Water Resources Carrying Capacity:
The Case of the Freeport Area of Bataan

Pamela Christine L. Clavio1, Marie Stephanie N. Gilles1,2,5,6, Kevin Jay R. Hinaloc1,3,
Alewijn Aidan K. Ong1,4, Eleonora Gretchel R. Silli1,6, Sheilette V. Untalan1,5,7

1 University of the Philippines School of Urban and Regional Planning; 2 SNG Design Enterprise;
3 Government of the Philippines House of Representatives Electoral Tribunal; 4 Authority of the Freeport Area of Bataan;
5 United Architects of the Philippines; 6 Philippine Institute of Environmental Planners; 7 Arup Group

古代文明が大河の流域に生まれたように、現代の大都市圏も水資源の安定的供給なくして成立しない。本稿ではフィリピン
で開発区域の拡張が予定されるバターン自由貿易港について、
水資源の将来的な持続可能性を検証した。

Abstract

In light of the growing universal sustainability agenda, it can be argued that policies, plans and programs must havea thorough consideration of the environment and the environmental constraints that affect or influence their direction. This general principle however may be further challenged in the context of areas designed to promote intense
economic activity, such as freeports and economic zones.
The Freeport Area of Bataan (FAB), one of several investment promotion agencies in the Philippines, is one suchcase. There are now more than 140 registered enterprises employing in excess of 38,000 laborers, figures that havetripled that of the 2010 statistics prior to its conversion as a freeport, attracting more than P130 Billion worth offoreign and domestic investments in the last 7 years and remains to be an ideal location to both locators andworkers.
The main objective of this study is to determine the implications of the water resources carrying capacity of the
FAB toward its planned expansion for the next 10 years and to provide appropriate recommendations based on thisenvironmental constraint. The results of this study can then contribute to its development to ensure sustainabilityof its resources, particularly water, in its goal toward becoming a center of trade in Asia. By extension, it can also
help inform policies to manage and support human capital and industries or locators. Moreover, it also hopes toenrich the scant body of research on water carrying capacity in the Philippines and promote its application in development and sustainable investment planning and governance.
Keywords

water carrying capacity, sustainable development

1.1 Introduction

A historical look at urbanization points to a central
element common and requisite to the establishment of
cities: a large body of water, oftentimes, a river. In fact,
Mesopotamia, recognized as the site of the earliest civilization, literally means “between rivers”. From then on,
many more ancient and modern cities have emerged
originating around or near bodies of water.
It is equally important then to recognize that water isa finite and limited resource. This characteristic makes
it a common factor limiting development potential, as

well as carrying capacity. It has been said that “the carrying capacity of limited-water areas is extremely low
for all forms of life, including man” (Durham 1991).
Carrying capacity in turn easily dovetails with the relatively younger concept of sustainable development,
giving rise to enhanced definitions such as “the numberof individuals who can be supported in a given area
within natural resource limits, without degrading thenatural, social, cultural, and economic environment for
present and future generations” (Qin, et.al, 2016). As
Wang et al (2014) aver, “carrying capacity is an essential

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Pamela Christine L. Clavio, et al.

component of sustainable development theory, which
relates eco-environmental integrity to socio-economic
development in situations with limited resource andincreased environmental pollutions”.
In light of the growingly universal sustainability
agenda, it can be argued that policies, plans and programs must have a thorough consideration of the environment — not only for the potential environmental
consequences, but just as importantly, for the environmental constraints that affect or influence their direction. This general principle however may be further
challenged in the context of areas established or designed
precisely to promote intense economic activity, such as
freeports and economic zones. The Freeport Area of
Bataan (FAB), one of several investment promotion
agencies in the country, is one such case.
The FAB was created through the passage of Republic
Act 9728 in 2009 and spans an area of approximately
1,700 hectares in the Municipality of Mariveles covering two barangays and an industrial zone. Prior to theconversion of the export processing zone into a Freeport,
there were 12,777 workers employed by 38 locators. Asof this writing, there are now more than 140 registeredenterprises employing in excess of 38,000 laborers, figures that have tripled that of the 2010 statistics, prior toits conversion as a freeport, attracting more than P130
Billion worth of foreign and domestic investments in thelast 7 years and remains to be an ideal location to both
locators and workers. To capitalize on the growing success of the Freeport, the FAB management is considering expanding the industrial area to accommodate more
locators. This would entail filling up the current phaseof the existing industrial zone and carving out 2 newphases from privately owned properties but are still wellwithin the FAB domain.
Given this direction, it is important to have an understanding of the FAB as part of an ecological system
instead of a self-sustaining organism, which it may
appear to be owing to the special powers and exemptions accorded by law. Especially with the expressedvision “to be the Freeport of Choice in the country by
2020, becoming a center of trade, innovation and sustainable development in Asia promoting work-life074

