Hello, I am an environmental engineer sharing my design for a ~300 gallon IBC tote rainwater collection system. What makes this different and beneficial for self-sufficiency is the low cost per gallon. This tote also provides a large enough storage tank to use a dedicated irrigation pump for reuse. You could make this as simple or as complex as you wanted to.
IBC totes are frequently used for storing and transporting food grade materials, so there is an aftermarket for cheap used totes, you just have to verify what they were used for. I got this 275 gallon tote off of marketplace for $100 USD. It was previously used to transport food dye. They are highly durable because they're built out of HDPE and galvanized steel.
Other Materials:
Leaf filter, from $10 to $70 - my preference is the Leaf Eater Advanced ($66)
Downspout diverter, my preference is Earth minded Flexifit diverter ($20)
PVC pipe and valves, figure $50
Total entry cost including tank: $180 - $240
Optional:
Lid adapter for two inlet ports $10
1 HP irrigation pump $140
Discharge splitter $10
Wi-Fi controller $30
Piggy-back Level float, alternative controller $50
Ozone injector to keep the water fresh and odor free: $400 (luxury) JED Engineering model 203
What would one use 300 gallons of rainwater for? I'm not trying to sound judgemental or whatever, I'm actually curious because 300 sounds like a lot. Is it mainly for irrigation? Would that make sense for a larger garden? I've heard that some people use graywater for flushing toilets, is this part of that?
Our UK garden is about 75x75m, which is a decent size, but not massive. About half to 3/4 of it is grass, which I hardly ever water, and haven't this year even though we had a drought.
We have 5 IBCs, and several other randomly-sized water butts (~7000l total (1500gal UK, 1850gal US)), to keep our veggies and fruit bushes watered. We ran out this summer, and had to use about 500l of tap water until it rained again :(
Dry periods are likely to get worse in future, so I need to get more water storage. I also want to start using rain water to wash clothes (or at least fabrics we use for our pet rabbit houses), but I need a good filtering system first.
We have 2 IBCs stacked, and I was trying to use the top one to gravity-feed our downstairs toilet cistern for flushing and worked well, although it took 7 minutes for the cistern to fill, which isn't great if you have to accommodate a lot of people. It is good enough for us though.
I could add a pump to speed up the process, but I'm trying not to add more cost and complications to the system unnecessarily.
I can fit 1 more IBC in somewhere - they don't look pretty, but they are very practical. I normally transport them home on the top of my car on a roof-rack.... and drive slowly! :)
When there isn't much rain in the summer and you try to keep your plants alive with collected rainwater, I assure you that it empties fast
It's just water bro. Shower, laundry, drink it, whatever. I have a thousand gallon tank, nice family home might have 10k. No other water source
Tbh even my fairly small garden could make use of this much water in the UK. I focused on keep stuff alive rather than optimal growing conditions.
Problem I find is that collecting rainwater is difficult to justify on the price of it. I looked at tanks out of curiosity, but water is so cheap that it could never realistically pay for its self.
Space is also difficult as my garden is fairly small. Looked at underground tanks but the prices there are even more crazy. I think the most cost effective option for me would be to just dump greywater on the garden instead. That just costs a pipe. Maybe something to put over the pipe where it crosses the path to avoid a trip hazard.
I am not the OP, but even if it doesn't have practical use, I just think this is coolest thing ever. It also aligns with self-sufficiency and resilience values of this solarpunk server