Catchment Rain Tank Tracker

Know exactly how much water your roof caught, and how much is left in your tank — using real rainfall data for your exact property.

Catchment is a rainwater-tank calculator built for people who actually rely on tank water — not another generic weather app.

Enter your roof size, tank capacity, and property location once. From then on, Catchment checks real rainfall data for your exact spot and shows you:

• How many litres (or gallons) your roof has likely collected — today, this week, and this month • An animated tank that fills to show your actual remaining water level, factoring in rain collected and water used since you last checked • Usage estimates based on your household size, or your own numbers • A running history of daily rainfall and collection

WHY CATCHMENT IS DIFFERENT

Most rainfall apps only talk about annual averages. Catchment answers the question tank owners actually ask: "based on what's actually fallen recently, how much water do I really have?"

HOW IT WORKS

Catchment pulls live rainfall data for your property's coordinates and applies the standard rainwater-harvesting formula — 1mm of rain over 1m² of catchment yields 1 litre, before losses — using your roof area and a configurable wastage factor for evaporation, overflow, and gutter losses.

NO ACCOUNT REQUIRED

Every feature works immediately — no sign-up, no login. Your setup is stored securely on your device.

FEATURES

• Real-time rainfall estimates for your exact location • Roof area entry by total size or dimensions, in metric or imperial units • Litres, US gallons, or UK gallons — your choice • Animated tank visualization with remaining-level and usage overlays • 7-day and 30-day rainfall history • Works fully offline once cached, with pull-to-refresh for the latest data

Catchment is free to use.

Rainfall figures are modeled from the nearest weather station, not a physical gauge on your roof — a strong planning estimate, not a substitute for your own gauge reading.