People have begun to understand that landscapes can be sustainable and still maintain their aesthetic appeal and function, by hydrozoning. Hydrozoning is defined as grouping each plant variety according to their water requirements. You can then water each group of plants according to its needs, ensuring that the irrigation system is specific to that hydrozone and that each group (hydrozone) has its own valve. This presently forms the basis of many landscape designs and ensures that water use is focused and applied in correct amounts.
A landscape can have four main hydrozones (hydrostations): high, moderate, low and very low water usage zones. Planting in these zones can reduce water usage by between 30% and 80%. These zones must each be watered individually and have their own professionally designed and installed irrigation sprinkler types and their own valve (whether manual or automatic). The concept can be applied regardless of the water source or how much water is available for use in the landscape.
When designing a landscape, it is suggested that you use a landscape irrigation water-use model. This technology can be used to determine the amount of water that is required in each hydrozone in the landscape, based on the unique site and environmental aspects for that hydrozone. There are several such models available internationally and one in South Africa.
The South African model incorporates a range of design, site, edaphic, climatic, hydrozone, irrigation and maintenance factors that all contribute to determining the amount of water that should be used in the landscape. It allows for landscape designers and maintenance managers to adapt designs up front as well as in the field to reduce water use.
Hydrozoning is an efficient tool that can guide landscapers and property owners in leading the way with regards to water conservation and ensuring that ornamental landscapes are more sustainable.