自来水公司正在以全新的眼光审视海水淡化。虽然公用事业公司内部的大部分分析都集中在当前成本上，但海水淡化替代方案对水资源组合的一些风险相关收益和成本却很少受到关注。本文探讨了几个问题，虽然难以量化，但确实构成了海水淡化项目收益和成本的一个非常真实的部分。这些风险和不确定性相关问题包括:未来资本和运营成本的不确定性；纯投资组合多元化价值；对冲未知的干扰；场地选择价值；以及与其他水资源替代品未来成本的相互作用。如果不对这些问题进行严格分析，就不应认为海水淡化作为水资源替代方案的评估是完整的。任何估值分析都需要首先将这些问题转化为一个可以给出实证答案的问题。 本文开始对定义过程提出质疑，并对负责水资源替代方案选择的水资源决策者或负责告知水资源替代方案选择的水资源专业人员感兴趣。

Water utilities are examining desalination with a fresh eye. While much of the analysis within utilities focuses on current costs, some of the risk-related benefits and costs that a desalination alternative contributes to a water resource portfolio have received considerably less attention. This paper examines several issues that, though difficult to quantify, do constitute a very real part of the benefits and costs of a desalination project. These risk and uncertainty related issues include: uncertainty in future capital and operation costs; pure portfolio diversification value; hedge against unknown disruption; site option value; and, interaction with future cost of other water resource alternatives. No valuation of desalination as a water resource alternative should be considered complete without rigorous analysis of these issues. Any valuation analysis will need to transform these issues first into a question that admits an empirical answer. This paper begins to question the definition process and should interest water resource decision-makers responsible for choosing among water resource alternatives or water resource professionals responsible for informing the choice among water resource alternatives.