Model available for efficient landscape water use

Landscapes consume between 0.52% and 60.79% of water supplied for urban use – proving that the ‘one size fits all’ approach does not work and does not support water conservation as required for the ornamental and amenity landscaping industry.

By Dr Leslie Hoy, Environmental Management Services, Rand Water

During times of drought or when there is insufficient water in storage dams, water restrictions are imposed. Note that a drought may be experienced in the catchment area of a dam while the urban area supplied with water from that dam may be experiencing good rainfall. In every single case to date in

South Africa, the watering of landscapes is impacted when restrictions are imposed. It is, therefore, critical that landscapes are: • designed, constructed and maintained in such a manner as to apply/use the least amount of water possible while still enhancing landscape aesthetics • managed with as little water as possible from the start – this ensures that the plants are sturdy, and robust and that root systems are more well developed and deeper growing • resilient in their entire make-up and functioning.

Low water use plants grouped together in the same hydrozone

Hydrozoning decreases water use and increases plant productivity Plants with the same water needs should be grouped

Intention and aim of LIMSA

The Landscape Irrigation Model of South Africa (LIMSA) is intended for use at the design, installation, and maintenance phase of a landscape. For the design phase, besides determining anticipated site water use, it allows for the landscaper to change some of the input factors for the design, thus influencing possible water use up or down. This could be used by the designer to assess input costs against long-term water savings and other water availability challenges that may occur. The intention of this model is to allow for a more accurate water use on any landscape site.

There are several high-level benefits that can be achieved with the use, implementation and continual updating of the LIMSA model for landscape sites. Some of these benefits are: • There is an increased awareness of specifically how much water should be required for the site, as well as each hydrozone. • By specifically calculating and improving water use on-site, this will result in

short-term (some) and long-term (more so) financial savings for clients and landowners. • The model is comprehensive in considering the most pertinent aspects of a site that will influence water use. • Implementing the aspects in the model on a site will assist in improving the overall management of the site beyond the design and construction phase. • Using and implementing the model requirements will allow for the site to be more resilient and more likely to be able to withstand dry periods. • Implementation will allow for landscapes to contribute in a positive manner towards water conservation in South

Africa, while still promoting aesthetically pleasing sites. For more information, visit the Rand Water website (www.randwater.co.za) and click on the Water Wise logo. Alternatively, email us at waterwise@randwater.co.za or call us at 0860 10 10 60. We also have a presence on YouTube, Twitter and Facebook.