Evolution of Hydro-Technologies and Relevant Associations Focusing on Hellenic World

Abstract

Hydro-technologies, and especially the need for developing drinking water treatments, have been known since the ancient times. Water supply treatment devices were developed even during prehistoric times but were especially improved during the Classical and Hellenistic periods. Nevertheless, after several centuries, particularly during the last two, intensive and effective efforts have been made all over the world to obtain sufficient amounts of water with the necessary quality to improve the quality of life and health of humankind. As a result, life expectancy has globally increased at unprecedented rates, especially in the developed world. This paper represents an effort to study the relationship between water history, the development of water-related technologies, and the health and quality of ecosystems, especially those affecting human beings. Thus, it should be pointed out that: The history of water is equivalent to the history of the world, and the history of water quality is equivalent to the history of quality of life (Andreas N. Angelakis).

1. Prolegomena

By studying ancient civilizations, we study ourselves and learn from the past about the present and the future.

Andreas N. Angelakis

“Currently, roughly half of the world’s populations are experiencing severe water scarcity for at least 1 month yr⁻¹ due to climate and other factors (medium confidence). Water insecurity is manifested through climate-induced water scarcity and hazard and is further exacerbated by inadequate water governance (high confidence). Extreme events and underlying vulnerabilities have intensified the social impacts of droughts and floods, negatively impacted agriculture and energy production and increased the incidence of water-borne diseases (high confidence)” [1]. The trend is negative, so humanity, and especially professionals in water-related fields, must find sustainable solutions to mitigate the current and future consequences. In the current challenging times, it is opportune to look into the past and study how past generations dealt with similar problems, and whether experiences and practices from the past can help us alleviate today’s problems. Among other things, this is the reason for writing this paper. By comprehensively assessing the knowledge and technologies of the past and present times, prerequisites are created for the creation and implementation of sustainable solutions in the current and future bio-geophysical and socio-economic environments.

In prehistoric times, theocracy was dominant, even in the development of water technologies. During the Minoan times (ca. 3200–1100 BC), in the first European civilization, matriarchy was dominant. An astonishing paradox about this civilization was present: A great power without a military aristocracy; a “palace” that was not a royal residence and neither the King was glorified; a religion with no greatness, while women were equal to men and free [2]. Additionally, at this time, the first water technologies were developed. During the historical times (ca. 750 BC–476 AD), prehistoric hydro-technologies were improved, and the philosophy and sciences appeared.

Thus, this review paper is organized as follows: Section 1 called Prolegomena is an introduction on the water history. Following this, Section 2 discusses the history of water hydro-technology and its relevance to modern times, in which three sub-sections on water quality, history of the IWA (International Water Association, London, UK), and the history of water from the Joint IWA/IWHA (International Water History Association)-SG Specialist Group) are included. Finally, Section 3 is the epilogue that includes, in brief, results and conclusions.

In archaic times, Thales of Miletus (ca. 624–546 BC), the founder of the first Ionian School of Philosophy and Sciences, formulated the “Arche” theory during the sixth century BC, which establishes that “Water is the principle of all things”. Thereafter, Anaximander (ca. 610–547 BC) was the first of the known Greeks to publish a written document “On Nature”, which was unfortunately lost. He understood the relationship between rainfall and evaporation by reporting that “Rain is produced by the evaporation (vapor) that is sent upwards from the earth due to the sun” [3].

Pythagoras of Samos (ca. 570–495 BC), an Ionian philosopher of numbers and mathematics, was one of the most famous student of Thales and the founder of Pythagoreanism. When Pythagoras arrived as an exile in Croton, southern Italy, his talks were so impressive that people from neighboring regions flocked in order to hear his teachings. It is said that his first public speech was attended by over 2000 people. Fascinated by his talks, those first listeners decided not to return to their homes and, together with their wives and children, stayed with him. They built a large teaching house, which was named Omakoeion [4]. Many prominent students at Pythagoras’ school were women, and some modern scholars think that he may have believed that women also should be taught philosophy [5]. His philosophical and religious teachings were well known in Magna Graecia (Megalē Hellas) and have influenced the teachings of Plato (ca. 427–347 BC), Aristotle (384–328 BC), and, of course, western philosophy [6]. Some written material of Pythagoreans was later delivered to Dion of Syracuse (408–354 BC), a student of Plato, resulting in the fruitful continuation of Pythagoreanism at the Academy of Plato.

