This document discusses flooding that occurred in Compostela Valley Province in the Philippines after Typhoon Pablo hit in 2012. It summarizes the impacts of the typhoon, which caused over 1,000 deaths and $42 billion in damages. It also describes how certain low-lying areas of Compostela Valley Province are prone to flooding from rivers overflowing due to heavy rainfall. The document aims to provide a flood mitigation plan and structural recommendations for flood-resistant housing in the province, focusing on cost-effective solutions. It reviews past studies on evaluating flood risks and assessing existing housing for flood resilience. The goal is to help the affected community safely rebuild housing that can withstand future flooding.

1. Introduction
Compostela Valley Province, which is a mountainous province in Mindanao, has a highest
elevation of 2000 meters above sea level in its area but also contains many areas in its municipalities an
elevation class of less than 100 meters above sea level. A river passed within the area named the Agusan
River (Graciadas, 2012). The topography of the province doesn’t concern much the communities living in
the lowland areas and near the flood zone areas until a rare incident happened.
Mindanao was hammered by typhoon Pablo on the 4th
of December 2012. With an intensity of
185 kph, the typhoon made the strongest landfall on that year and the strongest ever since the typhoon
Nitang in 1984 that hit Mindanao. In the last 15 years before Pablo, there were only 6 typhoons that
crossed Mindanao. The frequency of cyclones hitting in Mindanao was reported low from the recorded
years starting 1948 to 2010. This phenomenon was considered as an extremely rare weather event and
this might indicate a change in lifestyle trends in Mindanao (Panela, 2012)
Typhoons, like Pablo, are considered to be one of the most destructive natural disasters that
induce tremendous losses in lives and property. Strong and violent winds, high seas and storm surge,
flooding caused by heavy rain, and landslide are the damaging forces that cause havoc towards
countries that are hit by storms (“Effects of Tropical Cyclones”, n.d.). The impacts of these damaging
forces are physical, social and economical. The physical aspects are the destruction of buildings,
infrastructures and rural crops. The social aspects involve the lost lives of the people, health, poverty
and education. The economical aspects are the damage costs and repair costs, loss of production and
income, and other monetary expenses due to the disaster.
According to the Impact Forecasting of International Reinsurance Intermediary Aon Benfield,
Pablo claimed more than 1,000 lives, affected 710, 224 families, and estimated ₱42 billion damage cost

2. on agriculture, infrastructure, private property and rehabilitation (“Exploring Viable Options for
Rebuilding: Post-Typhoon Contact-Building Efforts of HPFP-Mindanao”, 2013).
One resident in Barangay Maparat, Compostela Valley Province said from an interview that a
certain purok in Barangay Maparat was flooded like no other puroks in the area for ten consecutive days
after the typhoon struck since it was near a river system. He added that most of the lowland areas in the
community, especially to the ones near the river system, were affected with flood due to excessive
rainfall and strong wind currents caused by the typhoon.
Based on the DENR-MGB 2006 Geohazard Assessment, Compostela Valley Province is at 23
percent high risk towards flooding; while in New Bataan, there is about 44 percent of the land area
prone to flooding. One of the possible reasons why flooding occur in New Bataan is the denuded forests
caused by past logging activities (“ComVal local officials did not heed landslide, flood warnings - DENR
exec”, 2012).
The Pablo calamity caused fluvial flooding in many parts of the community near the river and
pluvial flooding on the lowland areas where there’s no nearby river. Compestela municipality and its
nearby municipality Montevista have been streamed by the Agusan River. After the typhoon, the river
stream increased its area and its flow and damagingly overflowed thru the banks. However, after the
incident, some residents stayed within the floodplain area but many residents began to relocate their
houses far.
The approach of this paper, in general, is to provide flood mitigation plan for the flood-prone
communities in the province. It focuses, specifically, on providing structural means for a flood-resilient
housing in coherence with a cost-effectiveness plan. This study comes as an applied exploratory
research in direct response to the typhoon incident.

3. A flood proof housing study undergone in the University of Bristol was done thru the evaluation
of recent flood damages and the survey for the existing flood mitigation techniques. Flood data was
firstly acquired by the researchers of the study and was evaluated based on the floods around the globe.
The study then presented existing different mitigation techniques and examined the different
techniques from its advantages, disadvantages, and on the basis of innovation. The final output of the
study was a floating house (Han, et.al, 2002).
The evaluation of the likelihood of flooding is one of the components of flood risk assessment.
Here, the source of flooding, how and where it flows, and the people and assests affected by it are
determined for the understanding of the nature of flood towards the area of study. From the flood
source to the pathway and to the receptors, the flood risk preliminary assessment of this study is
determined thru the acquisiton of the topographic and geohazard map.
A study was conducted on the Flood-prone rural areas of Bangladesh wherein different existing
flood-prone housing types that were manually designed by residents were evaluated. The research
assessed the effectiveness of the designs based on the materials it used for the plinths (mitigation
strategy used by the residents), posts, walls and roofing. The study discussed the appropriate
construction options upon the housing parts of each type in order to become resilient in terms of flood.
From the cement stabilization of the plinths to the chemical treatment of thatch of the roof, different
housing design options were offered depending on the main building materials used. Innovative and
alternative methods were achieved from the research and livelihood options were given for the
community in Bangladesh (Ahmed, 2005).
Understanding the vulnerability of people, property and the environment is one thing to
measure the consequences of flooding. Existing housing types on the area of study are evaluated upon
their capabilities to withstand flood.

4. Information towards different existing mitigation techniques are gathered on this study. They
are then evaluated upon their capability to provide structurally the housing design needs for a flood-
resilient housing. Since this study also cater cost-effectiveness as one of its main factors, the chosen
flood mitigation technique is again evaluated upon its capability to support the socio economic needs of
the rural community in Compostela Valley Province.
The research gap of this study is upon the acquisition of concrete historical flood data since
flood investigations were not yet enquired within the area of study. The sole basis of the flood data of
the study is only on the data of Typhoon Pablo. Nevertheless, this study is beneficial towards the
affected community since it will ensure their future safety in the lowland area. And the cost-
effectiveness approach of the study will economically welfare the financial bouts of the residents to
reconstruct a house that will ensure the resiliency upon disasters, like flood.