11 November 2011

RAIN GARDEN INSTALLATION


Rain gardens are such an important and easy fix for managing stormwater on residential properties.  They also serve as a seasonal water feature and a beautiful focal point.  Committing to a rain garden does not mean that you will have a stagnant pond in your yard. In fact, rainwater should drain within 24 hrs. or it's not a good spot for a rain garden.
This is a rain garden that I installed over the summer in NE Portland.  It is about 180 sq. ft. and will accommodate all of the rainwater coming from the roof.  The plants in the bottom, mostly grasses and some ferns can be inundated with water and still thrive.
I put this basalt rock with a natural bowl in it to attract birds for a little bath.
This is where the water enters.

When landscapes are covered in vegetation, rainwater naturally soaks into the ground, but when we cover it with impermeable surfaces, like driveways, sidewalks, roofs, and even a grassy lawn that is compacted, the water runs off carrying pollutants into local creeks and streams, and taxes water treatment plants.  Here in Portland, when we get a good rainfall, and not even a huge event, our sewage system overflows into the river. Yuck.

All of this runoff  also creates 100 yr. flood-like conditions in streams every time it rains, causing serious erosion and sedimentation that chokes out wildlife.

Here's how we got it done:
The bottom of the rain garden only needs to be 6-8" lower than the surrounding ground.
Getting the water there... with a kitty.  The water can also travel above ground by creating a rocky creek like channel.
Gettin' it done.  Rain gardens need to be heavily planted to filter pollutants, absorb the water, and prevent erosion.

Other benefits of rain gardens are their ability to filter out pollutants before the water gets to the streams, and they recharge the water table keeping streams from drying up during times of low rainfall.
It can also be packed with perennials on the rim to include lots of color.
Proud new explorer.

Here are a few recent fall shots.  The plants grew so well in just a few months.  Good thing, because they are hard at work now.


There are lots of great resources on the internet to learn about rain gardens.  If you are in Portland the East Multnomah Water & Soil Conservation District is a great resource and even offers free workshops to help you build one on your own.  http://www.emswcd.org/raingarden
I love talking shop, so ask away if you have any curiosities.

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