Later on, in Athens, Greece, many hydro-technologies were transferred to the Walking School of Aristotle, whose ideas and practices were influenced by the Ionian philosophers who correctly formulated the hydrological cycle. Aristotle understood the phase changes of water and the energy exchange required for it, and he stated: “…. the sun causes the humidity to rise; this is similar to what happens when water heats up in a fire…” (Meteorologica, II.2, 355a 15).

Alexandria (in present-day Egypt) was a great place of culture and the home of Greek philosophy. This began with Alexander the Great (356–323 BC), who, after having conquered Egypt, founded more than twenty cities, with the most prominent being the city of Alexandria, which was built by Ptolemy Lagus (ca. 367–282 BC), who is considered its founding father. This town was the junction point of three continents. Additionally, it became a battlefield, where the religions of the East met with the philosophical ideas of the West, and where both were represented by their most skilled champions [7]. With this, all the prerequisites for a more complete analysis and interpretation of the water issue have been achieved, which has led to an emphasis on the importance of water for humans and the development of water technology.

Thereafter, the Greek geographer Pausanias (ca. 110–180 AD) declared that a city has no right to call itself a city if it does not have a large fountain at its center. Then, sources illustrated the idea of the prevalence of civilization over nature; in other words, that water, and especially its history, is life. The fountain symbolizes a real physiological and direct material fact, i.e., no city or country has been able to exist or develop without a sufficient quantity of good quality water to meet the demands of human society.

Roman writers Pliny the Elder (Naturalis Historia) [8] and Vitruvius (The Ten Books on Architecture) [9] have stated similarly: “Finally, water, not merely supplying drink but filling an infinite number of practical needs, does us services which make us grateful because it is gratis” (Vitruvius, Book VIII). This social fact in the natural universe makes water history very relevant to world history [10].

The history of hydro-technology is analyzed in relation to modern times as well as the historical relationship of water quality and quantity to life expectancy. Vitruvius (Book VIII) stated that “For it is obvious that nothing in the world is so necessary for use as water, seeing that any living creature can, if deprived of grain or fruit or meat or fish, or any one of them, support life by using other foodstuffs; but without water no animal nor any proper food can be produced, kept in good condition, or prepared. Consequently, we must take great care and pains in searching for springs and selecting them, keeping in view the health of mankind” [8]. This clearly emphasizes the importance of water quality for the livelihood of man, and that the issue of water pollution has become an important topic in water technology development.

Thereafter, little progress was made in water treatment and sanitation, and their connection to the public health field weakened. During the medieval period (ca. 476–1400 AD), also known as the Dark Ages, technological development, especially that related to water quality, was minimal due to the lack of scientific innovations and experiences [11]. It was a period in which the spiritual–religious paradigm was important, even more so than the hydraulic engineering paradigm. Rivers and wells were used as water supplies, which became highly polluted due to the discharge of wastes and others toxic substances. To face this problem, people started to bring water from unpolluted rivers located outside the cities. The Ottoman period (ca. 1400–1850 AD) was more or less a continuation of medieval times; however, the hydraulic engineering paradigm began gaining ground with spread of Islamic water technology and had become predominant paradigm in the industrial age.

Already in the 20th century and shortly before the end of the First World War, the application of chlorine highly improved the water quality as well as the life expectancy. It was a period when the scientific paradigm was developing. The relationship between water and disease was recognized. Thus, the relationship of water history to world history was further enhanced. Based on this, we must study the evolution of water resources issues, from prehistoric times to the present and through to the future, using several examples, such as the one from Angelakis et al. [12].

