How-to guide for harvesting and using rainwater

Rain can do a lot more than ruin parades or set the mood for romantic movie scenes. From reducing your water bill to making your lawn the envy of the neighbourhood, the collection and redistribution of rainwater is an economical and eco-friendly practice. Dip your toes into the world of rainwater harvesting with this handy how-to guide.

There are a number of ways you can put your potentially valuable rainwater to work rather than just letting it go down the drain.

• Watering lawns and gardens
• Irrigation
• Toilet and urinal flushing
• Washing clothes and vehicles
• General household cleaning
• Drinking and bathing water (where approved)

By harvesting rainwater for these uses, you can enjoy the following benefits:

• The conservation and replenishment of groundwater supplies
• A lower water bill and reduced dependence on the municipal water supply during peak summer season
• Reduction or elimination of stormwater runoff that can damage infrastructure and combined sewer systems
• Lower energy consumption rates than wells
• Convenient access to a sustainable, renewable water source 

Good to know!
Regulations for rainwater structures and usage can vary by province, territory and local jurisdiction. Check with local building authorities before constructing your rainwater-harvesting system.

Your rainwater harvesting methods will depend on your water needs and space limitations, but all rainwater collection systems involve the same basic components.

• A catchment area to capture the rainfall
• A conveyance system to move the captured rainwater to a storage tank
• A storage system to safely store the collected water
• A distribution system to utilize the stored rainwater

For watering your home lawn and garden, a basic rain barrel is a good place to start. You can purchase pre-built barrels or kits from home-improvement stores or specialty retailers. Or, follow these steps to build your own:

• Drill a hole near the bottom of a large plastic container (a garbage bin, for example), leaving enough space to fill your watering can
• Place a metal washer onto the threaded end of your spigot
• Place a snug-fitting rubber washer in front of the metal washer to prevent leakage
• Apply waterproof sealant over rubber washer and insert spigot into the hole in the plastic container
• Allow sealant to dry (follow instructions on label for drying times)
• Place a rubber washer followed by a metal washer onto the threads of the spigot inside the container
• Secure the spigot with a hose clamp
• Cut a large enough hole in the lid of the container to accommodate water from your home’s downspout
• Drill one or two small holes near the top of the container for overflow
• Cut and place landscaping fabric between the lid and container to keep pests out of your water
• Position your completed rain barrel directly beneath your downspout 

Good to know!
Collect and store even more water by connecting an additional barrel using a short length of hose or PVC pipe from the overflow hole.

A simple rainwater barrel may keep your flowerbeds happy, but when you really want to stretch your water supply, it’s time to up the ante. There are three categories of professionally designed and installed rain-harvesting systems to get things flowing.

Non-potable water, for outdoor use

• Provides water for irrigation, gardening, filling pools, cleaning vehicles and fire protection
• Usually only seasonal in operation
• Tends to be less expensive and have smaller storage tanks than the other two types of systems

Non-potable water, for indoor use

• Provides water for flushing toilets
• Operates year-round
• Requires removal of debris build-up in gutters and conveyance system to reduce discolouration
• Usually includes post-storage particle filtration, but not water disinfection equipment
• Requires clear labeling of rainwater lines to reduce risk of cross-contamination with potable water lines

Potable water

• Provides water for drinking, bathing, cooking, laundry and dishwashing
• Generally operates year-round
• More costly to design and build than the other two systems
• Requires more pre-cleaning and post-storage disinfection
• More storage capacity than the other two systems

Good to know!
Every rainwater catchment system should include a diverter to prevent overflow or contamination. Diverter pipes should always drain away from the home’s foundation to avoid flooding or water damage.

Whatever your intended use for it, rainwater is a viable resource worth tapping. From basic barrels to sophisticated in-ground systems, harvesting rainwater lets you harness the power of nature in a sustainable and economical way. By creating or implementing your own rainwater harvesting system, you’ll soon see the silver lining in every cloud.