balance and global competitiveness” juxtaposed withcore values of sustainability, innovation, and partnership, it will be interesting to see how it becomes definedby, and likewise manages, its given resource capacities
such as water. While economic development provides
social and financial benefits to the stakeholders of the
FAB, there is a need to balance this with the area’s maximum water resource carrying capacity to ensure thatcurrent and future generations will be able to enjoy
prosperity without compromising water supply.
1.2 Statement of the Problem
What are the economic, social, and ecological implications of the water resources carrying capacity of the
FAB to its expansion plans?
1.2.1 Research Questions
To further supplement the principal question of thisstudy, the following shall likewise be addressed:(1) What is the projected water demand in the next 10
years taking into account the type of locators basedon water use intensity?
(2) What is the projected water supply taking into
account the effects of climate change?
(3) What is the water resources carrying capacity of
FAB by 2027 considering the various water demandand supply scenarios?
(4)	W hat strategic policy recommendations can the FAB
employ to ensure sustainability of water resourceuse?
1.2.2 Research Objectives
The main objective of this study is to determine theimplications of the water resources carrying capacity of
the FAB toward its planned expansion.
The sub-objectives are:(1) To determine the projected water demand in the next
10 years taking into account the type of locators
based on water use intensity;(2) To determine the projected water supply by 2027
taking into account the effects of climate change;(3) To compute for the water resources carrying capacity of FAB by 2027 considering the various water

6th AFC Best Papers (2022)

demand and supply scenarios; and,(4) To provide recommendations to the FAB management for residential and industrial expansion plans of
the FAB based on its water resources carrying
capacity.
1.3 Significance of the Study
The double bind of sustainable development lies in
the argument that the path to further economic development or material growth also clearly necessitates the
exploitation of natural resources. Nonetheless, sustainability continues to be a resounding buzzword and, by
and by, concrete efforts are being introduced by various
sectors in their respective spheres of influence. This
study therefore aims to advance this agenda by underscoring the supply and demand factors in the biophysical support system to influence development andinvestment planning processes.
Economic developments, at times, progress to an
imbalance in the supply and demand for the biophysicalsupport system and worsen to environmental degradation. In almost all cases, such scenario can reverse thepositive impacts of economic development and may
even lead to losses in lives and properties. Thus, there isa need to strike a balance between supply and demandof scarce resources and understand the environment’s
limiting factors, including water.
Among other resources, water is particularly important to monitor and include in decision-making due to its
significance in settlements development and high vulnerability to climate change. Water shortage, defined as
the lack of access to adequate quantities of water forhuman and environmental uses (White, 2012), has
become a global phenomenon. The Food and Agriculture
Organization or the FAO (2012) noted that “unconstrained water use has grown at global level to a rate
more than twice the rate of population increase in the20th century, to the point where reliable water services
can no longer be delivered in many regions.” The FAO
added that demographic pressures, the rate of economic
development, urbanization and pollution are all putting
unprecedented pressure on this resource. Rathnayaka etal (2016) posit that “scarcity of traditional water sources,

such as surface and groundwater, coupled with low
water use efficiency are increasingly threatening thesecurity of urban, agricultural, and environmental waterneeds.” Obot (1984) stated that “water shortage makes it
impossible to implement regional development. Growth— including investments such as large-scale factories,
irrigation schemes, and so on cannot be started in thearea.”The Philippines is not exempt from such crisis.
Webster & Le-Huu (2003, as cited in Rola et al, 2015)
also noted that the per capita water availability in the
country has been declining over the years due to increasing water demand and decreasing supply. An AsianDevelopment Bank (2013) study reported that “growing
population especially in the urban areas together withwater pollution, wasteful and inefficient use, continued
denudation of forest cover (particularly in watersheds),
and saltwater intrusion caused by excessive withdrawalof groundwater (particularly in the metropolitan area ofCebu, Davao City, and certain areas of Metro Manila),
are the major challenges facing the country’s water
resources.”
The results of this study can then contribute to thedevelopment of the FAB to ensure sustainability of its
resources, particularly water, in its goal toward becoming a center of trade in Asia. By extension, it can also
help inform policies to manage and support human capital and industries or locators. Moreover, it also hopes toenrich the scant body of research on water carrying
capacity in the Philippines and promote its applicationin development and sustainable investment planningand governance.
1.4 Scope and Limitation
The study covers only the existing water-impounding facility (i.e., dam), the FAB watershed, locator water
consumption, and the barangays under the direct jurisdiction of the Authority of the Freeport Area of Bataan(AFAB). Territorially, the FAB covers five (5) barangays
in the municipality of Mariveles, however, only two (2)of these are being supplied water since these are theoriginal residential sites reserved for the zone workers.
Through the years, these areas were subsequently

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Pamela Christine L. Clavio, et al.

