City promotes water-harvest installations

The Jakarta Post, Jakarta

In an effort to avert floods, Jakarta's Environment Management Board has asked university students and companies to help residents make percolation pits and biopore absorption holes to harvest rainwater.

The board's head of environmental damage control Daniel Abbas told The Jakarta Post over the weekend this household intervention could help compensate for water catchment areas being lost to new homes, offices and apartments.

The environmental board hopes 4,000 people -- students and more than 24 companies -- will join the program, which will be launched by Governor Fauzi Bowo at the Sumantri Bojonegoro Stadium, South Jakarta on Dec. 8.

"We are asking the universities to let students assist in the installation of household percolation pits or biopore holes, while companies can use their CSR budgets to help with the financing," said Daniel.

There are at least 12 different types of percolation pits for draining rainwater. The cheapest and simplest is a 100-centimeter deep, 10-centimeter wide hole filled with compost. As worms, insects and fungi work together to decompose the waste, they create pore spaces, allowing rainwater to seep more quickly into the aquifer.

Daniel said residents could choose between percolation pits and biopore absorption holes depending on their budget and the height of the local water table.

"A percolation pit with a capacity of one cubic meter costs around Rp 1 million while creating a biopore hole requires only a drilling tool."

A biopore absorption hole can be as simple as a hole with a diameter of 10 centimeters and depth of 30 centimeters filled with organic waste.

As percolation pits are deeper than biopores they are suitable only in areas not located below sea level.

"Residents in North Jakarta will not be able to build percolation pits because the water level in the area comes within a half meter of the surface," said Daniel.

He suggested that universities make the program a part of the community service curriculum, which is mandatory in most schools.

"Students can transfer knowledge (of the conservation technique to the general public) while getting credit for the program," he said, adding that several universities including University of Indonesia and Trisakti University had confirmed their involvement.

The water-harvesting effort could be fast-tracked, said Daniel, if university students and companies got behind the 10-year program that covers five municipalities.

Water-harvesting is mandated under a 2002 ordinance requiring all building owners, regardless of building size, to set up percolation pits or biopore holes.

However, the environmental board said, so far, there are only about 100,000 pits, while the target is some 2 million pits. (lln)