WATER CONSERVATION - WATER CAPTURE

Calculationofrainwaterharvestingpotential

For our ecoblock, we expect to have at least 25,760 sqf of impermeable roof, at least 5,000 sqf of permeable green roofs, and at least 10,000 sqf of inground rainwater capture, such as french drains and dry stream beds. Assuming a depth of about 6" for our green roof substrate, we should double that area for the calculation, per Surfrider.org.

Simplerainwaterharvestingformula:

For every 1 inch of rain and 1,000 square feet of impermeable surface 620 gallons are generated, meaning you can capture about .62 gallons per sq. ft.

CALCULATION:

25,760 roof sqft x .62 = 15,971 gallons per 1 inch rainfall

Permeableareaharvestingformula:

Assuming a depth of 12” to your absorption area, divide the total gallons captured by 7.48 (gallons in a cubic foot of area).

CALCULATION:

20,000 roof sqft x .62 = 12,400 12,400 gallons/7.48 = 1,657 gallons per 1 inch rainfall

TOTAL:17,628gallonsperevery1inchofrainfall

Since Jackson receives about 21 inches of precipitation per year, our Eco Blockcanexpecttocaptureabout370,188gallonsofrainfallannually.