Experts suggest integrated engineering, nature-based solutions for flood control in PH

CEBU -- Experts from the Philippines, India, Thailand, and Germany gathered in Cebu for the WaterSecurePH Forum on November 27-28 to find suitable flood control measures and suggest solutions to water insecurity in the Philippines.

"We are happy to take part in the Water SecurePH Forum and Urban Water Security Transfer Workshop as a testament to our shared commitment to addressing one of the most pressing challenges of our time: ensuring reliable and resilient water systems in a rapidly changing climate,” DOST secretary Renato Solidum said in his keynote message at the forum.

Solidum said that water resources are under increasing stress, the signs everywhere, droughts that compromise supply, floods that devastate communities, saltwater intrusion into our aquifers, and the mounting pressure of growing cities whose demand often outpaces available supply. These challenges affect not only daily living but also national competitiveness, economic growth, and environmental stability.  Water is not merely a sectoral concern; it is a crosscutting national priority.

Dr. Danilo Jaque, Managing Director of Hydronet Consultants Inc and a consultant to various local government in the country underscored the need for mayors, planners, engineers, and water providers to work together and adopt both structural and nature-based solutions to river and watershed management and flood control measures.

“There is a need for an Integrated River Water Management System that goes beyond just flood control to prevent floods. The focus should be on upstream sources of water, including the presence of trees and catchment areas to prevent overflow during heavy rainfall,” Jaque said in a media interview.

He noted that the inundation caused by Tino is attributed to a combination of factors, including rainfall amount, upstream prevention mechanisms, and river pathway deviations due to development.   A systemic and strategic plan is proposed for River Water Management, requiring the study of proposed strategies and approaches.

Jaque said that there is an urgent need to review past master plans due to potential changes in topography and features. Collaboration with experts and academic institutions is suggested to guide the development of a comprehensive approach, with the goal to prevent future incidents by implementing an Integrated River Water Management System for each major river system.

He highlighted the importance of having a water body, the idea of a single body to manage the river system is proposed, but careful study is needed to determine its effectiveness and management mechanisms.

“The need for a whole-of-systems approach to address river management challenges; a well-coordinated effort among different agencies is necessary for effective river management and hope for future coordination and the establishment of a unified body to manage river systems effectively,” Jaque told the media.

Jaque emphasized the importance of integrating engineering structures with nature-based solutions to preserve ecology and maintain hydrology including the relevance of lagoon retention basins and the balance between gray structures and green solutions, and the need for watershed management, reforestation, and proper farming practices to address flooding issues.

Need to revisit, review watershed management and flood mitigation plans

Jaque and the other speakers highlighted the necessity of updating rainfall intensity data for better flood control system design, including reforestation and proper farming practices; the importance of downstream protection easements and the role of engineers in calculating necessary river widths.

The importance of integrating non-structural measures like watershed management with structural solutions to prevent overloading of installed structures and the need for continuous monitoring and updating of flood control plans to consider new data and land use changes, Jaque mentioned as some the important assessment and training for the local government units for them to make proper recommendations.

 

“Cost and practicality of flood control measures is a staggering minimum figure of about P25M for structural measures alone, excluding the various aspects like reforestation and proper farming practices, thorough investigations of catchment areas and the rehabilitation of watersheds to minimize silt,” Jaque added.

Lastly, Jaque suggested at the importance of looking at data without bias to understand the true impact of developments on flood control. He mentioned the need for proper investigation of contributions from different developers within the catchment area and proper data analysis to make informed decisions about flood control measures.

He also discussed the need for feasibility studies to determine the viability of dam construction for water supply and flood control, considering the social aspects and new information about fault lines in any feasibility study and proper studies to ensure the safety and effectiveness of any proposed dam construction. (Photos: MBCNewman)