Active Water Harvesting


By “actively harvesting” rainwater and greywater, we are referring to formal systems for collecting, filtering, storing and recycling water that would otherwise be sent to municipal sewer systems. Proper filtering and storage of harvested water are required to prevent the water from turning septic in storage – which could result in off-colors and odors. Local codes may or may not be in place that set standards for the required purity of stored water.

Rainwater Harvesting System Schematic
An system schematic for an Active Water Harvesting system that captures, stores, filters and pressurizes rainwater for reuse.

While these systems are more complex and more expensive than passive systems, they have the advantage of reducing the costs for municipal water and water treatment. It is considerably more expensive to retrofit these systems in existing buildings – particularly greywater systems that require separate internal plumbing. Rainwater systems can be more easily added if they are planned for irrigation or specialty uses, and there is adequate space available for the processing and storage systems.

A brief overview of active systems follows. For more information, see Our Services.

  • Rainwater harvesting systems: Our sophisticated systems filter, sanitize and store collected rainwater to produce near-potable quality water that meets strict water quality codes for commercial and institutional buildings. Rainwater is collected from impermeable rooftops and reused in toilet flushing, irrigation and other applications.
  • Greywater harvesting systems: Greywater harvesting systems utilize “gently used” water collected from showers, sinks, washing machines and dishwashers. Greywater harvesting provides a more constant water supply than a rainwater system due to the seasonal and regional nature of rainfall. Because greywater contains a higher level of biological and chemical contaminants than other sources, it requires more rigorous filtering and sanitation processing, but presents another excellent source for application in toilet flushing.
  • Stormwater harvesting systems: Stormwater is defined as rainwater that has reached the ground—it is water from parking areas and landscapes that is more likely to be contaminated with silt, hydrocarbons from automobiles, road salt in northern climates, nitrates, other fertilizers from landscaped areas and more. Water is treated and reused in one of two ways: for sustainable irrigation or to source a rainwater harvesting system.
  • Multi-source harvesting systems: In many cases, the most efficient way to meet the water needs of a particular building is to combine the capabilities of multiple harvesting systems. For instance, we may be able to maximize water savings by capturing both rainwater and condensate and using the harvested water to flush toilets and irrigate the landscaping of a facility. Our multi-source, multi-use harvesting systems are custom designed to utilize water from all possible sources and apply treated water to all possible uses.

In order to determine the most efficient sources and uses of water – and to develop a system concept that will deliver on that savings, Wahaso must first conduct a scoping analysis that is unique to your facility or property.  We do that at no charge, and it only takes a few days to complete.  Please Contact Us for your free analysis and consultation.