organized into political units but had likewise grown in
the number of informal settlements within and even outside the two (2) designated barangays. Other portions ofMariveles and the remainder of the province of Bataan
were not included in the forecasting scenarios due todata and time constraints. It should also be consideredthat the water-impounding facility was establishedaround the franchise territory of the FAB, and is therefore outside the general authority of the Local Water
Utilities Administration. Hence, resource sharing suchas the exportation of water resources outside the FAB is
not viewed as an urgently viable concern since this moveis subject to multiple legal and territorial impediments.
While the researchers recognize that water quality
factors can affect water resource carrying capacity,
especially when considering more specific uses, thevariable was not included in the study. Water supply isbased primarily on the precipitation and water ecological requirement; whereas demand is based on industrial
and residential water consumption and taking into
account the level of prosperity in the FAB. Population
was projected based on the eight (8) planned housingdevelopments of AFAB, which can approximately
accommodate 1,728 residents, as it seeks to limit settlements within FAB due to space limitations. Theseassumptions and consequent limitations will be elaborated on in the discussion on the study’s conceptual
framework.
Given the lack of current data, only information collected as of 2015 were deemed sufficient and complete.
As such, 2015 calculations will be used as the baseline
for this study.

2.0 Review of Related Literature

Durham (1991) identified water as a factor that limits
carrying capacity. He stressed that “the carrying capacity of limited-water areas is extremely low for all formsof life, including man.” Recognizing the important roleof water in socio-economic development, water
resources carrying capacity (WRCC) has attracted considerable attention.
“WRCC is based on the carrying capacity theory andthe exploration of response mechanism between human076

activities and water resources.” It “rationally evaluates
the socio-economic scale threshold that can be sustainedby the local water resources.” (Qin, et al., 2016). This
concept has been carried over in several studies proposing various methodologies to calculate it.
Dou et al (2015) defined in their paper water resourcescarrying capacity (WRCC) as the “maximum sustainable socioeconomic scale that can be supported byavailable water resources and maintenance of goodenvironmental conditions.” The paper presented a “distributed quantitative model for WRCC, based on theprinciples of optimization, and considering hydro economic interaction, water supply, water quality, andsocio - economic development constraints.” Dou et al(2015) elaborated the socio - economic scale as the“overall size of a regional socio - economic system in acertain period and represented by a “series of socio economic indices including total population, urbanization ratio, industrial structure, and grain yield.” Good
environmental conditions, on the other hand, was elaborated as a “suitable living environment for human beingsand the ecological system, in particular good water
quality and healthy aquatic environment (Dou et al.,2015).
The authors further emphasized that research on
WRCC should be based on two premises. First is that,
the WRCC must be able to “sustain the normal operation of a regional socio - economic system” which basically entails the calculation of the quantity of water
resources needed to sustain these social service functions. Second premise is that, the WRCC shall provide
for the “maximum socioeconomic scale that water
resources can sustain after meeting the needs of the ecosystem” (Dou et al., 2015).
Qin et al (2016) proposed the concept water resources
design carrying capacity (WRDCC) as a way to calculate WCCC projection. The authors defined this concept
as “the carrying capacity of water resources for humanactivity under a design condition, i.e., a design water
resources and design socio-economic development
stage.” In this concept, the word “design” is taken as
similar to “design flood” where flood is under a designed
standard of water conservancy and hydropower6th AFC Best Papers (2022)

engineering. Meanwhile, Peng & Xu (2012) used theEnvironmental Water Carrying Capacity (EWCC) tomeasure the carrying capacity of a 151.59 square kilometer Industrial Park in Zhuhai City with a populationof 350,000. In this study, the EWCC evaluation model,
which was established according to simulations ofsocio-economic activity, can forecast the value of
assessment indicators to represent their impact degree.
An entropy indicator assessment was then proposed toanalyze the changes in environmental water carrying
capacity and to obtain key indicators. While there aremany other studies related to WCC, these examples suggest that the concept is related to the interaction of man
and nature. As Peng & Xu (2012) pointed out, “it is acomplex, large-scale system, involving numerous factors (including but not limited to population, resource
availability, the environment, ecology, society, economics, and technology).
An earlier study of Ming in 2011, which presented
the Water Resource Carrying Capacity of Chongqing
Metropolitan in China, provided a computational modelfor the regional WRCC:

Where,
P = WRCC
WR = regional internal total water resources quantity
WEX = regional external water flow
WE = ecological water requirement, which “means theminimal water demand for supporting the integrality
and virtuous circle of ecological system in the region,
which can be divided into the ecological water requirement inside river channels and the ecological waterrequirement outside river.”
PRA = unit area agricultural average output value
AR. = area of agricultural production
PI = average industrial output of value per unit water
R AI = agricultural water consumption standard of effective irrigation area
AI = agricultural effective irrigation area
R DU = urban domestic water consumption standard
R DA = rural domestic water consumption standard
UP = per capita industrial and agricultural output value,

which for easier calculation, can be replaced by per –capita GDP
r = urbanization rate
He emphasized that if the regional available amountof water resources, urbanization rate, and other related
technical and economic indicator can be predicted in aregion, the WRCC can be calculated.
While there had been a number of studies related towater supply and demand in the Philippines, a review inthe literature will reveal that there is a lack of, if notabsence of studies related to WRCC in the country. This
presents a research opportunity to researchers to contribute to the field of water management and governance.

