The Department of Public Works and Highways (DPWH) is targeting early 2026 to complete pre-feasibility studies for major flood control projects in the Pasig-Marikina and Cagayan River Basins, in partnership with the Japan International Cooperation Agency (JICA).

DPWH Senior Undersecretary Emil K. Sadain said Wednesday the studies, once finalized, will be submitted to the Department of Economy, Planning, and Development for review and will serve as the basis for developing full-blown comprehensive analyses.

Sadain said the DPWH tapped JICA Study Team to expedite the completion of pre-feasibility studies for each river basin, following a directive to revise flood control master plans and expand infrastructure capacity in response to rising flood risks and the growing threat of climate change.

“These will then be developed into full-blown comprehensive analyses, to enable the timely implementation of the Detailed Engineering Designs,” Sadain said.

“These studies and proposed measures in a holistic approach are anticipated to support integrated water resources management, improve interagency coordination, and enhance the overall risk and reduction efforts in Luzon,” he added.

New flood control measures, including dams, retarding basins, and river improvement works, have been proposed under the updated master plans.

For the Pasig-Marikina River Basin, the DPWH said the proposed infrastructure includes two flow-through dams, four retarding basins in San Mateo, Rodriguez, and Quezon City, and extensive river improvement works such as dredging under Phases 2 and 3 of the Pasig-Marikina River Channel Improvement Project.

A separate plan for the San Juan River includes dredging, embankment upgrades, an underground retention channel in Quezon City, and an underground spillway from Quezon City to Manila.

Sadain said these measures aim to deliver flood protection equivalent to a 100-year return period.

For the Cagayan River Basin, JICA Study Team Leader Takahiro Mishina proposed the construction of five flood control dams—Alimit, Siffu, Malig, Ilagan, and Cagayan—as well as three cut-off channels in Tuguegarao, San Isidro, and Gabut.

River improvement works and dredging are also planned for the Magapit section of the lower Cagayan River.

The Japan-funded technical cooperation program began in May 2024 and is being implemented with CTI Engineering International Co., Ltd., Nippon Koei Co., Ltd., and Yachiyo Engineering Co., Ltd., under the supervision of the DPWH Unified Project Management Office – Flood Control Management Cluster.