How Many Gallons Is Your Catchment Tank?

[randomq]

100 gallons, enough for showers and dish washing for 2 people, except during drought when we haul. We also use about 10 gallons/wk of county water for drinking/cooking and dish rinsing.

[MarkP]

When you look at what people make do with in developing countries 100 gallons/day of clean water per family would be a huge luxury. This should not be dismissed. OTOH when company is here I go through more than 100 gallons/day easily. This should also not be dismissed. The culture we live in generally requires something like 50 gallons/day per person or more. If that amount of water is available as it is in Puna via catchment then there is no ecological downside to using that much, as long as you can dispose of the wastewater safely. There is also irrigation which is seasonal and fire suppression which you hope never to need but which is worth almost any price should you need it. Hence my decision to spend $3000 on a 10,000 gallon tank. Frankly that's a tiny cost given the budget for a modern house in the USA.

When I read survivalist and prepping websites I notice that some people who readily admit spending thousands on guns, ammunition, underground bunkers and the like that they will probably never use often get hung up on the mundane stuff. Before I put in my big tank I went a few times to the county taps. During drought periods it was kind of a circus and although I never saw anything bad other than some disgustingly unsanitary water containers like 5-gallon buckets with cracked lids that people had lain on the ground and stepped on and old gas cans, I could see how the distribution of such a necessary commodity based on the honor system could break down and I made a mental note that the truly prepared would provide for themselves otherwise.

[terracore]

^^ Good advice.

It's never a good idea to have all your eggs in one basket. I've posted before about those people in South Point where their tanks failed, one of which knocked a house off post and pier. To minimize water hauling we have a 50 gallon rain barrel out for the livestock with a repurposed satellite dish on top to catch more rain. It fills up quickly but during a drought it also empties at least weekly. Although we do have filters and UV to make our catchment water safe to drink, we also drink country water from the spigots because rain water has no minerals in it. Recently we "replaced" our 5 gallon water jugs with 3 gallon ones because they are easier to handle. So in addition to our 10,000 gallon tank we have 50 gallons livestock, pond of unknown gallons (though I would never use it, could be used for animals), 30 gallons in older 5 gallon jugs, and 3-24 gallons in 3 gallon jugs (depending on how many are full/empty at the time). We do live in a seismic area, and 10,000 gallons of water sloshing around in a bolted together galvanized tank not anchored to the ground... I wouldn't be surprised if it sprung a leak or the plumbing coming off it got severed and drained the tank.

[kalakoa]

never a good idea to have all your eggs in one basket

Exactly: not only do I have multiple tanks, they're all different types, so each has a different failure mode.

[MarkP]

I did not cast a concrete base for my tank, merely screeded an level spot on an ample bed of sand. I do wonder what would happen in an earthquake. I do somewhat regret not putting the tank on a reinforced concrete base. I suspect the primary failure mode would be having the base of the steel ring pinch the vinyl liner or having the liner bulge out from underneath as the ring tilted. I am not so worried about the steel ring splitting down the side as they are supposedly strong enough and usually they rip because overflowing water has caused rust.

[terracore]

We looked at SO MANY properties before buying our house, and we never once saw a catchment tank sitting on a concrete slab. The standard appears to be an alleged sand base, though I do know that some people use used carpeting. I like your idea of a slab, but my guess is that it would double the price of the install.

How long does a "standard" 10,000 gallon tank last, assuming it gets basic care?

[kalakoa]

sand base

Mason sand, ideally with concrete ring.

some people use used carpeting

Asphalt shingles seem to work.