The flooding experienced at the height of the sudden heavy downpour last Oct. 9 prompted a reassessment of the condition of the city’s drainage system as directed by Mayor Benjamin Magalong.
The City Engineering Office which conducted an investigation on the cause of the flashfloods along Session Road forwarded three findings:
* The drainage inlets were placed far apart from one another thus the need to install additional inlets to speed up water inflow. This will be endorsed to the Dept. of Public Works and Highways.
* Many establishments have their own downspouts directly tapped to the curb and gutter along the road while these are supposed to be connected to the drainage manhole. The matter will be referred to the City Buildings and Architecture Office for the establishments to correct their drainage pipe connections.
*Some concessioners of the Sunday activity at Session Road plugged some of the inlets thereby hampering water inflow. It was observed that water drained faster when the covers were removed.
The Session Road drainage infrastructure is just a tributary system that drains to the main drainage catchment pipes at the Lake Drive in Burnham Park.
CEO Maintenance Division Head Engr. Richard Lardizabal said the Burnham Park drainage line is large enough to accommodate large volumes of rain water.
The system has been upgraded starting 2020 with the use of new technology structured pipe system with the last of the three-phase project implemented this year. The first two phases that cut across Burnham Park were completed in July last year and was tested and found to be working properly when the city experienced days of continuous strong monsoon rains then. The third phase covering Kisad Road is about to be wrapped up.
Lardizabal said the tunnel cutting across Magsaysay Avenue going to Balili River is also large enough to accommodate large volumes of water.
As to the City Camp basin which also saw flooding at the height of the Oct. 9 torrential rains, Lardizabal said flooding could have been prevented had the inlet screens leading to the drainage pipe not been obstructed by waste materials washed into the passageway.
He said the drainage pipes could have accommodated the large volume of rain water and prevented the rise in water level but the screens were clogged and portions of the canal was blocked as this is being used as a water catch basin during normal days for watering plants by residents nearby.
Lardizabal said the screens were clogged after lumber, garbage and discards that included a damaged washing machine washed into the screened tunnel openings at the height of the severe thunderstorm.
“The main drainage tunnel appeared okay but the screens got blocked causing the rainwater to overflow,” Lardizabal said.
This was aggravated by the collapse of the retaining wall at Morning Star area and the diversion of the Naguilian Road water drainage system to the lagoon 2 drainage due to the ongoing project.
“Hopefully the project drainage at Naguillian will also be facilitated, so it will lessen the volume of rain water going to the lagoon,” Lardizabal said.
CEO personnel and volunteers undertook the clearing of the screened inlets on Oct. 10.