Disclaimer: Know the rules in your state, and county you live in. In most states it is legal to save a personal amount of rain water. However, there are places where it is illegal. In our state, Washington, it is OK to do. It is encouraged by King County, where we live, to do this.
When we started talking about learning homesteading skills, one of the first things Kirk and I discussed was water conservation. While it might seem odd in the PNW, where the image is of green forest and constant rain, the reality is a bit different. Yes, it does rain a lot. Except in summer. Right about when you really need water, the sun comes out for a few months. And it is often warm all July & August, in the 80’s and higher.
However, we went big. No small garbage can size rain urn. Go as big as you can handle. We ordered two 1100 gallon tanks, which were produced here in Washington State. You would see those normally in an agriculture setting. However, they work well even in town. The profile is low. To source them, look up agriculture supply manufacturers in your area.
The tanks themselves are very light. Once the flat bed truck dropped them off, it was an easy roll into our back yard (we thankfully have a double wide gate on one side).
We had leveled an area behind the house for the tanks. We layed out a blend of crushed gravel and sand on top, then put in the tanks. We live in an area that is prone to earthquakes and volcanic activity, so we went for low and wide, rather than tall and narrow. If an earthquake happened, we don’t want the tanks to slop much. It is something to consider. The other issue is we wanted them to be low profile so they were below the fence line, and out of site.
How you pipe them from the downspouts is up to you. A kit can be helpful, as you are cutting into them. Make sure you have a filter in place, to catch debris. One thing to remember: In winter, once your tanks are full, and you turn off the spigots (so the water goes through the downspout instead), that come the next fall when you turn them back on, you will want to wait for the first rain to wash off your roof, before you start catching again. This way the dirt, pollen, leaves and more get flushed down off the roof. You will want to check your filter as well. Then turn on, and start filling the tanks!
With our very steep roofs, we can pull in 500 gallons in each tank in a downpour. So it doesn’t take long to refill.
Kirk wanted the pipes to blend in more, so he spray painted them camo, using plants as the stencil.
The first summer the tanks paid themselves back. The spring and summer of 2015 was extremely dry, and entered into a drought. We got the tanks installed in late winter/early spring of 2015, and caught the spring rains. By mid-spring, the rain stopped. In 2015 the local water company was charging nearly 2x the rate for outdoor water use (it was metered separately). Having a source for watering became a huge deal.
Our first plumbing was very simple, and Kirk put a simple spigot with hose onto the second tank.
The first summer I used this to water using 5 gallon buckets I filled by hand. I at least trained the boys to do the filling for me. We used to fill the tree water bags as well.
When Kirk piped the first tank, he did this the first time.
We would put buckets under, open it, and they were filled in a minute. However, the ball valve was too difficult for me to open on my own.
Kirk built this on to help with the flow of the water in the second summer.
It has an on and off lever, to allow easy access to the water. I use this one to fill the buckets we use in the greenhouse, but also to fill the water bags we put on the trees in summer. More is coming, but it at least got us where we wanted to be. Eventually in the coming year we will pipe it to provide water to our irrigation in the gardens.
One Note: When you save water off your roof it is considered non-potable water. Meaning you should NOT drink it. If your tanks are in an area that isn’t fenced off, I highly suggest you buy stickers made for water tanks that clearly state to not drink it. They are usually bilingual.