Buried water infrastructure (BWI) services (drinking water, wastewater, and stormwater) are vital for sustainable urban development, which can be impacted by increasing densification needs. This study aims to develop an integrated level of service (ILOS) index to evaluate the performance of BWI underneath the urban densification. Development of the ILOS index involved identifying and selecting key performance indicators (PIs) under the pre-defined criteria and objectives. Initially, eighty-four PIs were identified through comprehensive literature. These PIs were reduced to sixty-two, based on experts’ judgment and feedback using three selection criteria and further grouped into a hierarchical structure.

A hybrid approach of dynamic fuzzy cognitive maps and an ordered weighted average operator was adopted to aggregate PIs into the ILOS index using the bottom-up approach. The developed ILOS index was applied to four municipalities within British Columbia, Canada. The results show that all four municipalities need to significantly improve their BWI for sustainable growth and effective urban management. A sensitivity analysis was conducted to identify the most important PIs for the design of the ILOS index. Future research will be conducted to apply the proposed approach for better decision-making of growth scenarios, which will provide early warning changes in urban densification.

埋地水基础设施（BWI）服务（饮用水，废水和雨水）对于城市可持续发展至关重要，这可能会受到越来越高的致密化需求的影响。这项研究旨在开发综合服务水平（ILOS）指数，以评估城市致密化下BWI的绩效。ILOS指数的开发涉及根据预先确定的标准和目标来确定和选择关键绩效指标（PI）。最初，通过综合文献确定了八十四个效绩指标。根据专家的判断和反馈，使用三个选择标准将这些PI减少到62个，并进一步分为层次结构。

采用动态模糊认知图和有序加权平均算子的混合方法，使用自下而上的方法将PI汇总到ILOS索引中。已开发的ILOS指数适用于加拿大不列颠哥伦比亚省的四个城市。结果表明，所有四个城市都需要显着改善其BWI，以实现可持续增长和有效的城市管理。进行了敏感性分析，以确定用于ILOS指数设计的最重要的PI。未来将进行研究，以将建议的方法应用于增长情景的更好决策，这将为城市密集化提供预警变化。