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MONTANAQUA: Water management in times of scarcity and climate change

 

The availability and consumption of water is changing as a result of climate change and socio-economic developments. This can lead to water distribution conflicts. On the basis of the Crans-Montana-Sierre region, the project shows how optimised management and distribution of water can be determined.

Project description (completed research project)

The MontanAqua project examined the water situation and water management of the Crans-Montana-Sierre (Valais) region. Within this framework, the researchers developed sustainable water utilisation strategies for the future together with the parties involved.

Methods

The research team first analysed the current water availability and utilisation as well as the current water management in the region’s eleven municipalities. This was taken as the basis for an examination of the future impact of climate, societal and economic change. The research team ascertained the current situation via quantitative and qualitative surveys in the terrain, and combined these with model calculations. When modelling the future, the research team considered regional climate scenarios and four scenarios of possible societal and economic developments, drawn up jointly with local players.

Results

The key results will now be presented on the basis of five questions.

1. How much water is available in the Crans-Montana-Sierre region?

At present, there is by far enough water available to cover the needs of society, economy and environment. By 2050, the annual water resources available will decrease to a small extent only. Seasonal shifts are, however, possible. Dry periods will occur more frequently. In such cases, water could become scarce in certain subregions, above all in late summer.

2. What is the role of the Plaine Morte glacier?

The glacier is an important water reservoir. In summer, the major part of the meltwater currently flows north; during the rest of the year, the water tends to run off on the Valais side, in particular via the sources of the Loquesse into the catchment area of the Liène. Due to the shrinking of the glacier, the run-offs from the glacier will increase up until approx. 2060 and will occur above all in a northerly direction. Thereafter, the volume of the glacier will be too small to contribute to notable additional run-offs. At the same time, the underground part of the run-off from the Plaine-Morte area is likely to increase. Even after the complete disappearance of the glacier around 2080, the contributions from the high-altitude, high-precipitation area of the Plaine-Morte are likely to remain significant. The Valais side will probably benefit most from this. Nevertheless, the run-offs in high summer will decrease greatly as a result of the reduced to non-existent glacier melt.

3. What is the level of water consumption?

Without taking account of hydropower, 10.5 to 13.5 million m3 of water is consumed per annum. This is less than 10% of the water resources available. An additional 60 to 80 million m3 of water per annum is diverted for hydropower. Depending on societal and economic developments, average water consumption will increase or decline slightly. The societal and economic development of the region is therefore a key factor in terms of future water consumption. The research results show that maximum consumption will increase by up to 60% in dry years due to the high demand for irrigation water. In dry years, the possibility of demand for water exceeding supply in late summer, perhaps resulting in shortages, will have to be expected.

4. What is the situation as regards water management today?

The current water management is highly fragmented. Its attention is directed above all to collecting and distributing water, while only low importance is attached to water demand management. Technical solutions predominate; there is no actual political debate on the optimisation of water management. The legal framework as far as water is concerned is very complex and frequently not transparent. The price of water is on the low side by national and international comparison.

5. Is this approach to water management sustainable?

Today’s water management is only partly sustainable overall. While it is relatively sustainable from an economic and ecological perspective, it is not equal for all parties concerned. The degree of sustainability of future water management depends on the development scenario chosen. Sustainability is significantly reduced in the growth scenario, while the scenarios of "Stabilisation", "green tourism" and "vision of the locals" will lead to an improvement in sustainability.

Relevance for research and practice

Five core messages with recommendations were set out on the basis of the most important results and findings.

Message 1: The effects of societal and economic change are more crucial for the water situation around 2050 than climate change.

If possible, regional development must be chosen such that it limits the need for water. This would result in a significant adaptation of current practice in terms of water and space utilisation.

Message 2: The annual water volumes available are sufficient overall, both today and around 2050; nevertheless, seasonal water shortages are possible in individual areas.

Regional water management, in which all municipalities are involved, must be encouraged. In addition to further technical development and the expansion of infrastructures such as (multi-purpose) reservoirs or interlinking the supply systems, there is a need for simplified legal bases with renegotiation of regional water rights. The franchise process for hydropower utilisation on the Liène (Tzeusier catchment lake) in 2037 should be regarded by the municipalities concerned as a unique opportunity for the development of a multifunctional management model for the Tzeusier catchment lake. This would benefit all water users.

Message 3: Water problems are above all management problems at a regional level.

To reduce the need for water and to coordinate water use, there is a need for improved cooperation between the municipalities and a change of direction towards demand management. Any such change requires the formation of a regional network with appropriate legal and financial resources as well as political muscle. The canton is called on to become more involved in regional water management and to support the development of such regional organisations for water management.

Message 4: Inter-municipality, infrastructure-related measures can contribute towards securing the water supply in a sustainable fashion, but only if they are taken within the framework of extensive social and institutional reforms.

More equitable water distribution requires a re-alignment of water management to include the common welfare of the entire population. This also applies, in particular, to the planning of technical infrastructure measures for which the renegotiation of the principles and rights as regards access to water resources is required.

Message 5: Improving the databases and transparency is indispensable for the efficient planning of a more sustainable regional water supply.

The Canton of Valais should draft a strategy for monitoring the water situation. Monitoring water (supply available, utilisation) on a regional basis will provide a solid foundation for sustainable water management planning. It is also recommended to carry out an expert assessment of the sustainability of current water management practice at a regional level. Finally, a comprehensive cantonal study on the possibilities for renewing and improving the legal situation in the field of water represents a fundamental prerequisite for sustainable water utilisation, in particular in periods of water scarcity.

Original title

Montanaqua: Approaching water stress in the Alps – Water management options in the Crans-Montana-Sierre region (Valais)

Project leader(s)

  • Prof. Dr. Rolf Weingartner, Geographisches Institut
  • Prof. Dr. Graefe Olivier, Département de Géosciences, Université de Fribourg
  • Prof. Dr. Reynard Emmanuel, Institut de géographie, Université de Lausanne
  • PD Dr. Rist Stephan, Geographisches Institut, Universität Bern