How to get the most out of rain

By Lori Huskey

If you’re sick of hearing about Portland, Oregon as the archetype green city, brace yourself for just one more lesson: the rain garden.

A rain garden uses the water harvested from roof gutters to irrigate a garden or yard, by redirecting the route of water that would normally go into sewers through drains.

Rain gardens keep rivers clean by limiting the debris that rain water normally pushes through the gutters and then rivers and can cut down on the amount of pollution reaching creeks and streams by up to 30 percent.

They also reduce rain runoff by allowing storm water to soak into the ground as opposed to flowing into storm drains and surface waters—a process that can cause erosion, water pollution, flooding and diminished groundwater.

Although the rain garden originated in the 1990s in Maryland, many Oregonians have adopted this eco-friendly gardening technique.

Many cities and towns, including Portland, offer incentives for residents willing to create a rain garden and may offer a nearly 100 percent discount on storm water charges typically found on water bills.

In fact, the home and garden crew from This Old House visited Portland and aired their making of a Portland, Ore. rain garden on PBS. Not surprisingly, the rest of the country, namely those in climates with high rainfall, has already caught on.

The key is to build a garden where there is a depression in the land. On This Old House the landscaper dug a two-foot-deep plot in the yard in order to enable a downhill flow.

Native plants are recommended for rain gardens because they generally don't require fertilizer and are more tolerant of local climate, soil and water conditions.

The plants — a selection of wetland edge vegetation, such as wildflowers, sedges, rushes, ferns, shrubs and small trees — take up excess water flowing into the rain garden. Water filters through soil layers before entering the groundwater system. Root systems enhance infiltration, moisture redistribution and diverse microbial populations involved in biofiltration.

Rain gardens are not just for homes and are designed to absorb rainwater runoff from impervious urban areas like roofs, driveways, walkways and compacted lawn areas for businesses or car parks.

The city of Portland currently provides residents with the tools required to build a rain garden and through Clean River Rewards, residents are working together for clean rivers. The rewards are reduced storm water charges for citizens, as well as cleaner water, healthy watersheds and more livable communities today and for future generations.

By disconnecting downspouts, rain gardeners will help the sewer system from overflowing when it rains and instead, can be directed to a yard, garden, swale, storm water planter or to a rain barrel or cistern for storage.

The rain garden is just one of many ways you can re-use water. The city of Portland has a comprehensive website with all the information you need to take advantage of your area’s annual rainfall.

For example, the website also has instructions on how to build a rain barrel. This makes sense for Portlanders since the city gets an average of 37 inches of rain per year.

If you contact your local water supplier, you’ll be surprised at how many cities that offer services and plans on how to keep the sewers lower and rivers cleaner.