6 Ways to Collect Rainwater

Rain drops falling off a ledge.

One of the essential elements we are provided with from nature is rainwater. The volume will depend on your geographical region, but you can harvest up to 80% of whatever amount falls from your roof. A stunning 600 gallons an hour can run off of a typical roof in moderate rainfall. That’s approximately 4,800 bottles of water. Let that image sink in...and now let's discuss ways you can catch rainwater for basic household and garden needs.

1. Barrel Systems / Cisterns

A large cistern next to a building for collecting rainwater.

An average sized rain barrel holds 50 gallons. Place one directly under a downspout for the most catch, or leave it in an open area close to gardens. Diverters fit in the middle of a downspout and connect directly to the barrel, filtering out debris and preventing any run-off from hitting the foundation of your house once the barrel is full. If you find yourself having to travel back and forth with a watering can, consider attaching a hose. Make sure the barrel is raised off the ground as gravity is what forces water to a can or hose. A screen at the top will keep out debris and animals. Cisterns are similar to a barrel, but will hold a larger quantity of water—usually 1000+ gallons—and can be installed above or below grade.

2. DIY Rain Barrel

As long as it’s waterproof and can hold liquid, you can make a rain barrel out of anything. Some DIYers creatively use plastic or galvanized garbage cans by making a hole in the lid for a downspout to connect and attaching a small tap at the bottom. Always add a screen or filter because otherwise the spout will plug up. You can find basic shut-offs and valves at the local hardware store and create your own hose attachment with some plumbing knowledge. Basic barrels can be made for around $50, or less if you already have a spare garbage can or container lying around.

3. Readymade Barrels

A black rain barrel with flowers next to it.

Hardware stores usually have a few ready-to-go options and the online selections are endless. They range from the rudimentary black PVC style barrel to highly decorative and trendy containers. Prices will range as well, so ask yourself if you want something that will fit in with your outdoor décor or something merely functional. Some act as a planter at the top where you can add flowers or herbs to spruce up the look and functionality. This can be a good option if you are worried about how they look and will fit in with the neighborhood; some community organizations are strict about the visibility of rainfall catch systems.

4. Larger Catchment Systems

You’ll need to install a larger rainwater system for any indoor use. The idea is similar to others in that you utilize the rain that falls from the roof, but instead of a barrel or cistern, a tank is set up next to the home, underground or in the basement. Tanks vary in size but can hold up to 10,000 gallons of water. The system connects to the home’s water pipes, filtering and purifying the water so that it can be distributed throughout the house. A typical system costs around $9,000, but the investment can be worth it depending on your yearly water usage or if you want to go off the grid.

5. Living or Green Roof

A cabin roof with green grass growing on top of it.

A fashionable but environmentally sound trend these days is the green or living rooftop. Commercial buildings tend to utilize their flat surfaced roofs to create these bio-diverse landscapes, but energetic homeowners can try their hand at it as well. The idea is straightforward, however, the preparation of the space isn’t that simple. Whether you have a flat or sloped roof, make sure the structure can withhold the extra weight of plant life and water. Also, you’ll need to install proper waterproof barriers, a layer of soil, and a selection of plants that can thrive without much care. A living roof provides excellent insulation for the building from the heat and cold and adds greenery simply with the use of excess rainwater.

6. Rain Garden

Rain gardens are a beautiful way to make optimum use of rainfall from a rooftop, driveway, and other run-off surfaces. Choose a low spot where water naturally runs to, away from the home’s foundation. Dig a shallow depression in the lawn and fill it in with perennials, shrubs, and flowers, focusing only on plants that will establish deep roots. The depressed ground will catch and absorb the rainwater before it hits the sewer system, which in turn fills groundwater systems, waters plants without extra irrigation, and prevents flooding in basements and yards. Rain gardens remove a large amount of chemicals and sediment from the runoff while utilizing the nutrients that would otherwise go unused. They are a great replacement for stubborn grass or soggy spots and add beautiful flora to your property.

There are many ways to catch rainfall, so ask yourself how much of that 600 gallons an hour you’d like to keep around. Also, check local laws to make sure how much you are allowed to harvest. Some areas are strict, while others may have tax credits for certain projects. Please note: never drink rainwater without a purification system. Feel free to use your catch to hydrate lawns, gardens, and plants—all while keeping a free resource from going down the drain.