3.0 Research Design

3.1 Conceptual Framework
The Water Resources Carrying Capacity (WRCC)
refers to the “number of individuals who can be supported in a given area within natural resources limits,without degrading the natural, social, cultural, and economic environment for present and future generations”(Qin, et al., 2016). Dou et al (2015), similarly, defines
WRCC as the maximum sustainable socio – economic
scale based on available water resources and maintenance of good, defined environmental conditions.
Drawing considerably from Dou et al (2011) and inconsideration with available resources pertaining to thestudy area, below diagram summarizes the variables orfactors determining the WRCC which basically are
clustered into three (3) modules including:• Socio – Economic Module;• Ecological Module; and• Water Quantity Module077

Pamela Christine L. Clavio, et al.

on the other hand, pertains to the water outflow due toevaporation and transpiration in the focus area.

Fig. 1. Conceptual Framework

3.1.1 Socio – Economic ModuleThis pertains to the pressures of the socio – economic
development on the water resources system of the focus
area. Indices included in this module includes population including the total population and the rate of urbanization; economic including industrial output, industrial
output growth; and the water consumption of residential
and commercial facilities.
Industrial output — refers to the total output (in PhP)
of all industries in a given location. In the case of FAB
and for this study, industrial output refers to the total
output of all locators inside FAB.
Urban Domestic Water Consumption — takes into
account water used for residential and commercial
purposes.
Average Industrial Output Value per Unit Water — is
the industrial output divided by the total industrial water
consumption.
Per Capita Output Value — is the industrial output
divided by the total population in a given area.
Rate of Urbanization — refers to the projected average rate of change in the size of the urban population
over a given period.
3.1.2 The Water Quantity Module and the Ecological
ModuleThe Water Quantity Module pertains to the totalinternal water resources including the surface groundwater and local precipitation. The Ecological Module,

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3.2 Analytical Framework
3.2.1 Geographic Information System (GIS)The fundamental objective of utilizing GIS in the
research is to spatially define the location and environment of the study area, as well as to construct the storage characteristics of the reservoir. Existing geographic
information in various format were collected from the
AFAB. Core GIS vector and raster datasets obtained
include: shapefiles of watershed, AFAB, and reservoir
boundary; rivers, roads, buildings, and land uses within
AFAB; satellite imagery; and, the reservoir’s Digital
Elevation Model (DEM). Other maps acquired weregenerated by AFAB’s previous partners—UP
Engineering, The Louis Berger Group Philippines, Inc.,and the Applied Planning and Infrastructure, Inc. (2012).
The format of GIS files was in shapefile (.shp), drawing(.dwg), and Tagged Image File (.tif), which were interoperable within any GIS software packages.
3.2.1.1 GIS Analytical Methodology
To display and analyze the data, this research applieddifferent spatial tools within an evaluation version of
ArcGIS software (ArcGIS 10.3). The geographic information needed in the study was modeled and examinedusing several tools in the ArcGIS Spatial Analyst and3D Analyst extensions. To standardize the spatial properties of GIS files from AFAB, the data were translated
to the reference system commonly used in thePhilippines—Projected Coordinate System World
Geodetic System of 1984 Zone 51.
3.2.1.1.1 Shape Analysis and Measurement
In assessing the study area’s carrying capacity, it isvery important to measure the shape area, length, andother geometric properties of the features. Specifically,
GIS aided in computing the parameters such as area,
perimeter, and centroid while making use of the formula
below (“Shape Analysis,” n.d.):6th AFC Best Papers (2022)(a) Area:(b) Perimeter:(c)	Centroid (Center of Gravity):
Where in each case above, X is the base and Y is
the height.

3.2.1.1.2	Digital Elevation Model (DEM) to Extract
Terrain Profiles and Hydrologic Information
The potential of remote sensing to construct the
topographical and hydrological characteristics of thereservoir is investigated in the study. A Digital Elevation
Model (DEM) of 1-meter spatial resolution enables theresearch to express the physical land and bottom terrainof the reservoir. A DEM is a raster-based representationof earth’s surface that composed of rectangular arrays ofcells or pixels (ArcGIS 2017). Each individual pixel
stores an elevation value (Manuel 2004). Hence, DEM
with its simple data structure that facilitates faster calculation, is frequently utilized to analyze topography(Arun 2013). The elevation model below served as thebasis for all the spatial calculation and prediction in the
study using GIS.
Several GIS approaches to the DEM produced relevant hydrologic information that can be used to delineate watershed boundaries and locate streams that
contribute runoff into the reservoir. An overview of the
GIS processes employed is given below:

Fig. 2. DEM of the Reservoir

The first step is to recognize and address erraticchanges in elevations especially the presence of “sinks”
or cells that are bordered by higher elevation values
which may hinder the flow of water through the slope.
GIS fills in the sinks and create a depressionless DEM
where runoff characteristics will be derived. By fillingin the DEM, GIS will be able to define the direction ofwater flowing from cell to cell (flow direction) and how
much water travels through a cell (flow accumulation).
The flow direction and accumulation information will
be inputs to delineate stream channels and watersheds
from the elevation model.

