Basic Rainwater Harvesting System
Rainwater Harvesting (RWH) has been seen in a new light with the emergence of Green Building. The truth is that RWH has been taking place for thousands of years. Today, all across the world, RWH is being used for domestic and landscaping water needs.
Our homes are designed and built to use RWH as our their only source of water. We know that a properly designed, professionally installed, and well-maintained system can supply the home with quality water that is superior to most city-supplies water.
The key to a domestic RWH system is proper maintenance. We design the system with simplified maintenance in mind. We also create a program and schedule for the owner to follow for regular upkeep and annual water testing.
- Collection Area. This is where a RWH system starts. Knowing the collection area will determine the amount of usable water. To find the collection areas, add all of the roof area square footage.
|2000 sq ft
560 sq ft
440 sq ft
3000 sq ft
|*Take the 3000 sq ft, divide by 1000 = 3
multiply 3x 600 ( number of gallons collected in 1000 sq ft for 1″ of rain)
rough estimate = 1800 gallons of water per 1″ of rain for that roof area
- Gutters and Leaves. We prefer to use one-piece aluminum gutters. Leaf screens are determined on a site-by-site design. We encourage our owners to clean the gutters a minimum of 2 to 3 times per year.
- Dry Line Valve. This is the lowest point in our supply line. We install valves when we do not have continuous fall from the roof to the cistern. Water should never sit in the lines, if it were to stand stagnant this would increases the opportunity for bacteria or viruses to breed.
- First Flush. This is one of the most important design features for a secure domestic water source. It is the place where we collect and dispose of contaminants that build on the roof and in the gutters, prior to the water entering the cistern. We design and build our own first flush system that collects a pre-determined amount of water, discards that first amount and then seals itself off from the continuing flow of water.
- Storage Tank or Cistern. The size of the storage tank needed is determined by several factors, such as the number of people living in the house, the size of the collection area, the annual amount of rainfall in the area, and the length of time between rain events.
- In Tank Basket.
- Floating In-Tank Water Pickup. The cleanest water will always be found at the top of the tank.
- Check Valve and Back Flow.
- Pressure Pump
- Pressure Tank
- Filters. Before returning to the home for domestic use, water goes through two more filters. The first is a 50 micron filter and the other is a 5 micron charcoal filter.
- Ultra-Violet Light. The ultra-violet light is a “must,” in our opinion, for all domestic water systems because it displaces remaining bacteria.
- Water Meter. The water meter is another key component of our maintenance plan. The owners must know their water usage and have the ability to adjust that usage if necessary. It is also important to keep a record of water usage to maintain an annual amount of great water.