4 ms·

Rain is an intermittent resource. You need to size your capacity to some standard deviation above the mean to get to some confidence level you’re agreeable with

Rain is an intermittent resource. You need to size your capacity to some standard deviation above the mean to get to some confidence level you’re agreeable with. In Central Texas, where I’m at, 10k gallon of for a family of four is sufficient for a Western style life. That’s about 200 barrels — which is way bigger & more expensive than a single system.

nomoreplease 5y ago
Right. I should clarify that I meant for eating & drinking (survival), not necessarily showering or gardening
- thechao 5y ago
  Having gone down this path while sizing my water system ... it depends: (1) environment; (2) precisely what you mean by "survive"; and, (3) how healthy the water is. There's a lot of variation there. If you look at off-grid and deep-back-packing sort of sites, they'll give you a good idea. For me, it came to 500 gallons per person, for Central Texas, to "stay alive through the worst historical drought I know of". We don't have any natural place to get rid of sewage (we're on a solid limestone hill), so that really complicates things for us.
  - nomoreplease 5y ago
    Thank you for the insight
  - dredmorbius 5y ago
    Keep in mind that your storage requirements are also dependent on other supplementation. Ready.gov suggests one gallon (4 litres) per person per day (https://www.ready.gov/water https://www.ready.gov/water) It's helpful to look at actual empirical usage. Van Lifers often give their own usage statistics. This article gives a 6.15 gal/day (23 litre/day) figure: https://musingsonentropy.com/2014/10/07/motorhome-living-one-month-in-daily-water-consumption/ https://musingsonentropy.com/2014/10/07/motorhome-living-one... Household-level usage might be closer to 60 gal/day (225 litre/day) (1996 New Mexico water usage report, table of estimated usage). Keep in mind that individual usage varies, emergencies (heat, illness, freezing) may change patterns, and that there is discretionary and nondiscretionary usage. Don't undercount sanitation requirements -- regular bathing and flushing toilets will keep you healthy. It's possible to reduce those demands, but entirely eliminating them (unless methods are changed) is likely a bad idea.
  - gremlinsinc 5y ago
    I've been researching micro-homes, alternative housing, etc. Mostly for affordability but also to be environmentally friendly. There are these earthship houses in New Mexico that are amazing. They stay 62-72 degrees year round. They have orange and banana trees in the atrium. They reuse all water, the water that goes down the sink/bathtub is used in the greenhouse/entry/atrium, then it goes to the toilet, then it goes outside to a kinda marshland or wetland area where they have all kinds of greenery or maybe vine-grown vegetables and fruits (don't want black water on root veggies).
    - blitzar 5y ago
      Thanks for the introduction - that is a research line I might get stuck down for a few days! Its a bit sad too see how the mainstream system pushes people way from this way of living. "It can be difficult to obtain a mortgage for an earthship home. Many banks are unwilling to lend money for earthship homes, since there are few (if any) comparable sales in the area the lender can use to determine the home’s value." https://www.realtor.com/advice/buy/earthship-home/ https://www.realtor.com/advice/buy/earthship-home/
      - dredmorbius 5y ago
        A slight tangent, but the degree of control imposed through financing and insurance mechanisms is staggering. I'd first recognised this by an aside in James Burkes's Connections, where adoption of the latten-rigged sail was delayed by over 1,000 years in the west by the fact that the financiers and insurers of sailing ship voyages would not permit ships with this "new" (it had been used throughout the Arabian region for centuries) and "unproven" technology. (It's worth considering that much of modern banking, finance, business, and insurance practices came directly from the shipping world.) More recently you can look at redlining in mortgage and small commercial insurance markets. Paul Baran, one of the co-inventors of packet-switched networking in the 1960s wrote of this in one of his RAND publications on the ethics of computer-science and information applications in the 1960s. https://www.rand.org/pubs/authors/b/baran_paul.html https://www.rand.org/pubs/authors/b/baran_paul.html
        5y ago
gremlinsinc 5y ago
Rain is intermittent sure, but there's many earthship homes in New Mexico that catch rainwater and are mostly self-sufficient. They get like 2 inches of rain per year, and on dryer years maybe need to pay $100/year for water to be delivered/trucked in. I think if we could catch a lot more water than we allow to evaporate, especially in places like Utah where we've been flooding lately and are STILL in a drought.. I can't wrap my head around that. Why aren't we trying to collect all that excess water like a rancher trying to catch stray cattle that wandered onto their ranch?
- hanniabu 5y ago
  > Why aren't we trying to collect all that excess water like a rancher trying to catch stray cattle that wandered onto their ranch? Capitalist society, no profit = no initiative
  - deleted 5y ago
    [deleted]
- Retric 5y ago
  It is being collected, that’s what dam’s do. Economy of scale means letting the water runoff into streams etc and just building a single collection point on a river is vastly less costly than millions of individual storage systems on each property. https://en.wikipedia.org/wiki/List_of_dams_and_reservoirs_in_the_United_States#New_Mexico https://en.wikipedia.org/wiki/List_of_dams_and_reservoirs_in... A fair amount is required to flow out of state due to laws and water treaties.
  - dredmorbius 5y ago
    That ... still depends. There are areas with highly permiable soil and scattered watersheds. Much of the rain that falls in such places either isn't captured by reservoirs, or is directed elsewhere (absorbed into the ground, perhaps refreshing aquifers or the water table, evaporation). Reservoirs themselves have evaporative losses (especially in dry and windy climates). At smaller scales, localised cisterns could make sense, especially as supplemental storage and when integrated into initial designs (the case for many traditional building styles in dry climates). Considering that existing building styles already provide virtually all that's necessary for rainwater capture except the storage containment itself, the additional marginal costs are fairly modest.
twic 5y ago
Rain is also strongly seasonal, so i'm not sure thinking about it as a random variable, via its standard deviation, is helpful.
- dredmorbius 5y ago
  You should be considering both. There's the seasonality, which is to say, the expected duration of dry spells. There's the variability, which is to say how much the total quantity varies year-to-year. There might be additional concerns such as bimodal or heavily-skewed averages --- a mix of very dry and very wet years, with few near the "average" arithmetic mean, for example, would change the calculus for how large collection and storage areas need be. (I suspect that much of California might be subject to such patterns given the El Nino / La Nina ENSO cycle.)

