Planning a Recycled Water Irrigation System Planning a Recycled Water Irrigation System

If your lawn is beautifully landscaped, you can keep it looking lush, green, and healthy throughout the year by taking advantage of wastewater from the sink, washing machine, and shower. Utilizing this greywater via a designated irrigation system is a better option than having it go down the drain to a septic system or into the sewer where it makes its way to a treatment plant. Additional advantages of installing a recycled water irrigation system are the convenience of having your plants and flowers watered manually, and if you live in a particularly dry region, a water recycling system is more than handy.

Using Recycled Irrigation Water Effectively

Irrigation tubing and fittings.

In planning for your own irrigation system, a good rule of thumb to follow is to use 75% or lower of your available flow for your different zones. You can refer to a chart for pipe friction loss to know the size of pipe that you should need for your irrigation system. If you are going to use a class 160 pipe that is 1-inch diameter, it will be able to carry as much as 16 gallons of recycled water per minute in five feet per second rate or lower. If you will use more water, the velocity will increase, thereby causing loss of pressure and too much friction. You would also have an additional water hammer, which is not good for the system.

Factors to Consider

There are two main factors to consider in your irrigation system planning: the flow, which is measured in gallons per minute, and the static pressure of the water or psi on the water source. Measure both of these factors as close to the output as you can.

Setting Up an Irrigation System

Black irrigation pipe laying in the middle of a garden on soil.

It's easy to set up a water irrigation system to recycle greywater. Once you have the layout of the piping installed in the yard, you can then choose which source or sources will supply the water. For example, if you plan to recycle water from the washing machine, all it takes is the installation of a few PVC pipes, a hose, and a three-way diverting system. The diverter is installed as an attachment to the washing machine and gives you the option of allowing the water to drain from the washer in the normal way to the sewer, or flipping a lever and having it go to select irrigation areas.

When using the washing machine as a source of recycled water, two things are important to remember: 1. If you use bleach in your laundry, do not allow the water to drain to the areas to be irrigated. Bleach is not plant-friendly. 2. Use eco-friendly detergent.

The piping runs from the water source (washing machine, sink, shower) in the house and to the pipes laid throughout the yard to address areas where plants are to be watered. Along the piping outside, individual "T" systems are installed to disperse water at these locations as it runs along the pipes.

The "Ts" are placed strategically along the entire irrigation route and placed inside a box that keeps it raised off the ground and allows the system to operate freely while remaining safe and secure. Mulch is then placed evenly around each of the valve boxes to act as a filter. The mulch captures lint, for example, which helps prevent clogs in the hose.

You can place as many "T" systems as you like along the hose to make sure the plants that need water will get it every time recycled water is diverted to the irrigation system.

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