DIY Rain Barrel System: 130-Gallon Capacity from Trash Cans

Reader Bob R. shares an inventive, low-cost rainwater harvesting setup he built four years ago—and it's still working beautifully.

System Design

Bob redirected roof drains to the downslope edge of his woods, then added catch basins to two downspouts. He connected the basins with 1.5-inch PVC pipe, then linked one basin to three heavy-duty trash barrels interconnected at the bottom. The result: ~130 gallons of storage that fills with even a small rain.

This gravity-fed system provides a reliable water source for outdoor plants without pumps or complex plumbing. The interconnected barrels equalize water levels automatically, and the catch basins filter debris before water enters storage.

Key Advantages

• Uses readily available materials (trash barrels, PVC, catch basins)
• Gravity-fed—no electricity needed
• Large capacity from modest rainfall
• Low maintenance once installed

This project demonstrates how simple components can create an effective rainwater harvesting system for landscape irrigation.