Wahaso understands that each building project has a unique set of variables for non-potable water supply and demand. For example, rainwater can be an inconsistent source, especially in drier regions, and may not be able to meet demand on a regular basis. While greywater from showers can be more consistent, non-residential projects may have limited supply and therefore are not cost-effective. In many instances, the best way to meet a building’s total non-potable demand is to combine multiple water sources.

Greywater uses

A single system that can properly treat multiple on-site water sources for multiple applications is more complex than a simple system that might only harvest rainwater. These systems require the experience and technical expertise that Wahaso offers. Wahaso offers a free analysis to evaluate all available sources and applications for reuse, helping to determine the right system for any project.

System Design

The goal with any multi-source water harvesting system design is to treat for the “dirtiest” water. When collecting rainwater and condensate, the Wahaso system would be designed to treat the rainwater. When collecting rainwater and greywater from showers, we would use our more robust greywater treatment system. This ensures that the total supply will be treated properly for safe,
non-potable applications.

A multi-source system can provide a greater supply, and therefore meet a greater demand. In the analysis stage, we look at the possible options for reuse to maximize water savings. The system design will ultimately reflect the best possible solution for all end uses.



  • Greater Return on Investment. Systems that can utilize multiple sources to serve multiple uses such as toilet flushing, irrigation and cooling tower make-up, are more likely to have year-round usage and a higher annual water savings. 
  • Single System. Collecting water from multiple sources does not mean multiple systems. Wahaso designs a hybrid system to treat all harvested water properly.
  • Wahaso Experience. Our expertise lies in looking at each project holistically. We’ve worked on hundreds of projects, analyzing each to find the most cost-effective solution that provides the greatest water savings.
4.3/5 (3 Reviews)