A SINKHOLE in the South Road Properties (SRP) or water cisterns for flood-prone barangays?
These two proposals were raised in response to a plan by Rep. Tomas Osmeña of Cebu City’s south district to use roads in the south district as a temporary impounding and catchment area for floodwaters.
City Councilor Roberto Cabarrubias, who heads the council’s engineering committee, said he finds the proposal of Osmeña a “good plan to solve the city’s drainage problem.”
But Yumi Espina, dean of the University of San Carlos’s College of Architecture and Fine Arts, said using the roads may just worsen the drainage in barangays Banawa or Labangon.
Cabarrubias said channeling the water from the upstream would lead water flow towards the downstream.
He said making a sinkhole in the South Road Propery (SRP) that would discharge the collected water to the sea is very feasible.
He said it’s better to build a sink hole in SRP than converting city roads to mini rivers since it would affect private properties.
Cabarrubias said the vertical sink hole will be covered with concrete materials like cement.
The sink hole must be 50 meters away from the mainland.
Espina, in a Facebook posting in the Stop Cebu Flyovers Movement page, said the flood hazard map marked the SRP in red, indicating that the area is flood-prone.
“This is because the SRP area is the outlet of the Guadalupe River flood plain,” he said.
Espina said building a water catchment that holds water from the uplands will worsen drainage in Banawa or Labangon.
“The natural contours of the mountains along the southern part of the city direct all run-off waters towards the Labangon flood plain area which is why these areas get flooded during heavy rains,” Espina said.
Espina said some of these waters work their way into the Guadalupe River but “most of it just meander through all those subdivisions along the way towards the SRP area.”
Espina said the SRP has a canal along its periphery which catches floodwater and conducts it towards the sea.
Depending on how the water catchment is built and maintained, “it could just as well get all clogged-up and cause a back flow.”
Instead, Espina called for setting up large cisterns which are a palliative measure but is doable.
“The cisterns should have partly open-bottoms and allow the waters to seep underground to recharge the acquirer and also recycle the water for cleaning, washing and fire-fighting in our barangays,” Espina said.
Aside from the SRP, Cabarrubias said Osmeña had already been identifying areas suitable for water catchment and impounding area.
“Basak-Pardo, where I used to be a barangay captain was one of the prospects for the project,” he said.
The size of the culvert will depend on its design, the councilor said.
“It could be rectangular or cylindrical. But a rectangular sink hole is not feasible if there’s a great volume of water,” Cabarrubias said.
He said structures in creeks like those in barangays Lahug and Tejero have small water exits.
Cabarrubias said it would be good if the national government helps in financing the city’s drainage projects. /Tweeny M. Malinao, Correspondent