6 ms·

With the water shortages around the world, can residential rain barrels provide a sufficient alternative? Is there a study for the number of barrels per person

With the water shortages around the world, can residential rain barrels provide a sufficient alternative? Is there a study for the number of barrels per person per climate?

thechao 5y ago
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.)
dredmorbius 5y ago
That depends on average rainfall, land area controlled per person, the variability of rainfall, and usage patterns. The simple answer is to look at average per-capita or household water use, average annual rainfall, and determine how much surface area (often a rooftop) is required to supply residential needs. Example: 15" (380mm) of rainfall over a 3,000 ft^2 (280m^2) roof is 28,000 gallons (100k litre) per year. That's 75 gallons/day (290 l/day). And would be typical of amounts that a Northern California suburban household might expect. Since rainfall is mostly in the winter months (November -- May or so), you'd likely want to have storage for at least half of that, which would be roughly the size of a typical backyard swimming pool (10' * 20' * 4' avg depth). Keep in mind that in many parts of the world, high populations corresponde to very high population densities, and the actual land-surface area per person is low. There are also regions in which residences are ephemeral or unstable, such that long-term investment is not attractive or individually sensible. Many high-population areas are also located in regions in which there is high rainfall (east, southeast, and southern Asia especially, also the Philippines and portions of South and Central America). Water may not be a limiting factor in those places. Water availability and access tends to be highly localised. There is a lot of water on the planet, the problems are having it where people are, when people need it. Household usage is one question, but if you're looking at agricultural water, the quantities and other requirements (when and where irrigation is required) scale up tremendously. Which is a long way of saying "it depends". Which is what I said at the beginning anyhow.
bluGill 5y ago
In some locations you are not allowed to do this because rain water is collected by someone downstream of you, and so your barrel is taking water from someone else. Check your local situation.
- dredmorbius 5y ago
  Note that this depends on the doctrine of water rights. The situation described is common in the Western US, where seniority of claims has priority over location in the watershed. Elsewhere, upstream users may have the rights to water. There's also been an increasing amount of explicit exception to seniority rules for the specific purpose of rainwater collection, though this may include limitations, notably that the water be used only on the property in which it was originally collected. That is: you cannot collect rainwater, then sell it to others.

With the water shortages around the world, can residential rain barrels provide a sufficient alternative? Is there a study for the number of barrels per person per climate?

thechao 5y ago

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.)

dredmorbius 5y ago

That depends on average rainfall, land area controlled per person, the variability of rainfall, and usage patterns. The simple answer is to look at average per-capita or household water use, average annual rainfall, and determine how much surface area (often a rooftop) is required to supply residential needs. Example: 15" (380mm) of rainfall over a 3,000 ft^2 (280m^2) roof is 28,000 gallons (100k litre) per year. That's 75 gallons/day (290 l/day). And would be typical of amounts that a Northern California suburban household might expect. Since rainfall is mostly in the winter months (November -- May or so), you'd likely want to have storage for at least half of that, which would be roughly the size of a typical backyard swimming pool (10' * 20' * 4' avg depth). Keep in mind that in many parts of the world, high populations corresponde to very high population densities, and the actual land-surface area per person is low. There are also regions in which residences are ephemeral or unstable, such that long-term investment is not attractive or individually sensible. Many high-population areas are also located in regions in which there is high rainfall (east, southeast, and southern Asia especially, also the Philippines and portions of South and Central America). Water may not be a limiting factor in those places. Water availability and access tends to be highly localised. There is a lot of water on the planet, the problems are having it where people are, when people need it. Household usage is one question, but if you're looking at agricultural water, the quantities and other requirements (when and where irrigation is required) scale up tremendously. Which is a long way of saying "it depends". Which is what I said at the beginning anyhow.

bluGill 5y ago

In some locations you are not allowed to do this because rain water is collected by someone downstream of you, and so your barrel is taking water from someone else. Check your local situation.

dredmorbius 5y ago
Note that this depends on the doctrine of water rights. The situation described is common in the Western US, where seniority of claims has priority over location in the watershed. Elsewhere, upstream users may have the rights to water. There's also been an increasing amount of explicit exception to seniority rules for the specific purpose of rainwater collection, though this may include limitations, notably that the water be used only on the property in which it was originally collected. That is: you cannot collect rainwater, then sell it to others.