In addition, the contributions of the IWA and IWA/IWHA-SG on water history are considered. The economic and social development of society and the sustainability of livelihoods have always been closely related to the sustainability and quality of three basic resources: water, food, and energy. Water is known as the foundation of life, societies, and economies. Society and water professions have been adapting constantly to changes, especially those that tend to have a long-term horizon and, subsequently, long-term variability. In recent centuries, the world has become globalized and integrated, which also applies to water-related professions. Globalization brings both positive and negative consequences for environmental safety and the sustainability of livelihoods, including water and water infrastructures. Global challenges require global answers and collaborative actions, which can only be successfully realized through global associations such as IWA. As water-related problems are essentially not new, the answers to these challenges should also not be new. It is appropriate to study the historical experiences, where water professionals draw lessons from the past and adapt them in a new socio-economic, natural, and technological framework. This is the role of the IWA/IWHA-SG on water history.

A good example of this is the use of the term “one water” as a holistic approach in water management. History teaches us that all water has a value, especially in water-poor environments. That is why the benefit of every drop of water should be maximized within the water system, either natural or built. This is how water poverty has been studied throughout history, so there is no reason why we should not act in accordance with the same principles today.

In addition, the “one water” concept should be considered for sustainable water resource management to effectively face the future challenges; especially, megacities should practice the “one water” concept. For example, the possibility of establishing criteria for water use categories that are independent of the water source or origin should be considered. In this way, the “one water” concept has been proposed by Angelakis et al. [12] to be used in historical contexts.

2. History of Hydro-Technologies through the Millennia

A lot of hydro-technologies (aqueducts, qanats, cisterns and reservoirs, siphons, pipes, fountains, baths, toilets, sewers, drains, water mills, etc.) have been developed since prehistoric times and have been in use for millennia [13]. Most of these techniques remain a suitable model for present and future applications in enhancing the sustainability of water services [14].

Looking back through the long past of human dwellings, some principles on which hydro-technologies have been based can clearly be outlined; Notably, they are the very same ones used in many present applications (e.g., qanats and wells). The history of water technologies is strongly linked to current water management and policy issues as well as their future implications. Different ancient civilizations solved their water problems in similar ways and constantly improved solutions using new materials and technologies based on natural forces and organic material (fossil or biomass). The growing energy need of water systems is a major driver of technological development and innovation. The water–energy nexus played a vital role in the development of urban regions in the past and will also play a vital role in present and future demands. The existential importance of water has always been encouraging the cooperation of experts among different generations and civilizations.

The hydro-technical parallels between some civilizations, e.g., Minoan and Indus Valley ones, suggests that civilizations may have indeed had significant contact with each other [15]. Today, we continue to cooperate and develop on such items through international organizations, such as IWA. This synopsis of advanced sanitation systems of ancient civilizations, including their long durability and sustainability should be concluded with the following statement of H. Gray (1940) [16]: “We frequently hear people speak of modern hygiene as if it something rather recently developed, and there appears to be a prevalent idea that municipal sewerage is a very modern thing that began some time about the middle of the (19th) century. Perhaps these ideas do something to support a somewhat wobbly pride of the modern civilization […], but when examined in the light of history that is far from new or recent. Indeed, in the light of history, it is surprising, if not bitterness, the fact that man has gone so poorly, if at all, in about 4000 years […]. Archaeologists researchers this [Minoan and Indus valley civilizations] space give us the image that people have come a long way towards a comfortable and hygienic living, with a considerable degree of beauty and luxury […]. And this was about 4000 years ago.”

Similarly, Angelo Mosso [17], an Italian writer who visited the Phaistos’ Minoan palace in the island of Crete, Greece in the early 20th century, noticed during a very heavy rain the still perfect functionality of their drainage system, and commented: “I doubt if there is another case of a stormwater drainage system that works 4000 years after its construction.”