nomoreplease 5y ago

Right. I should clarify that I meant for eating & drinking (survival), not necessarily showering or gardening

thechao 5y ago
Having gone down this path while sizing my water system ... it depends: (1) environment; (2) precisely what you mean by "survive"; and, (3) how healthy the water is. There's a lot of variation there. If you look at off-grid and deep-back-packing sort of sites, they'll give you a good idea. For me, it came to 500 gallons per person, for Central Texas, to "stay alive through the worst historical drought I know of". We don't have any natural place to get rid of sewage (we're on a solid limestone hill), so that really complicates things for us.
- nomoreplease 5y ago
  Thank you for the insight
- dredmorbius 5y ago
  Keep in mind that your storage requirements are also dependent on other supplementation. Ready.gov suggests one gallon (4 litres) per person per day (https://www.ready.gov/water https://www.ready.gov/water) It's helpful to look at actual empirical usage. Van Lifers often give their own usage statistics. This article gives a 6.15 gal/day (23 litre/day) figure: https://musingsonentropy.com/2014/10/07/motorhome-living-one-month-in-daily-water-consumption/ https://musingsonentropy.com/2014/10/07/motorhome-living-one... Household-level usage might be closer to 60 gal/day (225 litre/day) (1996 New Mexico water usage report, table of estimated usage). Keep in mind that individual usage varies, emergencies (heat, illness, freezing) may change patterns, and that there is discretionary and nondiscretionary usage. Don't undercount sanitation requirements -- regular bathing and flushing toilets will keep you healthy. It's possible to reduce those demands, but entirely eliminating them (unless methods are changed) is likely a bad idea.
- gremlinsinc 5y ago
  I've been researching micro-homes, alternative housing, etc. Mostly for affordability but also to be environmentally friendly. There are these earthship houses in New Mexico that are amazing. They stay 62-72 degrees year round. They have orange and banana trees in the atrium. They reuse all water, the water that goes down the sink/bathtub is used in the greenhouse/entry/atrium, then it goes to the toilet, then it goes outside to a kinda marshland or wetland area where they have all kinds of greenery or maybe vine-grown vegetables and fruits (don't want black water on root veggies).
  - blitzar 5y ago
    Thanks for the introduction - that is a research line I might get stuck down for a few days! Its a bit sad too see how the mainstream system pushes people way from this way of living. "It can be difficult to obtain a mortgage for an earthship home. Many banks are unwilling to lend money for earthship homes, since there are few (if any) comparable sales in the area the lender can use to determine the home’s value." https://www.realtor.com/advice/buy/earthship-home/ https://www.realtor.com/advice/buy/earthship-home/
    - dredmorbius 5y ago
      A slight tangent, but the degree of control imposed through financing and insurance mechanisms is staggering. I'd first recognised this by an aside in James Burkes's Connections, where adoption of the latten-rigged sail was delayed by over 1,000 years in the west by the fact that the financiers and insurers of sailing ship voyages would not permit ships with this "new" (it had been used throughout the Arabian region for centuries) and "unproven" technology. (It's worth considering that much of modern banking, finance, business, and insurance practices came directly from the shipping world.) More recently you can look at redlining in mortgage and small commercial insurance markets. Paul Baran, one of the co-inventors of packet-switched networking in the 1960s wrote of this in one of his RAND publications on the ethics of computer-science and information applications in the 1960s. https://www.rand.org/pubs/authors/b/baran_paul.html https://www.rand.org/pubs/authors/b/baran_paul.html
      - 5y ago

