Beijing will have to improve its ability to conserve water if the capital city is to ensure an adequate supply for the upcoming Olympic Games, a leading water official said yesterday.

Beyond diverting water from four reservoirs in neighboring Hebei Province, Beijing should do more to conserve water and collect rainwater, said Bi Xiaogang, deputy director of the Beijing Water Authority.

The huge scale of the sports venues and transportation facilities being built for the 2008 Beijing Olympic Games has raised questions about whether Beijing's water resources are up to the task. Conservation is seen as a key part of the city's ability to host such an event.

"We are strengthening efforts to conserve water, especially in agricultural irrigation," Bi said.

He said the increasing use of advanced technology like drip irrigation had helped reduce the volume of water used for agriculture by 100 million cubic meters a year since 2000.

The total volume of water used for agricultural purposes in Beijing last year was less than 1.1 billion cubic meters, representing a drop of more than 500 million cubic meters since 2000.

The city will expand the technology to more than 6,600 hectares of cropland this year.

Bi said that because Beijing is in an arid area with little precipitation, rain represents an important source of water.

He said 150 rain-collection projects would be built using old watercourses and ponds in Beijing's suburbs.

Twenty-two large-scale projects will also be built in the city's rural areas.

"We also encourage government buildings, office buildings and large-scale public construction projects to install rain water-collection facilities," he said. "Rain water can be used to irrigate park lands and for cleaning."

It is estimated that Beijing's various rain-collection projects will help the capital collect an estimated 40 million tons of water, Bi said.