Rain Catchment Systems

Good morning, I am designing a rain catchment system at my off grid cabin in the mountains of Oklahoma.  I am building a 24 X 48 foot garage/shop.  The structure will be 24 x 28 with 10 foot overhangs on each side and will have a North /South roof peak orientation.  I plan on putting in multiple food grade dark resin containers that will be connected at the bottom allowing rain water to fill each of them with a single entry point.  The tanks will be in one of the 10 foot overhang areas and should allow me to collect roughly 30,000 gallons per year.  My question is does anyone have a good source for containers and the attachments I will need to hook everything up?  I've seen pictures of gutter connectors that screen out or remove things like leaves and pine needles.  I plan on using a tractor sprayer 12 volt pump that can move 2.2 gallons per minute at 100 psi to move water through the filters ( I plan on having in the shop) to the off-grid cabin which is 40 yards away.  If readers believe there is a better way of doing this please let me know.

Thank you for your time and the sharing of your experience.

Cameron, have a look at the link in my signature it has a lot of information.
I suggest a single 20,000L tank will be better than what you have in mind.
The fittings to connect many tanks can be a lot of money. A 20,000L tank maybe $3000
and will not have leaking joints.
"Rain Harvesting" sells the filter systems

Those resin water tanks cost bookoo. They are coming down a little in the last few weeks. I know cause I have been watching them for a year or two, trying to up my storage as well. They were pushing a dollar a gallon for a long while there, not much better now. Of course I was looking at 5000 gallon tanks so you may be able to go bigger and save some money per gallon.

My setup is not the one you want to emulate, I can pretty much assure you. It is just gutters to a sump and then an old sump pump that fills my tanks. I have some IBCs that fill directly off my woodshed and pumphouse but they only total a hair over 1000 gallons. John is the guy if you want to do it right.

There are mountains in OK? That shatters my entire universe!

Consider your roofing material, if you are thinking of  using the water for household use.

We have a couple of IBCs that we connected at the bottom to harvest 2000 litres (~500 gal) of rainwater for irrigation. It's a very small system but it mimics what you are describing. Earlier this year the connecting pipe sprung a leak and we lost all of our water, from both tanks. I recommend, if possible, filling sequentially, or having several isolated systems, for some redundancy in case of similar problems.

Lu8ke, if connecting pipes are leaking you have a sloppy system.
Even an IBC tank has a high pressure caused by the height of the water.
Good fittings cost a lot of money, but last years and years.

John C Daley wrote:Lu8ke, if connecting pipes are leaking you have a sloppy system.
Even an IBC tank has a high pressure caused by the height of the water.
Good fittings cost a lot of money, but last years and years.

The hose connecting the two tanks was hit with a brushcutter. An avoidable accident but one that lost us a lot of water - right before a drought. Thankfully our no-dig beds haven't yet needed watering (we only water young transplants, and only then occasionally). If we have a really long drought, however, we will need the water in those tanks to keep our plants alive.

The accident highlighted two things to me:

The connecting hose needs to be proctected. MDPE (blue) pipe or garden hose isn't really suitable.

The connecting hose is a single point of failure for both tanks. We now shut off the connecting hose occasionally, filling one tank until full and then letting the two equalise. This means we will only ever lose ~60% of our water if a tank, or the hose, fails.

Sounds like an awesome project and very similar to what we built, view the build thread here if you want for reference.  We learned that getting the largest containers you can find is a lot better than many smaller ones, less connections means less points of potential failure.  We ended up with 6 x 2500 gallon black poly tanks for 15,000 total.  The tanks weren't cheap, $1100 each, but the shipping was brutal.  If you look around, you may be surprised to find a manufacturer or distributer of tanks close to you, This gets our garden and landscaping through the dry summer months here.  Also, I am a little concerned about your pump choice.  If it was moving water a shorter distance I think it would be fine but that is a long distance to run a 12v pump. The filters will slow the flow a bit plus if you have any elevation change that will effect it as well. Do you have any AC power at all? Maybe from a solar system with an inverter?

Cameron Green wrote:Good morning, I am designing a rain catchment system at my off grid cabin in the mountains of Oklahoma.  I am building a 24 X 48 foot garage/shop.  The structure will be 24 x 28 with 10 foot overhangs on each side and will have a North /South roof peak orientation.  I plan on putting in multiple food grade dark resin containers that will be connected at the bottom allowing rain water to fill each of them with a single entry point.  The tanks will be in one of the 10 foot overhang areas and should allow me to collect roughly 30,000 gallons per year.  My question is does anyone have a good source for containers and the attachments I will need to hook everything up?  I've seen pictures of gutter connectors that screen out or remove things like leaves and pine needles.  I plan on using a tractor sprayer 12 volt pump that can move 2.2 gallons per minute at 100 psi to move water through the filters ( I plan on having in the shop) to the off-grid cabin which is 40 yards away.  If readers believe there is a better way of doing this please let me know.

Thank you for your time and the sharing of your experience.

[quote=Cameron Green]Good morning, I am designing a rain catchment system at my off grid cabin in the mountains of Oklahoma.  [/quote]

My neighbor specializes in rainwater collection and storage systems, He may be able to help you plan out the best system for your place and help you find everything you'll need to build it properly.
If you want to get in touch with him let me know and I can get you his number.

Sounds like a great plan Cameron. I have an inexpensive box store gutter installed over the garage and back door, but it flows onto the driveway. All around the rest of the house there are no gutters but there are gulleys that flow downhill. I'm thinking of adding a small experimental humus well to divert some of the water to the garden below. On a small scale I should be able to do this by hand. I got the idea from the Humus Well at Wheaton Labs. Eliot, et al, did a fantastic job on it!

I will be interested to see how the humus well performs. I t sounds feasible.