When putting in perspective management principles and practices of ancient societies, it is significant to examine their relation to present times and to harvest some lessons learned which may be useful in the future. From here on, the relevance of ancient works will be examined in terms of technological advances, evolution of technology, design aspects, and management principles:

(a) Technological advances. The comparison of hydraulic technologies in ancient times to those in present times must be examined. Certainly, many modern advances were not known in antiquity, for example, the use of plastic and concrete pipes, pumps, and the automated pressurized water distribution systems, as well as effective mechanical, electric, and electronic functional equipment for building hydraulic projects. Nevertheless, few differences in mechanical devices are mentioned related to the scale of applications, but not in their fundamental principles. However, an environmental framework is the basis to any analysis on the energy-related environmental impact of human water demand on such technology. In the old cities, water movement was dependent on the available potential energy when water is abstracted (from natural sources or man-made sources) and the resistance of equipment (pipes) to internal water pressure determines the area that can be supplied in the city.

Even the modern lifestyle, in relation to the hygienic criteria of a society, may not be a recent consideration [18]. For example, underground hydraulic technologies, e.g. qanats in the Middle East, have been used as both a water supply and as irrigation until today. A qanat is a system for transporting groundwater from an aquifer to the surface, through underground channels. Numerous qanats have been constructed in Iran, Iraq, and many other societies of the world. In this way, water is transported over long distances in hot dry climates without evaporation losses, while maintaining water quality. The system has the advantage of being resistant to natural disasters such as floods, and to deliberate destruction from war actions. Furthermore, the technology is almost insensitive to the levels of short-term precipitation patterns, delivering a flow with only few gradual variations throughout the year [19]. When built, the minimum supply capacity must always be higher than the peak demand. It is a natural concept of balancing water supply and demand.

In addition, drainage and sewage systems and flushing toilets, with seats similar to the current ones, already existed since Minoan times, and in some cases have been in operation for millennia [13]. The current essential progress is the understanding and improvement of hydraulic works, which allows for better design, construction, an increase in the scale of applications, and its management.

(b) Consideration of philosophy and sustainability. Today, engineers typically employ a useful life span of about 40 to 50 years for hydraulic infrastructures. This is related to the standard service life of, e.g., a pipe and to economic considerations corresponding to the life cycle cost (LCC). Sustainability, as a design principle, has adapted the engineering lexicon very recently. Life cycle thinking (LCT) has been introduced as a systematic framework, that implies a holistic view of the service and its impacts, to assist decision-makers in that will benefit the environment. In modern times, it is difficult to infer the design principles which were developed in ancient times; however, it should be noticed, as mentioned before, that it is worth to point out that several ancient infrastructures have been operating for very long periods up until contemporary times [18]. With the present standards, ancient water systems can be considered “green” in every aspect, and one of their consequences is that they have a very long lifespan. For example, in the city of Athens, in order to face the serious problem of water supply in the sixth century BC, a large public infrastructure was built under the tyranny of Peisistratos and later on of his sons: the well-known Peisistratean aqueduct. It was used to supply water to the city of Athens for centuries up until the 20th century, and it is still in operation for the irrigation of the National Garden in the center of the city. Additionally, during the Roman domination period, at the beginning of the second century AD, the Hadrian’s aqueduct was built and used to supply water to the city up until the 1920s and to the National Garden until the 1950s. The city of Athens, in terms of water, can be considered as a unique example of a sustainable city, with its history extending for more than 3000 years [18].

Similarly, some other ancient technologies (e.g., underground aqueducts and cisterns) have gravity flow, are also environmentally friendly, and have been and are still used in regions facing water scarcity. Apart from those already mentioned, one of the major social advantages of underground aqueducts is their equity, for which multiple stakeholders are being sustainably served by existing nearly unmodified ecosystems instead of being supported by hard urban infrastructure proposals [20]. Therefore, considering the present global climatic variability and inequity to access water resources resulting in a water crisis, ancient underground aqueducts and particularly qanats should be considered and viewed as lessons to be learnt about how to find successful solutions for sustainability and resiliency of water management in the present and future times [20]. Most of the ancient underground aqueducts (i.e., qanats) are not only physical monuments, but also represent social lifestyle and cultural criteria, which have emitted a serious message to the future generations.

