After our initial site visit and observations, plus a closer examination of the World Bank JEDI Plan, we realized the importance of the large reservoir called Waduk Pluit just east of our given site boundary. For our return visit we decided to expand our area of interest and mapped out a walking tour to investigate the reservoir, the edge conditions and ancillary control structures. It might be fair to say our experiences can be grouped into two categories – water levels and trash. Let’s begin with trash.

(Credit: JOH)

As one of two outlets for the Ciliwung River our site receives a lot of solid waste from upstream. One of the ways the city tries to control the trash is with Surface Cleaners. Essentially, men punt downstream gathering the trash on the leading edge of their rafts. They then maneuver it to a collection point along the bank where it’s gathered onto trucks and hauled to landfill. The trash that isn’t caught by the Surface Cleaners carries on to a mechanical trash grate just south of Muara Baru close to the inlet of Waduk Pluit. Here we interviewed the workers on site as well as a family of recyclers and discovered that the volume of trash varies significantly with rainfall – almost a fourfold increase when it’s wet over when it’s dry.

(Credit: JOH) 

A woman picks through trash the city collects for recyclables.

(Credit: CP) 

Just beyond the trash grate is a dam controlling the water level entering Waduk Pluit. We continued along the east edge into the informal settlement of Muara Baru - originally built over the shallow waters of the reservoir the piles are now thick with solid waste.

(Credit: CP)

(Credit: CP)

(Credit: CP)

(Credit: CP)

At the northern most edge of Muara Baru we came across the construction of a large pumphouse being funded by the Japanese. In talking with the workers and observing the site we discovered that the entire Pluit, Muara Baru and Luar Batang lie below mean sea level. The new pumphouse is designed to pump water from the Pluit over the sea wall. This will replace the current pump system which pushes water underground and up into the sea, as a consequence, rising sea level has increased the back pressure on the pump to the point where the level of the Pluit can never be greater than 4 meters below sea level – thereby reducing the water retention capacity of the Pluit. It seems large infrastructure investments are being made in conjunction with the dredging undertaken in the World Bank plan.