Rain Barrels & Downspout Diverters
Toronto Complete Guide

Rain barrels are one of Toronto's simplest eco-upgrades — capture free rainwater for gardening, reduce stormwater runoff that causes basement flooding, and lower your water bill. Toronto receives about 831mm of rainfall annually. A typical 1,500 sq ft roof captures over 47,000 litres of rain per year. A single 200L rain barrel fills up in minutes during a moderate storm.

How Rain Barrels Connect to Your Downspout

A rain barrel sits at ground level under a downspout. A diverter — a small fitting installed in the downspout — redirects water into the barrel when it's not full, and automatically returns flow to the original downspout path when the barrel overflows. This means:

• When the barrel has capacity → water diverts into the barrel
• When the barrel is full → water continues down the original downspout path to your drainage
• In winter → remove the diverter, reconnect the downspout normally

Toronto Rain Barrel Setup

1. Choose location: Level, stable surface near a downspout. Ideally close to your garden (shorter hose run). A full 200L barrel weighs ~440 lbs — it needs a solid base (patio stones, concrete pad).
2. Elevate the barrel: Raise it 12-18 inches on cinder blocks or a wooden stand. This gives you gravity-fed water pressure and room for a watering can under the spigot.
3. Install diverter: Cut the downspout at barrel height, insert the diverter kit. Most kits include a flexible hose from diverter to barrel. No tools beyond a hacksaw needed.
4. Install screen: Fine mesh screen over the barrel opening prevents mosquitoes, leaves, and debris from entering. This is CRITICAL — a rain barrel without a screen becomes a mosquito breeding factory within days.
5. Overflow: Connect overflow hose from barrel to a splash pad or garden area at least 4 feet from the foundation. Never let overflow pool against your home.

The Dirty Eavestrough Problem

Here's what most rain barrel guides don't mention: your barrel water is only as clean as your eavestroughs. Water flows from your roof through the eavestrough, down the downspout, and into the barrel. Everything in your eavestrough ends up in your water:

• Decomposing leaves: Create anaerobic sludge, foul odours, and bacterial growth
• Bird droppings: E. coli, salmonella, and other pathogens — unsafe for edible garden use
• Shingle granules: Asphalt and mineral fillers that leach into water
• Road salt residue: Sodium chloride that damages salt-sensitive plants (tomatoes, peppers, beans)
• Moss and algae: Organic matter that feeds mosquito larvae in your barrel

Mosquito Prevention (Critical in Toronto)

Toronto's West Nile virus risk makes mosquito prevention mandatory for rain barrels:

• Fine mesh screen: 1mm or smaller mesh over every opening. Check monthly for tears.
• Sealed lid: No gaps. Mosquitoes can enter through openings as small as 2mm.
• Mosquito dunks: BTI (Bacillus thuringiensis israelensis) tablets — non-toxic to humans, pets, and plants. Kills mosquito larvae only. Available at Canadian Tire/Home Depot for ~$10. One dunk per barrel, replace every 30 days during mosquito season (June-September).
• Use water regularly: Don't let water sit stagnant for more than 7 days — mosquitoes need 7-10 days of standing water to complete their breeding cycle.

Toronto Winter Storage

• Disconnect in November: Before the first freeze. Water expands 9% when frozen — a full barrel will crack.
• Drain completely: Turn barrel upside down to empty. Leave spigot open.
• Reconnect downspout: Remove the diverter and reconnect the downspout sections. Water must flow to drainage during winter to prevent ice dams and foundation issues.
• Store barrel: Inside garage or shed is ideal. If storing outside, flip upside down so it doesn't collect snow and water.
• Reconnect in April: After the last freeze risk. Clean the barrel interior with diluted vinegar before first use.

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