Permaculture in Action: Swale Repair

In October of 2017 PermaBlitz #2 took place at a rural home in Butte Creek Canyon. The ~8-acre property is gently sloped in some strategic spots which provides considerable water harvesting potential. When the design team looked at how water was utilized they noted an existing on-contour swale that needed a bit of help.

What is a Swale?

How a swale works

How a swale works

A swale – which is a dead level ditch on contour – stops water from rushing over the land and instead sinks the water into the soil keeping the soil moist for longer periods of time while also aiding in groundwater recharge. It’s important to regard swales not just as a method of slowing and holding water but as a tree growing system. Tree roots stabilize the landscape and moderate the saturation levels by utilizing the water held in the soil. The illustration shows water in a swale as it sinks and plumes slowly down through the land. A mound or berm is used to plant trees downslope from the swale and a level sill spillway allows the water to passively flow to a predetermined area, such as another swale, a pond, much basin, etc.  One important goal in permaculture design is to re-use water as many times as possible before it flows off the land.

Existing Swale Problems

The PermaBlitz design team noticed that the back cut of the swale was too steep, the bottom uneven, and the level sill needed improvement.  Additionally, if the swale were to fill up, the overflow route took the water to only one apricot tree before moving down to a mulch basin. To gain insight and to problem solve, the design team drew up a Water Overlay for the property.

PB#2 Water Overlay

Water Overlay for PermaBlitz #2. The swale that was repaired is directly above DS-5 (downspout 5).

The design team decided to reshape the existing swale’s back cut, re-level the bottom of the swale and move the level sill spillway to different location entirely. The Host told us that this swale had never filled up with water, but with a recently installed 2,680-gallon rain tank, overflow water would now be able to move into the swale. During winter, water would certainly fill the swale and overflow. Note in the Water Overlay illustration how the water will now be able to move to several trees instead of the one. This zig-zag pattern SLOWS water and allows it to SPREAD out before SINKING into the ground.

Swale Repair Process

pb swale repair1

Reworking the swale

The first 2 steps in the swale repair was to smooth out the back cut and then level the base of the swale. The back cut was reshaped with a gentler slope for stability and so the overland flow of water would slowly move into the swale rather than cascade over the almost vertical cut that had originally been made. The bottom of the swale was re-leveled to allow water to spread out and evenly fill the from the bottom up to the level sill spillway.

Swale (12)The final step was to move the location of the level sill spillway and to make it wider. Wider sills allow for a more passive water flow. The Host had leftover paving stones, so these were re-used to stabilize the soil on the sill. Lest we forget the Oroville dam spillway debacle, level sill spillways are a very important design element -always plan an overflow route that will move excess water without damaging the land!

PB#2 Swale (11)

The new wider level sill spillway allows overflow water to gently move to the next area

sill overflow

Example of water moving over a level sill

This other photo shows an example of a swale from a different property that has filled up during a heavy rain event. This level sill spillway allows water to passively overflow to a pond lower on the property. Note, again, the width of the spillway. It’s wide! If spillways are too narrow, water will gain speed and pressure over the area and increase the possibility of erosion during times of intense rainfall. Gauging how extreme rainfall may be at times is another very important aspect of rainwater harvesting. Determine the volume of rainwater collection potential by doing some basic math using the calculations found here.

Finished Work

PB#2 Swale (5)

Swale repair finished

PB#2 Swale (1)

Rooftop rainwater from the downspout flows through a pipe and daylights into the swale here

To Build a Swale or Not?

