Midwest Permaculture

-Creating the Rain Gardens-

The first project we decided to undertake was the transformation of our front yard into a beautiful, but fully productive garden. We want to create something that looks good, feels even better to be in, while at the same time, producing food and herbs for our own consumption.

Our first task to find a way to hold the thousands of gallons of water that roll off of our roof when it rains and find a way to hold it on the property.

The answer: rain gardens and swales.

Before student began to dig, we marked out where we wanted our rain gardens to be.

2.

Every time we get an inch of rain, over 1,200 gallons of water comes off of our roof. When water flows down the drain spout it will now flow into three-shallow-retention ponds or 'rain gardens' by way of a swale or ditch, rather than just flowing off or our property.

3.

The purpose of the rain garden and swales is not to hold water year round (although we could build them that way) but rather to hold the rainwater on our property just long enough until it has slowly soaked into the ground.

Doing so will allow us to store the water in the subsoil beneath our gardens for long periods of time.

The excess storage capacity will significantly reduce our need to water or irrigate this garden area.

Digging the main swale or ditch that takes the water directly from our down spout.

4.

Our students learned to use a simply constructed 'A' frame to check the level of the swale and ponds.

5.

What would have taken me the better part of two days (and a sore back no doubt) was completed in 3 hours by the students from our October Permaculture Design Course.

In the permaculture world, when a bunch of folks get together to transform someone's yard, this is called 'perma-blitzing'.

This picture taken on:
10-29-07

6.

The first good rain following the digging of our rain gardens came about three weeks later on
11-21-07.

These next few pictures were taken early, however, it rained most of the day just about filling all three rain gardens to the top.

I estimated that we collect over 1,400 gallons of water, all of it being held on our property. By the next morning (Thanksgiving) it had all soaked into the ground.

Simply constructed, these rain gardens will support our ability to grow vegetables, herbs and flowers for decades to come.

Looking at it from the side.

7.

The mounds next to the impressions consist of the dirt we dug out which we have covered with a wood chip mulch.

The raised beds will give our garden some contour, making it a bit more interesting to the eye. They will also, as part of a permaculture design, diversify the micro-climates around the garden. The sides of the mounds facing the sun will be ideal places to raise sun loving plants, the back-side, cooler-moisture-loving plants.

The long dark strip to the rear is a berm made from the extra soil. It is a second catchment feature that will hold excess water on our property as the ponds overflow.

8.

The mulch on the mounds will prevent erosion, hold down weeds in the spring, hold in moister, and provide organic matter (food) for the micro-organisms in the soil that build fertility.

The swale/ditch next to the sidewalk not only connects the rain garden ponds, it also helps to drain the water off of our sidewalk. It has slowly sunk into the ground over the years, collecting water and making it an ice hazard in the winter. That problem now seems to be solved as well. Another permaculture principle at work -
"Stacking Functions".

9.

The narrow trench (center) connects pond #2 to pond #3. Water can be seen at the bottom of it.

We raked the yard leaves into the back 'pond' already so it is hard to see it and the small amount of water it is holding.

The leaves in the bottom of the pond/water gardens will minimize erosion over the winter while providing nutrients to the soils as they break down in the spring.

10.

At the down-spout, we attached a 5-6 foot drainage tile and buried it slightly into the ground, the fresh dirt, now covered with leaves.

The drain tile disperses the downward pressure of the rushing rainwater thus minimizing erosion at the base and leading the water more-gently into the swale that feeds the ponds.

Thank you to all of our student from our August and October design courses for your great work and ideas.
Bill (11-23-08)

This next set of pictures posted 1-24-08

11.

Well, we've had a couple of winter months to see how our 'rain gardens' perform with snow, freezing and thawing.

So far, we have had 3 pretty good snowfalls this season and following each one, the same succession occurs in the gardens.

First, the roof and yard fill with snow, almost eliminating any visible evidence of the rain gardens.

12.

Then it warms up and the snow begins to melt.

13.

All the melting snow from the front half of our roof makes its way to the one gutter that feeds into our rain garden swale.

From there it eventually fills all three of our rain gardens.

The water now follows in a horseshoe shaped path around the entire front of our yard.

14.

