Dry Argument

An innovative website can help users water their gardens more efficiently according to the type of vegetation and the area they live in, reports Geoff Connellan.After years of drought, many home owners are now facing high rainfall and even floods. Gardens have suffered through these harsh conditions, with lawns and trees lost. These experiences have highlighted the value and benefits that plants can bring to the home environment.

Knowing how much water to apply in dry times and selecting plants suited to a locality are key questions for gardeners. The website SmartGardenWatering.org.au has been developed by the University of Melbourne to assist gardeners in Melbourne and Geelong in choosing the most efficient way of watering. The program also helps select the right sized tank for the garden.

There are many things to consider in determining the right amount of water needed by a plant. The species, size, soil conditions, site exposure and weather all need to be taken into account. The researchers at the University of Melbourne applied scientific principles and comprehensive plant, soil and weather databases to build a tool that could make the necessary calculations. The website uses the Burnley Plant Directory, which has over 1,500 plants and allows users to determine water requirements for specific plants. It also allows users to select plants suited to their garden.

The project was initiated by Geoff Connellan who, with colleagues from the Burnley Campus, developed the water estimation tool. In addition to utilising existing knowledge and data sources, trials were carried out on irrigation systems, mulches and soil wetting treatments.

To bring the website online, a team from the Department of Information Systems led by Dr. Jon Pearce, developed the website interface and programming. A feature of the website is that is user friendly and highly interactive. The interactivity is very important to users as it immediately shows the consequences of making a decision. Select an inefficient watering method and the water demand graph increases.

How does it work?

The starting point in the program is the selection of a postcode. This generates information about the climate and the typical native soil of the locality.

It’s important to know the general area of the city, where rainfalls vary greatly from suburbs such as Sunshine (rainfall 469mm and clay soil) to Sassafras (rainfall 1016 mm and loam soil). In addition to determining the suitability of plants to particular areas, it also influences the amount of water required for irrigation. The area of the garden zone is selected, as this has a direct influence on the total water demands. The selection of plants is the next step. This can be done using a framework of plant type, category and species, or by searching the Burnley Plant Directory.

This database allows plants to be selected according to whether they are native or exotic, as well as their water use rate, drought tolerance and flower colour. An example of the framework selection technique would be the selection of ‘Tree’ (plant type), ‘Banksia’ (category) and ‘Heath Banksia’ (species). The water use rating of the species is ‘low’.

The next step in the process is to select the watering method. These include drips, above ground, under mulch, sprays, sprinklers and hose watering. The efficiency of the various watering methods is taken into account in the calculations. A graph of the monthly water demand is then produced.

Each time alternative selections are made, the graph change is smoothly animated in response to the selection. This shows very clearly the impact of the various decisions that are made.

Other garden factors that are taken into account are mulching and types of mulch, the slope of the ground, the microclimate (exposure to sunlight and wind) and the density of the planting.

In addition to a water demand graph, an irrigation schedule is produced. This advises on the likely required frequency of irrigation required (number of days between irrigation events) and the length of time to operate the irrigation system.

Tank selector

An additional feature of the program is that water tanks can be sized using a scientific approach. The tank size, garden area, planting and roof harvesting area can all be matched to determine the right sized tank. This removes the arbitrary choice approach to tank selection.

The tank selection is also strongly interactive. It uses an engaging, animated graph and is a very effective means of assisting the user in understanding the implications of choosing the wrong tank, particular ones that are too small.

Social media

An important aspect of the program is the use of features to encourage ongoing participation on the part of the gardener. Once a garden has been saved into the system, it is indicated on a Google map by a water droplet positioned on the appropriate suburb. Other gardeners can use this map to locate gardens in an area of interest and then view their details by way of a single click.

The program is tightly integrated with Facebook. When a garden has been created, a message containing a link to the garden can be optionally posted to the gardener’s Facebook page. From the program’s own Facebook page, gardeners can read news items, join discussions on gardening topics, and leave messages and images for others to view. Social networking has become a great asset to home gardeners, as they can now see what other gardeners are doing and share information and experiences on smart water use.

The program will not only help people save money on water bills and use water sustainably, but will also create a unique space where people can network and share ideas and thoughts about gardening.

Website host

In April 2011, the water conservation website savewater.com.au took over responsibility for hosting SmartGardenWatering.org.au as part of its commitment towards providing online resources to help local communities value water.

The savewater!® Alliance is a not-for-profit organisation that continuously develops and expands the website on behalf of water providers across Australia. The website informs and engages communities as an expert resource for being water efficient, inside and outside the house.

Resources include a detailed breakdown of how water is used and where it can be saved at home and in businesses. Sophisticated tools include a product library of water efficient appliances, an extensive ‘how to’ video library, Australia’s best grey water resources (including an advanced grey water calculator and list of garden-friendly detergents) and a very popular plant selector. Engagement tools for the site include a continuous competition for free water-efficient appliances, multi-award winning online games and our social media, including ‘The Ripple Effect’ blog.

Geoff Connellan can be contacted on email: Geoff.Connellan@nullbigpond.com

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