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When water becomes scarce

Only three percent of Earth’s water is freshwater. Despite freshwater being vital to us – we manage it recklessly. 2018 was the third consecutive year that Sweden was hit by drought and experienced a strained situation in terms of water availability. The water shortage had significant consequences for Swedish society. RISE provides municipalities and private operators with support in order to facilitate informed decisions when choosing and prioritising measures for our future water supply and water use.

A secure and reliable water supply is a prerequisite for a functioning society and for sustainable development. At present, however, almost half of the world’s population – approximately 3.6 billion people – live in areas where water shortages can occur at least one month per year. A figure estimated to increase to between 4.8 and 5.7 billion people by 2050.

In Sweden, we generally have good access to water. But both water supply and demand vary widely across the country and water shortages also occasionally occur, particularly in southern and central Sweden and around coastal regions. However, water scarcity only started being discussed in earnest in Sweden following the dry spells in 2016, 2017 and 2018.

“Water is our most vital resource and we must be able to cope with dry periods, water shortages, and other challenges in order to ensure adequate water supply,” says Karin Sjöstrand, whose work at RISE involves the development and application of decision support methods to promote more sustainable management of water as a resource. “In high-risk areas such as California and Australia, work has been under way for a long time to promote more efficient and sustainable water use. The need to do so in Sweden has not been as pressing and there has often been a lack of water saving incentive to save water. But the long dry periods over the last few summers have had major consequences for Swedish society, and it has become clear that we need to be better prepared for a future when water shortages and droughts may become more common.”

Prioritisation of abatement measures

In times of water shortages, a key question relates to how different abatement measures should be prioritised to ensure that water supply is able to meet future needs. To achieve better water situation, measures focusing on both demand and supply are required.

“In Sweden, we have typically responded to an increased need for water in society by simply taking more water from current raw water sources or exploiting new groundwater and surface water sources. But is this really the best strategy for the future? And can we even continue to do so in areas already afflicted by low water availability? From a societal perspective, it may be more apt to try reduce demand instead,” says Sjöstrand.

Efforts to achieve sustainable water availability can include different measures in different sectors of society. But determining the best strategy or best course of action is not always a simple matter. How should all potential abatement measures be prioritised to improve the water situation in an area experiencing water scarcity? On what basis should priorities be made and at what level? Should one consider what is best for society as a whole or what is best for each individual operator?

“Definitely not simple questions. But there are various methods that can be used to provide guidance and support for prioritisation and decisions, both for individual operators and for authorities, so that the decisions taken are informed and take into account aspects considered important for the specific situation or the region you are in,” says Sjöstrand.

RISE supports municipalities and private operators in decision-making related to water use and water supply. RISE works to adapt, develop and apply different decision-support methods in order to be able to weigh different abatement measures against each other in a structured and transparent manner , thereby facilitating informed decisions when choosing and prioritising actions. For example, decision support methods can be based on risk analyses, cost-benefit analyses or multi-criteria analyses in order to determine, among other things, which abatement measures are economically viable and which lead to increased sustainability.

Example from Gotland

A good example of this is a research project in which RISE, Chalmers, Anthesis, and the Geological Survey of Sweden collaborated with Region Gotland, LRF Gotland and many other players to evaluate how different sectors can contribute to a better water situation on Gotland, where water availability is very limited in certain areas. Limited availability notwithstanding, the total water needs on the island are expected to increase by roughly 40 percent by 2045.

“The project investigated how abatement measures from several different sectors of society could be compared to produce an overview of the sectors and measures with major potential to improve the water situation, as well as which measures are expensive and which are cheaper,” says Sjöstrand.

The project compared municipal abatement measures with agricultural measures and those for households, industry, and tourism.

“One example of decision support we utilised for Gotland is a visualisation tool referred to as a marginal abatement cost curve. Marginal abatement cost curves are frequently used in climate policy when various types of abatement measures need to be compared in order to, for example, reduce a country’s carbon dioxide emissions. A marginal abatement cost curve categorises abatement measures according to their cost-efficiency, and for Gotland we were able to equitably compare measures aimed at reducing water needs with measures aimed at increasing availability,” explains Sjöstrand.

17 possible measures

The Gotland project developed 17 abatement measures in a large workshop attended by various stakeholders in the region. The costs and potential of the measures were then analysed. Potential in this context refers to the theoretical potential water that the abatement measure can contribute per year if fully implemented by all operators. In other words, it was the upper limit of the abatement measure that was analysed. Estimates were also produced for both cost and potential with respect to the reliability of the information or its degree of disparity. Furthermore, uncertainties were applied to all the parameters.

“Marginal abatement cost curves can then be colour-coded based on all parameters essential to the individual decision. For instance, by visualising which measures save water or produce different types of water quality, which measures are associated with implementation difficulties, such as a legal obstacles, and which measures can be implemented immediately or which require a longer period. This is all done to produce an easily comprehensible overview of the difficulties associated with different measures,” says Sjöstrand.

Benefits increasingly being recognised

Working proactively to improve the management of water as a resource is imperative. Good decision-making support provides an understanding of which trade-offs are required and which measures are economically advantageous as well as socially and environmentally sustainable.

“Developing a better understanding of the socio-economic and financial costs and benefits of water saving measures, as well as the value of water for different uses is important to the well-founded prioritisation of measures aimed at strengthening Swedish society’s ability to withstand and deal with water scarcity and drought,” concludes Sjöstrand.

Supports the UN sustainability goals

6.Rent vatten och sanitet

17 möjliga åtgärder

I projektet för Gotland togs 17 åtgärder fram i ett stort workshoparbete med olika intressenter i regionen. Därefter genomfördes analyser av åtgärdernas kostnader och potential. Med potential menas här den teoretiska potentialen vatten som åtgärden kan bidra med per år om åtgärden utförs till fullo av alla verksamhetsutövare. Det var alltså åtgärdernas övre gräns som analyserades. För både kostnader och potential gjordes även uppskattningar om hur säker den informationen var eller hur den kunde variera. Och det ansattes osäkerhetsfördelningar på alla dessa parametrar.

– Åtgärdskostnadskurvorna kan sedan färgkodas baserat på alla de parametrar som är viktiga för det enskilda beslutet, till exempel för att visualisera vilka åtgärder som sparar eller tillför olika slags vattenkvalitet, vilka åtgärder som är förknippade med implementeringssvårigheter såsom juridiska hinder, vilka åtgärder som kan implementeras direkt eller vilka som kräver lång tid. Allt för att ge en lättöverskådlig bild av vilka möjligheter som finns och vilka svårigheter som olika åtgärder kan vara förknippade med, säger Karin Sjöstrand.

Allt fler ser nyttan

Att arbeta proaktivt för en förbättrad vattenresurshantering är viktigt. Med bra beslutsunderlag skapas förståelse för vilka avvägningar som krävs och vilka åtgärder som är ekonomiskt fördelaktiga samt socialt och miljömässigt hållbara.

– Att utveckla en bättre förståelse för vattenbesparande åtgärders samhällsekonomiska och finansiella kostnader och nyttor, samt värdet av vatten för olika användningsområden är viktigt för att kunna göra välgrundade prioriteringar om åtgärder som syftar till att stärka det svenska samhällets förmåga att motstå och hantera vattenbrist och torka, avslutar Karin Sjöstrand.

Published: 2020-01-27