The Water Dissensus – A Water Alternatives Forum
Water-related misconceptions – why do they still exist and why does that matter?
By Jan Seibert and Ilja van Meerveld
Water is a vital part of our lives, and everyone interacts with water in some way. This makes it easy for people to relate to water and hold opinions on it. However, members of the public, including politicians, hold many misconceptions about water and hydrological processes. These tend to persist in society despite progress in our scientific understanding. Especially among decision-makers, these misconceptions can lead to unrealistic expectations regarding water management and suboptimal decision-making.
Some misconceptions can be attributed to the repeated exposure to simplistic depictions of the water cycle, in children's books and even hydrology textbooks. People often imagine the water cycle as one cycle, with evaporation happening (mainly) over the oceans, as is shown in many schoolbooks. As a result, they do not realize the importance of evaporation over land, let alone that for many land areas, it is the largest flux. Furthermore, they may not realize that there are "water cycles" at different scales. Understanding the complexity of the water cycles is important because water issues are interconnected; land-use change in one region may, for instance, affect evaporation and precipitation in neighboring regions. Textbook diagrams of the water cycle frequently overlook major human impacts like dams, irrigation, groundwater extraction, pollution, and changes in land use (Abbott et al., 2019). Again, this may lead to a misunderstanding of the impact of these activities on groundwater levels or downstream streamflow.
Other misconceptions are based on people's own observations and inferences. People observe that streamflow increases in response to rainfall and therefore conclude that the water in the stream is the rainfall itself (i.e., correlation instead of causation). However, isotope tracer studies have shown that in most studied cases, "old" water (i.e., water that was already in a catchment before a rainfall event) is the main source of water in streamflow, even during high-flow events (Buttle, 1994; Klaus and McDonnell, 2013). The large portion of old water in streamflow, the importance of underground flow pathways, and general long residence and transit time are important to recognize because the effects of improved land management or pollution control may appear only after a long delay. Understanding the importance of this delay helps set realistic expectations and monitoring horizons until when impacts of new policies might become visible.
A third group of misconceptions may be based on notions about what is "good". A widely held misconception is related to the role of forests in water resources, particularly as a source for streamflow during dry conditions (Calder, 2007; van Meerveld and Seibert, 2025). Forests are often seen as "good" in themselves and, therefore, beneficial for streamflow. This often leads to the expectation that afforestation and reforestation will lead to increased streamflow during dry conditions. The reality, however, is more complex. In most cases, increasing the forested area in a watershed will actually lead to decreased flows as evaporation from forests is generally higher than for other vegetation. This is due to the higher interception losses, i.e., precipitation being held on the trees and returned to the atmosphere by evaporation, and because of the higher transpiration losses of forests than for shrubs, crops, or grasslands. The background to this misconception might be the basic idea that forests are "good" for the environment (which is certainly the case for many aspects) and, thus, are good for everything (Calder, 2007). Alternatively, it may be based on observations that forests are often cooler than surrounding areas, forest soil may feel wetter, or the occurrence of clouds above mountain forests. Misconceptions regarding the role of forests in providing streamflow are problematic when these guide land management decisions or payments for ecosystem services, and the proposed benefits are not delivered. They are also especially damaging when dry season flows decrease (or streams even dry up) and impact people's access to water and their livelihoods.
The three examples above highlight specific water-related misconceptions. Such misconceptions can be based on repeated exposure to simplistic depictions (e.g., the water cycle), naïve interpretations of one's own observations (e.g., the origin of stream water), and predetermined ideas on what is "good". While all such misconceptions are understandable, they are problematic when they lead to water management decisions that are not based on scientific knowledge (Calder, 2007). In some cases, "good" decisions may still be made, but for the wrong reasons (i.e., reforestation based on the promise of increased streamflow during the dry period may bring many benefits, such as improvements in water quality, biodiversity, or carbon storage). However, such decisions may lead to unrealistic expectations and harm environmental decisions in the long term.
