Blue and green infrastructure (BGI) provides a wide range of ecosystem services (ES) and other benefits when managing stormwater, beyond flow and pollution control. A number of tools have been developed to value these benefits. In the UK, stormwater measures that utilise BGI are known as Sustainable Drainage Systems (SuDS). This paper outlines the Benefits of SuDS Tool (B£ST), developed in the UK by the Construction Industry Research and Information Association (CIRIA) for valuing the benefits of BGI stormwater measures. The tool has been applied to case studies across Europe. B£ST includes a set of benefits based on ecosystem services applied to the use of BGI for stormwater management. The paper focuses on the uncertainties in this multiple benefit assessment, detailing the processes used in the tool. Examples illustrate the scale of the uncertainties in tools like B£ST. The uncertainties when using BGI valuation tools such as B£ST to help inform the delivery of stormwater measures are demonstrated in the paper as potentially of sufficient magnitude to warrant explicit consideration by professionals and decision makers.

在管理雨水时，蓝色和绿色基础设施（BGI）提供了广泛的生态系统服务（ES）和其他好处，而不仅仅是流量和污染控制。已经开发了许多工具来评估这些好处。在英国，利用BGI的雨水措施被称为可持续排水系统（SuDS）。本文概述了由建筑行业研究和信息协会（CIRIA）在英国开发的SuDS工具（B£ST）的好处，以评估BGI雨水措施的好处。该工具已应用于整个欧洲的案例研究。B£ST包括一套基于生态系统服务的收益，这些收益适用于将BGI用于雨水管理。本文着重于这种多重收益评估中的不确定性，并详细介绍了该工具中使用的流程。实例说明了B£ST等工具的不确定性规模。本文证明了使用BGI ST等BGI评估工具来帮助提供雨水测量方法时的不确定性，其潜在程度足以保证专业人员和决策者的明确考虑。