RAIN GARDENS - LETTING STORMWATER SOAK IN
It typically runs off the roof, driveway and other surfaces, ending up in the municipal storm sewer system. Because it often picks up road salt, heavy metals and other harmful substances along the way, stormwater run-off can impact the water quality in your area and the health of lakes, rivers and streams.
One way to minimize stormwater run-off is with a rain garden. A rain garden is a garden that is designed to capture stormwater and allow it to be absorbed into the soil. Canada Mortgage and Housing Corporation (CMHC) offers the following tips on how to design and install a rain garden in your yard:
. Choose a location along a path that stormwater generally flows through your yard, particularly at an existing low point. To ensure that water soaks in and does not stand in the garden for more than two days, choose a location with well-drained soil, such as soil that is sandy, gravelly, loam or no more than 10 per cent clay.
. To avoid creating moisture problems, direct stormwater away from vulnerable areas, such as your house's foundation, septic beds or neighbouring homes. Place your rain garden at least 4 m (13 ft.) away from such areas.
. Lay out the size and shape of the garden with a rope or hose. To capture as much water as possible, a rain garden should be at least 1.5 times longer than it is wide.
Many people prefer kidney or oval shapes, but you can create any shape that suits your taste and yard.
. If the existing area is a lawn, use a sod cutter, spade or edging tool to remove your existing lawn from the garden space, making sure to get rid of the roots.
. Dig the bed of the garden to between 7.5 cm to 15 cm deep, depending on the soil. To help the new plants take root, add a layer of compost to the top few inches of soil.
. Rain gardens can be planted or covered with a permeable hard surface such as river stone, or a combination of both. If planting, choose species that tolerate both wet and dry conditions.
For a free copy of the "About Your House" fact sheet Rain Gardens: Improve Stormwater Management in Your Yard, or for information on any other aspect of owning, maintaining or buying a home, visit www.cmhc.ca or call CMHC at 1-800-668-2642.