ensured much higher productivity through genuine community participation.

Let me recount some grassroots innovations which made us aware of the range of creative responses communities have shown in dealing with variable topographies, water level, pressure, distribution requirements and so on.

Where else will you see an old widow, Doodhiben in Bhavnagar district, contributing her lifelong savings for the creation of a common water supply facility, or another lady, Ambaben, donating for a similar purpose the amount she had saved for her last rites?management

When it was realised by some farmers that the guidelines provided for making a chamber for controlling water supply underground invariably lead to water collection which led to dirtiness and mosquito breeding, they decided to make a chamber above the ground. The programme managers did not have a problem with that. In another village, the source of water and the pump were eight km away from the village, and going there every time power came would have been tiresome. Why not use the mobile phone switch on/off system along with a status report on whether power was available or not, and if so in how many phases? The whole village could send an SMS to that water supply phone and get to know when the water would be supplied. All automatic.

We had a similar innovation in the National Innovation Foundation (NIF) database but this one was surely meeting local needs well and was developed by local people through their own ingenuity. In another place, the local community developed water supply points ensuring that every household in every locality got water at the same pressure. Even in this, to calibrate the pressure, they would keep a regulatory point which was sealed after testing it for 15 days. Nobody could change the pressure or add a water point or cheat the system. The additional cost of this system was over Rs 1 lakh, but the equity does not come cheap.

I wish various developmental programmes study the way people have decided to pay more amount (as much as Rs 600 per household per year or Rs 14 per capita per month in some villages) for water. Let us find out how much we pay in cities, how many housing societies deliver water at the same pressure to everybody.

There are many more innovative examples of water conservation, distribution and utilisation which we are studying to draw lessons for participatory development. It is not for nothing that the Rajasthan assembly speaker came along with MLAs and chief water supply engineers to study how Gujarat had done this miracle.

That also shows when best practices will be learned across party political lines, nothing will come in the way of overcoming the shame of this nation, which cannot provide safe drinking water to thousands of villages after so many years of independence. Gujarat will have solved this problem soon and for good.

But on the sanitation front, there is still a long way to go. While thousands of toilets have been built, there is still a need to persuade people to understand that microbial load in water in many places is very high because of contamination of catchments. We need to create a consciousness that every drop of water counts. Not one tap should leak, not one drop should drip. Every village community has to clean the catchments from where water drains into the water body before rains. And reverse osmosis (RO) water needs to be re-mineralised, otherwise there will be a major micro-nutrient crisis and public health problem.

GOVERNANCE NOW 28-2-2011

Saving the Bath Water Too

Would you water your garden with what goes down your shower drain or out your washing machine? In Tucson, Arizona, and an increasing number of water-starved western cities, more and more residents are saying yes.

If you've never contemplated what happens to the water that gets you or your clothes clean, you're far from alone. But for cities and environmentalists trying to head off the growing threat of drought and rising water costs, so-called graywater — differentiating it from the "black water" that goes down the toilet — is getting a lot more attention. A decade ago, Tucson, which has about a million residents in its metro area and is a liberal and environmentally conscious oasis in a red state, convinced Arizona legislators to make it legal for homeowners to irrigate their trees and plants with the water that was going down their drains or out of their washing machines without a permit. Now, graywater use is not only legal in Tucson, and indeed the rest of Arizona, but promoted, and, in some cases, required. In 2007, the state rolled out a tax credit of up to $1,000 for homeowners who install graywater systems. Last year, a law — believed to be the country's first — went into effect in Tucson that requires builders to include graywater plumbing in new construction.

"If there are higher stages of drought, there will be more watering restrictions," says Ilene Grossman, who is the city water department's conservation program manager. "We're not at the critical stage right now, but we are planning for that."

There's not good data on how close our nation's cities are to a water crisis, or how many people are using graywater. But the picture is this: Climate change, the cost of water treatment and rising populations will eventually, if nothing is done, run some US cities, particularly western ones, dry. Tucson, for instance, is already in what's called stage one drought, which means it's too dry but not yet critical. If a worse drought were to occur, there would be restrictions on gardening. Outside of desert areas like Tucson, there's issues of climate change and the cost of building sewage treatment plants to accommodate an expanding population. "It's crazy that we do so much to get water, and then it gets dumped down the drain," says Laura Allen, a founding member of Greywater Action, who set up her own Oakland, California home's graywater system illegally and has advocated for California's recent rule changes.

