Volunteers from the Santa Monica Bay Restoration Foundation completed this demonstration rain garden in 2012. In 2015, DWP featured it in a Public Service Announcement: Pretend.
No herbicides were used in the turf removal. After not watering for a while, they simply dug it up.
All the plants are CA natives. The garden is full of sedges, rushes, grasses with interspersed colors and scents of California Rose and Yerba Mensa, Canyon Sunflower, Monkeyflower, Sages, Yarrow, Mugwort.
Milkweed is planted for Monarch butterflies. The garden attracts many butterflies, bees, birds & insects.
All the rainwater, which is captured by house and garage downspouts, flows into the garden. It is dispersed by the plants, and by French drains and underground gravel pits.
All of the hardscape except the driveway is permeable. A redwood bridge across the swale connects with a pathway of small rocks leading to the house. In the backyard, the owners removed the concrete in front of the garage, replacing it with gravel. Living low water ground cover and mulch cover other exposed areas.
What qualifies it as a rain garden?
A rain garden is a garden of native perennials, shrubs and small trees planted in a small depression designed to temporarily hold and soak in rainwater runoff that flows from impervious surfaces such as roofs, driveways, walkways and compacted lawn areas. Basically a rain garden receives rainwater channeled via gutters and connected pipes, allowing the rainwater to soak into the ground, as opposed to flowing into storm drains. Compared to conventional lawns, rain gardens allow for 30% more water to soak into the ground. Most rain gardens are built to hold a 1" rain event.
Every time it rains, the water runoff from impervious surfaces collects pollutants such as particles of dirt, fertilizers, chemicals, oils, garbage and bacteria along the way. The pollutant-laden rainwater enters the storm drain untreated. Storm water runoff accounts for 70% of all the water pollution nationwide. Rain gardens collect rainwater runoff allowing water to be filtered by vegetation. A rain garden retains water just long enough to percolate into the soil where the plants and soil microorganisms breakdown and remove the pollutants. By keeping the water onsite and preventing it from flowing onto impervious surfaces, a rain garden lessens the amount of contaminated water entering storm drains.
Native plants are recommended for rain gardens because they have adapted to Southern California's dry conditions. Native plants attract birds, bees, wildlife and beneficial insects that have evolved alongside these plants. In keeping with the idea of improving water quality, they do not require fertilizers. A rain garden using selected plants native to the region requires little watering once it's established. The plants are selected with large root structures to allow runoff to soak into the ground. Water that makes it past the roots moves through filtering soil layers before entering the groundwater system. Rocks may be strategically placed so that storm water runoff is slowed, allowing for better absorption and preventing erosion.
In summary, a rain garden:
A rain garden is a garden of native perennials, shrubs and small trees planted in a small depression designed to temporarily hold and soak in rainwater runoff that flows from impervious surfaces such as roofs, driveways, walkways and compacted lawn areas. Basically a rain garden receives rainwater channeled via gutters and connected pipes, allowing the rainwater to soak into the ground, as opposed to flowing into storm drains. Compared to conventional lawns, rain gardens allow for 30% more water to soak into the ground. Most rain gardens are built to hold a 1" rain event.Every time it rains, the water runoff from impervious surfaces collects pollutants such as particles of dirt, fertilizers, chemicals, oils, garbage and bacteria along the way. The pollutant-laden rainwater enters the storm drain untreated. Storm water runoff accounts for 70% of all the water pollution nationwide. Rain gardens collect rainwater runoff allowing water to be filtered by vegetation. A rain garden retains water just long enough to percolate into the soil where the plants and soil microorganisms breakdown and remove the pollutants. By keeping the water onsite and preventing it from flowing onto impervious surfaces, a rain garden lessens the amount of contaminated water entering storm drains.
Native plants are recommended for rain gardens because they have adapted to Southern California's dry conditions. Native plants attract birds, bees, wildlife and beneficial insects that have evolved alongside these plants. In keeping with the idea of improving water quality, they do not require fertilizers. A rain garden using selected plants native to the region requires little watering once it's established. The plants are selected with large root structures to allow runoff to soak into the ground. Water that makes it past the roots moves through filtering soil layers before entering the groundwater system. Rocks may be strategically placed so that storm water runoff is slowed, allowing for better absorption and preventing erosion.
In summary, a rain garden:
- Attracts a diversity birds, bees, and beneficial insects.
- Protects oceans land-based runoff pollution.
- Provides an attractive alternative to a traditional lawn.
- Doesn't need mowing or fertilizer as with traditional lawn.
- Requires little watering after plants are established; 60% to 70% of drinking water is used for conventional landscaping.
- Saves money that would be spent on irrigation.
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