1500 square feet of useful roof area that could feasiblely be used for cistern rainwater collection with a 75% collection rate, this amounts to roughly 680,000 gallons of rainwater which could be collected annually - 1,850 gallons per day.
(useful roof area; could feasiblely be used; for cistern rainwater collection) (this; amounts; to roughly 680,000 gallons of rainwater) (roughly 680,000 gallons of rainwater; could be collected; annually - 1,850 gallons per day)
useful roof area this roughly 680,000 gallons of rainwater
could feasiblely be used amounts could be collected
for cistern rainwater collection
to roughly 680,000 gallons of rainwater
annually - 1,850 gallons per day