Combined Rainwater Catchment/Cistern - Can it Be Done?

I'm renting a small property in really rural Montana, and I have a problem - there is no outside water spigot. We don't require much water outside for plants, but occasionally we do need access to water for things like butchering, laundry, cooking, etc. And dammit, it's just nice to have access to water without running a hose out our back door from the washing machine line.

We're thinking of putting up a water container/cistern this year. There's a small slope to our property, and on the uphill side, we can get about 3 feet of fall from the back of our yard to our house. We were thinking of rigging up a water container of some kind, and using gravity feed to access water. Of course, we're renting, so we can't really go putting up any permanent structures. We're also running into the problem of supply the tank with water. There are no structures on that side of the property to capture rainwater off of, and I'm just having a hard time picturing how it'll work.

Does anyone have any ideas as to how you could incorporate a free standing water cistern with a rainwater catchment system, without using roof runoff or altering the property? Hoping to get an idea of what direction to take this in from you brilliant permies over here

I think the main issue you'll run into is the amount of water you'll be able to capture. A roof has so much surface area that even small amounts of rain add up to a large volume of water.

For example, say your house has a footprint of 1000 square feet. If you get 3 inches of rain in a month, that's 250 cubic feet of water, or about 1870 gallons. (1000 square feet x 3/12 foot x 7.48 gallons/cubic foot).

Say your cistern is 5'x5'. If you can only collect the rain that hits the top of the cistern, that same 3 inches of rain will only amount to 47 gallons! you really need some kind of large surface to collect the rain. You could take a few pieces of metal roofing and increase your collection area, but it has to be above the cistern, and that starts looking like a permanent structure. Or you could try to rig up some kind of tarp to funnel water into the tank.

Are there any water sources nearby, like a pond or stream, even downhill of you? It's pretty easy to set up a solar pump if it doesn't have to overcome too much head. If you can find some secondhand gear, it can be as simple as connecting a solar panel straight to the pump, hooking up a hose, and dropping it in the water. That could pump into the cistern whenever it's sunny. Either size it for how much water you need or just figure out where to send the overflow. Or get really fancy with a float switch.

Ben de Leiris wrote:I think the main issue you'll run into is the amount of water you'll be able to capture. A roof has so much surface area that even small amounts of rain add up to a large volume of water.

I completely agree - unfortunately we just have no other options for water sources around here. We get some decent rain in the spring, so I was hoping to capitalize on that, even with so little surface area, but I'm beginning to think an outdoor water source at this location just might be too much of a stretch. So frustrating, it complicates a lot of things. The landlord is pretty much okay with us doing any kind of gardening, but fixing the outside spigot is going to be a bit more money than we'd be willing to spend on a rental property, and it's so unlikely that he would consent to paying for it.

Looks like it's going to be another season of hauling buckets and running hose through the back door.

Alternatively you could get the cistern and run water from your indoor spigot to the cistern and fill it up some amount. Then run a hose from it. That way you would only have to fill it up once and a while instead of running stuff every time you needed water.

I was actually just thinking the same thing - it would at least mean having a water source out there. We're also on the local volunteer fire department and live right next to the firehouse haha just kidding, not worth the hassle of running the hose out to drain afterwards!

If the main problem you want to address is less 'how do I have some water storage in case the existing supply has an issue, and also have access to water outside', and more 'how do I get access to water outside without all this bucket BS', it's probably less work to plumb in something semi-permanent.

I'd probably try T-ing off from the washing machine line, out a window; cut a board to fit a window left slightly open, and run the hose through a hole in the board. Add a valve and splitter if desired on the end of said hose, and you're in business... All removable when you move on.

Dillon Nichols wrote:If the main problem you want to address is less 'how do I have some water storage in case the existing supply has an issue, and also have access to water outside', and more 'how do I get access to water outside without all this bucket BS', it's probably less work to plumb in something semi-permanent.

I'd probably try T-ing off from the washing machine line, out a window; cut a board to fit a window left slightly open, and run the hose through a hole in the board. Add a valve and splitter if desired on the end of said hose, and you're in business... All removable when you move on.

That's true - We'd have to cut a hole through one of the walls to run the hose to make it accessible outside, but I bet we could get the landlord on board with that. Worth calling and asking at any rate.

Might not apply in your situation, but I've kept holes in rented walls inconspicuous by removing the baseboard, putting the hole behind it, and just using a length of 1x2 cut to size as a temporary baseboard; once it's time to go, replace the original baseboard, and all is good. Only works with adequately sized baseboards though... If not that, it's pretty easy to fill a small hole in at time of departure.

Honestly, this place is so old and falling down, I think as long as we did it properly and kept the weather out it would probably be okay. Especially since the stupid outdoor spigot doesn't work. Part of renting in a realllly small town - pickin's are slim.