Misconceptions are very persistent and are difficult to change. Only if one is aware of the misconception is it possible to explicitly address the misconception. This requires that scientists carefully listen to non-scientists, particularly policymakers, to identify any misconceptions they may have. Sometimes, there is overcompensation once people are made aware of the initial misconceptions. This can lead to another, but opposite, misconception. For instance, one might switch from ignoring the effect of evaporation from land surfaces to overestimating the effect of changes in evaporation on precipitation because of land-use change. One can sometimes see statements on the increased evaporation of forests as being good because it will increase precipitation downwind. While this can be the case, inefficient irrigation would also increase air humidity and lead to increased precipitation downwind. However, most people do not view inefficient irrigation in a positive light.
Beyond the general demand for scientific literacy, hydrologists and the media are called upon to address water-related misconceptions. The media is important, but unfortunately, headlines often oversimplify findings to attract attention and, in doing so, contribute to or reinforce existing misconceptions. Hydrologists need to explain the complexity of hydrological processes in clear and understandable terms. Therefore, it is important to work with science communicators to provide simple, but not simplistic, explanations and the implications for various policy options.
PS: We assume there are more examples than those we are aware of on how water-related misunderstandings have led to suboptimal or even bad decisions and outcomes. Therefore, we invite readers to provide such examples in their responses.
References
Abbott, B.W., Bishop, K., Zarnetske, J.P. et al. (2019) Human domination of the global water cycle absent from depictions and perceptions. Nat. Geosci. 12, 533–540). https://doi.org/10.1038/s41561-019-0374-y
Buttle, J. M. (1994). Isotope hydrograph separations and rapid delivery of pre-event water from drainage basins. Progress in Physical Geography: Earth and Environment, 18(1), 16-41. https://doi.org/10.1177/030913339401800102
Calder, I.R. (2007) Forests and water--Ensuring forest benefits outweigh water costs. Forest Ecology and Management 251, 110-120.
Klaus, J., McDonnell, J.J. (2013) Hydrograph separation using stable isotopes: Review and evaluation. Journal of Hydrology 505, 47-64.
van Meerveld, I., & Seibert, J. (2025). Reforestation effects on low flows: Review of public perceptions and scientific evidence. WIREs Water, 12(1), e1760. https://doi.org/10.1002/wat2.1760
Comments 17
A valuable piece. The failure to understand the water cycle was probably the most fundamental reason for the failure of the Australian water market. There were others but this was the most important. When the market was established 25 years or so ago water rights were handed out. These rights were based on the 18th century ideas of land rights. They completely ignored the 19th reforms which limited the ownership of farm land to the land the farmer actually farmed. That is the top few metres. No such restrictions were place on water. Farmers obtained a right to the water they used to grow crops and the water they did not use but which passed through their fields.
The result has been an increase in real water consumption. A farmer with flood irrigation sells his water right to a farmer on better drained soil to grow almonds using drip irrigation. The real consumption in terms of evaporation and transpiration has increased by perhaps three times. That is 100 ha of irrigated lucerne has been converted to 300 ha of almonds. The return flow which would have been used by other farmers has been reduced.
The counter argument used by supporters of the market is that the return flow in Australia, unlike Egypt, is usually saline so reducing the return flow is good for the quality of the water. That misses the point completely. If the farmers had water rights based on ET the almond grower would be leaving perhaps 60 or 70% of the water in the river. He would only be allowed to use the same ET as the flood irrigation farm. In other words 100 ha. of lucerne would be used for about 100 ha of alomds.
Thanks for sharing this nice (well, rather not so nice) example
Nicely explained, Brian.
FAO drafted a report on the impacts of switching to “efficient” irrigation, including a couple of pages on the multi-million dollar program in the Murray Darling, along similar lines to Brian’s comment. The Australian government objected, proposing alternative “facts” to support their case. FAO didn’t agree. The compromise was to omit the section on Australia from the report.
Regarding the Australian water situation. The water rights (entitlement) for irrigation relate to water delivered to a farm via an irrigation system (channels, pipelines..) or from licence diversions from a regulated river (a river with a dam upstream). Farmers get an progressive (nominally fortnightly) allocations based on availability. They can use it, trade it or carry it over till the next season. The systems have measurement, compliance, water registers to account for water use. The introduction of these water reforms and climate and market influences has seen a reduction in total water use for irrigation, whilst maintaining production value. Trading has allowed water to move from lower value crops to higher value crops. It is up to each farmer to decide what to grow, how to irrigate and when to order water.
