The Water Supplies Department is installing 23,000 water-saving devices in government buildings and schools.

Secretary for Development Carrie Lam told legislators today that when completed in 2011, the move will bring annual savings of 2 million cubic metres of potable water, 800,000 cubic metres of flush water, and 1.5 million kilowatt-hours in energy consumption.

The Government issued an internal technical circular in April last year, requiring all new government buildings to install water-saving devices, such as low-flow water taps and dual-flush cisterns.

There have also been trial schemes on recycling grey water and harvesting rainwater for non-potable use in several government buildings. The department will review the standards adopted in the trials when compiling comprehensive standards and technical guidelines, Mrs Lam said.

A consultancy study on the water consumption of major government departments will also be commissioned.