Thirst: When our water disappears (2): What happens when our water dries up?


Synopsis/content of the film

The documentary begins in the Taunus Mountain region, in Germany, where the strong water abstraction upstream of the Userlbach river to supply the city with drinking water, among other things, reduces the water flow in this river. In addition, global warming is increasing the duration and frequency of dry periods, shortening the winter period and lengthening the spring and summer. All this induces an increased consumption of water by the vegetation and thus a decrease in groundwater reserves, impacting low water flows, urban withdrawals, and terrestrial and aquatic biodiversity.

Part of the water used by the city and industry is treated and then discharged into streams and rivers, however the treatment is not sufficient to remove all macropollutants and micropollutants. Moreover, agriculture pollutes streams and rivers with its pesticides and fertilizers. Biodiversity is therefore further impacted. When surface water infiltrates into groundwater, this pollution reaches the water table and is therefore found in drinking water.

But anthropogenic impacts are also due to the overexploitation of water. The Salton Sea, "the largest saltwater lake in California," is almost completely dry due to evaporation and reduced irrigation returns from the Imperial Valley district upstream. In Mexico City, the overexploitation of groundwater leads to shortages but also to catastrophic land subsidence. Every year the city sinks, in some places, up to 30-40 cm. But the drought accentuated by global warming also impacts the forests, as in Bavaria, where maple soot is growing rapidly on the trees and killing them.

Jay Famiglietti, filmed in Colorado (a state ravaged by overexploitation), concludes these evocations by stating that we are on a "path of self-destruction".

Critical analysis

This documentary is one of the many films released in recent years that illustrate the 'water crisis' in its various forms. The difficulty then often lies in the choice of the cases addressed: too anecdotal, not varied enough, too much of a caricature, not detailed enough, etc. "What happens when the wells run dry?" succeeds in highlighting both the overexploitation and the anthropic pollution of water resources, and on the other hand, the different impacts (on societies, the environment and biodiversity). The main case is that of Germany, not necessarily the first country we think of when we mention the water crisis, but the film also takes us to California and Mexico.

Some impacts are straightforward (e.g. the drying up of the Salton Sea) but others, more indirect, are less known and allow the viewer to be alerted to dramatic consequences that were little anticipated or even understood: this is the case of soil subsidence, which cracks buildings, breaks pipes and even increases the seismic risk (in Mexico City); but also of the greater evapotranspiration of vegetation, which impacts the level of the water table and, ultimately, the flow of rivers; or of diseases such as maple soot, the spread of which is accentuated by the drying out of the vegetation cover. According to George et al (2021), the long-term monitoring of European forests reveals a constant increase in tree mortality linked to the decrease in soil moisture and increasingly frequent droughts.

The documentary gives a large place to scientists, who we see taking measurements in situ or in their laboratory in Germany, such as Jay Famiglietti, American hydrologist and director of the Global Institute for Water Security, a familiar commentator in this kind of reportage, but also to an ecologist, or political representatives such as Klaus Arzet of the Bavarian Ministry of the Environment. If the arguments are generally well illustrated and the explanations clear, the documentary displays some figures intended to underline the seriousness of the situation without however giving the keys to understand or qualify them. A professor from the Senckenberg Institute for Biodiversity Research in Frankfurt, for example, states that "60% of all streams and rivers are drying up"; it is also said that "40 million people are facing water shortages and drought" in California; or that "In Germany, only 7% of rivers and streams are considered to be in good ecological condition". The viewer will have to look for themselves to better understand these figures, for example that the latter is due to both the use of agricultural chemicals and the discharge of wastewater into low-flowing rivers, which impacts their quality (Büttner et al., 2020). The film indicates that "groundwater is more contaminated when it is close to agricultural areas", a situation that is unfortunately true at the global level according to Unesco (2022).

With regard to form the images are of good quality, occasionally reinforced by spectacular drone shots. The image is accompanied by a narration that clarifies what the scientists have explained in order to ensure a good understanding by the viewers; a narrator who sometimes asks questions, allowing to arouse the interest of the public and to bring it to reflection on the topics addressed. The tone set by the introduction is dramatic: catchy images and statements ("we are certainly headed for a grave hydrological catastrophe") follow one another at a steady pace, accompanied by shrill music that builds to a crescendo. At the end of the video, Jay Famiglietti declares that "we are on a path, a trajectory of self-destruction" and that "our decision-makers must see this and understand how we got here".

This documentary for the general public avoids the weaknesses often encountered (untruths, approximate causalities, omissions that change the understanding, anecdotal examples,...) and allows any audience to open their eyes to various effects of the 'water crisis'. The zoom on Germany, if it is explained by the origin of the production of the film, also makes it possible to become aware that these problems also touch temperate countries which one thought to be protected from such problems.

This film is the second part of  a series of three. It partly overlaps with Part 1, in that several issues are addressed again, albeit in a slightly different way (the drought situation in Germany, The Salton Sea, the doomsday prophecies of Jay Famiglietti…). This creates sometime a feeling of déjà vu as the respective scopes of Part 1 and Part 2 are not clearly distinguishable.

(avec des contributions de Honorine Bas  et Emma Pairault, Université de Montpellier)


This is a three-part documentary series:

Part 1: The fight for water -

Spanish version:

Part 2: What happens when our water dries up? -

Part 3: Who owns water? - Series playlist:

Other films on the water crisis in Germany:



Büttner, O., Jawitz, J. W., & Borchardt, D. 2020. Ecological status of river networks: stream order-dependent impacts of agricultural and urban pressures across ecoregions. Environmental Research Letters, 15(10), 1040b3.

Happe, D. 2022. « La suie de l’érable: une maladie végétale mais pas que... », Mediapart. mais-pas-que (consulté le 2 novembre 2022).

Senckenberg Society for Nature Research. « Dry Rivers », (consulté le 2 novembre 2022).

George, J. P., Sanders, T. G., Neumann, M., Cammalleri, C., Vogt, J. V., & Lang, M. (2021). Long-term forest monitoring unravels constant mortality rise in European forests. bioRxiv.

The Groundwater Foundation. Groundwater Contamination, (consulté le 2 novembre 2022).

Saade Hazin, L. 2001. La gestion de l'eau à Mexico DF: La participation du secteur privé. Flux, (44-45).

UNESCO, « Eaux souterraines rendre visible l’invisible ». (consulté le 13novembre 2022).

Zhongming, Z., Linong, L., Xiaona, Y., Wangqiang, Z., & Wei, L. 2021. Most rivers run dry--now and then.

Additional Info

  • Director: -
  • Producer: DW
  • Language: English, Spanish
  • Year: 2022
  • Duration (min): 42
  • Theme: Environmental degradation, Water governance, Water and health, Water allocation, Water and community, Aquatic ecosystems
  • Access: Free
  • Country: USA, Germany
  • Technical quality (star): Technical quality (star)
  • Academic interest (star): Academic interest (star)
  • Societal interest (star): Societal interest (star)
  • Technical quality: 4
  • Academic quality: 4
  • Social interest: 4