Nonstorage systems

The conventional landscape is often flat or mounded in shape, which causes it to spill water rather than absorb it. A water-harvesting landscape is concave (bowl-shaped), with plenty of low points to hold valuable rainwater on the site and keep it out of the streets, where it can cause flooding and wash pollution into nearby bodies of water. This type of landscape is well suited to a nonstorage water-harvesting system. Nonstorage water harvesting involves making your landscape as absorbent as possible so that water soaks into the ground instead of running off. Figure 7-2 shows a system that uses gutters and downspouts to direct water toward plants and a concave terrain that holds water naturally.

Figure 7-2:

A concave landscape works like a sponge to catch and hold water.

Figure 7-2:

A concave landscape works like a sponge to catch and hold water.

A nonstorage system is the cheapest and easiest way to make use of rainfall, and therefore it should be your first choice if you're looking to use rainwater without investing in a costly cistern or other storage system. You may even be able to develop a zero-runoff landscape, which sheds water only during the biggest storms.

A nonstorage water-harvesting landscape can include the following features:

  • Swales, dry streambeds, and bioswales: A swale is a shallow ditch with gently sloping sides that runs very gradually downhill in the direction in which you want water to flow. It allows rainwater to soak in as it goes. You can incorporate rounded boulders to create a naturalistic dry streambed or plan the swale so that the plants and soil purify the runoff water using natural biological processes (this is called a bioswale; see Figure 7-3).
  • Percolation chamber: Underneath your swale or at any appropriate, stable low point on your property, you can dig a percolation chamber (see Figure 7-4). Water drops into the chamber and continues to percolate down into the soil, recharging the groundwater. The water goes below the roots of most plants but stays out of the street — and out of trouble.

Figure 7-3:

A bioswale.

Native plants promote good soil composition and allow for better infiltration of water into the ground.

Native plants promote good soil composition and allow for better infiltration of water into the ground.

Permaculture Swale Infiltration

Rocks slow water and allow it to penetrate

Strong root structure helps prevent erosion and improves absorption of water.

Plants and soil microorganisms purify water, which soaks into the soil instead of running off and causing pollution.

Rocks slow water and allow it to penetrate

Strong root structure helps prevent erosion and improves absorption of water.

Plants and soil microorganisms purify water, which soaks into the soil instead of running off and causing pollution.

Figure 7-4:

A typical swale atop a percolation chamber.

Figure 7-4:

A typical swale atop a percolation chamber.

Percolation Chamber

^Gravel inside

Arrows indicate percolation Native soil percolation chamber of water through gravel and filter fabric into the native soil

^Gravel inside

Arrows indicate percolation Native soil percolation chamber of water through gravel and filter fabric into the native soil

Even when water isn't running, dry streambeds and bioswales in particular are lovely additions to any landscape. But doing water harvesting the wrong way involves risks, so be sure to read more about these systems in Chapter 8.

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Homeowners Guide To Landscaping

Homeowners Guide To Landscaping

How would you like to save a ton of money and increase the value of your home by as much as thirty percent! If your homes landscape is designed properly it will be a source of enjoyment for your entire family, it will enhance your community and add to the resale value of your property. Landscape design involves much more than placing trees, shrubs and other plants on the property. It is an art which deals with conscious arrangement or organization of outdoor space for human satisfaction and enjoyment.

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Responses

  • ren ebersbach
    How plants prevent percolation?
    8 years ago
  • callan
    How to water percolation filter?
    8 years ago

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