A number of city and state legislatures are coming to the same conclusion. Depending on the climate and the size of the yard, graywater reuse can lower a household's total consumption by as much as 40%. In November, Pacific Institute, which is an influencing water conservation research group, said that graywater reuse was an important strategy in improving a city's water resiliency against climate change. At a time of tight budgets, increased graywater usage could reduce the need for cities to spend money on costly new water supply projects. "It's almost at the tipping point where there are more states in the west that have graywater regulations than those that do," says Val Little, director of the Water Conservation Alliance for Southern Arizona (Water CASA).
Time 25-2-2011

For want of a drink

WHEN the word water appears in print these days, crisis is rarely far behind. Water, it is said, is the new oil: a resource long squandered, now growing expensive and soon to be overwhelmed by insatiable demand. Aquifers are falling, glaciers vanishing, reservoirs drying up and rivers no longer flowing to the sea. Climate change threatens to make the problems worse. Everyone must use less water if famine, pestilence and mass migration are not to sweep the globe. As it is, wars are about to break out between countries squabbling over dams and rivers. If the apocalypse is still a little way off, it is only because the four horsemen and their steeds have stopped to search for something to drink.

The language is often overblown, and the remedies sometimes ill conceived, but the basic message is not wrong. Water is indeed scarce in many places, and will grow scarcer. Bringing supply and demand into equilibrium will be painful, and political disputes may increase in number and intensify in their capacity to cause trouble. To carry on with present practices would indeed be to invite disaster.

Why? The difficulties start with the sheer number of people using the stuff. When, 60 years ago, the world’s population was about 2.5 billion, worries about water supply affected relatively few people. Both drought and hunger existed, as they have throughout history, but most people could be fed without irrigated farming. Then the green revolution, in an inspired combination of new crop breeds, fertilisers and water, made possible a huge rise in the population. The number of people on Earth rose to 6 billion in 2000, nearly 7 billion today, and is heading for 9 billion in 2050. The area under irrigation has doubled and the amount of water drawn for farming has tripled. The proportion of people living in countries chronically short of water, which stood at 8% (500m) at the turn of the 21st century, is set to rise to 45% (4 billion) by 2050. And already 1 billion people go to bed hungry each night, partly for lack of water to grow food.

People in temperate climates where the rain falls moderately all the year round may not realise how much water is needed for farming. In Britain, for example, farming takes only 3% of all water withdrawals. In the United States, by contrast, 41% goes for agriculture, almost all of it for irrigation. In China farming takes nearly 70%, and in India nearer 90%. For the world as a whole, agriculture accounts for almost 70%.

Farmers’ increasing demand for water is caused not only by the growing number of mouths to be fed but also by people’s desire for better-tasting, more interesting food. Unfortunately, it takes nearly twice as much water to grow a kilo of peanuts as a kilo of soyabeans, nearly four times as much to produce a kilo of beef as a kilo of chicken, and nearly five times as much to produce a glass of orange juice as a cup of tea. With 2 billion people around the world about to enter the middle class, the agricultural demands on water would increase even if the population stood still.

Industry, too, needs water. It takes about 22% of the world’s withdrawals. Domestic activities take the other 8%. Together, the demands of these two categories quadrupled in the second half of the 20th century, growing twice as fast as those of farming, and forecasters see nothing but further increases in demand on all fronts.


That’s your lot
Meeting that demand is a different task from meeting the demand for almost any other commodity. One reason is that the supply of water is finite. The world will have no more of it in 2025, or 2050, or when the cows come home, than it has today, or when it lapped at the sides of Noah’s ark. This is because the law of conservation of mass says, broadly, that however you use it, you cannot destroy the stuff. Neither can you readily make it. If some of it seems to come from the skies, that is because it has evaporated from the Earth’s surface, condensed and returned.