Fig. 3. Flowchart to Delineate Stream Network from DEM
modified by the author
Source: http://pro.arcgis.com

3.2.1.1.3	Triangulated Irregular Network (TIN) to
compute for Reservoir Volume
The study also utilized the Triangulated Irregular
Network (TIN) interpolation method for extracting theparameters used for approximating the amount of water079

Pamela Christine L. Clavio, et al.

that can be stored in the reservoir. TINs are used in GIS
to illustrate surface morphology of land and sea floor.
Compared to the DEMs, TINs are geographic vector-based data consisting of points (nodes) and lines(edges) which are arranged to form non-overlapping
irregular triangles to cover a surface (“Fundamentalsof,” n.d.). Each node has an x, y coordinate and a z value
or surface value (McPherson et al 2009). Utilizing thetriangular facets constructed by TINs, the elevation canbe calculated at any location on the TIN using the geometry of the triangles (Walsh, n.d.). Figure 4 illustrates
the comparison of grid surface and triangle surface.
Both datasets can provide lake depth and volume, but
the density of irregularly spaced network of points in
TIN can calculate for the most accurate representationof a 3-dimensional structure of the reservoir basin.

Since the DEM is observed to have appropriate resolution to address the objective of the research, the TIN
created from the DEM is considered as the most realistic
representation of the actual reservoir-bed surface.
Hence, the TIN will give a more precise estimate of calculating the volume of the reservoir.
There are many forms of triangulation, but ArcGIS
supports the Delaunay triangulation method which“creates triangles that collectively are as close to theequilateral shapes as possible” (McPherson et al 2009).
This type of triangulation “ensures that no vertex lies
within the interior of any of the circumcircles of the triangles in the network” (“Fundamentals of TIN,” n.d.),thus having a surface output with minimal densificationof long and thin triangles. A Delaunay triangular surface is illustrated below.

Fig. 5. Comparison of Non-Delaunay and Delaunay
Triangulated Surface
Source: Kudowor and Taylor 1992

Fig. 4. Comparison of Topography Surface using Rasterand TIN interpolation, modified by the author
Sources: https://serc.carleton.edu, http://www.edc.uri.edu

Variations in methods to estimate lake volume wasdescribed by Hollister and Milstead in their 2010 study.
The figure below showed that among the four methods—formula for volume of a cone; formula for frustumof a cone; using depth as a function of distance; and TIN
created from bathymetric survey—the latter expresses amore realistic depiction of the lake basin (Hollister and
Milstead 2010). However, it should be noted that in thisresearch, the TIN was not obtained from a bathymetricsurvey but from a DEM with a raster resolution of 1
meter (having a cell size dimension of 1 x 1 meter).

080

The general volume calculation of triangulated surfaces is carried out by using the following formula(Kudowor and Taylor 1992):(X1, Y1), (X 2, Y2), (X3, Y3)
Z1, Z2, Z3Planar coordinates of the triangle
vertices
Elevation with respect to sea levelor thickness between geologicalhorizonIn applying the Delaunay algorithm to volume calculation in GIS, the succeeding processes are required: a)6th AFC Best Papers (2022)

Convert the DEM information to a contour line featureclass, b) Create a triangular irregular network by importing the contour map; c) Generate a closed reference
plane to define the area over which to compute thevolume; d) Define the height as basis for volumetric calculations; and, e) Use the 3D TIN surface and the reference plane to compute for the summation of eachtriangular prism volume between the reference plane
and the topside of the reservoir bed.
Using the formula and notation discussed for individual triangular surface earlier, the integration of all volumes to determine the total volume is specified in theequation below:

3.2.2 Revised Water Resource Carrying Capacity
Ming’s (2011) version of the WRCC takes into consideration other economic activities, besides industries,that require intense water use in the Chongqing
Metropolitan area such as agriculture. Furthermore,
Ming makes a distinction between rural water use
against urban water use to take into account the effect ofhigher incomes on demand for water. However, giventhat there is no agricultural activity in the FAB and thisstudy makes little or no distinction between rural andurban water use, a simplified version of the Ming modelis hereby adapted by the study, to wit:

Where,
WR = Total water resources
WE = Total water ecological requirement
R DU = Urban domestic water consumption
R = rate of urbanization
UP/PI = Per capita output value and average industrial
output per unit water
For the net water supply side of the model, total water
resources cover water absorbed by the entire FAB
watershed resulting from precipitation, surface runoff,
infiltration, interflow, and water that goes into aquifer

