Cole Mills and Michelle Tashima's backyard in North Portland's St. Johns neighborhood looked like a marsh after heavy rains. Now, water no longer puddles on the surface. Instead, it funnels into a basin-like depression, past carefully placed rocks and native plants, and into a French drain.
Their new rain garden not only functions well, but enhances the appearance of their property. "I just love how it turned out," said Mills. "It aesthetically changed the complexion of the yard."
The rainy season is a pounding reminder that there is more to yards than pretty flowers and pathways.
Stormwater management can keep top soils from sliding, basements from flooding and standing water from undermining a home's foundation, said Brit Sastrawidjaya of Portland's Blueprint Earth, who designed Mills and Tashima's new landscaping
A well-designed drainage and landscaping strategy can safely redirect water. Specifically, Sastrawidjaya recommends rain gardens that allow stormwater to soak into the ground rather than flow into storm drains.
Rain gardens with drought-tolerant and pollinator-friendly native plants also add beauty and sustainability to yards, enrich the land and create thriving, resilient ecosystems. she said.
"That muddy water running down the street?" Sastrawidjaya said. "It's carrying fertilizers, pesticides, oil and sediment straight into our ecosystems."
Stormwater management solutions such as rain gardens, rain barrels, ecoroofs or trees can prevent soggy lawns and protect downstream habitats from runoff, erosion and water pollution.
For those reasons, Oregon residents may be able to tap into government programs and incentives to manage the rain on their property.
A sustainable, native garden is also far less maintenance than a mowed lawn with hedges, according to experts.
"If we all make cleaner decisions and accept rain gardens and pollinator gardens as beautiful, we'll start understanding that these gardens need very minimal input," Sastrawidjaya said.
Rain gardens are essential for the Pacific Northwest, said Sastrawidjaya, who launched Blueprint Earth in 2020. She is the landscape designer and her partner, husband Eric, is the onsite landscape construction manager and arborist. Each has more than a decade of experience in the landscape industry.
Here are the first steps to creating a Blueprint Earth rain garden or bioswale, according to the Sastrawidjayas:
Choose the right location. Select a low area in the yard where water naturally collects. Avoid placing it less than 10 feet from the home's foundation.
Dig to the right size. Measure the size of the surface that will collect rainwater such as a roof, driveway or patio. A rain garden should be about 20% of the runoff area if there is sandy or well-draining soil; and 30% with clay or poorly draining soil.
Prepare the soil. Mix in organic matter like compost to improve drainage. Well-draining soil is crucial for water absorption.
Install native plants that thrive in both wet and dry conditions such as Oregon grape shrubs, sedges or ferns. Native landscaping supports local wildlife and adapts to the Pacific Northwest climate.
Layer boulders and rocks to make a naturalized pattern like the edge of a riverbank. Use varied sizes, from 2-inch stones to bench-sized boulders.
Top with mulch for moisture retention and weed control. Rain gardens are low maintenance but need occasional checks and watering during dry spells.
Brit Sastrawidjaya said that sustainable landscapes with proper stormwater management can reconnect people to nature and show what's possible when working with living systems instead of against them.
"We're proving you don't have to choose between beauty and ecology," she said. "You can have both, and it can feel incredible."
Proper stormwater management can protect homeowners from home foundation damage and cracking from hydrostatic pressure, and neighborhoods from dealing with destabilized slopes and landslides, said Brit Sastrawidjaya.
When basements are leaking or wet, check downspouts, gutters, grading and other landscape elements to see if they are the cause before investing in an expensive interior water remediation system or a French drain, she added.
Water overwhelming municipal systems can lead to combined sewer overflows and contaminated drinking water, she said.
Other issues can be dead zones in rivers and bays from nutrient loading, habitat destruction for aquatic species and increased urban heat island effect when water isn't absorbed and transpired by plants, said Sastrawidjaya.
State and local programs can offset stormwater management costs. Here are some programs:
The Portland Bureau of Environmental Services offers free workshops, onsite technical assistance and design guidance to residents of the city of Portland. For more information, visit portland.gov/ppd/infrastructure/managing-rain-your-property.
Oregon State University Extension Service offers rain garden information, native plant recommendations, rainwater harvesting regulations and permit information at extension.oregonstate.edu.