Slow The Flow
For the health of our waterways, it’s wise to minimise stormwater run-off from your property, writes Sarah Pickette.
Minimise storm run-off for the environment’s sake.
After the rain comes the run-off. Rainwater should evaporate, settle on plants and other greenery or seep down to the water table, but when there are houses, concrete driveways and roads in the way, all too often it heads straight into our waterways as polluted stormwater.
“Urban environments handle water very differently to natural areas,” explains Georgia Harper, a Melbourne-based landscape designer and board member of Landscaping Victoria. “That’s where the principles of watersensitive urban design come in. It focuses on retaining as much water as possible on site and slowing the flow of water from your property.”
If every homeowner made a little effort to capture this water, the environment would benefit enormously, she says. “Stormwater often contains pollutants such as nitrogen and phosphorus. Grass, plants and soil can easily handle these, but they create problems in our water supply.”
Opting for plants over hardscaping slows erosion, can promote biodiversity and helps keep the temperature down around your home.
‘HOMEOWNERS CAN MAKE A DIFFERENCE BY PUTTING IN RAIN GARDENS, FROG PONDS OR EVEN SOMETHING AS SIMPLE AS A SMALL DEPRESSION ALONG THE FENCELINE.’ Jean Brennan, Inner West Council
“Directing water into your own surrounds, instead of down the drain, not only tops up the water table but also protects your top soil and might even stabilise your building envelope,” says Harper.
You don’t need to devote huge areas of space to creating a water-sensitive garden. Installing a rainwater tank and dedicating even a small corner of your garden to water retention can make a difference, says Jean Brennan, urban ecology manager for Sydney’s Inner West Council, which has been running workshops on water-sensitive urban design over the past decade.
“Homeowners can make a difference by putting in rain gardens, frog ponds or even something as simple as a small depression along the fenceline to help slow run-off,” she says. A rain garden is a garden bed designed to catch run-off from gentle rainfall and filter it through loam or sandy soil that drains quickly and won’t release nutrients into stormwater.
To find plants suitable for a water-sensitive garden, look at what grows at the edge of dams and creeks in your local area, says Harper. She suggests lomandra (all species), knobby club-rush and sedges such as Cyperus (pictured, bottom) for sunny spots. In shady spaces, taro ( Colocasia, top), sweet flag ( Acorus) and flax lily ( Dianella, middle) are good options.