Rainwater Harvesting for the Garden

Catch roof runoff to water your beds. Use your own numbers — roof area, local rainfall, and water price — and we'll size a tank and estimate the payback. Every figure is labeled with its source.

⛲ Tank sizing

Roof area + rainfall → annual gallons and a recommended cistern size.

Size my tank →

💰 System ROI

System cost + water price → annual savings and payback years.

Calculate ROI →

🌱 Pair with watering

How many gallons your garden needs each week.

Watering calculator →

Rainfall defaults are NOAA/NCEI 1991-2020 statewide averages; your roof is one spot, so override with your local station value for accuracy. Tanks follow common U.S. above-ground cistern sizes.