Location: Lower Mainland British Columbia Canada Zone 8a/ Manchester Jamaica
posted 7 years ago
i do, just about every water harvesting system has a formula. im on the bus atm but ill dig it out of brad langcasters rainwatef harvesting book when i get home. try his book name plus the word formulas maybe you can find it on the net in the meantime
Forgive a question from someone just learning? Why wouldn't it be 30 gallons?
At 7.5 per cubic foot, 12' holds 90 gallons. Divide by 3 since it's only 4"deep would put it at 30 capacity. Presumably percolation rate, runoff and rainfall amounts change the equation but I haven't learned those details yet.
^if the swale is full then i think that 30 gallons is the correct answer, however, one inch of rain would be 7.5 gallons from my calculations... apparantly there was another thread on here and i did some calculation after figuring out an acre inch of rain is 27000 gallons