There are many things to consider before making a swale. Here are just a few:

  • Do you need a swale, or are other methods more applicable?
    • What might work better? Keyline, mulch basins, wattle across contour, etc. Earthworks are a disturbance and a smaller intervention may be best suited for the site.
  • From which direction does water enter your property? How does it flow through and where does it leave?
  • What is the degree or percentage of slope on the area intended? A swale can be used when the slope is less than 15%.
  • What is your soil type? Has a soil percolation test been done?
  • How would water flow into the swale? Where is runoff coming from? Is there enough water flow to need a swale?
  • Calculate your largest one-day rain event. Will your swale be big enough to accommodate that event? Ensure the level sill spillway is wide enough to allow the water to passively flow from the swale.
  • Stay at least 10-20 feet from any foundation. This distance ensures that water seeping into the ground won’t cause moisture problems with the building’s foundation.
  • Always check for underground utility lines, water mains and irrigation pipes.
  • Make sure to place the swale at least 20-30 feet from a steep bank.
  • What will be planted on the berm and in the swale and up and down slope from them? Keep in mind, swales are a tree planting system, without trees and plants the swale could fail and cause more problems than you are trying to solve.

Remember, swales are one part of an integrated plan or design and permaculture is all about integrated design. Based on the Ethics (Earth Care, People Care and Fair Share) and the Principles we utilize the design methods to configure what is needed to meet our vision and goals. If swales are applicable, then we have to make sure we do our due diligence and factor in all the variables for success. Good design is based on rigorous observation and thoughtful design.

Permaculture Principles Applied

9

Use Small Slow & Solutions

Small & Slow Solutions: By moving the level sill from one side of the swale to the other side – a fairly easy job – we were able to move water to mulch basins for three more trees, rather than just the one tree. Spreading and sinking water throughout the landscape is always a key design goal in permaculture.

“Work at the human scale so you can build and repair everything. Many small strategies are far more effective than one big one when you are trying to infiltrate water into the soil.” -Brad Lancaster

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Catch & Store Energy

Catch & Store Energy: This principle tells us to store energy when it is abundant. Water falls into that category and in the winter, when our rainfall is generally abundant, earthworks can store thousands of gallons of water in the soil.

Rather than having water run erosively off the land’s surface, encourage it to stick around, “walk” around, and infiltrate into the soil. Slow it, spread it, sink it.-Brad Lancaster

 

PermaBlitz #4 is October 20th!

PermaBlitz #4 is in Paradise, where we will be learning more about rainwater harvesting. The pads (base) for large above ground rainwater tanks will be built which will be used in a “wet” rainwater harvesting system. Learn more in our previous blog post or click here for details on how to RSVP!

 


 

PermaBlitz cover collage

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Permaculture in Action: Lasagna Beds

On April 14th, 2018 Earthshed Solutions held its third PermaBlitz at a rural property in Paradise. The ‘Blitz Hosts, as part of their goal for the property, wanted additional raised beds so they could increase the amount of food they produced.

lasagna bed in design

Section of the Permaculture Design for PermaBlitz #3

Ahead of the ‘Blitz the Hosts constructed two raised beds to match existing beds on site. One method recommended to the Host, was to use resources on site to fill the 24” high beds. This style of bed is called a lasagna bed. Like the lasagna you eat, it is filled with layers, but instead of noodles, vegetable/meat sauce and cheese, it is filled with layers of brown (carbon) and green (nitrogen) organic materials.

The empty beds were first filled with wood, twigs and leaves from the owner’s property.

This was the first carbon layer. Carbonaceous materials are things like: straw, cardboard, newspaper, wood chips, shredded paper, leaves, corn stalks, etc. These materials generally have a Carbon to Nitrogen (C:N) ratio of over 60:1. Examples are (all are approximate): leaves are 60:1 while certain wood chips are 500:1.

Next, came a layer of nitrogen material: bunny poo, grass clippings, fava bean plants, and coffee grounds.

lasagna-bed-nitrogen.jpg

The bed filled with nitrogen materials: bunny poo, grass clipping and fava beans plants and coffee grounds.

Not all “greens” are the color green. Some, like manures and coffee grounds, are brown or black. Other nitrogen sources are: feathers, hair/fur, actual green plant material, alfalfa, spent brewery grain, fruit and vegetable waste from the kitchen, etc. The carbon to nitrogen ratio of a green is less than 60:1. Examples are: urine, which is 1:1 while horse manure is approximately 30:1.

