7.7 WATER
Background
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
Objectives
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.
Implementation
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.