Rainwater Collection for Fresh Water on the Go

An trailer and a truck in front of a house under construction.
  • 2-6 hours
  • Beginner
  • 50-250

Occasionally life affords us exciting opportunities that sound great but for a few minor details. For me, one such opportunity was to help build a custom timber frame home for a couple of friends. The catch was that I’d be living on their 18 acres of Hudson Valley property in my 26-foot travel camper for as long as I was working on the project. The other catch was that, until they drilled the well 19 months later, there would be no running water on the property. So for the first couple of weeks I bought my water from the grocery store in 5-gallon increments. But it wasn’t long before I realized that wasn’t going to be a sustainable system if I was going to be sticking around this job for the long haul.

Personal Water Needs

You might be shocked to learn how much fresh water you could be using on a daily basis for drinking, bathing, washing dishes and the like. According to the United States Geological Survey’s Water Science School (water.usgs.gov), one ten-minute shower, three teeth-brushings, five toilet flushings, a load of laundry, a sink of dishes, and eight glasses of drinking water could consume up to 118.48 gallons of water in a single day. That’s almost 24 five-gallon water jugs (like you’d see on top of a water cooler). If you’re on-the-go or in a prolonged camping situation like the one I was in, you will probably already be thinking in more conservative terms about your water budget. But while some campsites do offer freshwater hookups as part of your site fee, what are your options if you find yourself without easy access to fresh water?

A Good Backup

If you’re going to be traveling through some desolate territory, it’s vital that you keep a fresh water reserve of about one gallon per person, per day on hand just for drinking. For this I would not advise waiting for a rainstorm to come around. But if you’re looking to subsidize your drinking water reserve with some water for bathing and washing clothes and dishes, a good rain can yield plenty of water that’s perfectly suited to these tasks. All you need is a means to collect it. However, keep in mind that while rainwater itself might not make you sick, it could potentially pick up some microbes during the collection and storage process. If you find yourself needing to drink collected rainwater in an emergency situation, be sure to boil and filter it first, to avoid risk of illness.

A Simple System

I created my own rainwater collection system out of scrap materials and a few old five-gallon water jugs that I had neglected to return to the supermarket:

Simply find some scrap plywood, stand your water jugs upright next to one anothe

Simply find some scrap plywood, stand your water jugs upright next to one another (leaving enough room between them for a 2x3 or 2x4 cross brace), and mark out a rectangle on your plywood that will be big enough to support the two jugs upright. Take your measurements and cut the holes in your plywood base where you will position the neck of each jug. Cut the bottoms off your jugs, build a frame to support your plywood base, and position the jugs upside down on your base as in the photo above. I chose to position my water jugs upside down in case I ever wanted to attach a valved feed from the mouth of each jug directly into my camper’s fresh water tank. If you think you can get away with siphoning, you can save yourself some trouble and simply cut the top off each jug so it sits flat on its base.

Find a Large Surface Area

If you were to simply leave this collection system out in a rainstorm, you’d probably be pretty disappointed with your water yield. I was fortunate to be working on a gutter-less house with a massive roof, so all I needed to do was position my collection system under one of the waterfalls that would pour out of the roof valleys during any rainstorm. If you don’t have access to a large roof or something like it, consider purchasing a tarp and creating your own catch system by setting it up so it drains into your collector. In a camping or travel scenario, you can create a highly effective catch system with little more than a 12’ x 16’ tarp, some tent poles (or sturdy sticks), and some rope. Bonus points for creativity.

Harvest Your Water

As long as you can do it safely, siphoning is a great way to harvest your rainwater yield. As my collector filled during storms, I would siphon the water into more five-gallon water jugs that I had collected just for this purpose.

Using this system, I once collected 50 gallons in a single storm, landing myself

Using this system, I once collected 50 gallons in a single storm, landing myself a surplus that lasted me about ten days.

A World of Options

Siphoning not for you? Consider rigging up a drainage system leading from your collection receptacle into a larger storage container – whether it’s your camper’s freshwater storage tank, a rain barrel, or a rainwater cistern that holds a thousand gallons. When it comes to projects like this, the sky (and its contents) are literally the limit.