Last Sunday, we installed the Tiny House’s first rain barrel (left). By Tuesday, courtesy of one of several recent storms, we had our first fifty gallons of captured urban runoff. We are now self-sufficient in water for our crate garden, and need no longer use valuable treated water on our plants. We are also making a contribution, albeit a very small one, towards improving water quality in Lake Ontario.
Urban runoff is a major source of non-point source (NPS) pollution in the Great Lakes. Water flowing across impermeable urban surfaces can contain oil-based residue from vehicles, pesticides and fertilizers from lawns, salt from winter roads, excess sediment and simple garbage. Where we live, in one of Toronto’s older neighbourhoods, this water flows directly into the sewerage system. Intense rainfall or heavy snow melt easily overloads this system, allowing untreated overflow to enter local water courses and prompting the intentional discharge of partially treated sewer contents into the lake by overburdened wastewater treatment plants—a process known as a “bypass”. According to Lake Ontario Waterkeeper, the last weekend of June, for example, saw Toronto’s Humber and Ashridges Bay treatment plants undertake combined bypass operations lasting over twenty hours.
What difference does a rain barrel make?
We have roughly 400 square feet of roof surface. Based on the Toronto Homeowner’s Guide to Rainfall (THGR) from the RiverSides Stewardship Alliance, our fifty-gallon barrel would capture all the runoff (about 49 gallons) we could expect our roof to generate during a typical rainfall event of 0.2 inches. Even during a (rare) event as heavy as 1 inch total rainfall, the THGR suggests our single barrel could capture about 20% of the runoff (about 244 gallons) from our property.
Our entire lot is almost completely impermeable. When we moved into the Tiny House last year, almost 100% of rainwater falling on the property went into the city’s sewers. By “greening” over twenty square feet of extant paving, the crate garden we started last year already helps to keep some of the water where it falls. A rain barrel further and more significantly lowers our impact on Toronto’s water management infrastructure and our local watershed.
About the barrel
We bought our barrel for $25 from a local shop and connected it to our downspouts using two EarthMinded™ DIY rain barrel diverter kits. (One kit would normally be enough, but we wanted to connect two downspouts to the same barrel.) We got the diverter kits from Amazon for about $35 each plus shipping, which contributed to a total set-up cost of less than $100.
The EarthMinded kit was by far the simplest we found. Others, such as this one (right) from RainBarrel.ca, require cutting out a section of downspout and replacing it with a bulky external diverter unit, which, in our case, would have worked on one downspout, which is vertical, but not on the other, which is angled. Also, whereas the RainBarrel.ca-style set-up requires attaching a separate overflow hose to the barrel, our diverter rather elegantly sends excess water back into the downspout when the barrel is full. As with other diverters, ours can be disconnected during the winter and the downspout plugged using a hole cover included in the kit.
Installation was straightforward except for drilling the downspouts. Ours are flimsy and we didn’t want to destroy them with a 2-1/8˝ hole saw, so we practised on a scrap section until we achieved a drill speed and pressure that neither skidded off nor gashed the metal.
Less work for the sewers means less work for us
Until now, the nearest water supply for our outdoor plants was the kitchen tap, using which involved slopping a full watering can across the kitchen and down a flight of stairs. The rain barrel gives us the water we need exactly where we need it, right beside our crates. Reducing runoff is a very good thing, but we’re equally delighted to have reduced the need to mop the kitchen floor.