A RECENTLY completed pilot test, carried out by the Metropolitan Manila Development Authority (MMDA), of two autonomous river cleanup vessels in tributaries of the Pasig River proved the effectiveness of the technology as a tool for improving the health of Metro Manila’s waterways. At the same time, however, the six-month-long experiment also revealed serious gaps in planning and management, and the need for better top-to-bottom coordination of river and drainage cleanup efforts across government units.
The small vessels used in the pilot run are called Clearbots, developed by a company called Clear Robotics. The electrically powered boats, which can be equipped with solar panels to extend their endurance, are artificial intelligence-enabled and can operate either autonomously, following a programmed pattern or by remote control. Along with employing a conveyor-type mechanism to sweep up floating waste, the vessel is also equipped with numerous sensors that collect data on water quality and pollution flows.
The pilot program was supported by the Asian Development Bank (ADB) under a regional technical assistance program designed to support private sector development in climate action and innovation. This allowed the MMDA to evaluate the Clearbot technology at minimal cost to the government, as well as providing the developer valuable test data that can be used to make product improvements where needed.
The Pasig River system is, unfortunately, absolutely the best place to test this sort of pollution control technology, because it is the single most polluting river in the world. Despite being only 27 kilometers long, the Pasig River contributes disproportionately to global ocean plastic pollution, accounting for roughly 6.4 percent of plastic waste entering the world’s oceans from rivers, or about 63,000 metric tons each year.
In spite of numerous cleanup initiatives carried out on the Pasig River and its tributaries by government agencies, private enterprises and communities, the pollution persists. Waste continues to flow into the Pasig River from upstream tributaries and a dense network of “esteros” (urban creeks), largely offsetting the positive impacts of the well-meaning but often uncoordinated cleanup operations. In addition, because the Pasig River is a tidal river and water flow can reverse depending on tides, seasons and floodgate operations, the flow of floating waste and water hyacinth is complex, often circulating or accumulating in the river rather than flowing downstream.
The Clearbot vessels are designed to work best in narrow waterways such as river tributaries and esteros, provided the water depth is at least about 30 centimeters, and so for the pilot test they were deployed in the San Juan River in San Juan City and the Ilugin River in Pasig City. In terms of results, according to a brief by the ADB, the vessel in the Ilugin River cleared 138 metric tons of water hyacinth — a volume that filled 277 trucks, and would cover an area of more than 7,000 square meters — in a three-month period between October 2025 and January 2026. In the San Juan River, the vessel collected 5.3 metric tons of floating waste in two months, complementing the MMDA’s existing cleanup equipment and personnel.
The main takeaway from the pilot test was that while the Clearbot, or technology similar to it, is a very effective river cleanup tool, it is just that, a tool that needs to be used as part of a comprehensive and integrated water pollution management strategy. The analysis of the pilot test noted that, while the Clearbot performed very well, new waste continuously arrived from upstream sources; this seemed to be a particular problem in the San Juan River. The ADB brief on the project concluded, quite correctly, that, “[e]ffective river rehabilitation therefore requires a broader set of interventions, including improved upstream waste management and changes in community behavior.”
Managing waste of any kind is always the most effective if it is done at its source, and unfortunately, this is something that has been done poorly here, especially in densely populated areas. The country has a workable legal framework in Republic Act 9003, or the Ecological Solid Waste Management Act, but its enforcement is inconsistent at best, largely because technical and material support to local communities to facilitate their compliance is woefully inadequate. Correcting this with a bottom-up approach not only will benefit water pollution efforts and maximize the effectiveness of tools like the Clearbot, it will also contribute greatly to flood control efforts, something that is a significant concern in our dense urban landscape.
