From steved@ncatark.uark.edu Tue Oct 21 00:04:25 1997
Date: Mon, 20 Oct 1997 16:00:29 +0000
From: Steve Diver
To: permaculture@listserv.oit.unc.edu
Subject: Calcultations for rain water catchment
Some useful figures and calculations for rain water catchment:
1st
Inches rainfall x Square feet of surface area = Amount
2nd
Amount x 0.625 Factor
Factor = (12-inch depth per cubic foot and 7.5 gallons per cubic
foot of water) or (7.5 divided by 12 = 0.625)
Example:
30-inches per year is equivalent to 18.75 gallons per of water
collected from each square foot of surface area.
30-inches of rainfall collected from the roof of a 1,600 square
foot home = 30,000 gallons water
30-inches of rainfall collected from the roof of a 2,500 square
foot home = 46,875 gallons water
Storage tank capacity will depend on total rainfall, surface area
collected, seasonal rainfall patterns, and seasonal water use patterns.
If ya'll got any other handy calculations and figures, please
share them.
Steve Diver
--
steved@ncatark.uark.edu