SEMARANG — A lecturer from the Faculty of Social and Political Sciences (FISIP), Universitas Negeri Semarang (UNNES), conducted a study on the management of waste carried from inland waters, particularly rivers, toward the sea. The study aims to understand how waste can be managed before it reaches marine waters.
The field study was conducted on June 26, 2026, at the Kali Semarang Pump House through interviews and observations. The informants included officers at the Kali Semarang Pump House and staff from the Water Resources Division of the Semarang City Public Works Agency.
The Kali Semarang Pump House was initially built to help control flooding in Semarang City. The system works by pumping water from several flood-prone areas into Kali Semarang and then collecting the water in a large retention pond at the pump house. The water is subsequently pumped from the pond and discharged into the sea.
In addition to flood control, the pump house system also contributes to managing waste carried by the water flow. During the rainy season, increased river discharge can carry various types of waste, both organic and non-organic.
Before the water enters the retention pond and pumping system, a waste trap is used to collect and prevent waste from entering the pump. The collected waste is then removed by officers. This mechanism prevents waste from entering the pumping machinery and reduces the amount of waste transported toward the sea.
The waste trap is also important for maintaining the performance of the pumping system and preventing damage caused by waste entering the machinery.
The field observations also found that river waste does not come only from people disposing of waste into rivers. Organic materials such as branches, leaves, and vegetation along riverbanks can also be carried by water during heavy rain and flooding. In addition, land-use changes in upstream areas can increase erosion, causing sediment to accumulate in rivers and narrowing their flow channels.
These findings indicate that the pump house not only plays a role in flood control but also contributes to preventing waste from rivers from reaching the sea.
Therefore, river waste management needs to be carried out through an integrated approach, starting with waste prevention on land, river management, and the handling of waste carried by water flows. Such efforts are important to reduce the amount of land-based waste entering marine waters.
