Assessment of Masacpasac Water Supply Source: A TechnicalStudy

Felisa E. Gomba1, Ronald L. Orale2,

Introduction 

The availability of water in water supply system is

essential in the delivery of the required volume of water to

the serviced community. Philippine urban water supply is

mainly provided by about 612 water districts under the

authority of Local Water Utilities Administration, or by

more than 1000 local government-operated water utilities

that lack skills in handling new water supply projects (ADB

Review 2006). Water supply scarcity is experienced in most

water districts in the country especially during the period

of dry season that they could not deliver the required water

volume consumption of the human society. The world

projections virtually show that all of the countries’

available water resources could be exploited by 2030(Basson,

et.al,, 1997). Thus, there is a need to develop strategies

for sustaining the water resources for distribution and this

requires intensive management tools, physical understanding

of hydrological nature that affect the water availability,

and engineering concepts/processes to enhance the water

resources supply.

The Catbalogan water supply source is Masacpasac spring

has been established as early as 1945, which was discovered

by the Americans. Masacpasac water supply source is located

in Barangay Cawayan in a mountainous terrain. It has been

the major source of water for Catbalogan and has been1 Associate Professor, College of Engineering, Samar State University, Catbalogan City, Samar.2 Instructor, College of Engineering, Samar State University, CatbaloganCity, Samar.

1

utilized since 1945. There were several developments and

structures installed in the source, but there were no basic

properties of the water source such as minimum and maximum

flow, depth, and other relevant properties. These properties

are necessary data for planning and sustainable development

for the Masacpasac water supply source.

In this context, the Catbalogan Water District through

its Board of Directors requested Samar State University to

conduct a technical study at the Masacpasac water supply to

evaluate its technical status relative to water supply

source of Catbalogan and to determine the sustainable

strategies for the Catbalogan Water District Operations. In

February 3, 2007, the Catbalogan Water District and Samar

State University signed a Memorandum of Agreement for the

conduct of the technical study of the Masacpasac water

supply source.

Objectives

The technical study is guided by the following objectives:

1. to conduct on-site technical evaluation;

2. to assess and evaluate the sources of water losses

along the distribution lines from the water source to the

water treatment site (kulador); and

3. to develop and come up the following:

3.1 technical report;

3.2 water protection plans and design concepts; and

3.3 water quality monitoring program.

Materials and Methods

The technical study was conducted on –site from the month of

March, April, and May 2007. The methodologies were: on-site

evaluation and assessment at Masacapasac sub surface channel;

2

topographic survey from Masacpasac water source to Kulador; and

water quality analysis.

On-site evaluation and assessment of Masacpasac sub-surface channel. The

team conducted this activity to determine the volume of the

water. A hydrographic survey within the channel was conducted to

identify the dimensions of the channel. The materials of the

channel bed were evaluated through disturbed soil sampling

techniques at random point of sampling. The soil samples were

brought to the SSU Soils and Materials Testing Laboratory for

analysis. The variability of the depths and water quantity were

observed from 4:00 AM to 4:00 PM based on continuous water

sampling techniques. The streamflow records were established at

different variations of time.

Topographic Survey from Masacpasac to Kulador. A topographic survey

was conducted from Masacpasac to Kulador to determine the

elevation and profile of the pipelines. The survey (using

Theodolite) was conducted in a 50-meter radius from Masacpasac to

Kulador.

Water Quality Analysis. The water quality at the Masacpasac

source was analyzed. Water samples were collected using water

grab sampling techniques in two different periods(AM and PM). The

water samples were brought to SSU for further analysis.

Materials and Instruments. The activity utilized the equipment and

surveying instruments of the Samar State University College of

Engineering. One theodolite was dedicated to the extension

services on the assessment and technical study of the Masacpasac

water source

Results and Discussions:

The section presents the results of the technical study

which is presented in three sub sections, namely: Masacpasac

water supply source; pipeline system from Masacpasac to Kulador;

and Kulador site(treatment).

Masacpasac Water Supply Source

3

This is located at Barangay Cawayan, Catbalogan City, Samar.