Most of this surface is sea, and the water below it—over 97% of the total on Earth—is salty. In principle the salt can be removed to increase the supply of fresh water, but at present desalination is expensive and uses lots of energy. Although costs have come down, no one expects it to provide wide-scale irrigation soon.

Of the 2½% of water that is not salty, about 70% is frozen, either at the poles, in glaciers or in permafrost. So all living things, except those in the sea, have about 0.75% of the total to survive on. Most of this available water is underground, in aquifers or similar formations. The rest is falling as rain, sitting in lakes and reservoirs or flowing in rivers where it is, with luck, replaced by rainfall and melting snow and ice. There is also, take note, water vapour in the atmosphere.

These geophysical facts affect the use of language in discussions about water, and the ways in which to think about the problems of scarcity. As Julia Bucknall, the World Bank’s water supremo, points out, demand and supply are economic concepts, which the matchmakers of the dismal science are constantly trying to bring into balance. In the context of water, though, supply is also a physical concept and its maximum is fixed.

Use is another awkward word. If your car runs out of petrol, you have used a tankful. The petrol has been broken down and will not soon be reconstituted. But if you drain a tank of water for your shower, have you used it? Yes, in a sense. But could it not be collected to invigorate the plants in your garden? And will some of it not then seep into the ground to refill an aquifer, or perhaps run into a river, from either of which someone else may draw it? This water has been used, but not in the sense of rendered incapable of further use. Water is not the new oil.

However, there are some “uses” that leave it unusable for anyone else. That is either when it evaporates, from fields, swimming pools, reservoirs or cooling towers, or when it transpires, in the photosynthetic process whereby water vapour passes from the leaves of growing plants into the atmosphere. These two processes, known in combination as evapotranspiration (ET), tend to be overlooked by water policymakers. Yet over 60% of all the rain and snow that hits the ground cannot be captured because it evaporates from the soil or transpires through plants. Like water that cannot be recovered for a specific use because it has run into the sea or perhaps a saline aquifer, water lost through ET is, at least until nature recycles it, well and truly used—or, in the language of the water world, “consumed”, ie, not returned to the system for possible reuse.

The problems caused by inexact terminology do not end here. Concepts like efficiency, productivity and saving attract woolly thinking. Chris Perry, an irrigation economist widely considered the high priest of water accounting, points out that “efficient” domestic systems involve virtually no escape of water through evaporation or irrecoverable seepage. “Efficient” irrigation, though, is often used to describe systems that result in 85% of the water disappearing in vapour. Similarly, water is not saved by merely using less of it for a purpose such as washing or irrigation; it is saved only if less is rendered irrecoverable.


Soaked, parched, poached
Many of these conceptual difficulties arise from other unusual aspects of water. It is a commodity whose value varies according to locality, purpose and circumstance. Take locality first. Water is not evenly distributed—just nine countries account for 60% of all available fresh supplies—and among them only Brazil, Canada, Colombia, Congo, Indonesia and Russia have an abundance. America is relatively well off, but China and India, with over a third of the world’s population between them, have less than 10% of its water.

Even within countries the variations may be huge. The average annual rainfall in India’s north-east is 110 times that in its western desert. And many places have plenty of water, or even far too much, at some times of year, but not nearly enough at others. Most of India’s crucial rain is brought by the summer monsoon, which falls, with luck, in just a few weeks between June and September. Flooding is routine, and may become more frequent and damaging with climate change.

Scarce or plentiful, water is above all local. It is heavy—one cubic metre weighs a tonne—so expensive to move. If you are trying to manage it, you must first divide your area of concern into drainage basins. Surface water—mostly rivers, lakes and reservoirs—will not flow from one basin into another without artificial diversion, and usually only with pumping. Within a basin, the water upstream may be useful for irrigation, industrial or domestic use. As it nears the sea, though, the opportunities diminish to the point where it has no uses except to sustain deltas, wetlands and the estuarial ecology, and to carry silt out to sea.
These should not be overlooked. If rivers do not flow, nothing can live in them. Over a fifth of the world’s freshwater fish species of a century ago are now endangered or extinct. Half the world’s wetlands have also disappeared over the past 100 years. The point is, though, that even within a basin water is more valuable in some places than in others.

