Planning to build your home outside of any municipal water zones? Or maybe you just like the thought of being self-sustainable? Either way, rainwater harvesting provides a viable water source other than the options of drilling a well or paying the local municipality to lay piping to your home.
We’ve been a part of multiple projects where the homeowner had drilled a well once, twice, or even three times and came up dry each time, or they drilled a well and the water was so bad that it would have cost a fortune to treat the water to a useable level.
We’ve also seen projects where they could use the water coming from the well, but it would be forcing them to use a very low flow rate. And when all that has failed, we’ve seen the projected cost of having a local municipality run a water line to the project site astound the homeowner!
Living off the grid has another water alternative to consider. Rainwater harvesting provides fresh, clean water that can be at high flow rates and provide water in excess.
Why Rainwater Harvesting Over Well Water for Off-Grid Water Supply?
It comes down to guaranteed and not guaranteed.
- Not guaranteed to reach water at all when drilling, but still liable to pay for the drilling.
- Not guaranteed that if one does reach water, that the recovery rate will meet the supply needs of the family.
- Not guaranteed to have quality water from the well. Many wells are high in iron, sulfur, and other unpleasant contaminants.
- Not guaranteed that well water, if one does have useable well water, will stay that way. Wells are prone to change in water chemistry, and that will lead to different types of water treatment equipment to remove the contaminants that were once not there.
- 100 years of rainfall data show us rain patterns and amounts of water that are expected in each region every month.
- This rainfall data provides the information needed to allocate proper storage to completely supply the family with water.
- With exception to countries that have high amounts of aerial pollutants, rain, while falling is the freshest naturally clean water to be found.
Because rain just went through the natural water cycle, it was sent through the stage of distillation, which highly purified the water, right before it hit your roof. Therefore, it only requires minimal filtration for a level of high purity and quality water.
How to Harvest Rain Off-Grid – System Design
A properly designed and installed system is critical for using rainwater harvesting as the sole-supply for one’s family. Everything from the home location, roof, gutters, downspouts, conveyance, pre-storage filtration, storage, pumps, controls, sensors, electrical, post-storage filtration, to entering the whole-house plumbing must be considered and designed to meet the supply and demand of each specific home.
The system must be calculated to store water that matches at least one full month of water demand from that specific home. If calculated or designed improperly, running out of water becomes a serious risk.
Electrical requirements coming from a rainwater harvesting are minimal, much less than a well pump. Keep that in mind when designing your off-grid home.
Rainwater Harvesting for an Existing Home – It is not a requirement for rainwater harvesting to come in during new construction, it is possible to design and install a system for an existing home. The main considerations for an existing home are if the downspouts are accessible, trying to limit the number of boars needing to take place underneath a driveway or sidewalk, and what the landscape grade is like. This will determine if an above ground or underground system will be needed.
Roof type is also a major consideration. Read this article to learn more about roof types for rainwater harvesting!
What if there is a drought?
While this should be a concern and thought about, in Tennessee and the southeast, the likelihood of a drought lasting over a month is minimal. But if one was to run out of water, there are solutions. Each sole-source system should include a fill port going into the storage tank, this allows water to be tanked in, such as from the local fire department who usually will only ask for a donation in return.
And another solution for homes that already have a secondary water source such as a well or municipal water, is to install a crossover so that the water can easily be switched over to the secondary source in case of drought.
Are families living off of rainwater harvesting right now?
YES! We have multiple customers who are living in a secluded area and have fresh, clean rainwater as their sole source of water! We have many families who would be more than happy to talk with you if you would like to hear it from them directly.