Recycling Laundry Water for use with Landscape Irrigation

Grey water from your washing machine is a great source of year around water to irrigate your landscape. According to Procter and Gamble, the average family washes 600 loads of laundry every year. At 25 gallons per load, it means the average family uses 15,000 gallons of water a year to wash their clothes. This is a lot of water that could be used to irrigate your yard.


The year around source

The great thing about grey water is it is being produced daily as long as people are home. This means even in the summer when the demand for landscape irrigation is the most you have a constant source of irrigation water. The problem with using rain water for irrigation is that you have to collect it and store it until it is needed – and its hard to store enough of it to last though the times when it doesn’t rain.

Types of washing machine irrigation systems

When reusing washing machine water to irrigate your landscape there are basicly two differnet types of systems:

Laundry to Landscape

A simple system commonly known as a laundry to landscape system allows for a limited number of trees and shrubs to be irrigated by utilizing the built in pump within the washing machine. The water being pumped from the washing machine is unfiltered and must be simply dumped onto the plants and trees. Valves can be added to provide some flow balancing to the system. Because the greywater is unfiltered it cannot be used in a drip irrigation system

Filtered System

In a filtered greywater irrigation system the greywater from the washing machine (and optionally the shower and bathroom sink in addition) is sent into a greywater processing unit where all of the lint and other debris is removed and the greywater is re-pressurized and distributed throughout the landscape in a drip irrigation system. This system setup is ideal for landscapes where more than just a few trees or shrubs are being watered or where there is an elevation gain in the landscape. With this type of system the greywater is evenly distributed throughout the landscape via above ground or sub-surface drip irrigation and can be pumped hundreds of feet from the processor to spread out the greywater throughout the landscape. Additionally, with a filtered system supplimental potable water can be added to the system to ensure that an adiquate amount of water is availabe to properly irrigate the landscape.


Greywater & Drip Irrigation


Lint is the problem

Lint is the problem with irrigating your yard with grey water from your washing machine – unless you are just poring the water out onto your yard without any form of irrigation system. Without proper filtration, the lint will plug up the pump and the emission devices whether they are sprinklers or drippers. We recommend that if you want to irrigate your yard with laundry water that you use a drip irrigation system. It is much more efficient than a conventional sprinkler system so you can cover a much greater planting area than you can with a conventional sprinkler system. Unfortunately, a drip system requires fine filtration with at least a 150-mesh filter and the filter clogs up quickly with lint.

The Flotender solution to lint

The Flotender utilizes large 150-mesh filter baskets with advanced spry ring technology to filter out the lint from the laundry water. The filter basket is conveniently removed through the top access port of the Flotender when it needs to be serviced. All of the tolerances have to be precise where the filter fits into the Flotender otherwise the lint will pass by the filters. The spray ring constantly washes the lint back into the center of the basket filter so that the filter doesn’t clog up. After the water passes through the filters, a pump that puts out enough pressure to properly pressurize the drip system, pumps it out of the Flotender. A smaller external 150-mesh filter is connected to the outside of the Flotender to capture any lint that happens to get through the internal filtration of the Flotender.

Connecting to the outlet from your washing machine

You have to find a way to get the water from your washing machine to the Flotender. The Flotender can be placed either in the garage, under the house or outside of the house. It is most preferable to have it where it can be accessed easily. If the Flotender is located outside of the house, a pipe has to be run from the washing machine to the Flotender. If the Flotender is located in the garage or under the house, a pipe needs to be run from the Flotender to the outside of the house where the irrigation system will be installed.

The irrigation system for washing machine grey water

After the Flotender has filtered and pressurized the laundry water it is now ready for the drip irrigation system. The water then flows through the distribution tubing that runs out from the Flotender to the planting areas. It is then fed through smaller feeder tubing, which is connected to the distribution tubing, and finally it drips out the dripper and onto the root zone of the plant.

The advantage of using drip irrigation with laundry water

Since the washing machine water is grey water it shouldn’t be sprayed around into the air with sprinklers. Drip irrigation is ideal for this application because it feeds the water right to surface of the root ball of the plant. Since drip irrigation is some much more efficient than other forms of irrigation, you washing machine water will be able to water much more of your landscape.

Using washing machine water to water your lawn

Washing machine water can also be used to water your lawn through subsurface irrigation. Netafim makes a great product for grey water subsurface irrigation. It is tubing that has emitters built into it at specified intervals. It is placed below the surface and with spacing depending on the soil conditions. In order for this to work great care needs to be taken when installing the product and with preparing the soil. We recommend you consult their web site for details.

Do your part

It is a real shame to be using drinking water to water our landscape. In western states of the United States, up to 70% of household water goes to landscape irrigation. Instead of building new dams, drilling new wells, and running new and bigger pipelines we all started using grey water to water our yards, we could just start using the water we already use but twice instead of once.