(c) The evolution of technology. The development of water science, technology, and practice does not appear to have been linear, but it is often characterized by discontinuities and regressions. Minoans have built connections with neighboring civilizations such as the Mycenaean, Egyptian, and Etruscan civilizations [21]. Additionally, several civilizations established links between the past and the present, which significantly influenced the development of water technologies. A clear example is evident in the Classical Greek and Roman periods, and this is an important part of Europe’s past. It should be noted that a lot of very old facilities have been in operation continuously or intermittently, up to the present. A lot of information from ancient civilizations has survived, including written contracts with details between public administrations and hydraulic constructors [22], which helps to establish these links.

(d) Management principles. The present water supply system in the city of Athens is showing an admirable balance between: (i) institutional measures relevant to structural and nonstructural data; (ii) small- and large-scale underground hydraulic structures, e.g., wells and cisterns; and (iii) the interest of the private sector in small-scale works, and that of the public sector in large-scale works [18]. This third balance is apparently operating at the same time with the ultimate purpose of balancing private and public interest in the construction and operation of wells. A similar practice was also implemented in Roman water supply systems, where water from the public fountains in the city area was free of charge and constantly available for residents, while use within private homes and businesses had to be paid for depending on the quantity [22].

Private property, legal framework, and local constraints had to be respected in the construction of the Roman water supply systems (WSS). The water rights of citizens had to be respected, and water resources had to be allocated according to need. To avoid this problem and reduce costs, the system sought to build on public/state property instead of on private property. When it was inevitable, the state would purchase the private property or would arrange compensation. It was thought that there was an ancient right to use land that was once public but later privatized for the good of the state. A similar procedure is carried out today.

However, once the system was built, the property and protective land corridor, which covered 15 feet on each side of the springs, arches, and walls, and along the subterranean conduits and channels, become public property and were protected so as not to damage the conduits or restrict block maintenance access (Frontinous, 1899, pp. 126 to 128) [23]. Public interest is always the most important factor, especially in the case of drinking water supplies which was legally regulated (Frontinous, 1899, p. 129) [23]. Namely, asset management is a long-term commitment crucial for quality of life, livelihood and sustainability of the city. Roman law and practice cited by Frontinous primarily relates to the water management in the City of Rome but also applies to other cities of the Empire in accordance with the local configuration on water rights and management. Similar approaches and solutions are often sought in modern times all over the world, as neither the private nor the public sector alone can provide sustainable water supply and management.

Today, global challenges of growing urbanization, climate change adaptation, as well as the increasing water scarcity are driving the need for an integrated urban water management (IUWM) system as a prerequisite for successful implementation of resources recovery (water, nutrient, and energy). It is an approach that includes interventions in the entire integrated urban water cycle, reconsideration of how water is used (and reused) and provide water fit for every purpose, diversity of water sources, innovation in urban water technologies, maximization of the benefits obtained from wastewater, and greater application of natural systems for water and wastewater treatment. All this provides an alternative to the conventional approach for an effective and efficient management of scarce water resources. The global shortage of drinking water requires the application of new technologies, large investments and enormous inputs and efforts. Transformation technologies (transport, wastewater processing, water purification, system operation, water saving, etc.) have led to change in water-management paradigms. Today, sustainability paradigms are dominating (social, legal–ethical, economic–financial, ecological, and managerial). This hastened the emergence and development of scientific paradigms (empirical, theoretical, computational, and data-driven) and managerial– governance paradigms (establishment of national and international institutions, integrated water-basin management plans, international water laws, etc.). The extent to which this approach has been used in the past is difficult to assess; nevertheless, the basic goal is the same as today: to ensure healthy living conditions in cities. A good example of ancient management practices is described in the two books of De aquis urbis Romae (Concerning the Waters of the City of Rome) that presents a history and description of the water supply of Rome, including the laws relating to its use and maintenance of infrastructures and other matters of importance in the history of urban water system management [23].

