Reasons Why We Flood

Why we flood?

Environmental Planner, Arch. Armando Alli shares his insights on why we flood.

In his facebook post, the Architect mentioned two main reasons we why flood especially in Metro Manila.

Here is what he wrote:


Two (2) other key reasons as to why we flood i.e. aside from the Metro Manila Area (MMA) being a large floodplain, high tide situations seaside, excessive rainfall, denuded elevated areas at upland side, and our antiquated and clogged i.e. poorly maintained drainage systems are :


Too much paving around buildings/ dwellings prevent surface water percolation (water seeping into the soil to help recharge aquifers and in a way, the percolated water helps retard soil subsidence and saltwater intrusion); the very same over-paving does not retard surface water flow and instead accelerates the transfer of storm/ rain/ drainage water to clogged drainage systems and/or onto the heavily concreted roads that then act as large surface canals that bring such collected storm/rain/drain water to lower elevations at a very fast clip (resulting in flash-floods or even inundation, and therefore misery and extensive damage to properties and health/ well-being of the populace); and


There are limits on what can be built on a property and these have all been set in laws such as P.D. No. 1096 (the 1977 National Building Code of the Philippines/ NBCP), P.D. No. 957, B.P. Blg. 220, R.A. No. 7279.

LGU zoning ordinances (ZOs) and their respective regulation streams e.g. IRRs, guidelines, standards, procedural manuals, department administrative orders (DAOs), memorandum circulars (MCs), etc., and in a plethora of other recent executive issuances, including the 2015 DPWH Design Guidelines, Criteria & Standards (DGCS, particularly Volume 6 on Buildings and Other Related Structures), the 2015 DPWH PH Green Building Code (PGBC), the 2000 Architectural Code, etc.;

YET, both the private sector (particularly building designers) and the supposed regulators in Government think that most of these are mere suggestions (and since we are apparently a soft state, they expect no punishment for their act/ non-action relating to required compliances).

In the 2004 Revised IRR of the NBCP alone, percentage of site occupancy (PSO), setbacks, percentages of impervious surfaces (i.e. those that prevent water percolation), and the like have already all been set in great detail; yet, we see illegal construction such as firewalls, yard and road right-of-way (RROW) encroachments, lack of open spaces, illegally-reclaimed legal easements, etc., all with pavement, by the way, more as the rule rather than an exception, with the sole reason being that the regulators have NOT done their jobs (although of course, there are permitted exceptions in cases of extreme hardship of lot owners to comply, a matter also determined by the regulator).

Both the DPWH and its deputized LGU (local) building officials and the DILG and its LGU officials (including municipal/ city engineers who are unable to protect the mandated legal easements along waterways that have been illegally reclaimed, thus narrowing these drainage-ways), share a large part of the blame for the perennial flooding, especially at low-lying areas.

Over-building and over-paving have been regulated since mid-2005 when 2004 Revised IRR of P.D. No. 1096, the 1977 NBCP was promulgated by the DPWH i.e. the first time that the regulation of both physical planning (macro-micro) concerns and building design (micro) concerns have been integrated into a single rule book.

Unfortunately, its implementation and enforcement have been weak at a most critical period (2005 to date).

We are now reaping the results of that weakness over the nearly 1.5 decades when development and construction nationwide were already at an all-time high. Thanks.

——— side note —— end of the post

With that said, I think there is a lot of things we need to overhaul in our system here.