Adequate water of suitable quality is vital for maintenance of the living collections. In Canberra water comes from the city water supply and the Gardens is accorded the same allowances and faces the same charges as a suburban block. The irrigation system supplies water from the Black Mountain Reservoir; it is supplied directly to the eastern parts of the Gardens and is pumped up to the Gardens' reservoir and then supplied to the western parts of the Gardens.

The irrigation systems for the Canberra site were evaluated in 1988. Since then measures have been taken to use water more efficiently. Among such measures are checking water use along individual lines to find leaks, reducing the amount of misting in the Rainforest Gully, and installation of micro-irrigation where appropriate, particularly in new garden beds.

At Jervis Bay, water pumped from Lake Mackenzie is used for most of the irrigation. Water for domestic purposes, fire protection and irrigation in the Nursery and trial plots is collected from roofs and stored. The pump that takes water from Lake Mackenzie has recently been upgraded.

Management prescriptions


The objectives are to provide sufficient water of suitable quality to maintain the health and vigour of the living collections and to provide potable water for the use of visitors and staff.


Methods of irrigation will continue to be evaluated to determine the most appropriate method and to minimise costs and wastage. The possibility of using alternatives to drinking-quality water for irrigation in Canberra will be pursued with the responsible authorities. At Jervis Bay the possibility of providing a potable water supply for use by visitors will be examined.