Case study
Multi-Unit Development Achieves 60% Potable Water Reduction Through Integrated Water Reuse
Executive Summary
A 190-unit residential community demonstrates how integrated water reuse systems revolutionize urban water management while delivering substantial returns. By implementing greywater recycling and rainwater harvesting, the development achieves 60% reduction in potable water consumption. With a $4.3 million investment and 8-11 year payback, the project saves 200+ million gallons of water and generates $13 million in utility savings over 25 years.
The Challenge
Multi-unit residential buildings create immense pressure on local water supplies. Developers face escalating water costs, growing regulatory requirements for conservation, and increasing drought vulnerability—while needing cost-effective solutions that don’t compromise resident quality of life.
The Solution
Integrated Water Reuse Infrastructure
The development implemented a dual-system approach combining greywater recycling and rainwater harvesting.
Greywater Recycling System
- Captures greywater from showers, sinks, and bathtubs
- Advanced multi-stage treatment for non-potable reuse
- Distributes treated water for toilet flushing and laundry operations
- Achieves net-neutral water usage for these applications
Rainwater Harvesting Infrastructure
- Collects rainwater from building rooftops
- Underground concrete cisterns beneath driveways for storage
- Provides sustainable irrigation water source
- Reduces irrigation demand by 30%+
Results & Impact
Development Size
190 residential units
Potable Water Reduction
60%
Total Installation Cost
$4.3 million
Cost per Unit
~$22,600
Payback Period
8-11 years
Water Saved (25 years)
200+ million gallons
Utility Savings (25 years)
$13+ million
Carbon Emissions Prevented
535 million tons
Key Takeaways
For Developers
- Strong financial returns with 8-11 year payback periods
- Long-term operational cost savings enhance property value
- Potential for density bonuses and expedited approvals
For Policymakers
- Density credits can accelerate water reuse adoption
- Reduces strain on municipal infrastructure
- Enhances community resilience through diversified water supplies
For the Industry
- Multi-unit developments are ideal for water reuse systems
- Technology is proven, scalable, and economically viable
- Environmental and financial goals are mutually reinforcing
Conclusion
This project proves that integrated water reuse systems deliver both environmental impact and financial performance. By achieving 60% potable water reduction and $13 million in utility savings, it establishes a new benchmark for sustainable multi-unit housing. As water scarcity intensifies, these systems transition from innovative amenities to essential infrastructure—demonstrating that sustainable housing is both environmentally responsible and economically compelling.