Decision support for sustainable water security

Society’s large dependence on water, in combination with climate, socio-economic and demographic changes, places a massive pressure on our freshwater resources. As a result, water crisis, defined as a significant decline in the available quality and quantity of freshwater, is now considered to be among the most critical global risks to society. The overall aim of this thesis is to increase the understanding of how decision support methods based on risk, cost-benefit and multi-criteria decision analyses can be used to facilitate our collective action towards water security. In the thesis, a sustainability assessment model is presented which can rank alternative drinking water options from the most preferred to the least preferred within each of the social, environmental and economic sustainability domains and with regards to all domains. The thesis further presents a marginal abatement cost curve to provide a common starting point for cross-sectoral dialogue on water scarcity mitigation. It enables a comparison of the cost-effectiveness of alternative mitigation measures, providing guidance for businesses, households, farmers and water utilities. Furthermore, a scenario-based risk assessment approach is presented to enable a comprehensive view on risk when evaluating water supply systems and risk reduction options. The approach allows for thorough analyses of economic losses under a range of water supply disruption scenarios, facilitating prioritizations on measures that aim to reduce the overall risk rather than individual risks. The provided methods are all exemplified in Swedish case studies, demonstrating different ways of evaluating and comparing management responses to the water-related challenges we face. In conclusion, the methods can help us strengthen the ongoing discussions regarding challenges and opportunities while providing structure and transparency to decision-making, and by that contribute to an enhanced water security

Decision Support Model for a Sustainable Regional Water Supply

Water supply provision has traditionally been a municipal responsibility. However, environmental, social and economic drivers are now making it more attractive to manage the water services in a more aggregated way. Yet, even though municipalities have cooperated to improve their water supply provision for decades, the topic is fairly under-researched and advantages and disadvantages not fully understood. Further, decisions regarding drinking water cooperation and other regional interventions are often made without a proper method of balancing, for example, the economic, health and environmental effects thereof. This thesis presents a decision support model to aid in regional water supply decision-making. The model is based on a combination of cost-benefit analysis and multi-criteria decision analysis for sustainability assessments of regional water supply interventions, including formations of inter-municipal cooperations. The proposed model integrates quantitative and semi-quantitative information on sustainability criteria, and it provides a novel way of presenting monetized benefits and costs with non-monetized social and environmental effects of regional water supply alternatives. The decision support model is based on a probabilistic approach where uncertainties are represented by statistical probability distributions and modeled by means of Monte Carlo simulations. A case study is used to exemplify and evaluate model application in decision situations regarding regionalization of water governance, (de)centralization of water production, and source water quality and redundancy aspects. The proposed model can be used by decision-makers to develop coherent preferences within economic, environmental and social sustainability so that decisions on regional water supply interventions can be taken with a higher degree of confidence. The results of the thesis contribute to a decision support toolbox needed to make proper evaluations and informed decisions in order to achieve long term sustainable water supply solutions

Cost-Benefit Analysis for Supporting Intermunicipal Decisions on Drinking Water Supply

Several countries promote a regionalization of the drinking water sector; however, few decision support tools are adapted to the intermunicipal level to aid in regional decisions. The aim of this paper is to describe and demonstrate a probabilistic cost-benefit analysis approach to assess the societal effects of regional water supply interventions to constitute support for decision makers. A special focus is given to the quantification of effects on consumers’ health, water supply reliability, and operation and maintenance costs. The uncertainties of the quantified values are represented by probability distribution functions and analyzed by means of Monte Carlo simulations. The proposed approach was demonstrated in the G\uf6teborg region in Sweden, for which five alternative interventions were evaluated. In conclusion, the proposed approach facilitates the identification and prioritization of societal effects so that costs and benefits normally overlooked in evaluation processes can be explicitly considered and addressed. The paper provides a transparent handling of uncertainties and enables a structured approach to improve decision makers’ ability in making informed choices on regional water supply alternatives