recharge areas. On the other hand, water ecologicalrequirement involves evaporation and transpiration,
both processes that are necessary for the sustenance of
the watershed.
The water demand side (denominator) of the formula
begins with total urban consumption whereby, for purposes of this study, the aggregate water consumption of
FAB residents and locators will be used. Rate of urbanization is computed based on population growth while
the total value of products (Net Sales) will be used tocompute for (UP/PI) in conjunction with population andwater consumption.
The resulting WRCC will give the researchers of thisstudy the total number of population that the water
resources can sustain based on the existing economic
activity and prosperity being enjoyed in the FAB. Given
that FAB management would like to further attract new
locators, it should be guided accordingly since there areindustries that are water-intensive while others are not.
Ecological consideration must also be looked into eversince climate change has become a clear and present
danger. According to the Hydrologic and HydraulicCharacterization Study of the FAB (2015), the lowest
recorded water level in the dam was 133 meters above
sea level (masl) in 1984 while the highest recorded levelin the dam was in 2015 at 164 masl. The average dam
level for the base year stood at 152.52 masl. Do note,however, that in order to maintain the structural strengthand integrity of the FAB dam, water is discharged
should it go beyond 157.7 masl.
Hence, on top of just computing for the WRCC for2015 (base year), this study will project water use
assuming water-intensive companies locate in the FAB
versus another scenario where non-water-intensive
companies locate in the Freeport. The results will thenbe juxtaposed with extreme cases of high precipitation(assuming dame level is at 164 masl) and low precipitation (assuming dam level is at 133-masl). The resulting
sensitivity analysis should guide the researchers on what
policies to recommend to the management of the FAB.

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Pamela Christine L. Clavio, et al.

3.3 Research Design
The research follows the case study design employing primarily quantitative methods to satisfy the statedobjectives. Data was collected from existing plans andstudies vetted by the FAB, and in some cases, transformed or extrapolated on through GIS. It must be notedthat access to and understanding of the FAB’s data wasfacilitated through a member of the research team who
is an official of the AFAB, as of this writing.
The researchers placed heavier attention on data
analysis, anchored on an assessment of the quality andcompatibility of various data, and the development of aworkable water resource carrying capacity (WRCC)
model tailor fit with the area-specific characteristics ofthe FAB.
3.4 Study Area
3.4.1 Geography and Land Use
The FAB is located at the southern tip of the municipality of Mariveles, province of Bataan. According to its
master plan, the area is 160 km by land from Manila andabout 85 km from the Subic Bay Freeport Zone. It isbound by the West Philippine Sea on its west and theManila Bay on its eastern part, converging within the
FAB’s coast. A previous study on the area highlighted
Mariveles’ deep water bay and relative proximity to
Manila as notable features that make the economic zone
suitable for trade that especially involves shipping,although key infrastructure and services must complement this (Malate, 2015). The area is also part of theZambales Mountain Range and is closest to Mt.
Mariveles, considered an inactive volcano. Below is its
general location map relative to Manila and other major
freeport zones.

Fig. 6. General Location Map of the Freeport Area of Bataan
Source: Google Map

The FAB has an effective jurisdiction of 1,700 hectares, technically occupying portions of five out of 18
barangays of Mariveles. It may be noted that Mariveles
has the highest total population among the municipalities and cities in Bataan.
The total developed area is 304.58 hectares, of which
235.46 hectares are occupied, representing a 77.31%
occupancy rate. Figure 7 shows the existing land use of
the FAB per its 2012 masterplan.

Fig. 7. Existing Land Use Map of the Freeport Area of Bataan
Source: Authority of the Freeport Area of Bataan, the Philippines

0826th AFC Best Papers (2022)

3.4.2 Masterplan
As previously noted, FAB aims to expand its operations and attract more locators. Presently, over threefourths of its 304.58 hectares of leasable land is occupied,leaving 69.12 hectares as available land area fordevelopment.
Its land use plan is therefore premised on a scenario
where there will be increased demand for industrial,
residential, and commercial land. The AFAB is looking
to have five (5) expansion areas for to accommodate
more locators. Two of these will be for industrial use,
one area will be for a township project, a fourth for aterminal, and last will be for a central business district
and ferry terminal.
Table 1. Description of Leasable Land3.4.3 Water Resources
The FAB core area is drained by 3 rivers and waterways including the Paniquian river which runs from thenorthern forested slopes, and the Aguawan river whichruns through the entire length of the FAB.
Upland reservoirs are available and part of the riverand drainage systems recharged by precipitation on thewatershed area. The watershed of the FAB is composedof 21 sub-basins, with four contributing to the AFAB
reservoir. Malate (2015) indeed observed that the natural mountainous terrain of Mariveles served the area
well in that it supports water supply necessary foreveryday operation. Further, the availability of clean
mountain water makes it appropriate for water-intensive
industries such as food processing.
Inside the FAB is an impounding facility or water
reservoir constructed in the 1970s. According to theHydrologic and Hydraulic Characterization (2015)
report commissioned by the FAB, the reservoir has acapacity of 9 million [cubic meters], water sourced fromthree rivers, particularly the Paniquian river, and goes
through a water treatment plant that is capable of processing 15,000 liters of raw liquid daily. Through nearlyfour decades of operation, however, the dam has beenfound to have accumulated more than 400,000 cubic
meters of sediments, averaging 11,500 cu.m. of sediments per year

