Royal Botanic Gardens is a recognised leader in water conservation for large landscapes. Since 1994, we’ve reduced water consumption at the Royal Botanic Gardens Melbourne by more than 60 per cent.
With more than 10,000 species and 50,000 individual plants at Melbourne Gardens – including trees and plants of great cultural value; many irreplaceable, endangered or even extinct in the wild – it is important that the survival of these plants is guaranteed by an adequate supply of water.
Horticulture staff have extensive training in current irrigation management principles and efficient operation of the irrigation system.
Turf areas are being converted to warm-season grasses such as Kikuyu, which are more water efficient than cool-season turf like Ryegrass. Warm-season grasses typically use up to 30 per cent less water than cool-season species.
A weather-based irrigation scheduling system is also employed that accounts for plant requirements, climatic conditions, soil water-holding capacity and rooting depths to maintain plant health, rather than promote excessive growth. This means that plants are not watered too frequently – increasing the opportunities to make best use of any rainfall. Efficient irrigation scheduling means that the right amount of water is applied at the right time.
Mulch is used on garden beds. About 1500 cubic metres of recycled plant material is composted to apply 300 cubic metres of mulch to garden beds every year. Mulching minimises soil water loss from evaporation and improves water-holding capacity of the soil.
Water-sensitive design principles are used in all new landscape areas. The Water Conservation Garden, indigenous plant landscape at Long Island, and Guilfoyle’s Volcano are key examples of this approach.
Strategic Water Plan
The Strategic Water Management Plan (2012–2016) commits the Royal Botanic Gardens to implementing an integrated approach to water management that maintains biodiversity, minimises consumption, evaluates and utilises alternative water sources and demonstrates leadership in efficient water use.
The Royal Botanic Gardens remains committed to reducing its use of mains water at both Cranbourne Gardens and Melbourne Gardens.
The recently completed Working Wetlands stormwater harvesting project at Melbourne Gardens will reduce the use of mains water for irrigation by 40 per cent when working at full capacity.
At Cranbourne Gardens, the construction and planting of a water-efficient landscape in the Australian Garden supported by weather-based irrigation scheduling, including an automated weather station on-site, supports our commitment to the sustainable use of water.
The Working Wetlands project has seen the revitalisation of the lake system at Royal Botanic Gardens Melbourne.
Stormwater is harvested, filtered and then stored for future use in holding tanks in the Gardens. The lake wetland areas are planted with aquatic species that clean harvested water by removing harmful elements, thus ensuring its quality for irrigation within the Gardens. Increased water self-sufficiency has restored lake water levels and water flow in Fern Gully, introducing attractive new wetlands.
These wetland areas provide habitat for native wildlife populations such as waterbirds, frogs and other native aquatic fauna including long-necked tortoises, eels and native water rats.
The system is integrated with the Guilfoyle’s Volcano reservoir, which acts as a water storage and distribution facility, a public recreation zone, and an education zone.