The value of water—estimating water-disruption impacts on businesses

As water serves as a necessary and often irreplaceable input in a range of goods and services, a disruption in water supply can cause lost production and sales for businesses. Thus, large benefits may be generated by reducing the risk of water disruptions. To enable selection of economically viable risk mitigation measures, the investment costs should be weighed against the benefits of risk mitigation. Consequently, quantitative estimates of the consequences of disruptions need to be available. However, despite the importance of water to businesses, the literature on their financial losses due to short and long-term water disruptions is still scarce. The aim of this paper is to estimate time-dependent water supply resiliency factors for economic sectors, i.e., a metric focusing on the level of output that businesses can uphold during a disruption, to contribute to better decision support for water supply planning and risk management. An online survey was used to gather data from 1405 companies in Sweden on consequences of complete and unplanned water supply outages. Results show that Food and beverage Manufacturing and Accommodation and food services are the two most severely affected sectors over all analyzed disruption durations

Input data report for economic assessments of water supply interventions in the G\uf6teborg region

This report is part of a research project funded by the Swedish Research Council Formas withsupport from RISE Research Institutes of Sweden, The G\uf6teborg Region Association ofLocal Authorities (GR) and the City of G\uf6teborg. The study was performed at the centre fordrinking water research (DRICKS). The research project aims to develop a decision supportmodel for sustainability assessments of regional water supply interventions and cooperationsbased on a combination of multi-criteria decision analysis (MCDA) and cost-benefitanalysis (CBA). This report focuses on the CBA part of the model.In the process of developing the model, five alternative water supply interventions for theG\uf6teborg region were evaluated. By applying the decision model to alternatives focusing onestablishing inter-municipal organizations, (de)centralization of water production, as well assource water quality and redundancy aspects, the model was tested for some commondecision situations in the water supply sector. The application in the G\uf6teborg region was away to develop the model, and at the same time demonstrate and evaluate its feasibility.This report presents input parameters of the CBA for the alternative interventions.For the G\uf6teborg region, it was found that the alternative which comprised a regionalizedgovernance and maintained semi-decentralized production had the highest probability ofbeing the most profitable solution, whereas the alternative which comprised maintainedgovernance with additional source waters and treatment plants had the second highestprobability of being the best solution

Sustainability assessments of regional water supply interventions – Combining cost-benefit and multi-criteria decision analyses

To cope with present and future challenges, a growing number of water utilities in Sweden, Europe and elsewhere initiate various forms of inter-municipal cooperations creating a new regional level of drinking water governance. In order to reach viable decisions of alternative ways forward, there is an international consensus that sustainability needs to be addressed in water supply planning, design and decision-making. There are, however, few decision aids focusing on assessing the sustainability of inter-municipal cooperations and the inter-municipal policies and interventions that regional decision-makers are faced with. This paper presents a decision support model based on a combination of cost-benefit analysis and multi-criteria decision analysis for assessing the sustainability of regional water supply interventions, including formations of inter-municipal cooperations. The proposed decision support model integrates quantitative and semi-quantitative information on sustainability criteria. It provides a novel way of presenting monetized benefits and costs, capturing utilitarian aspects of alternative interventions, with non-monetized social and environmental effects, capturing aspects based in the deontological theories of moral ethics. The model is based on a probabilistic approach where uncertainties are defined by statistical probability distributions. A case study is used to exemplify and evaluate model application in decision situations regarding regionalization, (de)centralization, source water quality and redundancy. All evaluated alternatives were expected to contribute to a slightly improved social sustainability, whereas the results were more varying in the economic and environmental domains. A structured and transparent treatment of uncertainties facilitates a better understanding of the results as well as communication between decision-makers, stakeholders and the community

Sustainability and Water Supply Governance - A Literature Review on Regional Water Governance, Multi-Criteria Decision Analysis, Cost-Benefit Analysis and Sustainability Assessments

