Page 5 - LandscapeSA Issue 106

ADVERTORIAL

THE LANDScAPE IRRIgATION MODEL

fOR SOUTH AfRIcA (LIMSA) AND

HYDROzONINg IN AMENITY LANDScAPES

Rand Water’s Dr Leslie Hoy has developed a model possible water use up or down. This could be
used by the designer to assess input costs
for efficient landscape water use and an associated against long term water savings and other
hydrozone plant data base. water availability challenges that may occur.
The intention of this model is to allow for a
more accurate water use on any landscape
site to be determined.
outh Africa is facing many It is therefore critical that landscapes:
challenges, one of the greatest a. be designed, constructed and maintained Benefits of using the model and
Sbeing insufficient water to meet in such a manner as to apply/use the applying principles
current and future demand. Added to least amount of water possible while still There are several high level benefits that can
this, landscapes use between 0.52% enhancing landscape aesthetics; be achieved with the use, implementation
and 60.79% percent of water supplied b. are managed with as little water as possible and continual updating of this LIMSA model
for urban water use (percentages vary from the start. This ensures that the plants for landscape sites. Some of these are:
hugely depending on a range of factors are more sturdy and robust and that root • an increased awareness of specifically how
including sample size). The most common systems are more well developed and much water should be required for the site
value quoted for South Africa is between deeper growing; as well as each hydrozone;
30% to 50%. Historically, and in some c. become more resilient in their entire • by specifically calculating and improving
older irrigation design standards, the set makeup and functioning. water use on site, this will result in short
amount of 25mm of water per week was term (some) and long term (more so)
quoted as being the required irrigation The role that landscapes play in our financial savings for clients and landowners;
volumes standard. No evidence was environment is well documented, with • the model is comprehensive in considering
found that this value was ever determined benefits ranging from noise abatement, to the most pertinent aspects of a site that
or tested against any landscape standard reducing heat islands, psychological benefits, will influence water use;
or landscape requirements. This type recreational benefits, improved productivity, • by implementing the aspects in the model
of “one size fits all approach” should no reduced erosion, reduced impact of raindrops on a site, this will assist in improving the
longer be considered relevant, efficient on soil, and so much more. In order for our overall management of the site beyond
or beneficial to industry or landscapes, as landscapes to stand the test of time, the the design and construction phase;
it does not support water conservation as entire value chain from conceptualisation, • by using and implementing the model,
required for the ornamental and amenity design, implementation and maintenance the site will be more resilient and able to
landscaping industry. needs to be above reproach, and water withstand dry periods;
conservation must always be at the forefront • implementation will allow for landscapes
During times of drought or when there of these processes. to contribute in a positive manner towards
is insufficient water in storage dams, water conservation in South Africa, whilst
water restrictions are imposed. Note that Intention and aim of LIMSA still promoting aesthetically pleasing sites.
a drought may be experienced in the The model has been developed in such
catchment area of a dam, whilst the urban a way that it allows for use at the design, For more information visit the Rand Water
area supplied with water from that dam installation and maintenance phase of a website www.randwater.co.za and click on
may be experiencing fairly good rainfall. landscape. For the design phase, besides the Water Wise logo. Alternatively, email us at
In every single case to date in South Africa, determining anticipated site water use, it waterwise@randwater.co.za or call us at 0860
watering of landscapes is impacted when allows the landscaper to change some of the 10 10 60. We also have YouTube, Twitter, and
restrictions are imposed. input factors for the design, thus influencing Facebook!

Hydrozoning decreases water use and Plants with the same water needs Low water use plants grouped
increases plant productivity should be grouped together together in the same hydrozone

Landscape SA • Issue 106 2021 3