You can see the change in water use in the Murray Darlin Basin in Figure 3-2 for the report available at https://www.mdba.gov.au/sites/default/files/publications/Annual%20Water%20Take%20Report%202023%E2%80%9324.pdf
In 2010 the Rural Water Supply Network published its 'Myths' paper. This has been well-received and widely read over the last 15 years. The link to it is here https://www.rural-water-supply.net/en/sustainable-services/myths
Many thanks for writing and posting this interesting and thought-provoking piece.
There can be no doubt that there are many misconceptions with regards to hydrology and water management. Science clearly has an important role to play in providing evidence, and promoting better understandings.
In addition to 'misconceptions', however, there are often many competing and equally valid 'conceptions' or explanations for the various water-related challenges we face as societies.
A great term which really captures this idea nicely is 'ambiguity' - the presence of a type of uncertainty resulting from the simultaneous presence of multiple valid - and sometimes conflicting - ways of defining and understanding a (water) problem. Science in general, and hydrology in particular, has an important role in helping us all to deal with ambiguity. However, ambiguity is as much about normative, values, ethics and attitudes as it is about the limits of factual knowledge or 'proof'.
If we are to cope with the increasingly ambiguous world of water, we will need (more) effective systems of water governance, based on principles of democracy, systems thinking, deliberation, trail-an-error experimentation, openness, accountability and transparency, in addition to improved scientific understanding of the water cycle.
There are many misconceptions. Examples: Alfalfa as "low value" crop (it's highly profitable), indoor use is "wasted" (most of it is cleaned and can be reused), a "human right" to water means people will get it (not without spending a lot of money and resisting corruption).
Academics may talk about these issues, but they waste their time if only in academic journals. Profesionals SHOULD talk about these issues, but they are not encouraged (and often discouraged by interest groups who benefit from misconceptions) from speaking out. We need more public discussions and citizen assemblies on water!
New Zealand water management is the polar opposite of the Australian Water Market and provides an interesting case study. The starting point is evaporation and transpiration which is measured by a number of weather stations in the Marlborough region. From this data a monthly allocation is determined. It can be translated into a volume of water because there is only one crop - grape vines - and they are all on drip systems. The allocations cover the whole water resource in that area - both pumping from the river and wells. The next stage is to divide the allocations into three classes. The first has top priority for the critical summer months of December and January. The next has a much lower expectation for these months and the third no expectation . As abundant water is available in other months these allocation holders build reserves. The system has strong approval from growers to the extent that valves are turned off electronically if growers exceed their monthly allocations. The fact that there is one crop and one irrigation system throughout the 30,000 ha district means it has a limited application elsewhere.
Decisions are too often based on simplified narratives rather than on the complex realities of water governance. From my perspective, correcting misconceptions is not only a scientific challenge but a democratic one. When policymakers and the public misunderstand how water systems truly function, they also misunderstand who is responsible, who is affected, and what solutions are just and equitable. Strengthening public participation, improving transparency, and promoting rights-based water governance are key to ensuring that scientific evidence leads to fair decisions—especially for people who are most vulnerable and most often left behind.
An additional example of a persistent misconception in water management arises in semi-arid river basins. It is often assumed that building new reservoirs will automatically solve water scarcity because they “allow more water to be stored”. This narrative overlooks the hydrological reality that storage capacity is not the same as water actually available, especially when inflows are declining due to climate change. In several basins, investments have prioritised expanding infrastructure rather than improving allocation rules, monitoring systems, or coordination across sectors and jurisdictions. As a result, many reservoirs have operated far below their design capacity, while expectations among users and decision-makers have remained unrealistically high.
This misconception has two major consequences. First, it diverts attention away from the need to address groundwater over-extraction, land-use change, and environmental flows—factors that strongly shape long-term water availability. Second, it erodes trust in water institutions when promised benefits fail to materialise. For these reasons, fostering transparent dialogue about hydrological limits, variability, and uncertainties is essential.
The observation that basic information about water resources lags change in science and in the world is a fair one. Readers might like to know that in 2022 the US Geologic Survey released an updated version of their official water cycle diagram that explicitly includes human interventions as part of the cycle. While long overdue and likely too late to change any deep misconceptions, it's a nice example of how the conventional wisdom about water resources might be changed in the next generations.