4.0 Results and Discussion

4.1 Water Quantity Module
The DEM analysis has recorded the following topographical values of the reservoir. The surface area isabout 321,510 m2 with a mean depth of 140 masl. The
generated elevation map from the model revealed thatthe reservoir’s highest elevation, is accounted to be 176
masl and lowest elevation is 118 masl. The reservoir is
4,696 meters (4.7km) long. The slope map, on the other
hand, shows the range of slope within the reservoir.
Steep slopes with greater than 50% are predominant
specifically in areas near the dam, and surrounding thelowest surface elevation. Gentler slopes, with 0-18%,
can be found on areas that are relatively flat and withhigher surface elevation. Average reservoir slope is41%. Vector-based contours, with 5-meter and 1-metervertical intervals, were also created using the same
DEM information. Contour data defining the reservoir-bed surface is required in estimating the volume
capacity of the reservoir at different elevation levels.
The generated contour map showed that there are relative spacing of contours at the upper end of the reservoir. The lowest contour line which is located at thecenter and basin floor of the reservoir is 119 meters.

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Pamela Christine L. Clavio, et al.

Fig. 8. Interpolated TIN surface & Estimated Volume ofReservoir

Areas of watersheds and streams are consideredenvironmentally sensitive and should be defined since
they may affect the quality and quantity of water being
fed to the reservoir. Utilizing the hydrology tools of
GIS, the study extracted the locations and characteristics of the contributing watershed and stream networks
from the DEM file. In GIS, watershed boundary isdefined by computing the flow of water across the steepest downslope direction. In the study, it was found thatthe watershed boundary extends down to the areas withlowest elevation (55 masl). The region and streams
draining into the reservoir were also illustrated. Anotherinteresting output from the hydrology analysis is theidentification of areas with high water flow accumulation across the surface. Taking a closer look at the profile of concentrated flow, it shows the elevation (inmeters) along the Y axis, and distance (in meters) along
the X axis. The highest masl for that section is 160 andlowest masl is 120. As discussed in the methodology, theDEM was processed and converted into triangularfacets also known as the Triangular Irregular Network,
using a particular approach called the Delaunay
Triangulation. The resulting TIN map above was utilized to obtain various reservoir height, water volume,
and area at different scenarios or water levels.
After having estimated the watershed area as well as
the different flooded areas, it is now possible to calculate
the amount of water resources available. This study has
considered three precipitation scenarios of high,084

medium, and low with the business as usual (BAU) category (medium) acting as the baseline. According to themodelling of the Hydrologic and Hydraulic Study commissioned by the AFAB in 2015, the measured rainfall
for the said year was around 3.306 meters for a total
water resource of 59.9 million cubic meters. By virtue ofextrapolation using the recorded highest and lowest dam
levels, the highest water rainfall yielded a total of 64.86
million cubic meters of water resources while the lowest
recorded precipitation (at the 133 masl dam level in1984) was estimated to be around 52.27 million cubic
meters of water resources.
4.2 Ecological Module
To determine the net water supply, the amount ofwater lost due to evapotranspiration was estimatedusing a high, medium, low scenario and the resulting
values were deducted from the total precipitation annual
volume. The BAU category was considered as themedium scenario and was estimated using the model ofthe Hydrologic and Hydraulic Study (2015) that yielded
an annual approximate of 0.9072 meters of water or a
total of 16.45 m3. Given the same dam levels (highest
and lowest recorded) as the precipitation estimate, thehigh and low scenarios were extrapolated, thus, giving a
volume of 17.79 million m3 and 14.34 million m3,
respectively.
4.3 Socio-economic Module
The population projection is needed to determine theurbanization rate. But due to space limitations within
the Freeport, the AFAB has expressed its intention tolimit housing developments, which consequentially will
restrict population growth. In this study, 1,728 people isexpected to be added until 2027 based on the planned 8
housing developments of AFAB, each having a capacityof 216 occupants. Using the formula for Compounded
Annual Growth Rate, the urbanization rate of 1.56%
was derived.
Urban Domestic Water Consumption considers waterused for residential and commercial purposes. For the
projection of residential water use, linear progression
was used based on the 2012 to 2016 data. For6th AFC Best Papers (2022)

commercial water use, a 3% growth (based on averageincreases from 2013 to 2016) was applied for 2017 toreflect natural increase (using linear progression will
result to a decline in water use) then linear progression
was done for 2018 to 2027. To compute for the urban
domestic water consumption rate, the Total Urban
Domestic Water Consumption, which is the sum of residential and commercial water use, was divided by total
population.
Computing for the Average industrial output value
per unit water will need two inputs: industrial output
and industrial water consumption. For this study, industrial output value was projected using the 2015 data asbaseline. The projection used the annual growth of 7%
based on the projected growth of the Philippines’ GDP
in the medium-term. Note, however, that this study
assumes that the total output of FAB will be the same
regardless of the type of industry (based on water use) it
attracts because there are no available data or study that
correlates water use intensity and output value.
With the study’s aim to reveal the effect of industry
mix, based on water use intensity, on the WRCC, three(3) different scenarios on industrial water consumption
were made: BAU, more water-intensive industries, andmore non-water-intensive industries. BAU means
growth in water for the two industry sub-sectors, water
intensive and non-water intensive, will track historicalperformance in which the former was growing at a rate
of 7% while the later at a rate of 5.75%. With this projection, composition of industrial water consumption will
be at the vicinity of 80% from water-intensive industries
and 20% from non-water-intensive industries until 2027.
For the second scenario, which is having more water-intensive industries in the FAB, a 10% annual growth inwater consumption for such industries was applied
while the BAU growth for non-water-intensive wasretained. The 10% growth was based on the average
growth on the total industrial water consumption from2015 and 2016 when the growth of such consumption
normalized. For the third scenario, which is having
more non-water-intensive industries in the FAB, a 10%
annual growth in water consumption for such industries
was applied while the BAU growth for water-intensive

