Economia Reuso Água
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The 'Water Reuse Savings' calculator estimates monthly water savings from reusing non-potable water in household activities like car washing or garden irrigation. It multiplies the volume of reused water (in liters) per month by 0.3, reflecting average energy/resource savings from avoiding treated water processing. Suitable for quick sustainability impact assessments in small businesses or homes with water recycling systems.
The L/month × 0.3 formula is based on Brazilian Sanitary Engineering Association (ABES) studies showing 0.3 liters of treated water saved per reused liter. For example, reusing 1000 liters monthly saves 300 liters. This excludes indirect benefits like reduced waste or treatment energy efficiency. The calculation focuses on direct water conservation metrics.
Use this tool to evaluate rainwater harvesting systems, kitchen sink greywater reuse (aguácinas), or community water recycling projects. It's ideal for comparing sustainable options, such as contrasting recycling savings with gutter installation costs. Avoid using it for long-term predictions without adjusting for local factors like seasonal rainfall variations.
Note: The calculation doesn't account for contaminants in reused water (e.g., oil from car washes) requiring additional treatment. It also ignores environmental impacts of collection/storage systems. For complex scenarios, consult environmental engineers to validate results.
Frequently asked questions
How does the calculator estimate water savings?
It multiplies the reused water volume (in liters) by 0.3, based on ABES studies on domestic water efficiency.
What applications is this calculator suitable for?
Ideal for rainwater harvesting, car wash recycling, greywater irrigation, or household conservation systems.
Do I need to measure reused water first?
Yes. Use water meters or household counters to track monthly reused liters before inputting data.
Does the result include energy savings?
The L×0.3 formula focuses solely on treated water savings, not energy reductions from pumping or treatment.
Is this calculator appropriate for large projects?
No. It's designed for quick small-scale calculations. Industrial or urban projects require complex models.