Jun 11, 2015

Turning Runoff Into Green Space

Indonesian storm water project eliminates aboveground storage in populous area

Jakarta, Indonesia, is a region known for its rainy season, located on the northwest coast of the island of Java. This urban agglomeration boasts the 17th-highest population density in the world (50,000 people per sq mile).

With its large population and an eight-month rainy season spanning from October to May, Jakarta is prone to flooding. This problem is often exacerbated during the months of January and February, when it rains for 18 to 20 days on average, dumping nearly 12 in. of rain on the area.

In an effort to alleviate the flooding issue, areas have been created to provide aboveground storage. However, these areas have proven to be health and safety hazards, as they can become breeding spots for bacteria, draw mosquitoes and present drowning risks. Additionally, regulations have been implemented to promote subsurface rainwater harvesting systems. This approach allows for storing the runoff from the rainy season for use during the drier months of the year without the negative aspects of the aboveground systems.

Brentwood partnered with PT. Grahadika Adipurnajasa to reduce the impact of the flooding situation and provide free space for citizens’ use. An aboveground structure was replaced with the StormTank Module system and a vegetated area. The system is 412.5 ft long and 27 ft wide, utilizing 26 inlet points along the adjoining roadway. Each inlet location is connected through a concrete structure containing a StormTank Shield, which prevents debris and trash from entering the system. After the runoff enters the system, it is stored until the neighboring river subsides and is then discharged.

Completed in the fall of 2014, this project created valuable free space within Jakarta’s heavily populated landscape and eliminated the health and safety risks associated with the aboveground structure that was replaced. The innovative design met the needs of the designer, owner, and regulatory agencies while providing a valuable resource for the community.

Jason Bailey, P.E., can be contacted at 610.347.8867 or [email protected].



621 Brentwood Drive

Reading, PA 19611

United States

Phone: 610.374.5109