RAINSAVE
Catch the rain — barrels, water conservation, and home savings.
From sizing a rain barrel off your roof and seeing where your indoor water actually goes to pricing out a slow drip, timing an irrigation session, estimating greywater reuse, and turning savings into dollars, RainSave pairs free hands-on calculators with practical, honest guides. Catch more, waste less.
Rainwater & Water-Conservation Calculators
Free tools for catching and saving water at home — rain barrel calculator, household water-use calculator, leak drip-loss calculator, irrigation timing calculator, greywater estimate, and water-savings calculator.
Rain Barrel Calculator
Turn your roof area and local rainfall into gallons of harvestable rainwater, plus how many barrels you'd need to catch it and how much would overflow
Household Water Use Calculator
See where an average home's indoor water goes — showers, toilets, faucets, laundry, and dishes — in gallons per day, month, and year
Leak Drip Loss Calculator
Turn a dripping faucet's rate into gallons and liters lost per day, month, and year — a slow drip adds up faster than it looks
Irrigation Timing Calculator
Work out how long to run a sprinkler or drip line per session to hit a weekly watering target from your system's application rate
Greywater Calculator
Estimate how many gallons of shower, sink, and laundry water a household could realistically reuse for irrigation
Water Savings Calculator
Convert gallons saved into dollars saved on your water bill, combining your local rate with your usage reduction
The Water Museum
Wander an immersive, richly illustrated collection spanning the long human history of moving and storing water — cisterns and rain barrels, the aqueducts and ancient waterworks that carried it for miles, the wells and pumps that lifted it from the ground, and the modern rainwater and greywater systems that carry the same idea forward today. Every entry, image, and fact is drawn from Wikipedia and Wikimedia Commons.
Tour the museum →From the Journal
Practical guides on rain barrels and first-flush diverters, household water audits, fixing leaks, smarter irrigation, greywater reuse, and getting the most out of every gallon.
How Much Rain Can You Actually Harvest From Your Roof?
The math behind rainwater harvesting is simpler than it looks — a fixed conversion constant, your roof's footprint, and local rainfall are all you need to get a real number.
First-Flush Diverters Explained: Why the First Few Gallons Matter
The first water off any roof carries the dust, pollen, bird droppings, and grit that built up since the last rain. A first-flush diverter routes that dirty water away before it reaches your storage — here's how to size one.
A Home Water Audit: Where Does It All Actually Go?
Most households have a rough sense that showers and toilets use a lot of water, but few can say by how much. A simple room-by-room audit turns that hunch into real numbers you can act on.
The True Cost of a Dripping Faucet
A faucet that drips once a second looks like nothing. Run the numbers over a year and it stops looking like nothing — here's the arithmetic and why fixing it is almost always worth ten minutes with a wrench.
How Much (and How Often) Should You Really Water Your Lawn?
The '1 inch a week' rule is a good starting point, but a fixed schedule ignores your soil, your sprinkler's real output, and your climate. Here's how to build a schedule around actual measurements instead of guesswork.
Greywater 101: What You Can (and Can't) Safely Reuse
Not all household wastewater is created equal. Understanding the difference between greywater and blackwater — and what greywater can realistically be used for — is the first step before considering any reuse system.
Keep Learning
Plain-language explainers on the basics of harvesting rain, conserving and reusing water indoors, the history of water engineering, and smarter irrigation and landscaping — everything you need to go deeper with confidence.
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