2.1. Water Quality Trough the History

A brief historical overview of the evolution of public water supplies and water treatment technologies over the centuries from the Hellenic world to modern times is presented. The most significant innovations in the abstraction, purification and distribution of water in the Hellenic world are listed in a paper from Angelakis (2020b), although, in this paper, emphasis is placed more on the application of drinking water disinfection and the impact of water quality on life expectancy in the 20th century [24,25]. It is also highlighted that the hygienic aspects were decisive for water supplies in the ancient world to prevent the infection and spreading of diseases and epidemics. The ancient Greeks also built wastewater systems to collect and transport sewage out of the towns and away from humans since the prehistoric times. For example, Minoans developed sedimentation tanks, sand filtration, and ceramic filters to purify water since the prehistoric times (Figure 1).

In contrast to prehistoric times, in Archaic and Classical Greece (ca. 750–323 BC), more than 400 Asclepieia (curative temples) were established, operating, and offering their medical services, in which improving water quality was included. Ancient Greeks were among the first to understand and gain an interest in water quality [3]. At that time, Hippocrates, who is considered the father of medicine and is one of the most famous physicians in the whole of history, invented and used the first water-filtering system. It had the form of a cloth bag, known today as the Hippocrates’ sleeve, and was built around 500 BC (Figure 2).

In addition, Hippocrates attributed the appearance of some diseases, or even the weakness of some people to bad water quality. This might have meant one or more of characteristics of water such as salinity, bitterness, nitrites, sulfites, ferrous iron, acidic, or polluted rainwater may damage human cells or irritate the skin [3]. In his aforementioned Book VIII, Vitruvius (80–15 BC), a Roman architect and engineer, described the characteristics of good water, among other things. Water also appears in Chapter IV in the Book “Tests of good water,” and in Chapter III he states: “Various properties of different waters pointing out effects of different waters on human health” [9]. Later on, the link between water quality and health, and of course disinfection technology, was recovered only at the beginning of the 20th century. Additionally, the mechanism of elimination of the causative agent was known only recently in the 19th century.

As it was also mentioned before, in the period after the Roman Empire, from 476 to 1400 AD, there were scarce developments in the field of water treatment. It took a long time before the ancient practice of water treatment began to be applied again; the knowledge was disregarded and forgotten, so in the Middle Ages, water quality and pollution prevention were given no importance, as the belief in the divine influence dominated once again over technological capacities. The consequences are well known: an increase in the number of outbreaks of waterborne diseases, such as cholera and typhoid.

After a long time, the first use of multiple filters was developed in Italy in 1685. Years later, in 1746, the French scientist Joseph Amy received the first patent for a filter design. Sometime after these inventions, the concept of a water treatment plant with settling basins and filters became standard practice in the water treatment for drinking water supplies in 1804 in Scotland, 1806 in Paris, and 1827 in England [26].

The need to purify raw water before supplying it to the population, and the importance of proper sanitation was not very well understood or taken seriously until the 19th century. Then, the importance of sanitation and healthy drinking water began to be comprehensively looked at and solved, and there was a significant development of water technologies, especially in relation to drinking water quality and pollution prevention. At the beginning of the 19th century the drinking water quality and water pollution control management were gradually improved.

In the same century, the effect of disinfectants, such as chlorine, on the inactivation of harmful microorganisms which can cause illnesses, was discovered. In the United States, in 1908, the disinfection of water for urban supply started in Jersey City. Over the next decade, numerous cities and towns in the United States began disinfecting their drinking water supply, contributing to a drastic decrease in the number of diseases across the country (Figure 3).

Chemicals other than chlorine were used for disinfection; in 1902, calcium hypochlorite, and in 1906, ozone were applied for the first time. The regulations on drinking water quality started in 1914 in the USA, when the US Public Health Service set standards for the bacteriological quality of drinking water [27]. In the year 1940, drinking water standards were applied to all municipal drinking water supplies in the USA as well as in other developed countries more or less at the same time.

During the last two centuries, great efforts have been made towards providing communities, mainly in the developed world, with water of much better quality, which led to an increase in human life expectancy (Figure 4). This is considered to be due to a decrease in childhood mortality and infectious diseases, with chronic diseases such as cardiovascular and neoplastic diseases gradually becoming dominant [28].

Figure 3. Rate of deaths/100,000 inhabitants and year in the USA due to water related infectious diseases in the period from 1900 to 1996 (with permission of Angelakis et al., 2021 [29], https://doi.org/10.3390/w13060752).

