Since September 2020, we have been developing a research project on the diversification of the purposes of dam reservoirs in Switzerland. More specifically, we seek to understand and explain the growing interest in the concept of "multifunctionality" and in the multipurpose management of alpine dams and reservoirs in Switzerland.

Contrary to many foreign dams and reservoirs, Swiss Alpine dams have been designed almost exclusively for one purpose, hydropower. However, these dams are fullfilling other purposes: for e.g. their heritage, recreational and touristic values have been recognised (Loloum, 2016). In the context of the renewal of dam licenses and of the results of the National Research Program 61 "Sustainable Water Management in Switzerland" (SNSF, 2010-2015; http://www.pnr61.ch/fr), the diversification of dam purposes to "compensate for the disappearance of glaciers and the reduction of snow cover" (Thut et al., 2016, p. 4) seems to be promoted; hydropower reservoirs could contribute to the water supply of municipalities, and to the irrigation of agricultural land (Björnsen Gurung, 2018; Kellner, 2019). Several reports by the Swiss Federal Office for the Environment and the Swiss Federal Office of Energy have mentioned the need to assess the possible multipurpose use of reservoirs (FOEN, 2020; SFOE, 2019; Schädler et al., 2012). At the same time, the management of dam reservoirs must be made compatible with the protection of river ecosystems and aquatic environments (LEaux, SR 814.20). While the evolution of dam uses may be consensual (Marnezy, 2008), it may also be a source of increasing rivalry (e.g. Bréthaut & Pflieger, 2020), or even conflict.

In recent years, social science research has addressed the changing purposes of dams in relation to the redefinition of the missions of hydraulic companies (Pritchard, 2011) and the emergence of new water needs and uses (Marnezy, 2008). In addition, social sciences, environmental sciences and also engineering, have raised the issue of the evolution of dam uses and their management in relation to socio-environmental problems such as biodiversity erosion (Barthélémy & Souchon, 2009; Boyer et al., 2019) or climate change (Berga, 2016). However, this work, although generally focused on existing infrastructures, rarely specifically addresses the purposes and uses of dam reservoirs and their evolution and has not dealt with the call to multiply the purposes of already existing dam reservoirs. In order to study these historical and also spatial evolutions, we draw on the "hydrosocial cycle" (Linton & Budds, 2014) literature, which we seek to cross-reference with reflections on uses (Calianno et al., 2017).

Within this framework, we raise several research questions:
(1) Which actors are driving forces in promoting the diversification of dam purposes and since when?
(2) What spaces and contexts could be concerned by the diversification of dam purposes (municipalities? infrastructure systems? watershed?)?
(3) Does the diversification of dam purposes lead to increasing rivalry between stakeholders or, on the contrary, to a better integration of the different water uses?
(4) If it leads to more rivalries, do these rivalries relate specifically to the use of dam reservoirs or more generally to the use of rivers and water?

In order to answer these questions, we plan to carry out, first, a survey among different stakeholders (elected officials, scientists, administrations, organizations) which aims at clarifying the emergence and promotion of "multifunctionality"/the diversification of dam purposes. Second, our research will focus more specifically on local translations of multifunctionality; we will focus on the diversification of reservoir purposes based on case studies on Alpine dams and through surveys with local stakeholders (Cleuson Dam in Valais, and Hongrin Dam in Vaud).

From Sept. 2020 to Sept. 2021, this project wa funded by UNIL and carried out at the Institute of Geography and Sustainability (IGD). Since Sept. 2021, the project has been co-funded by Alpiq with which we collaborate for the case studies. The projet will be pursued after August 2023 by Andréa Savoy (https://igd.unil.ch/andreasavoy/) and included in a broader project (https://igd.unil.ch/projrech/index.php?idPage=69&page=viewDetails&id_projet=404&lang=en)

References

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Berga, L. (2016). The Role of Hydropower in Climate Change Mitigation and Adaptation: A Review. Engineering, 2(3), 313‑318. https://doi.org/10.1016/J.ENG.2016.03.004
Björnsen Gurung A., Brunner M., Stähli M., Kellner E., Clivaz M., Reynard E., Douarche M., Gökler G., Schmocker-Fackel P. (2018). Alpine multipurpose reservoirs: future potential and relevance, conclusions. In: Füreder, L., Weingartner, R., Heinrich, K., Braun, V., Köck, G., Lanz, K., & Scheurer, T. (Éds.). (2019). Alpine Water: Common good or source of conflicts? In Alpine Water – common good or source of conflicts? Austrian Academy of Sciences Press.
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Bréthaut, C., & Pflieger, G. (2020). Governance of a Transboundary River: The Rhône. Palgrave Macmillan. https://doi.org/10.1007/978-3-030-19554-0
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Thut, W. K., Weingaftner, R., & Schädler, B. (2016). Le changement climatique conduit à des pénuries d'eau pour l'homme et la nature. Des réservoirs à buts multiples asssurent l'alimentation en eau et énergie (p. 8). Université de Berne.