Control Storm water Runoff
International Federation of Landscape Architects
The Key to Being Storm-Proof: Control Storm-water Runoff
When a hard rain hits hard surfaces, such as dry, clay soil or pavement, it quickly runs off to where it may cause harm. To make matters worse, without significant vegetation or porous surfaces to sink into rain sweeps across yards and streets and carries pesticides and sediment into the water system. Urban storm-water runoff is the leading contributor of water resource pollution. And runoff is also a primary cause of residential flooding. Storm-proofing your property will save money in other ways. For example, when you divert drainage and reduce impervious surface areas, you will significantly lower your utilities bill.
A swale directs excess water flow to channel it somewhere it can be released safely.
Here are 5 Tips to Better Storm-Proof Your Landscape:
Channel with swales
A swale is a depression in a landscape that redirects water drainage. You can maximize swale use by lining the lowest point with rocks and adding deep-rooting plants to the slopes, slowing water’s path to the drain. A swale directs water flow, rather than stopping it. Therefore, you must make sure that it’s channeling to somewhere excess water will be released safely. Direct swales in frequently flooded areas to a dry well, or a garden bed with very good drainage and high water tolerance. To avoid utility charges, never have a swale draining straight off a property.
Even a small, inexpensive rain garden can significantly reduce flooding and runoff
Install a rain garden
Rain gardens add beauty and storm-proof functionality to any property. Although similar to swales, rain gardens don’t redirect water. Instead, they provide a place for water to pool during a downpour. This allows excess water to slowly percolate back into the soil. Most range from 50-100 square feet, and even a small, inexpensive rain garden can significantly reduce flooding and runoff.
Keep these tips in mind when planting a rain garden:
Put plants with the highest wet-soil tolerance in the center,
Plants at the edge will drain fairly quickly while the middle remains submerged,
Use native plants whenever possible, as they require little to no watering in between rainfall,
Native plants make a more low-maintenance yard and cut down on the need for harmful pesticides.
A downspout diverter is essential to prevent flooding next to the walls
Divert rain spouts
Don’t forget the smallest changes. A downspout diverter prevents flooding next to the walls, and gets water out to lower ground.
The City of Chicago recognized the positive environmental impact of a green roof– and installed one on City Hall!
Install a green roof
Green roofs are being installed more and more, and have become increasingly affordable. If you have a flat or gently sloping-roof, modular units are becoming popular for their ease of installation. People often worry the added load will cause extra-strain, but a study by the city of Portland, Ore, found that green cover actually increases the longevity of the roof. Also, the study found that ecoroofs provided better insulation, reducing heating and cooling costs.
Using pavers, Greenwise created a beautiful and functional driveway for a Northshore client
Switch to permeable driveways
Driveways made of impermeable surfaces, such as asphalt and concrete, are the biggest contributors to storm-water runoff. To mitigate flooding, add drainage on the sides of the pavement. Or ditch the asphalt or concrete pad altogether.
Gravel, spaced paving, permeable paving stone and other attractive hardscape materials that have spacing in between them will make a driveway an asset in the rain. Watch this video to see how quickly rainwater can drain into a permeable driveway where is will be safely returned to the water table: Permeable driveways
Storm-proof landscape design– with storm-water in mind– will keep your wallet, yard, and environment a little greener in the long run. And take some worries out of rainy days.