Figure 3. Rate of deaths/100,000 inhabitants and year in the USA due to water related infectious diseases in the period from 1900 to 1996 (with permission of Angelakis et al., 2021 [29], https://doi.org/10.3390/w13060752).

As an example, available historical data in England and Wales did show a great increase in life expectancy, from 40 years for males and 42 for females in 1851, to 59 and 63, respectively, in 1930. The changes occurred in the period before the discovery and use of antibiotics, and should be attributed to other factors, among them is health-safe drinking water [30]. During these times, several infectious diseases (e.g., pneumonia, tuberculosis, meningitis, and others) still contributed to most of the years of life lost, thus shortening life expectancy at birth.

Kramek and Loh (2007) [31] reported a prominent example of the water treatment impact. In Philadelphia, USA, due to water pollution, typhoid deaths were reaching several hundred per year until 1911. In that year, a filtration system was completed, and the chlorination of the city water supply started almost immediately. As a consequence, typhoid deaths were significantly reduced, showing a direct connection between water disinfection, water quality in general, and human health (Figure 5).

Similar effects and trends could be expected in other areas of the world. For example, in Greece, according to historical data, the development of disinfection technology had significant effects on life expectancy. Moreover, during the Minoan era (ca. 3200–1100 BC), the life expectancy was about 30 years, and during the Archaic, Classical, and Hellenistic periods (ca. 750–31 BC), it was just a little over 30, while in the 20th century, in particular with the introduction of chlorination in 1947, it had reached 45 years. At present, the life expectancy is 84 years for women and 81.5 for men with an ever-increasing trend [30]. Today, it is widely known that well-organized supply systems for safe drinking water, together with sanitation and purity, better conditions for hygiene and standards of living, and, in general, environmental livelihood security, are playing a major role in the extension of our lives.

2.2. The IWA History

The IWA (International Water Association) is an international association dedicated to water resources management. If the term water is enlarged, all water sources (existing and/or produced) are included in the objectives of the association. In addition, the “one water” concept, which emphasizes a new holistic approach to water management, must be considered a leading idea that represents a major trend in the field of environmental engineering and water resources [32].

The IWA was founded in 1999 by merging two former associations, the International Water Supply Association (IWSA) established in 1947, and the International Water Quality Association (IAWQ), which was originally the International Association for Water Pollution Research (IAWPR), acting under the umbrella of the IWA.

The IWA is a very fast developing and growing association worldwide, based on the 75-year legacy of its parent associations, linking the historic water resources activities, sciences, technologies, and practices. It consists of a network of professionals, scientists, researchers, technology companies, and water utilities from 150 countries, working for a world community in which water is managed wisely, fairly, and in sustainable way. Additionally, more than 70 specialist groups (SGs) have been set up, which are at the heart of the IWA. During the last and most successful event of all time, the 2022 IWA World Water Congress and Exhibition, gathered 8900 water professionals from the scientific community, utilities, private companies, governments, and global organizations in Copenhagen, Denmark. There, water leaders discussed and presented innovative solutions to rethink urban water management in order to transform the cities of the future. The next biennial IWA World Water Congress and Exhibition will be held in Toronto, Canada, 11–15 August 2024 and is expected to be bigger and more interesting. Such a strong community of experts is a constant driver of innovations in water knowledge and a critical auditor of the results of their application, all in order to achieve the goal of sustainable development.

IWA members contribute to and develop the IWA’s agendas. Members can be met at international events such as the IWA World Water Congress and Exhibition, the IWA Water and Development Congress and Exhibition, and the SGs Conferences around the world, which are organized every two years. The IWA is guided by science and technology and annually sets the agendas with the publication of 12 scientific journals and more than 40 books by IWA Publishing. It is suggested that a brand-new journal on the history of water and climate be published. In addition to the history of climate, further work is needed in the domains of technology and in research focusing on the climate–resources interactions, implications on the functioning and productivity of ecosystems, resources management, as well as in rules, legislation, and policy issues [33]. The role of SGs is very important in these aspects because they deal with the specific topics for which they were established in more detail. One of them used to be the IWA-SG on water in ancient civilizations (WAC).

