Within the contemporary view of stormwater management, introduced through integrated urban water management approaches (e.g., low impact development [LID]), there are several strategies that can be used in urban settlements to enhance sustainability. These strategies include the construction of runoff source controls and changes in development patterns. To understand the environmental trade-offs, the comparison of single LID devices using life cycle assessment (LCA) is spreading. However, assessing both LID practices and the urban catchment hydrological response is a less explored field – especially in regions under climate conditions other than the temperate urban areas where LID first emerged. In this context, this paper aims to assess the environmental impacts and the hydrological effects of applying LID practices in a highly urbanized area in the tropics. Using a settlement in Brazil as a case study, three projects were developed and assessed using a hybrid framework based on hydrological modeling and LCA. Even though the projects had different elements, their system function was the same: assure flood protection for rainfall events with a 2-year return period and for a 30-year service life. The business-as-usual scenario, entitled Scen.CONV, used a conventional urbanization and storm-sewer conventional drainage system (CDS), commonly known as gray infrastructure. The alternative scenario, entitled Scen.WELL, used a conventional urbanization and CDS associated with the use of the LID controls to disconnect the lots (infiltration wells). The last scenario, entitled Scen.LID, used LID controls to disconnect both lots and streets (infiltration swales and swale trenches, considered green infrastructure measures) integrated with changes in development patterns. The hydraulic-hydrologic results pointed out Scen.LID as the best alternative for flood protection (100% of runoff source control), followed by Scen.WELL (60% decrease in the peak flow compared to Scen.CONV). The LCA total results indicated Scen.LID as the scenario with lower life cycle impacts, and Scen.WELL as the most impactful. However, this capacity-based approach could not capture the hydrological benefits of Scen.WELL, which were addressed using a performance-based functional unit. Assessing potential impacts per managed stormwater volume, Scen.WELL’s life cycle impacts were 51–65% lower than Scen.CONV, and Scen.LID’s were 74–82% lower than Scen.CONV, both in all life cycle impact categories. This joint approach provides a new perspective to stormwater systems assessment, enhancing their hydrological benefits, without burden shifting.

在通过综合城市水管理方法（例如，低影响开发[LID]）引入的当代雨水管理观点中，有几种策略可用于城市居民区以增强可持续性。这些策略包括构建径流源头控制措施和改变发展模式。为了理解环境的权衡，使用生命周期评估（LCA）的单个LID设备的比较正在扩展。但是，对LID做法和城市集水区水文响应两者进行评估的领域较少，特别是在气候条件不属于LID首次出现的温带城市地区的地区。在这种情况下，本文旨在评估在热带高度城市化地区采用LID做法的环境影响和水文影响。以巴西的一个定居点为案例研究，开发了三个项目，并使用了基于水文模型和LCA的混合框架进行评估。尽管这些项目具有不同的要素，但它们的系统功能是相同的：确保对降雨事件的防洪保护，具有2年的恢复期和30年的使用寿命。名为Scen.CONV的照常使用方案使用了常规的城市化和雨水排放的常规排水系统（CDS），通常被称为灰色基础设施。名为Scen.WELL的替代方案使用常规的城市化和CDS，并与使用LID控件相关联以断开批次（渗透井）。最后一个名为Scen.LID的方案使用LID控件断开与开发模式变化相结合的地段和街道（渗入的潮水和潮水沟，被认为是绿色基础设施措施）。水文水文结果指出，Scen.LID是防洪的最佳替代方案（占径流源控制的100％），其次是Scen.WELL（与Scen.CONV相比，峰值流量减少60％）。LCA总结果显示Scen.LID是对生命周期影响较小的场景，而Scen.WELL是影响最大的场景。但是，这种基于能力的方法无法捕获Scen.WELL的水文优势，而使用基于性能的功能单元可以解决这一问题。评估每个受控雨水量的潜在影响，Scen.WELL的生命周期影响比Scen.CONV和Scen。低51-65％。在所有生命周期影响类别中，LID均比Scen.CONV低74–82％。这种联合方法为雨水系统评估提供了新的视角，在不转移负担的情况下增强了水文效益。