Hidden Catch Basin, Gravel Blockage & Family Relief
PROJECT REF #26-07R
Background
Today we attended a residential drainage restoration job in one of the popular hillside subdivisions in Cebu City.
The homeowners were a young couple living together with the rest of their family in the traditional Filipino way—children, parents, and extended family all under one roof.
They had been living in the house since 2017 without any drainage issues.
Then, about two weeks ago, everything changed.
Their drainage system suddenly began backing up.
Wastewater overflowed into the rear extension of the house where they had built a beautiful kitchen. The kitchen floor drains backed up, causing considerable stress for the entire family.
The Property
Like many homes in Cebu, the owners had extended the rear of the house over the years.
During those renovations:
The original catch basin had been covered.
Concrete was poured over it.
The area was tiled, making the catch basin completely inaccessible.
From the surface, there was no indication it even existed.
Fortunately, once we eventually located it, we discovered it was only around 7–8 inches deep, making restoration possible.
Initial Inspection
We began from the front of the property by opening the downstream manhole.
Our intention was to work upstream.
Using our sewer camera, we immediately discovered something unusual.
The pipeline wasn't full of grease.
Instead, it contained a huge amount of:
construction gravel,
sand,
concrete chippings,
and building debris.
The pipe wasn't completely full, but enough material had accumulated to severely restrict flow.
Over the course of the job we eventually removed approximately two 20-liter buckets of gravel and debris.
One unusual observation:
The water escaping through the blockage was almost crystal clear.
The gravel had effectively become a filtration bed, allowing only filtered water to pass through while trapping everything else.
First Attempts
From inside the house we attempted to restore flow first.
Using an auger through:
the kitchen drain
and the bathroom floor drain, we worked downstream.
Although we managed to create slight movement, it wasn't enough to restore proper drainage.
Hydro Jetting From the Front
We then began hydro jetting from the downstream manhole.
Using a Bulldog nozzle, we repeatedly worked upstream, dragging gravel back out of the pipe.
Again and again we removed debris.
Eventually we reached what felt like a completely solid obstruction.
Rather than giving up, we continued working patiently.
Finally...
The blockage suddenly gave way.
A burst of milky water rushed out.
At first we believed we had entered the hidden catch basin.
Camera Investigation
The jetting nozzle still couldn't travel freely.
So we inserted the sewer camera again.
That's when we discovered something unexpected.
Inside the obstruction was a large white plastic sack.
The type commonly used in the Philippines beneath freshly poured concrete when constructing catch basin covers.
Part of that material remained lodged inside the basin.
There was no practical reason to remove it because it wasn't preventing drainage.
It simply occupied space where the nozzle couldn't travel.
Cleaning the House Side
Since the nozzle couldn't effectively continue through the restricted opening, we changed strategy.
Working from inside the house, we switched to our standard penetrator nozzle:
one forward jet
six rear jets
The two-inch branch lines from the kitchen and floor drains were then thoroughly restored until the pipe walls were completely clean.
Restoring the Catch Basin
Once the branch lines were restored, we deliberately allowed the hydro jet nozzle to remain inside the small catch basin.
The basin itself was heavily packed with grease.
Rather than simply blasting it, we continuously introduced bucket after bucket of clean water while the nozzle agitated the grease.
This created constant flushing action toward the downstream pipe.
Gradually the grease broke apart.
The basin cleaned itself.
Flow increased steadily.
Eventually the entire drainage system was restored to full operation.
The Human Side
As the work progressed, neighbors began gathering outside the house.
Many watched with curiosity.
By the end of the restoration, they were amazed at what they had seen.
The homeowners were visibly relieved.
Their family no longer faced overflowing drains.
And the neighbors had witnessed something many had never seen before—
a drainage system restored without demolition or repiping.
The entire household—husband, wife, children, and older family members—could finally return to normal life.