September 25, 2023 | 12:00am
MANILA, Philippines — Heavy flooding along EDSA last Saturday was due to garbage clogging the highway’s drains, the Metropolitan Manila Development Authority (MMDA) said yesterday.
An entire panel of plywood, along with plastic materials, impeded the flow of water in the drainage system, MMDA general manager Procopio Lipana said in a dzBB interview.
“Despite our continuous cleaning of waterways, we still get a lot of garbage,” Lipana said in Filipino.
On Saturday, the agency recorded flooding along the northbound lane of EDSA-Ortigas in front of Camp Aguinaldo.
Lipana appealed to the public to be responsible in disposing of their garbage.
He also pointed out that aside from the substantial volume of garbage that had blocked the drainage systems, the sudden and significant volume of rainwater and the relatively modest capacity of the drainage system were contributing factors to the flooding.
Meanwhile, Infrastructure Committee of the Management Association of the Philippines chair Eduardo Yap proposed a solution to the perennial flooding in EDSA.
He suggested the construction of large-diameter underground drainage tunnels to efficiently channel floodwaters from low-lying areas to the nearest creek, regardless of the distance.
Yap’s proposal involves the use of tunnel boring machines (TBMs), similar to those employed in subway projects, to minimize surface disruption during tunnel construction.
These TBMs would be deployed from a pit located off EDSA, facilitating the excavation process without causing significant disruptions to the busy roadway.
Yap said that drainage methods attempted in the past are not suitable due to their large construction area requirements and because they create intolerable disruptions during extended construction periods, along with the unavailability of necessary right-of-way.
Some of these unsuitable flood control methods include sub-surface covered drainage canals like those on Gil Puyat Avenue and underground storm catchments similar to the one at Maysilo Rotunda in Mandaluyong, according to Yap.
Conventional curbside drains are also ill-suited for the task as water cannot naturally flow by gravity from these low-lying areas, and they are often clogged by plastic waste, rendering them unreliable, he added.
MMDA Chairman Don Artes said one of the primary challenges in Yap’s proposal is the acquisition of right-of-way for construction.
Artes suggested that placing drainage tunnels beneath existing roadways would eliminate the need for extensive right-of-way acquisition, which can be both costly and time-consuming.
By utilizing the space beneath the roads, Artes said, larger drainage channels could be created to handle significant volumes of water efficiently.
He told The STAR that the agency is in the process of developing a comprehensive 50-year drainage master plan that takes into account weather patterns and rainfall projections.
Part of the initiative, Lipana said, involves expanding the drainage infrastructure to accommodate the increasing volume of water during heavy rains.