What is interesting however, rarely does the water make it all the way back to the side of the house. The rain gardens hold an estimated 1,400 gallons of rain water. They fill and drain with every rain or snow-melt, rarely overflowing.

I am guessing that 80% of the water that used to leave our front yard now stays on the property, charging the subsoil with moisture that we will be able to use all summer long.

Sometime over the next several weeks Becky and I will be deciding on many of the plants that we will put into our newly formed rain-garden beds.

We'll share some of that with you after we do some of the research.

Bill --
This is one thing I don't understand:  I can see the point of swales on a hillside such as in the excellent video you have here, where the swale catches water that otherwise would have headed down a hillside, and retains it in the soil.  It's a variation of traditional terracing methods.  But  you estimate that the swales in your rain garden catch 80% of the rain that normally would have left your property.  Why do you think that the swales in your rain garden catch and absorb any more water than the grass cover that was there originally?  The rain can't roll off a flat yard, can it?  And it's not like the grass is an impermeable surface like a parking lot.

Also, if in fact the swale IS catching all that extra rain, aren't you going to have water seepage problems in your basement from all that extra water retained in the soil?  Again, the result of living on a flat savannah landscape and not on a hillside.  Is it really appropriate for a flat suburban landscape? 

This is really basic stuff, I know, but I can't figure it out.  I am eagerly awaiting the result of your experiment.  I love the idea of rain gardens but these points are eluding me.

Thanks -- Edie

Good to hear from you Edie,

What great questions…!  If you don’t mind Edith, I would like to post your questions right on our website along with my answers.  If you have these questions, I bet there a many others who do as well.

Almost all surfaces have the ability to absorb some amount of water.  A concrete parking lot for example might be able to absorb 1 inch of water over the course of two days if it comes as a mist over that amount of time. My yard might be able to absorb 1 inch of water over an hour period if it comes down evenly and the ground is dry.  However, if it rains cats & dogs giving me an inch of rainwater in 10 minutes, there is no way my lawn can absorb it fast enough, so the excess runs off.  In a dense forest, this same inch of water in 10 minutes is no problem.  The leaves and bark from the top of the trees and all way to the ground will absorb a tremendous amount of water (approximately an entire inch of rain) and then the ground litter and soil will absorb even more.

What the rain gardens, swale (ditch really), and berm do in my yard is to collect the excess, holding it on my property until it has time to soak in slowly.  The key here is the word ‘slowly’.  With typical rains and snow thaws, only a certain amount of water will penetrate into the subsoil. Create a way to hold it in place for awhile and you can store much greater quantities – much, much greater quantities.  

Now, if I had a basement, then having excess moister would be something to seriously consider, however, I have seen suburbanites actually use swales and rain gardens to pull excess water away from their foundations and soak the water in away from their home but still on their property, and solve a wet basement problem on top of that.  A basement can also be constructed to handle almost any amount of excess moister and have it wicked away to a low spot or to a sump pump.

All this being said, not all yards or landscapes can benefit from swales or rain gardens.  Some property is already very low lying, even boggy and really needs some draining to increase its use and productivity.  One again however, a permaculturist would take land like this, plant moisture loving trees and shrubs that will wick away excess moister (harvesting multiple benefits from these trees and shrubs in some way), and contour their land with slightly tipped swales, raising some places and lowering others, which would allow excess moisture to more quickly drain away, while planting their edibles and other useful plants on the drier berms created by the swales.

The idea behind doing earthworks in permaculture is to create more ideal growing conditions from whatever you started with.  

Does this make anymore sense Edith? 

Warmest Regards… Bill

This is my reply... 3-14-08

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Thanks for your quick response!  Yes, that helps! And please feel free to post this.  
 
One thing, though -- I don't think we would want to depend on sump pumps to get rid of basement moisture -- that's using fossil fuel most likely, and we don't want to do that.  Better to have the land scheme organized to wick the moisture away from the houses foundations and toward a more useful spot.
 
I appreciate the personal response!  It's always great to hear from you and see what you are doing.
 
Best wishes, Edie

And her response...

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Right she is about the sump pumps.

Check Back - More pictures to follow as things progress... Bill (3-14-08)

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