Tall buildings must have catchment wells: Geologist

JAKARTA (JP): High rise buildings should have water catchments to help save ground water, a geologist said yesterday.

The water catchments would not take up space because the wells (aquifers) could be covered with gardens, Deny Juanda Puradimaja from the Bandung Institute of Technology said.

"The aquifers can even be used as parking spaces as long as buses or trucks do not park there," Deny said.

Another benefit is that no more water would be needed to water the gardens, Deny said.

Ideally the aquifers should be between two buildings to enable cost sharing.

"Building the wells would show awareness of saving precious ground water," Deny said.

Deny was one of the speakers at a one-day water supply discussion, held by the Jakarta municipality, the Indonesian Journalists Association and a non-government organization, the Kelompok Sepuluh Foundation on Wednesday.

Deny said artificial aquifers were the most feasible way to help save ground water because artificial lakes took up too much space.

If all high rise buildings had aquifers to retain shallow water, this would reduce the water run off waste, he said.

The idea of catchments for high rise buildings is to compensate for ground water pumped through artesian wells, Deny said.

"Jakarta will need 100 to 150 liters per day per person by the year 2000," he said.

Deny said the size of the wells would depend on the amount of water necessary. This depends on a building's specific needs and the possibility of shallow ground water being nearby, he said.

"Many geologists could be consulted on this," Deny said.

A well with a 15,000 cubic meters volume would be three meters deep and "half of a soccer field" in size, he said.

To save ground water, a 1992 governor's decree states all buildings should have water catchments. However officials have admitted the decree lacks enforcement.

The South Jakarta mayoralty, which has been designated as the city's water catchment area, has ruled that building permits for houses measuring more than 100 square meters must have water catchment wells.

Deny said to make these household wells more effective, geologists should help the municipality make a map of potential shallow ground water locations.

"In some areas the well might have to be deeper than the city's recommendation of at least 1.5 meters," Deny said.

The rule could be more flexible by ruling aquifers must be installed for blocks of houses rather than per building.

Other speakers were the director of the city-owned water firm, PAM Jaya, Syamsu Romli, and the head of the mining agency, Arifin Akbar. (anr)