Marikina River not suited to ‘bamboo defense’

This refers to the letter written by Chester C. Chang titled “Nature as solution to ‘river issues’” (Opinion, 2/8/17).

In his letter, Chang cited that the Department of Public Works and Highways “would be spending much, much less if it had resorted to planting the riverbanks with different bamboo species” to address river overflow, siltation and soil erosion problems in the country.

Chang specifically mentioned the riverbank revetment projects of the Unified Project Management Office-Flood Control Management Cluster (UPMO-FCMC) in Marikina River below Tumana Bridge in Barangay Tumana, extending to Barangay Malanday and Barangay Tañong with combined budget allocation of P578 million.

According to UPMO-FCMC director Patrick B. Gatan, planting of bamboo grove along the river has been recognized as an effective solution to mitigate flood damages, as practiced in Japan since the 17th century. However, it could not be directly applied in highly urbanized area with narrow river channel such as in the case of Marikina River.

The riverine areas of Marikina River require structural measure like revetment with concrete wall to confine flood water inside the river channel and prevent overflowing. This will address the progressive deterioration of bank erosion and maximize river width and flow capacity.

Furthermore, the infrastructure projects are part of the Pasig Marikina River Channel Improvement project which was reviewed and updated through the “Master Plan for Flood Management Metro Manila and Surrounding Areas” in 2012.

On the other hand, planting of bamboo grove could still be applied to rivers located in urban or rural areas where there are still available spaces for planting, and where flood inundations are not critical to human lives and properties.

With this we hope to enlighten the reading public on the matter.

ELIZABETH P. PILORIN, Stakeholders Relations Service, Department of Public Works and Highways