# Sustainability Assessment on an Urban Scale: Context, Challenges, and Most Relevant Indicators
## 3 Results and Discussion Regarding the Selected Indicators within the Potential Categories
### Water-Saving Measures  
The next category focuses on the analysis of issues related to water-saving measures. It is assessed through four indicators, as presented in Figure 5. Water and water resources are unlike other natural resources as they are a critical necessity for human survival. The long-term neglectful exploitation of water resources has become a critical issue due to human effects on the water cycle. Humans directly affect the water cycle by removing water from various reservoirs for agricultural, urban, and industrial purposes [41] and indirectly impact the water cycle in drainage basins through land use transformation. Additionally, climate change caused by fossil fuel combustion significantly influences the water cycle [42]. Water consumption metering in the cities can improve the performance of water distribution systems [43]. However, efficient water consumption in cities is a critical phase, leading to a conceptual framework for planning and investing in urban water infrastructures, targeted by SDG 12 for sustainable consumption and production. Furthermore, resource recovery and reuse, the efficient management of rainwater, and conservation of water bodies are issues targeted by SDG 6, which emphasizes sustainable management of water and sanitation. Effluent reuse arising from particular collection or treatment systems leads to the protection of water surfaces, groundwater, and land [44]. Additionally, ISO 37120 developed an indicator for wastewater that receives centralized treatment. Consequently, to assess the water-saving level in every neighbourhood, the following three main indicators (Figure 5) are deemed important:  
Efficient drinking water consumption: This indicator promotes reducing water consumption and improving water conservation practices in a neighbourhood to reduce the production of effluents and pressure in the drainage systems. This indicator is addressed by SBTool(PT)_Urban (2018), SNTool Min (2020), BREEAM-C (2012), and LEED-ND (2018), and supported by SDGs and ISO 37120. The main factors that should be considered to determine the efficiency of drinking water consumption in a neighbourhood include the management of water consumption in public spaces and all buildings on the site, an analysis of the current availability of water and demands, the future predicted availability while taking climate change into account, and the expected water demand in the area as a result of growth and climate change.  
Effluent management: The objectives of this indicator are to promote the recharge of underground water reserves, which are under decontamination conditions, reduce the risk of flooding, reduce the load on public drainage and effluent treatment systems, and promote the adequate design of domestic wastewater treatment systems, which are a response to the needs increased by the site. This indicator is addressed by SBTool(PT)_Urban (2018), SNTool Min (2020), BREEAM-C (2012), and LEED-ND (2018), and supported by SDGs and ISO 37120.  
Rainwater harvesting and water body conservation: This indicator promotes the efficient use of surface water run-off and the conservation of wetlands and water bodies to preserve water quality, natural hydrology, habitats, and biodiversity. This indicator is covered by BREEAM-C (2012), and LEED ND (2018), and supported by SDGs.