Almost anywhere arid, the water underground, once largely ignored, has come to be seen as especially valuable as the demands of farmers have outgrown their supplies of rain and surface water. Groundwater has come to the rescue, and for a while it seemed a miraculous solution: drill a borehole, pump the stuff up from below and in due course it will be replaced. In some places it is indeed replenished quite quickly if rain or surface water is available and the geological and soil conditions are favourable. In many places, however, from the United States to India and China, the quantities being withdrawn exceed the annual recharge. This is serious for millions of people not just in the country but also in many of the world’s biggest cities, which often depend on aquifers for their drinking water.

The 20m inhabitants of Mexico City and its surrounding area, for example, draw over 70% of their water from an aquifer that will run dry, at current extraction rates, within 200 years, maybe much sooner. Already the city is sinking as a result. In Bangkok, Buenos Aires and Jakarta, the aquifers are similarly overdrawn, polluted or contaminated by salt. Just as serious is the depletion of the aquifers on which farmers depend. In the Hai river basin in China, for example, deep-groundwater tables have dropped by up to 90 metres.

Part of the beauty of the borehole is that it requires no elaborate apparatus; a single farmer may be able to sink his own tubewell and start pumping. That is why India and China are now perforated with millions of irrigation wells, each drawing on a common resource. Sometimes this resource will be huge: the High Plains aquifer, for example, covers 450,000 square kilometres below eight American states and the Guaraní aquifer extends across 1.2m square kilometres below parts of Argentina, Brazil, Paraguay and Uruguay. But even big aquifers are not immune to the laws of physics. Parts of the High Plains are seriously overdrawn. In the United States, China and many other places, farmers probably have to pay something for the right to draw groundwater. But almost nowhere will the price reflect scarcity, and often there is no charge at all and no one measures how much water is being taken.


Liquid asset or human right?
Priced or not, water is certainly valued, and that value depends on the use to which it is harnessed. Water is used not just to grow food but to make every kind of product, from microchips to steel girders. The largest industrial purpose to which it is put is cooling in thermal power generation, but it is also used in drilling for and extracting oil, the making of petroleum products and ethanol, and the production of hydro-electricity. Some of the processes involved, such as hydro power generation, consume little water (after driving the turbines, most is returned to the river), but some, such as the techniques used to extract oil from sands, are big consumers.

Industrial use takes about 60% of water in rich countries and 10% in the rest. The difference in domestic use is much smaller, 11% and 8% respectively. Some of the variation is explained by capacious baths, power showers and flush lavatories in the rich world. All humans, however, need a basic minimum of two litres of water in food or drink each day, and for this there is no substitute. No one survived in the ruins of Port-au-Prince for more than a few days after January’s earthquake unless they had access to some water-based food or drink. That is why many people in poor and arid countries—usually women or children—set off early each morning to trudge to the nearest well and return five or six hours later burdened with precious supplies. That is why many people believe water to be a human right, a necessity more basic than bread or a roof over the head.

From this much follows. One consequence is a widespread belief that no one should have to pay for water. The Byzantine emperor Justinian declared in the sixth century that “by natural law” air, running water, the sea and seashore were “common to all”. Many Indians agree, seeing groundwater in particular as a “democratic resource”. In Africa it is said that “even the jackal deserves to drink”.

A second consequence is that water often has a sacred or mystical quality that is invested in deities like Gong Gong and Osiris and rivers like the Jordan and the Ganges. Throughout history, man’s dependence on water has made him live near it or organise access to it. Water is in his body—it makes up about 60%—and in his soul. It has provided not just life and food but a means of transport, a way of keeping clean, a mechanism for removing sewage, a home for fish and other animals, a medium with which to cook, in which to swim, on which to skate and sail, a thing of beauty to provide inspiration, to gaze upon and to enjoy. No wonder a commodity with so many qualities, uses and associations has proved so difficult to organise.

