How do you calculate how much land you need?

I'm sure there are more factors, but right now I'm thinking about Water. Do any of the  books give you some guidelines

number of people
gallons of water needed per person (to grow food, sanitation, etc)
average rainfall for the area

what else? I'm sure it depends on the soil and summer temperatures and how well you can direct and keep the water where you need it.


(average rainfall * acres ) - (number people * water person) > 0


Alternative answer: move to pacific northwest or tropics

I guess we could talk about the other necessities too, not just water. That little house in Pasadena grows enough food for the family, but I'm sure they need to import a lot of water, soil, wood ...

maybe this should have gone in homesteading

Are you asking how much area you need to capture rainwater for household use?  Or are you planning to capture it for irrigation also?

Some links to calculators and other helpful info:

http://www.rain-barrel.net/rainwater-calculator.html

http://www.western-water.com/Acre-Foot_formula.htm

http://www.kascomarine.com/pondsizing_calculator.html

http://www.virtualsecrets.com/annual-rainfall-water-calculator.html

http://www.harvestingrainwater.com/

keep in mind that except in a few truly arid climates, there is a roughly inexhaustible supply of water in the atmosphere.  takes a little bit more ingenuity to capture it for use than rainwater or surface water, but there are many methods of doing so.

tel jetson wrote:
keep in mind that except in a few truly arid climates, there is a roughly inexhaustible supply of water in the atmosphere.  takes a little bit more ingenuity to capture it for use than rainwater or surface water, but there are many methods of doing so.

You're talking about this?

mos6507 wrote:
You're talking about this?

that's pretty much what I had in mind, but my hat's got a wider brim.

i dont think my wife will drink her own water no matter much i tell her the stilsuit filters it

Collecting rainfall: check with your local authorities.  Some places do not allow you to collect rainfall.     Crazy, but true.

Assuming you are allowed to (or don't care about the regulations)...

Don't assume that moving to the Pacific Northwest will provide all your water needs without a major effort.  I live in the PNW, and we have had essentially no rain this summer.  The last significant rain was in early June.  You need serious water storage to get through the summer on rainwater alone, since it is the winter's rainwater that you will be using.  Our well is only good for 2 or 3 gallons per hour  () , so ground water may not be a lot of help, depending on where you are.

KeithBC wrote:
Collecting rainfall: check with your local authorities.  Some places do not allow you to collect rainfall.   

As far as I know, there are no locations which do not allow rainwater collection in the soil.

I might be wrong, if I am, I hope someone will correct me. 

featherboa wrote:
i dont think my wife will drink her own water no matter much i tell her the stilsuit filters it

beat me to it.  to digress: I saw a chap who had tattooed the whites of his eyes blue.  ouch.

Ludi wrote:
As far as I know, there are no locations which do not allow rainwater collection in the soil.

Probably true, but not a lot of help if the water is wanted for household use too. 

I've come across the story a number of times in permie materials that a series of swales on a hillside can give rise to a spring... is it a myth?  a permie legend?

definitely would take a decent amount of land, but it would certainly make a hillside useful.

KeithBC wrote:
Probably true, but not a lot of help if the water is wanted for household use too. 

It might be possible to produce water for the household from a condensation pit, or as mentioned above on a larger property, an emergent spring.

Or maybe one should move to where rainwater collection is legal! 

besides water issues,you might be able to find a good soil map.My county has one that shows what your yields will be for various crops irrigated and not,animals too.My easily worked soil is very low in organic matter and leaches it easily.The maps and personal observation over 10yrs have confirmed that 1 ac of the best soil will produce the same amount as 5 ac of my soil with most common crops.Ive been really successful with N.fixers though and hope to lower that gap through research into more suited alternative crops.Annual precipitation,soil structure,and water table will all effect yields in non irrigated landscapes.