was retained.
With the industrial output and industrial water consumption computed, the Average industrial output value
per unit water were derived for the 3 scenarios. To compute for the Per capita output value, industrial output
value was divided by the total population.
4.4 Computation of FAB WRCC
Using the derived values of the indicators, the WRCC
was then computed for the baseline year 2015 and forthe various water demand and supply scenarios by 2027.
In this study, there are five (5) expected scenarios: theBAU, which serves as the control of the study; the Highwater-intensive (more water-intensive locators) andHigh Precipitation; High water-intensive and Low
Precipitation; Low water-intensive (more non water-intensive locators) and High Precipitation; Low water-intensive and Low Precipitation.
In the year 2015, the study revealed that the FAB was
still operating at a sustainable level as its WRCC was
258,288 people — way beyond its population of 9,317.
However, it can be noted that for all scenarios by 2027,
there is a significant drop in the WRCC. For the worst
case scenario, the High water-intensive and Low
Precipitation, the WRCC drops to 92,946 or a reductionof 165,342; while for the best case scenario, the Low
water-intensive and High Precipitation, the WRCC goes
down to 153,825 or a decrease of 104,463. For Businessas Usual, it declines to 146,686 (less 111,602); for Highwater-intensive and High Precipitation to 132,058 (less125,780); and for Low Water-Intensive and Low
Precipitation to 108,267 (less 150,021).
While the study shows that FAB will still be able tosustainably operate by 2027 given the 5 different scenarios, the researchers went on to explore its sustainability beyond the 10-year projection. This was done tocome up with more substantial recommendations on thelong-term plans of AFAB. To do so, the annual rate ofdecay, or the annual rate of decline, of the WRCC wascomputed using the 2015 and 2027 values. This assumes
the continuation of the projections of all indicators in
the 5 scenarios, including the urbanization rate. Thismeans that it is also assumed that the AFAB will be085

Pamela Christine L. Clavio, et al.

Table 2. Computation of FAB WRCC

considering more housing development although at apace that will increase population at the same rate of
1.56%.
Following the WRCC concept, the FAB is considered
to be sustainable until its population already exceeds the
WRCC. Applying the rate of decay, it was found out that
under the worst-case scenario, the FAB will only be sustainable until 2045, and for the best-case scenario until
2072. For Business as Usual, it will be until 2065; forHigh water-intensive and High Precipitation until 2059;
and for Low Water-Intensive and Low until 2051.

5.0 Conclusions and Recommendation

Based on the foregoing discussion, it can be concluded that the FAB will still be sustainable in its operations by 2027 in any of the 5 scenarios: Business as
Usual; the High water-intensive (more water-intensive
locators) and High Precipitation; High water-intensive

086

and Low Precipitation; Low water-intensive (more nonwater-intensive locators) and High Precipitation; Low
water-intensive and Low Precipitation. However, its
maximum sustainability will only be until 2072 at thebest case scenario of Low water-intensive (more nonwater-intensive locators) and High Precipitation.
The best way to prolong the sustainability of FAB’s
operations, AFAB must take measures to attract morenonwater-intensive industries, such as BPOs/KPOs,
banking and finance, research and development, and thelike, in order to reduce pressure from the water demandside. To increase supply, it is highly recommended that
the FAB initiate dredging in the water reservoir toincrease its water storage capacity, instead of increasing
the height of the dam wall, which will prove costly due
to sophisticated engineering interventions since it will
necessitate massive structural retrofitting of the existing
dam wall. A study has estimated that the amount of

6th AFC Best Papers (2022)

silting and deposits have reached approximately 400,000
cubic meters which when removed, shall increase storage capacity considerably and enable FAB to capitalize
on water retention during periods of high precipitation.
To complement this, the FAB should also implement
watershed protection activities such as reforestation,
fencing, regular monitoring of water quality, anddeploying forest guards. For further studies, human-related threats to water quality as well as identification ofalternative water sources such as springs may also be
looked into.
This study sets a precedent on incorporating water
resources carrying capacity in local governance, especially in a Philippine setting. It is hoped that more government agencies, local and national, will follow inmainstreaming this concept to promote the sustainable
use of our finite water resources as we pursue inclusive
growth.

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