The Economist 20-5-2010

Mineracqua, quando la pubblicità è ingannevole

C’ha provato, Mineracqua, ma è stata colta in fallo. Se non vedete più su quotidiani e periodici la pubblicità istituzionale della federazione nazionale delle aziende che imbottigliano e vendono acqua minerale, infatti, non è perché sono finiti i soldi.
È stato il Giurì di autodisciplina pubblicitaria (www.iap.it) a “bocciare”, giudicandolo ingannevole, il contenuto dello spot, il cui claim era “Acqua minerale. Molto più che potabile” e il cui messaggio era una (presunta) comparazione tra le caratteristiche delle acque minerali e di quella erogata dagli acquedotti (vedi Ae 121). Una comparazione a senso unico.
Ettore Fortuna, presidente di Mineracqua, intervistato a metà gennaio da Radio 24 in merito alla decisione del Giurì ha spiegato come, a suo avviso, si trattasse di “una decisione politica e non tecnico-giuridica”.
Altreconomia ha potuto visionare in anteprima la pronuncia del Giurì (la decisione è stata presa a fine novembre 2010, ma la sentenza non è stata ancora pubblicata), un testo che smonta la “tesi” di Fortuna e fornisce spunti di riflessione in merito al rapporto tra diritto a una corretta informazione e informazione commerciale.
Il Giurì, infatti, ha scelto di trattare (e sanzionare) il messaggio pubblicitario tanto nel merito quanto sul metodo. Da un lato scrive che “i quattro aspetti che il messaggio evidenzia quali caratteristiche che accrediterebbero alle acque minerali un grado di sicurezza per i consumatori maggiore rispetto a quello della cosiddetta acqua di rubinetto -sintetizzati dai titoli 'senza cloro', 'senza deroghe', 'senza trasformazioni' e 'senza paragoni'- risultano trattati con una impostazione non corretta, idonea ad ingenerare nel pubblico convinzioni errate e timori non giustificati circa una tendenziale insicurezza delle acque potabili, in particolare per la salute dei fruitori”. In particolare, l'affermazione secondo la quale l'acqua minerale è “solo” bevibile -scrive il Giurì- “ha in sé una valenza spregiativa non giustificabile”.
Poiché la pubblicità si chiude con la frase “Da un'informazione trasparente nascono scelte libere”, il Giurì ha ritenuto opportuno censurare anche il metodo utilizzato da Mineracqua, secondo la quale la pubblicità era una forma di contro informazione necessaria per pareggiare il conto con le campagne che, come la nostra “Imbrocchiamola!”, “hanno promosso verso i cittadini il consumo di acqua potabile a discapito della minerale imbottigliata”. “L'annuncio, che promette oltretutto una 'informazione trasparente', quasi a sottolineare una carenza di corretta informazione che circonderebbe e proteggerebbe il mondo delle acque di rubinetto, fa così leva sulla enunciazione di dati parziali, o di suggestione, per pervenire al risultato di una comunicazione tendenziosa che getta ombre di potenziale insicurezza, o comunque discredito, sull'acqua erogata dagli acquedotti” spiega il Giurì.
Mineracqua esce così con le ossa rotte dal primo tentativo di pubblicità istituzionale. Ettore Fortuna, cui la bocciatura ha senz'altro dato fastidio, nell'intervista con Radio 24 aveva fatto intendere anche che l’azione presso il comitato di controllo sia stata promossa da alcuni enti locali, con riferimento in particolare al Comune di Milano. Niente di più sbagliato, anche in questo caso: Vincenzo Guggino, segretario generale dell’Istituto di autodisciplina pubblicitaria (Iap), ci ha spiegato che “l’istanza è un’iniziativa autonoma del Giurì. La materia -ha continuato- è d’interesse perché la pubblicità mette in discussione la qualità dell’acqua di rubinetto. Il comitato di controllo, che istruisce l’istanza, è una sorta di pm; il Giurì, organo giudicante, è un giudice terzo”. Guggino ha definito “bizzarro” l’atteggiamento di Fortuna, visto che in passato “le associate a Mineracqua in più occasioni hanno usato il Giurì per ‘guerre commerciali’”. Non oggi però, e l’attività e i giudizi dell’Istituto vanno delegittimati.

Sintesi della decisione del Giurì

Altreconomi: Mineracqua, quando la pubblicità è ingannevole

be water my friend