This literature review is part of a PhD project funded by the Swedish Research Council Formas with support from RISE Research Institutes of Sweden, the Gothenburg Region and the City of Gothenburg, performed within the centre for drinking water research (DRICKS). The research project aims to develop a decision support model for sustainability assessments of regional water supply interventions and cooperations. The decision support model is planned to be performed through a combination of multi-criteria decision analysis (MCDA) and cost-benefit analysis (CBA). In the process of developing the model, national and international studies on regional water governance, as well as on applications of MCDA, CBA, sustainability assessments, sustainability criteria and economic valuation techniques within water supply management were reviewed.The MCDA approach is often used for complex decision problems with large amount of information and when several, possibly contradicting, views needs to be considered in a coherent way. It can, for example, be used to rank alternative interventions, find the unacceptable alternatives, and identify alternatives that need more detailed assessments. MCDA provides a means for integrating quantitative, semi-quantitative and qualitative information concerning alternative interventions. It allows for comparison between objectives and can be used for integrating social, economic and environmental analyses into comprehensive sustainability assessments.CBA can be used to measure the economic profitability of alternative interventions. The method relies on the anthropocentric foundation of welfare economics in which benefits are defined as increases in human wellbeing and costs are defined as reductions in human wellbeing. Welfare economics is based on the assumptions that each individual is the best judge of his or her wellbeing at a given situation. Individuals’ wellbeing depends on market goods and services as well as non-market goods and services, such as health and environmental quality. An intervention is considered economically profitable when its total benefits are larger than its total costs.Both MCDA and CBA have been used in several applications in the water sector and numerous evaluation criteria have been proposed to assess the sustainability of alternative interventions. This review: (1) gives an overview on literature on regional cooperation in the water sector; (2) provides a general description of the decision-support techniques MCDA and CBA; and (3) presents an overview of applications of sustainability assessments and the use of MCDA and CBA as decision- support in the water sector

Marginal Abatement Cost Curves for Water Scarcity Mitigation under Uncertainty

As water scarcity and drought become more common, planning to avoid their consequences becomes crucial. Measures to prevent the impact of new climate conditions are expected to be extensive, costly and associated with major uncertainties. It is therefore necessary that policymakers and practitioners in both the public and private sector can compare possible mitigation measures in order to make economically rational investment decisions. For this to be successful, decision-makers need relevant decision support. This paper presents a novel approach of constructing marginal abatement cost curves for comparing water scarcity mitigation measures while taking the underlying uncertainties into account. Uncertainties in input variables are represented by probability distributions and calculations are performed using Monte Carlo simulations. This approach is applied on the island of Gotland, one of the most water-stressed parts of Sweden, to provide the first marginal abatement cost curve in Europe for water scarcity mitigation in which municipal, agricultural, industrial and household measures are compared. The results show that the agricultural measure of on-farm storage has the greatest potential to increase water availability on the island. Among municipal measures, increased groundwater extraction and desalination offer the greatest potential, although desalination is almost 25 times more costly per cubic meter. The most cost-effective measure is linked to hot water savings in the hotel industry. The approach presented provides a quantitative visualization of the financial trade-offs and uncertainties implied by different mitigation measures. It provides critical economic insights for all parties concerned and is thus an important basis for decision-making

N\ue4r vattentillg\ue5ngen brister

Access to good quality water in sufficient quantity is essential for people’s everyday life and for most businesses and economic sectors. However, water scarcity and drought are emerging as some of the most important global risks to society with both short-term and long-term effects on people, ecosystem services, biodiversity and the economic activities that depend on a reliable water supply. This is a global problem, and Sweden is not spared. The low precipitation and high summer temperatures that hit Sweden for three consecutive years between 2016 and 2018, caused a vastly reduced access to water and led to major consequences for the Swedish society.In most Swedish regions, however, there is usually more than enough water to meet the growing needs of society and at the same time maintain a good environmental status even during drought. But to ensure a long-term sustainable water supply, all parties, i.e. households, water-dependent businesses and authorities, need to take measures. Drought and water scarcity are challenges that do not only affect, or can be solved by, the municipal drinking water supply. Each and everyone who uses and is dependent on water, regardless of whether the water is supplied through public or private systems, is part of the problem and should therefore also be part of the solutions.This report provides information and material to help companies contribute to a better water situation in areas with low water availability. The report describes the water usage and water availability in Sweden today and how they are expected to change in the future. Incentives and driving forces for water savings are described as well as methods for identifying inefficient water usage and improvement measures. A review of studies from various countries provides information on challenges as well as good examples of water scarcity mitigation measures in various economic sectors. Examples of decision support methods that can be used to evaluate and prioritize between alternative measures are also described. Finally, potential implementation barriers are discussed and examples of policy instruments which can facilitate implementation of beneficial measures are given