It is a sub surface channel with a length of 50 meters from the

outflow pipe to the end of the channel, mean width 8.0 meters,

and mean depth of water of 2.20 m. It has a computed area of

185.2 square meters with an elevation of 155 m above sea level.

It is approximately 4.5 kilometers from the city proper of

Catbalogan.

Fig 1. The areal view of Catbalogan Fig. 2. The insideview of the sub-surface and Masacpsac water supply source channel atMasacpasac

Status of the immediate environment. The Masacpasac source is

located along a mountainous and rocky terrain with degraded

vegetation along 100 meter radius. There is a massive illegal and

indiscriminate cutting of new growth trees. Small tributaries or

water ways exists along the sides of the sub surface channel. The

small tributaries have sufficient water that can be utilized as

Masacpasac Water supply source

Catbalogan Proper

4

additional water in the Masacpasac. During rain, sufficient and

excess water were observed in these tributaries which flowed

outside the impounding dam. The impounding dam at Masacpasac is

not functional and it is structurally degraded.

Figure 4: Survey along the Watershed Area

The Pipe Distribution Line Status. The topographic survey by the CE-4students of SSU was conducted to determine the basic information

Figure 3. The Watershed of Catbalogan

Figure 5: Students conducted

5

of the main distribution line, namely: length, elevation, pipecharacteristics flow and pipe materials and pipe losses. The pipenetwork and its characteristics are shown in the attachment.

In terms of pipe losses, it is observed that there is noslope followed in the installation of the pipe. The pipe has nodefinite gradient and other characteristics are shown in thefigure.

The Masacpasac Water Supply Source. The water source of Catbaloganis known as a spring, but in th observation and geologiccharacterization of the place, it is an sub-surface channel witha length of 183.5 meters from its earth outskirt to the endopening.

Gradient: No desired gradient

Pipe size: Appropriate

Flow: Partiallyfull

Loss: High Loss

Figure 6: The problematic pipe network

6

Kulador Site. The water at Kulador is transient. It has a slowsand filter that is greatly influenced by hydrologic factor suchas rainfall. The water has high turbidity value. The status ofthe site are as follows:

Channel bed material:

Ash, silt and clay; about 1.5 ft to 2.0 ft thick or more that greatly affect the water quantity and quality

Water Quality: Negativeof E.coli Water depth: 2.5 m to 3 m

Minimum flow: 4 liters/sec

Figure 8. The non-functional dam at theKulador

Figure 7: The masacpasac

7

Status at the Kulador Site: The following are the statusreport of the Kulador treatment site.

Technical Properties

Type of Flow: Transient Flow

Pipe Network: entangled

Technology: Slow sand filter but materials arenot appropriate

and no sedimentation tank/basinImpounding

Structure: Mini dam (not functional)

Disinfection: Chlorination but no detention time

Dose method: Manual

Method of backwash: Manual

Figure 10: The Kulador Treatment Site:Slow sand filter

8

Recommendations:

The following are the engineering recommendations:

1. Improve the sub-surface channel bed. Replace theash, silt and clay with permeable material toincrease the water level.

2. Provide fish way at the sub-surface channel.

3. Provide a well-designed protection cover.

4. Lower to 1-meter the intake pipe.

5. Install primary treatment structure at the intake.

6. Construct water impounding structure at Masacpasacsite to store excess water during rainy season.

7. Set an average gradient from Masacpasac source toKulador based on the actual topographic records.

8. Lower the existing pipe to conform the designedgradient.

9. Replace damaged pipes.

10. Avoid minor losses. Minimize bends, obsructionsand unnecessary joints

11. Evaluate the pipe network at Kulador.

12. Introduce appropriate water treatment technologies(conventional or tertiary treatment process) to

Figure 11: The Pipe network at

9

solve the turbidity problem of the water supply.This will require big budget for the structures tobe used.

13. Construct sedimentation basin after filtrationprocess to provide settling time for the dissolvedsolids water particles.

14. Construct water impounding structures by utilizingthe existing impounding dam located along the eastside of Kulador.

10