Most rainwater calculators give you a single number based on average rainfall. But you don't live in an "average" year. Some years it pours. Some years there's drought. Your water system needs to handle all of them.

That's where this simulator comes in...Real Weather Data, Real Answers.

This tool pulls 5 years of actual historical rainfall data for your location—real day-by-day rainfall from 2020-2024. It runs a complete simulation of your proposed system through each year, tracking every liter collected, used, and most importantly: every day your tank runs dry.

Here's What You'll Discover:
The Big Picture: See how your system performs across multiple years. Maybe 4 out of 5 years work perfectly, but year 3 was a disaster. Now you know exactly what conditions cause problems and how to fix them before you build.

Worst-Case Planning:
The tool identifies your worst-performing year and uses that for design recommendations. If your system works in the worst year, it'll work in most years. That's conservative, reliable design.

Climate Variability
Exposed: Watch rainfall swing from 1,200mm in a dry year to 1,800mm in a wet year. See how this affects your water security. Understand why average annual rainfall doesn't tell the whole story.

When Things Go Wrong:
The year-by-year performance table shows exactly which months had water shortages, how many days you went without water, and why. This isn't abstract—it's "You'll run out of water for 8 days in February" level of specific.

Drill Down to Daily Details
Click "View Daily Details" on any month for the full day-by-day breakdown: rainfall amounts, water collected, tank levels, and exact days your system failed. It's like watching your water system operate in fast-forward, letting you spot problems before spending a penny.

Interactive Year Comparison:
Use the year selector to jump between different years. Compare how your system handles a monsoon year versus a drought year. See how that 30% rainfall reduction caused 3 weeks without water, or how a deluge kept your tank overflowing for months.

Visual Insights:
Annual Rainfall Bars show year-to-year variation. Reliability Trend Line tracks your percentage of days with water. Detailed Performance Table breaks down every year with monthly rainfall, days without water, and system status.

Statistical Insights:
The tool tells you things like: "Your worst year had 15% below average rainfall" and "Year-to-year reliability variance: ±8%"

Optimization Tips:
After showing you the problems, the tool provides Smart Optimization Tips with personalized advice:
System Design Recommendations: Downspout sizing, gutter selection, first flush volumes, pump requirements, and filter specifications tailored to your roof size and rainfall patterns.

Seasonal Strategies: When to clean gutters, how to prepare for monsoon season, when your tank must be full, and how to manage overflow.
Maintenance Schedules: Monthly, quarterly, and annual tasks to keep your system running perfectly.

The Bottom Line:
This isn't just a calculator—it's a risk assessment tool, a design validator, and a teacher. It takes the guesswork out of rainwater system design by showing you exactly how your proposed setup would have performed during recent years.

Want to know if that 10,000L tank is big enough? Run the simulation. Wondering if you can skip the expensive second tank? Check the worst-case year. Curious whether your family's water usage is sustainable? The data doesn't lie.

In 5 minutes, you'll know more about your water system's reliability than most people learn after years of trial and error. That's the power of real data, smart simulation, and design tools that actually care about whether your system works in the real world.

Ready to see how your system really performs? Explore your multi-year analysis now.