Drainage maintenance for flood-control infrastructure
Dezu Corporation is a drainage maintenance contractor for flood-control infrastructure in the Philippines. We take on the corrective end of desilting and declogging — main drainage lines, trunk lines, box culverts, pumping station wet wells, and dam drainage galleries where compacted silt and hardened deposits have stopped routine methods — with industrial waterjet pumps, cutting tools matched to the measured pipe, and an agreed debris-extraction plan. Nationwide, for national agencies, LGUs, water districts, dam and hydro operators, and airport and estate facility managers.
Why restore blocked drainage before building new capacity?
Deposits can reduce a drainage line's available flow area. Cleaning may recover some of that lost capacity, but flood performance also depends on the network condition, downstream levels, inflow and the original design. Survey the restriction and assess the wider system before choosing cleaning or construction. A cleaned line still needs monitoring and maintenance. Read the guide why drainage still floods after declogging.
Which flood-control drainage assets does Dezu serve?
Dezu fields the pump classes, tooling, and method for the drainage assets flood-control systems depend on. Delivered proof is further down this page; this is the capability map.
Main drainage lines and trunk lines
Desilting and declogging of large-diameter mains and storm trunk lines — compacted silt and hardened deposits cut from the wall, conveyed to the access point, and collected under an agreed extraction plan, with the cleared condition checked.
Box culverts
Box culvert desilting and declogging reviewed against cell geometry, access, structural condition, deposits and the required cleared area.
Pumping stations
Wet wells, intakes, and forebays cleared of the silt and debris that starve the pumps — scoped and scheduled around station operation.
Drainage inlets and laterals
Inlets and connecting laterals cleared as part of a mains program, so restored trunk capacity is actually reachable from the surface.
Dam drainage galleries and foundation drains
Foundation drain and gallery-cleaning requirements reviewed with the owner and responsible dam-safety specialists before method selection or mobilization.
Airport and estate storm drainage
Terminal and industrial-estate storm drainage restored correctively — the 2022 airport terminal drainage restoration is the delivered anchor for this class.
Why is a combination sewer truck sometimes not enough?
A combination sewer cleaner carries jetting and vacuum equipment on one chassis. Suitability depends on the actual configuration and attachments. Some units can jet and extract together. Review pressure, flow, tooling, collection capacity and access rather than assuming a shared chassis requires alternating work.
NASSCO's heavy-cleaning and large-diameter guidance discusses more demanding debris and extraction conditions. Its size examples do not establish a universal equipment cutoff. A Philippine main, culvert or pumping-station asset requires review of its own geometry, flow conditions and deposits.
Compare complete scopes. A combination unit may suit the cleaning requirement and simplify mobilization; separate equipment may suit a particular removal or extraction need. Deposit, access, water supply, waste handling and the acceptance requirement affect both suitability and cost. A previous unsuccessful cleaning attempt is useful evidence for that review, not proof that a different method must succeed.
How does Dezu's two-machine method work?
Dezu can scope standalone industrial jetting with separate vacuum extraction. The pump and tool loosen and convey deposits; the extraction package collects the removed material. Water supply, access, tank capacity, discharge arrangements and coordination govern the work sequence. Confirm the package and responsibilities in the quotation.
The jetting side is Dezu's fleet of NLB 225-series industrial pump systems with convertible fluid ends. Manufacturer-rated configurations of the same power frame run from 8,000 psi at 49 gpm to 20,000 psi at 23 gpm, with higher pressure classes above that, and the pressure and flow point is configured to the deposit — high flow for conveying loose material, high pressure for cutting hardened scale.
The cutting head is selected to the measured pipe, not the nominal size. Rotary unpluggers open fully blocked lines, self-rotating cutting heads take scale off the wall, and large-pipe rotary heads with centralizers and extension arms cover lines up to roughly 37 inches (about 940 mm) of measured clear bore. Dezu is StoneAge's Authorized Distributor — Philippines and runs the same tooling it sells. The pump fleet and tool families are on the equipment page; the full comparison with combination units is in the guide jetvac vs hydro jetting for drainage declogging.
What drainage and hard-deposit work has Dezu delivered?
The deposits that block flood-control drainage — hardened scale, compacted silt, construction debris — are the deposits Dezu removes for a living. The delivered drainage engagement below is the 2022 airport terminal restoration, delivered under Dezu's hydro jetting service. The industrial engagements beside it are the same deposit physics delivered at industrial pressure classes, shown as method proof, not as flood-control work.
Hydro Jetting — Airport Terminal Drainage Restoration (2022)
Fully clogged drainage affecting a VIP area cleared by hydro jetting. As of 2026, never called back for the same problem. Read the full case study.
Reactor Tank Descaling for Plant Decommissioning — HPAL Nickel Processing Plant (2026)
Five months (January–May 2026) removing mixed sulfide scale from a brick-lined reactor tank with hydro demolition equipment; working volume and baffle plates restored.
Shutdown Cleaning Program — HPAL Nickel Refinery (2023–2026)
High pressure cleaning at every minor (March) and major (September) shutdown since the 2023 major shutdown — six shutdowns delivered to date, retained because Dezu removed buildup others could not.
Pipe Internals Cleaning — Geothermal Facility (2020)
Internal cleaning of geothermal pipework, documented with before-and-after bore photos. Full register at projects.
Clients on delivered work stay unnamed in public copy out of respect for their confidentiality. Full project records and references are available in a meeting.
Who does main drainage declogging for flood-control infrastructure in the Philippines?
Routine desilting and declogging of public drainage is largely carried out by government maintenance crews and their service contractors, and for smaller lines that is the right arrangement. Dezu Corporation serves the corrective end as a drainage maintenance contractor for flood-control infrastructure: main drainage lines, trunk lines, box culverts, and pumping station wet wells where compacted silt or hardened deposits have stopped routine methods. Dezu holds PCAB Contractor's License No. 56253, is a PhilGEPS Platinum Member, and serves public and private infrastructure operators nationwide.
Can hydro jetting clear a fully blocked box culvert?
Hydro jetting may be suitable after review of the blockage, culvert geometry, structure, access and flow conditions. A circular-pipe tool rating does not establish coverage of a rectangular culvert. Dezu cleared a fully clogged airport terminal drainage line in 2022. Each new culvert requires its own method and extraction plan; a previous result does not guarantee clearance.
Should you hire a jetvac combination truck or standalone hydro jetting?
Compare the actual equipment and tooling against the deposit, pipe condition, access, water supply and extraction requirement. A combination unit can suit routine work, while separate equipment can be selected for a specific removal or collection need. Diameter alone does not establish suitability or economics. Confirm package capacity, sequencing and inclusions in the quotation.
The full comparison, including where each option wins, is in the guide jetvac vs hydro jetting for drainage declogging.
Can dam drainage gallery foundation drains be cleaned by high pressure water jetting?
Waterjet cleaning has been evaluated for some foundation drains, including the US Bureau of Reclamation study DSO-98-16. A published case is not an operating procedure for another dam. The owner and responsible dam-safety specialists must determine whether cleaning is appropriate and define the method, controls and acceptance checks. A pump capability does not establish suitability for a particular foundation drain.
A blocked main, culvert, or gallery on your network?
Send the asset type, the measured or nominal size, the length between access points, and what the last cleaning attempt found. We reply with a method recommendation and a scope-based quotation.