gremlinsinc 5y ago

Rain is intermittent sure, but there's many earthship homes in New Mexico that catch rainwater and are mostly self-sufficient. They get like 2 inches of rain per year, and on dryer years maybe need to pay $100/year for water to be delivered/trucked in. I think if we could catch a lot more water than we allow to evaporate, especially in places like Utah where we've been flooding lately and are STILL in a drought.. I can't wrap my head around that. Why aren't we trying to collect all that excess water like a rancher trying to catch stray cattle that wandered onto their ranch?

hanniabu 5y ago
> Why aren't we trying to collect all that excess water like a rancher trying to catch stray cattle that wandered onto their ranch? Capitalist society, no profit = no initiative
- deleted 5y ago
  [deleted]
Retric 5y ago
It is being collected, that’s what dam’s do. Economy of scale means letting the water runoff into streams etc and just building a single collection point on a river is vastly less costly than millions of individual storage systems on each property. https://en.wikipedia.org/wiki/List_of_dams_and_reservoirs_in_the_United_States#New_Mexico https://en.wikipedia.org/wiki/List_of_dams_and_reservoirs_in... A fair amount is required to flow out of state due to laws and water treaties.
- dredmorbius 5y ago
  That ... still depends. There are areas with highly permiable soil and scattered watersheds. Much of the rain that falls in such places either isn't captured by reservoirs, or is directed elsewhere (absorbed into the ground, perhaps refreshing aquifers or the water table, evaporation). Reservoirs themselves have evaporative losses (especially in dry and windy climates). At smaller scales, localised cisterns could make sense, especially as supplemental storage and when integrated into initial designs (the case for many traditional building styles in dry climates). Considering that existing building styles already provide virtually all that's necessary for rainwater capture except the storage containment itself, the additional marginal costs are fairly modest.

twic 5y ago

Rain is also strongly seasonal, so i'm not sure thinking about it as a random variable, via its standard deviation, is helpful.

dredmorbius 5y ago
You should be considering both. There's the seasonality, which is to say, the expected duration of dry spells. There's the variability, which is to say how much the total quantity varies year-to-year. There might be additional concerns such as bimodal or heavily-skewed averages --- a mix of very dry and very wet years, with few near the "average" arithmetic mean, for example, would change the calculus for how large collection and storage areas need be. (I suspect that much of California might be subject to such patterns given the El Nino / La Nina ENSO cycle.)