DPWH wants quarrying near Davao bridge stopped

DAVAO CITY (MindaNews/03 October) — The Department of Public Works and Highways (DPWH) on Thursday asked the city government to stop illegal quarrying that has caused erosion at the base of the Generoso Bridge on Davao River.

In a press briefing held Thursday at the DPWH regional office, director Mariano Alquiza said quarrying along the banks of Davao River has led to scouring near the base of the bridge.

The bridge was undergoing rehabilitation resulting in heavy traffic on both sides.

Task Force Suba vice chair Leonardo Avila III, meanwhile, said that their team would start monitoring the river banks for any illegal activity as soon as they meet next week.

Duterte issued an executive creating the task force last week. Its task is to investigate illegal quarrying and identify the sources of siltation in rivers within the city.

In the same briefing, DPWH Project Leader Alvin Cabueñas said retrofitting of the structure was already 90.55% complete.

Originally scheduled to be completed by October, Cabueñas said the bridge needs another month to be operational, citing unforeseen factors such as water turbulence during heavy rains and further erosion at the base and nearby parts of the river banks.

He said that the bridge could be operational by November 6.

He added that the team doing the retrofitting asked the regional office to revise the contract amount of the project from P63 million to P69 million, since the contractor will also be reinforcing the slope near the base as well as rehabilitate a nearby drainage system, which has contributed to the soil erosion.

The slope retrofitting involves the placement of gabions to replace mesh wires that used to protect the bank.

Cabueñas said the contractor will use strong nylon fiber in protecting the slope near the base because it is stronger than steel mesh wire, which used to be the main protection against scouring.

According to a knowledgeable source, gabions can withstand pressures of 30,000 psi, which makes it perfect for erosion protection in bodies of water.

The source added that steel mesh wire would be useless since it would deteriorate due to rust.

DPWH had come under fire from the city government, especially from Mayor Rodrigo R. Duterte, who said the traffic congestion in the city has become unbearable because of several construction projects.

Alquiza, however, said that they regularly coordinate with city officials regarding updates on any public works.

He said the project was supposed to start last year but was delayed for four months owing to the request of the city government itself.

Duterte had to meet with residents living under the bridge last year to convince them to leave for the construction of two bridge projects, one by the DPWH and another by the Davao City Water District.

Alquiza said the structure where the DCWD placed its pipes obstructed the boring of piles by DPWH causing the month-long delay to the retrofitting.

Duterte, in previous interviews, had asked why only a few personnel were working in construction sites for public works.

Alquiza said the number of workers would depend on the kind of work being done at a particular time. (MindaNews)