A professor from Faculty of Civil and Environmental Engineering of ITB, Prof. Ir. Indratmo, M.Sc, Ph.D., explained about ways of storing rainwater, including with engineering and vegetative methods.

“Abundant water during rainy season is accumulated by storing it since at the upstream. It is storable in the central part of river basin or downstream. The storing is possible above or below ground surface,” said this professor from Water Resource Engineering Research Group.

Prof. Indratmo explained that, on the upstream, water is accumulated using vegetative method. This water storing process is related to conservation area. The conservation area functions as follows: during rain falls, the water does not flow downstream directly but is stored partly in the soil and gets filtered to produce good quality water that comes out of springs. “We know that soil is the best filter. If we have a good protected forest, the produced ground water will also have good quality because filtration process occurred in the soil,” he said.

The second method to store water is by using engineering. For example, lake revitalization on upstream river and construction of retention basin. In the river that flows wide and far, such as Citarum, the center of the river basin is made into a reservoir, similar to Saguling, Cirata, and Jatiluhur.

“In West Java, such place does not need to be built on the main river or first order river. Tributaries can be made into big retention basin. On downstream, it can be built using engineering by making reservoir on river mouth,” he said.

On a micro scale, houses can also store water. This is done by making biopore infiltration holes and infiltration wells. When rain falls, the community can make a storage tank on the roof of their house. The stored water can be used for daily needs. “It is very easy and feasible. We can use existing tank or make underground tanks, and we can use the water during dry season. It also helps reduce flooding. During rainy season, the water is collected. At the end of dry season we use the water for our needs during dry season,” he said.

The government has implemented the Citarum Harum program to normalize the Citarum River. According to Prof. Indratmo, the program must carry good, comprehensive planning that is implemented correctly and consistently. "It is not a project but a sustainable program. (It requires) leadership, a clear vision. This program will not succeed if it does not actively involve the community. The community must be subjects who have responsibility in improving the Citarum Harum program," he said.