Thanks for reminding everyone of the 'new' water cycle diagram published by the USGS. I fully agree that this is a valuable attempt to reduce misconceptions.
Engineers, opinion leaders, and industry players in the water conservancy must practicalize robust methodologies to help educate citizens on the use of water, what constitute water cycle, and water security. The literature have become too much; that professionals now turn to publish more, but fail to put any into practice. without a clear implementation, this water issues would never be properly addressed.
The idea that water is common (cheap) in our communities must be reviewed. leakages and other pipe anomalies are not taken serious by communities since they assume water will always be available, regardless.
With intensive education and practical implementation of whatever robust scientific methodologies we have developed, i think the concept of water and its conservation would be in good condition
Thanks for launching this thought-provoking post. The causes of misconceptions are well illustrated and indeed partly result from problems of miscommunication. It seems to me, however, that many misconceptions or myths reflect the interests and ideologies of the dominant actors that propel them.
Take the idea of drip-irrigation as a water-saving 'best practice', agricultural water pricing as a tool to reduce demand, or the idea that it is 'safe' to pump groundwater as long as pumping is less than the aquifer 'recharge'. These are 'zombie ideas' that have largely been discredited and yet are conspicuously sticky. Double-accounting when considering interconnected surface and groundwater resources, the failure to consider what happens to return flows and their prior-appropriators when shifting to drip irrigation, or whether the treated wastewater was already used before (in its untreated state), are mistakes that basically promise there is more water than actually available. In other words, not making the mistake leaves you with the conclusion that there is no 'new water', or less water available than you initially thought … countless basin masterplans self-servingly make these mistakes, whether out of incompetence, lack of data, or concern not to make the water balance worse than what is said…
As Javier mentions above about the difference between dam physical capacity and actual storage, there are countless countries where a powerful dam lobby sustains this fatal fallacy, for obvious reasons. Wherever big 'industries', which do not include only companies and consultants but also epistemic communities, NGOs, development banks or agencies, etc. coalesce around a 'solution' they will sustain the narratives that propel it (beyond dams, think of desalination, river restoration, drip irrigation, etc). It does not mean, of course, that these actions are not needed or will be harmful, but -as we all know- there is no shortage of plans and projects where interests trumped economic or hydrologic rationality. Hegemonic unchallenged ideas thus have the potential to legitimate and foster undesirable actions.
For those interested in these questions a book (Best practices in global water policy: revisiting water mantras) will be published by Routledge in 2026. It revisits critically 20 ubiquitous (water) best practices.
Pérez-Blanco, C.D., Loch, A., Ward, F., Perry, C., & Adamson, D. (2021). Agricultural water saving through technologies: a zombie idea. Environment Research Letters, 11(16), 114032.
Molle, F. (2023). Aquifer recharge and overexploitation: The need for a new storyline. Groundwater, 61(3), 293-294.
Molle, F. and Barone, S. 2026 (forthcoming). Best practices in global water policy: revisiting water mantras. Routledge.
As a water lawyer, this very thoughtful post raises broader questions about the fundamental nature of water entitlements. In allocating water among competing uses, especially for agriculture, we tend to focus on projected catchment stream flows. The catchments water cycle has been assumed to be relatively stable over time, and comparatively little attention has been given to impacts of the way water is used and the impacts of these uses on water cycles at different scales. Climate change is gradually forcing adjustments in projected water availability, but the focus remains primarily on making better projects at the catchment level. If we are to deal effectively and fairly with projected climate change induced shortages in many areas, we need to make decisions about water availability at large geographic scales in assigning water entitlements entitlements.
Thank you, Ilja and Jan, for initiating this discussion.
Hydrological (and, more in general, scientific) misconceptions are indeed rooted in many aspects of a community's life.
These thoughts remind us, as academics, of the importance of looking beyond our university classes and starting to look for methods to "educate" the general public. This is important to create a basic water science culture that can make people more aware of how difficult and complex "generating" water is.
One method, perhaps, is the use of social media, at least for the youngest portion of our society.
I'm sure there are more and possibly more efficient ways to do that, according to different targets.
These are just my two cents, but the topic deserves more discussion.
I'll keep thinking about this.
Best,
Daniele