Collecting rainwater for use in the garden, toilet, and washing machine can lower your water bill, and decrease your ecological footprint. Benjamin Morrison is a national sales representative and technologist for Cleanflo Water Technologies, based in Regina, Saskatchewan. He helps homeowners design water collection systems to suit their needs.
“We’re using that water, that otherwise would be discharged either to the ground or into a storm system, to reuse on the property,” says Morrison. You can use the collected rainwater for gardening, irrigation, and in toilets and washing machines. For potable water, you’ll need a professional to ensure proper filtration. “There’s going to be debris from all sorts of things in the rain water,” says Morrison. “That debris itself is both what carries the bacteria and the nutrients that feed the bacteria.”
But for outdoor use, he says a do-it-yourself approach is an affordable option. Check your municipality’s rainwater collection rules before starting this project. Morrison advises drawing a diagram of your system first, before anything is purchased or installed, to reduce excess costs and unforeseen hiccups. If you’re smart and thrifty, Morrison says an effective and efficient rainwater collection system is within the reach of those with even the tightest budgets.
1. Gather supplies
2. Roof drainage
“Your first and most important thing is your roof and your piping, collecting that water and transferring it to a specific point,” says Morrison. Build your collection system on your existing eaves trough system.
3. UV light
It’s important to minimize the amount of sunlight entering the tank, because it encourages contaminants like algae to grow. “If you put your head in there and it’s bright as day, that’s UV,” says Morrison. “You want to eliminate that UV light.”
On a small-scale system like this, you won’t completely eliminate all light. But by using an elbow with a bend in it at the top where the water enters, or a pre-filter designed with light reduction in mind, you can minimize UV light.
4. Your tank
For a small-scale system, nearly any storage container can work. “Find a tank that you like,” says Morrison, who says even a simple blue barrel from a hardware store will do. “Find something that’s going to be safe to use, and within your budget.”
Ensure the tank doesn’t touch your home because it could damage your foundation. Place your tank 15 to 40 centimetres away from any building.
Cut a hole in the tank top that is large enough to accommodate the water from your downspout.
Install an overflow run off to prevent your tank from getting too heavy. It should be the same diameter or slightly wider than the point where the water enters the tank.
“From a safety perspective, you want an overflow on the tank, near the top,” says Morrison. It should drain off somewhere safe, preferably near where your gutter runoff would deposit. A few elbow pipes and some hose should suffice.
There are many items on the market that can do this, costing between $15 and $500. Several layers of simple window screening will help reduce the potential for contaminant growth in your tank.
Place the screen over the spout that directs water into your tank.
The water enters the tank from the eaves trough, which should end just above your collection tank. Direct water into the tank using the downspout elbow. From there, the water will pour into the tank through the screen filter.