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Understanding Rainwater Harvesting
Formula
Rainwater harvesting collects and stores rainwater from roofs for later use in gardening, landscaping, and other non-potable purposes. One inch of rain on 1,000 square feet of roof yields about 623 gallons of water.
With 36 inches of annual rainfall and 80% collection efficiency, a 1,000 sq ft roof can collect about 18,000 gallons per year — enough to significantly reduce irrigation water costs and stormwater runoff.
Common use cases:
- Garden and lawn irrigation
- Reducing water bills
- Stormwater management
Frequently Asked Questions
Sarah Chen
Financial Analyst, CFA
Sarah is a Chartered Financial Analyst with over 8 years of experience in investment management and financial modeling. She specializes in retirement planning and compound interest calculations.
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