Water was applied between each layer to help fill any holes and wet the material. Applying water is important to ensure biological activity begins to take place in the layers.

The cycle was then repeated: brown layers approximately 3-4” thick then a green layer approximately 1” thick. The final layer on top was 12” of soil – a mix of good garden soil and mushroom compost which was then topped with straw to protect the soil until it was ready to be planted.

lasagna bed -filled.cropped

Lasagna beds filled and ready to plant

There are many methods to creating a lasagna garden. For the Host’s purpose, these beds used materials on-site so they weren’t hauling anything to the landfill or buying anything other than the mushroom compost. And in approximately two years, most of the material placed in the beds will decompose down to rich, wonderful soil.

Here is what one of the lasagna beds look like in September, 5 months later!

Permaculture Principles Applied

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Obtain a Yield

Obtain a Yield: Two more raised beds = more food on the table. Food can account for a substantial amount of our ecological footprint, so it makes sense to grow our own. Not only from a cost perspective of buying organic produce at the store, but knowing the food is pesticide free, grown in healthy soil and is nutrient dense. Another yield from the PermaBlitz was the yield of building community: 30 people working hard and learning = priceless!

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Use & Value Renewable Resources & Services

Use and Value Renewable Resources: Where possible, we need to use resources at hand. In this case, wood, twigs and brown leaves for carbon materials and the grass clipping, bunny poo and coffee grounds for nitrogen materials which will eventually become healthy, biologically active soil. The wood and twigs were too small for the fireplace so rather than burning them, they were put to use in the lasagna beds. Composting this material produces substantially less greenhouse gas emissions as compared to burning! The grass clippings came from mowing the fields and meadows and the coffee grounds came from the kitchen of both the Hosts and friends and the bunny poo was a gift from friends. All of the resources combined came from the site itself or from around the
local bio-region ensuring we are valuing our renewable resources.

These permaculture principles are just two of the 12 principles that we ensure remain the backbone of all of Earthshed PermaBlitz designs.

PermaBlitz #4 is October 20th!

At this ‘Blitz we will be doing many more projects and activities which apply the permaculture principles in several ways. Learn more in our previous blog post or click here for details on how to RSVP!

PermaBlitz cover collage

Permaculture in Action: Wicking Bed

Design

During the design phase for PermaBlitz #3 the PermaBlitz design team recommended a wicking bed system for the Host. This particular type of system would efficiently utilize their well water to irrigate annual vegetable plants in their fenced edible garden. A wicking bed is a self-watering garden bed. The water, held in a reservoir at the bottom of the bed, moves upward by capillary action to water the plants in the soil above. It is estimated that this type of system can save anywhere from 40-90% of water used.

wicking bed system design

Wicking bed system design

Pre-‘Blitz Construction

Before PermaBlitz #3 took place the Host constructed an outdoor sink using an old cast iron sink. A three-way valve in the plumbing was installed so that water, which may not be suitable for vegetables in the wicking bed can be diverted to the mulch basin. The sink was placed just outside the fenced garden and will be used to rinse vegetables from the garden and rinse pots from the fabric dying process (the Host works with natural dyes, specifically their abundant Toyon shrub).

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Earthshed Blog -hey, this is new!

Welcome to our first Blog post!

We have a few PermaBlitzes under our belts, several Hands-On Workshops over the last few years and countless photos of it all, so now we have loads of Permaculture in Action examples to share with you.

Our aim is to help you learn about permaculture design through our volunteer work in the local community and how specific design elements are being implemented in our unique bio-region -the beautiful northern Sacramento valley and foothills beyond.

Stay tuned for fun and, hopefully, inspiring posts in the months to come. You can always keep tabs on us by following our blog right here on the website, signing up for our newsletter and connecting with us through social media.

And now a little teaser for the next post