Rainwater harvesting is the collection and storage of precipitation (rain and snow) for use in and around a home or homestead. The concept is to temporarily divert water falling on the site for domestic and irrigation use, then return it unscathed to its never ending journey on the wheel of the hydrologic cycle. The beauty of this approach is that the most important component, a large impervious surface area directing water to collection points, is already a part of every residential design. It’s called a roof.
For some purposes, such as irrigation to an elevation below a house, all that’s required to create a functioning rainwater harvesting system is to install a tank to collect water exiting roof gutters, along with basic sediment filtration and simple plumbing such as a hose bib. The addition of special filters, a pump, more complex plumbing, and a few other components can produce potable (drinking) water. The size, type, and application of rainwater harvesting systems are variables specific to each project. Each Nauhaus is designed with the potential to provide all the domestic and irrigation water required for building and homestead inhabitants.
There are two potential types of water moving through a drain. Blackwater contains potential toxins such as meat grease, human feces, and chemical cleansers. Greywater doesn’t contain these contaminants.
Greywater irrigation is the use of greywater to irrigate plants in or around the house. Effective greywater systems are conceptually simple. First, you separate the water toilets (if you have any, see composting toilets below) from the rest of the drains. Next, use biodegradable soaps and cleansers and keep meat grease out of the drains. You now have a nutrient rich plant food that can be directed to mulch basins and planting beds. If these are below the house gravity alone will do the job.
What have we accomplished? One of the best things you can do for the developing ecosystem on your homestead is to coax water to soak into the soil instead of leaving your site as run-off. In most situations, especially urban ones with streets, drives, patios, roofs, and other surfaces impervious to water, most precipitation leaves the site quickly before plants can take advantage of it. However, by utilizing rainwater harvesting and greywater irrigation, we have collected run-off water, used it to cook or clean, then directed it at a low velocity to plants that need it. From here it will either soak into the water table or evaporate, the result of both mechanisms will be a return to the hydrologic cycle without the addition of contaminants.
Unfortunately, greywater irrigation systems are illegal in many jurisdictions. Yes, partly this is due to the soul crushing ignorance of the Man, but, to be fair, the primary reason is probably that greywater systems require intelligent users. Uh-oh! Municipalities are resistant to allowing systems that can fail through misuse. For example, if some Bozo poured a five gallon bucket of bleach down your greywater drain, that would constitute a failure and a potentially hazardous situation. Other than banning Bozos, there are solutions to this problem and as our water resource becomes more precious in the public mind, acceptance of greywater systems will spread. If legal, we always include a greywater system in Nauhaus designs. If illegal, we plan for them anyway, so that they can be incorporated as a retrofit when we achieve a Bozo-free society…or at least direct greywater irrigation is universally legal.
Okay, this where we often lose people, so let’s make this clear: a Nauhaus doesn’t have to have a composting toilet. There are even situations where we’d probably agree that it would be ill-advised. In any case, we won’t even try to force you. So, sit back, relax, and read the following tirade:
First of all, you are full of feces and urine. Get over it. Processing food is one of your body’s most basic and continual functions and a substance often called “human waste” is the result. What should we do with it?
Here’s a quick description of the most common modern approach: First, collect water from a river, stream, reservoir, or well. Now, “disinfect” it, usually with the poison chlorine (made popular as a chemical weapon in WWI) in order to theoretically make it safe to drink. After piping it to a house, put much of it in the toilet. Deposit “human waste” and flush. Combine with everything else going into every unregulated drain to create a hazardous material including solids, chemicals of all kinds, oil runoff, and who knows what else. Go through involved and costly methods to clean up this mess, often finalized with the addition of chlorine before releasing the water back into the ecosystem. Finally, collect this water again, add more chlorine and send it back to the toilet for our own strange variation on the hydrologic cycle.
Now, we’re not belittling the major issue of sanitation in a crowded urban environment. Our point is simply that putting “human waste” in clean water isn’t really a rational approach. If considered dispassionately, feces and urine aren’t really “waste” at all. They are materials taken from our precious topsoil resource in the form of plant tissue or animal tissue that has eaten plant tissue. The protocol for every other animal is to pass this resource through the body, extract nutrients, then return the raw materials to become topsoil once again. We can join the rabbits, deer, and American eagles (it’s patriotic!) in this practice by using a simple technology called a composting toilet. Composting toilets use aerobic (“requiring air”) composting to break down organic matter into constituent parts. Other materials such as kitchen scraps, sawdust, and covers like straw can be added to create the right carbon to nitrogen balance for efficient decomposition. The process produces heat (thermophilic composting) which kills pathogens. The end result is the production of humus which is the organic matter found in top soil.
There are a variety of commercially available and homemade composting toilet systems. Some use fans, rotational drums, and/or electrical elements. Others are completely passive, consuming no power to produce topsoil for use in a variety of applications. Every Nauhaus is designed with composting toilets as an option.
Through a combination of rainwater harvesting, greywater irrigation, and composting toilets, a Nauhaus can be water neutral, meaning that inhabitants don’t consume or pollute water, but simply slow its movement long enough to be used on site, then release it untainted to continue a timeless journey on the hydrologic cycle.