Utilities in larger cities have to make complex decisions planning future investments in urban water infrastructure. Changes are driven by physical water stress or political targets for environmental water flows e.g. through the implementation of the European water framework directive. To include these environmental, economic and social sustainability dimensions we introduce a novel multi-criteria assessment method for evaluation of water supply technologies. The method is presented and demonstrated for four alternatives for water supply based on groundwater, rain- & stormwater or seawater developed for augmenting Copenhagen's current groundwater based water supply. To identify the most sustainable technology, we applied rank order distribution weights to a multi-criteria decision analysis to combine the impact assessments of environment, economy and society. The three dimensions were assessed using 1) life-cycle assessment, 2) cost calculations taking operation and maintenance into account and 3) the multi-criteria decision analysis method Analytical hierarchy process. Specialists conducted the life-cycle assessment and cost calculations and the multi-criteria decision analyses were based on a stakeholder workshop gathering stakeholders relevant for the specific case. The workshop reached consensus on three sets of ranked criteria. Each set represented stakeholder perspectives with first priority given to one of the three sustainability dimensions or categories. The workshop reached consensus and when the highest weight was assigned to the environmental dimension of sustainability then the alternative of ‘Rain- & stormwater harvesting’ was the most sustainable water supply technology; when the highest weight was assigned to the economy or society dimensions then an alternative with ‘Groundwater abstraction extended with compensating actions’ was considered the most sustainable water supply technology. Across all three sets of ranked weights, the establishment of new well fields is considered the least sustainable alternative.

大城市的公用事业公司必须做出复杂的决策，以规划未来在城市水利基础设施方面的投资。变化是由自然水压力或环境水流量的政治目标驱动的，例如通过执行欧洲水框架指令。为了包括这些环境，经济和社会可持续性方面，我们引入了一种新颖的多标准评估方法来评估供水技术。提出并论证了该方法用于基于地下水，雨水和雨水或海水的四种供水替代方案，这些替代方案是为增加哥本哈根目前的地下水基础供水而开发的。为了确定最可持续的技术，我们将排名分配权重应用于多标准决策分析，以结合对环境的影响评估，经济与社会。使用1）生命周期评估，2）考虑运营和维护的成本计算以及3）多准则决策分析方法层次分析法对这三个维度进行了评估。专家进行了生命周期评估和成本计算，多标准决策分析是基于一个利益相关者研讨会，该研讨会收集了与特定案例相关的利益相关者。研讨会就三套排名标准达成了共识。每组代表利益相关者的观点，并且优先考虑三个可持续性维度或类别之一。研讨会达成共识，当将最大的精力放在可持续发展的环境方面时，则选择“雨水和雨水”。雨水收集”是最可持续的供水技术；如果将最大的权重分配给经济或社会各个方面，则可以选择“采用补偿措施扩展地下水抽象”的替代方案，认为这是最可持续的供水技术。在所有三组排名权重中，建立新的井场被认为是最不可持续的选择。