2.3. Joint IWA/IWHA-SG on Water History

In 2005, an IWA-SG on WAC was established. It is a dedication to the disclosure hydro-technological heritage worldwide in order to: (a) assist in making visible what remains of ancient hydro-technologies and to describe and evaluate them, (b) develop new sustainable water and wastewater systems based on old principles and today’s knowledge and infrastructure, (c) develop sustainable adaptation strategies for water-related heritage, and (d) create monuments of inspiration for present and future cities.

The SG on WAC focuses on the study of hydro-technologies over the centuries in ancient civilizations around the world. The relevance of the ancient works is examined in terms of the evolution of technologies, the security of the country, and the management principles. History is studied not only to learn from the past but also to understand the present and trace the future. Activities of the IWA-SG on WAC includes the organization of international, regional, and workshop events.

Three years ago, the SG known as the Joint IWA/IWHA-SG on water history was reorganized and co-founded with the IWHA. The history of the IWHA was discussed by Dr. David Pietz, vice-chair of the management committee of the Joint IWA/IWHA-SG on water history and was presented during a webinar. The topics covered by the new SG can be summarized as: (a) the history of water resources; (b) the past, present, and future of hydro-technologies; (c) what and how we can learn from the past; (d) the relationship between traditional knowledge and sustainability of hydro-technologies; (e) water in the ancient, present, and future cities; and (f) the history of hydroclimate.

Finally, the SG is in contact with other entities, associations and groups (e.g., UNESCO, IPOGEA, and IOCOMOS) that are interested in the history of water resources in order to increase its size and widen its interests. The Joint IWA/IWHA-SG on water history should further be extended so that the idea of “one water” concept must be considered.

With the increasing worldwide awareness of the importance of water resources management in ancient civilizations, the Joint SG has organized 10 IWA International and Regional Symposia and Workshop on water and wastewater technologies in ancient civilizations in different countries and continents so far. At this time and within the coming years, once the pandemic is over, the Joint SG will be reorganized, and several International and Regional Symposia and Workshops are expected to be convened.

Finally, a very brief description of the very long history of water focusing on Geek history is presented in Appendix A.

3. Epilogue

Water history is parallel and equivalent to world history [10]. Centuries ago, Vitruvius concluded and wrote that water supports “an infinite number of practical needs” and that “all things depend upon the power of water” [9]. It should be noted that there is no life without water, and the improvement in the quality and quantity of available water is increasing life expectancy and quality. Additionally, through the study of ancient civilizations and the dynamics of cultural and sanitary engineering, we can understand ourselves and we can learn how to be more creative and innovative. While there may be nothing that can appropriately be called a universal value, water history should definitely be universal knowledge.

All people in all times have, had, and will have water of different quantities and qualities and have had to adapt to the water flowing in their societies, even controlling it, if possible. Water technologies and infrastructure design are rapidly advancing at present, thus improving overall systems efficiency. For this reason, water engineers and scientists are combining and must combine existing technologies and infrastructures in new ways. In doing so, it would be desirable to reimagine and rethink traditional technologies and infrastructures to improve water-use efficiency and, at the same time, achieve social benefits. It should be considered, nevertheless, that the development of new technologies and systems is very demanding and expensive. So, it would be rational to analyze what and how something has been working well in the past under similar conditions before starting to design new solutions for the future.

Summarizing, the lessons learned are as follows:

(a)

The meaning of water-related sustainability in modern times should be re-evaluated and rethought under the light of ancient public works and management practices, from past to present. Developments based on sound principles and practices enhance livelihood security and extend useful lives.

(b)

Water safety is of critical importance in the sustainability of any human population on Earth.

(c)

In water-short areas, development of robust and cost-effective decentralized water and wastewater facilities and management programs is essential.

(d)

Traditional knowledge could play an important role in sustainable water supplies in future cities.

(e)

Finally, it should be noted that by looking at our roots we can see and learn about the present and the future.