Rainwater capture project for off-grid cabin

DeMyer talks about her experience utilizing rainwater.

By Yana DeMyer

Photo by Maridav

Two years ago, my husband Jim and I started building a 12-foot by 16-foot cabin in a remote wooded parcel in Wisconsin. Because it is land-locked, but on a river, we had to float every stick of it, via our aluminum boat. Although I was more of a “Prepper” at the start (which was right about that time “Doomsday Preppers” aired on TV) we now only semi-jokingly refer to it as our “bug-out” location of last resort. I am happy to report that Jim has steadily bought into the idea over the years, and we truly enjoy our time there, pre SHTF. It’s our little getaway and hunting/fishing cabin.

A year later, we added an eight foot by 10-foot “master bedroom”, which fits two beds and has a door to a small deck outside. It can now actually sleep eight people pretty darn well, as it has two loft areas above. One thing it still lacked was water for drinking and washing up. So, our next project became a rainwater catchment system. While It’s not 100% complete, I hope you will find value in seeing what we designed, and essentially installed, in just one day.

Now, for sure, it took at least five trips to the hardware store for everything which was needed, but at least now we can share with you a list of what we eventually used. Hopefully this could save you much time and frustration, should you wish to build your own.

First let’s talk about our goals. We wanted a system that would:

  • Catch water, filter out leaves and gunk and keep bugs and pests out
  • Let the water be easily purified using a series of products that would:
  1. Not clog and therefor require filter replacement.
  2. Guarantee water safety in a non-chemical-dependent way.
  3. Require only a bare minimum of power to be operational.
  4. Cost under $500.

We decided on a rain gutter-based system, which we lined with a sponge filter to keep out the large bits of leaves and twigs. The downspout water is intercepted by a rainwater colander, which has fairly large holes, so, we lined it with a nylon stocking. This catches the smallest bits. The colander comes with a bracket that makes it easy to remove and clean out.

We used an RV drinking-water-safe hose to connect the colander to a barrel. The barrel we chose was a food-safe pickle barrel, found on Facebook marketplace for $20. This barrel has the advantage of having a big screw-on top. This allows smaller persons to reach in to be able to tighten bulkhead fittings with relative ease.

The hardest part of the whole exercise was figuring out what fittings we needed to connect what to what. Finding a hardware store employee who knows the plumbing parts aisle well is essential. We collared them and used the list detailed here, to get what we needed. The next hardest part was determining the order to do things in. This is what we recommend doing:

Start with drilling a one-and-a-half-inch hole for the inlet bulkhead fitting on the top of your barrel. Install the bulkhead fitting. (11) Next, install the brass fitting (12) that will adapt to your drinking water hose. You can figure out where to place the outlets later once you have your barrel in place.

Next, place your endcaps on the gutters, using metal screws. You can then hang the high end of the gutters on your house. A one-fourth drop per foot is the angle you need and using a string will help you keep things aligned. Work your way to where you want the downspout. Place the end of the gutter where you want the downspout to be and insert your “drop with outlet”4). This will determine how high you can go with your barrel. We wanted ours to be as high as possible, as we wanted to use gravity rather than a pump to get water to our outlet fixtures. It is possible to use barrels lying on their side to gain greater height, but since ours had a screw-on top which we didn’t really trust it to be leak-free. In the end, we decided to use it standing upright.

Once you know how high your barrel will be, build your base for the barrel with two-by-fours and wood screws. At 8.33 pounds per gallon, our pickle barrel is 65 pounds which equals about 541 pounds. Make sure you build it nice and sturdy.

Place the barrel on the stand in its permanent place. We only had about four inches to spare so that became the dimension of the downspout that led into the colander. Cut the down spout (6). For a good video describing how to do this, check out “Cutting Downspout: Starting the Cut, Making Straight Cuts, Tool Use, Crimping, and Connection!” on YouTube, by AC Service Tech LLC. Then attach the downspout to the outlet with metal screws.

We then attached the colander bracket and then the colander (7). The center of the colander connects to a standard downspout and goes down to the ground. The rainwater collector part of the colander shunts the water to a male garden hose, to which you will attach the first part of your RV drinking water hose. Measure how much hose you will need and cut it. Place the swivel barb fitting (9) in the cut end of the hose and secure it with a hose clamp (10). You can then screw it into colander, and the top of the barrel. The rest is pretty self-explanatory.

You will continue to locate and drill holes where you want your outlets. In our case we wanted one for inside the cabin, one for an outside shower, and one for an overflow hose near the very top. The parts specified here all connect to garden hose style fittings. The outlets all have shut-offs so you can work on adding in sink fittings, etc., without having to fight the water later on.

You are now on your own for how to attach the garden host to what ever fixture you have in your house. There are just too many ways to do it! As far as making sure the water is safe to drink, we chose a unique new technology that you may not have heard of yet. An electrolytic ozone generator made by a Wisconsin based company, Roving Blue (our invention). We have a small device, called the Ozo-pod 10, which infuses the water with ozone. Not many people know this, but ozone, when dissolved into water, is actually far stronger than chlorine. So, in minutes, a drinking water dispenser such as the one we chose, will be zapped with ozone strong enough to kill any microbes that might make a person sick. The neat thing about ozone is that it quickly reverts to ordinary oxygen. This means there are no chemicals to buy, no filters to clog and no chemicals remain in the water. You can check these out at www.rovingblue.com.

Remember, in some areas, collecting rainwater for human use can be considered illegal, even if there is a clever and effective way to purify it installed. Please check local regulations before attempting. Included is the list of parts we ended up using and a diagram of where they were used that follows the article.