To support water management, reduce freshwater consumption and encourage to move towards a net zero water city.
Water balance statement
Develop an integrated water management process by developing a water balance statement for the city by projecting the total water demand based on various uses and designing the supply side to meet the total water demand. Demonstrate that the ratio of water withdrawals for human use to the total freshwater resources is less than 0.2. Develop Water balance calculator which consist of the following to demonstrate flow of water within the city:
1. Water Availability Assessment
Assess the total quantity of water available for use to the city or community.
2. Water demand
Estimate water demand for all of the following sectors and use types present within the city or community for a period of one full calendar year:
- Buildings – All use types such as residential, commercial, institutional and industrial buildings under the public and private sector.
- Landscaping for public spaces such as parks, alongside roadways and open spaces.
- Any other sector as applicable to the city.
3. Water supply
Identify the sources of water supply that will be used to meet the total water demand of the city or community. Sources of water supply may include but not be limited to the following:
- Desalinated water
- Reclaimed water: Reclaimed water includes:
- Treated wastewater- For each of the sectors identified in Water Demand, identify the wastewater generated. For reusing treated wastewater at city level, provide centralized water treatment plant. Support treated waste water reuse which is within the scope of the development authority’s direct execution, such as at building or community level by adopting appropriate regulations, policies or ordinances. In addition, meet the requirements for waste water quality as per WE Prerequisite Water Access and Quality.
- Harvested stormwater- For each of the sectors identified in Water Demand, identify the quantity of stormwater harvested. For harvesting stormwater at city level provide stormwater infrastructure. Support stormwater harvesting for areas within the scope of the development authority’s direct execution, such as at building or community level by adopting appropriate regulations, policies or ordinances. In addition, meet the requirements for stormwater quality as per WE Prerequisite Water Access and Quality.
Reference: Variation on STAR v2 BE-2 Community Water Systems Outcome 2
© Copyright U.S. Green Building Council, Inc. All rights reserved.