From piedmont@sunsite.unc.eduTue Aug 6 22:12:53 1996 Date: Tue, 6 Aug 1996 21:47:41 -0400 (EDT) From: Piedmont Communities Online To: london@sunsite.unc.edu Subject: Rainfall/cistern calculation - results (fwd) - Piedmont Communities Online http://sunSITE.unc.edu/piedmont mailto:piedmont@sunsite.unc.edu - ---------- Forwarded message ---------- Date: Mon, 5 Aug 1996 19:40:10 -0600 (MDT) From: blissv@nmhu.campus.mci.net To: piedmont@sunsite.unc.edu Subject: Rainfall/cistern calculation - results >X-Sender: beauty@batnet.com >Date: Tue, 30 Jul 1996 15:19:53 -0700 >To: permaculture-mg@amani.ces.ncsu.edu >From: Loren Davidson >Subject: Rainfall/cistern calculation - results > > >I was asked by one list member to post any response I got. I've received >two versions of this, one in English and one in metric terms, and I think >I'll quote both here. (I haven't tested the metric one.) > >>From Jeff Jacobsen in Washington state (US)(English measure): > >>Here is what I do for my calculations: >> Roof size has to be the calculated equal to the ground area the roof >>covers. Hence, do your measurements parallel to the ground; if you >>measure at an angle your result will be too high. Determine area, i.e. >>length x width. Add all roofs or roof segments together to get your >>catchment area. If you work in inches you won't have to worry about >>conversion. Include your gutters too, since they catch water too. >> >>Divide by 231, the number of cubic inches in a gallon. >> >>This gives you the number of gallons for one inch of rainfall. >> >>Mulitply by annual rainfall to get annual catchment. > >And from Murray Hopkins in Australia (Metric): > >> If you want to do the conversions, the metric formula is: >> >> 1 litre of water per 1 mm of rainfall per square metre of roof. >> >>(4.5 litres per gallon, 305 mm per foot, approx 39 inches per metre.) >> >>You then need to subtract a percentage for losses. This depends upon how >>hot the roof is; how much water ends up in the gutters etc etc. >>We work on about 10% here but thats very variable. > >I also got some suggestions as to storage media, from stock tanks to 40 gal. >plastic barrels to ferrocement to pre-formed large plastic tanks (we've got >one already -- they're not cheap!). We're leaning toward ferrocement at >this point, but with at least a year before we have the resources (time and >labor) to essay this, anything is still possible. > >Again, thanks to those who wrote! > >Loren >Loren Davidson >loren@wombat.net >http://www.batnet.com/beauty/ >The First Amendment went too far. It should have said, "Congress shall >make no law". > Hi Piedmont! Here are the calculations you requested. Thank you for the soil mix recipes you sent on to me. It gives me a good jump on playing with the mix even before I locate the Coleman books. Appreciate your response. Vicki Garland >