Rehabilitation of Upper Makulapnit Dam Proposal

8/11/2019 Rehabilitation of Upper Makulapnit Dam Proposal

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Rehabilitation of Upper Makulapnit Dam

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1.0 INTRODUCTION

1.1 BACKGROUND

Upper Makulapnit Dam is located across the Makulapnit River, 132429 N 1215847 E, at the

Marcopper site, Makulapnit, Sta. Cruz, Marinduque. It was owned by the Marcopper Mining Company,

and was designed by Engineering Development Corporation of the Philippines (EDCOP). It was built in

1975 to impound storm water originating from Makulapnit River which was intended to use as water

supply in the Marcopper mining operation and for the residence near it. Padolina and Ordillano, (2003)

After the March 1996 mining disaster, the Marcopper Mining Company was forced to close and since

then, this structure has not been used.

According to the Dioceses of Boac (2008), since the mining operation seized, the Marcopper

structures including the Upper Makulapnit Dam were not properly maintained, that there is no regular

inspection done by the government to those structures, and if there is any, the results were not given to the

public, letting them unaware on its status. Those structures are still holding back millions of cubic meters

of water and poisonous mine wastes, that if happened to fail will bring severe flash floods and will swamp

the affected areas with poisonous mine wastes. Poverty is widespread in this province, any kind of

disaster should the structures cause may bring huge impact to the peoples daily lives.

According to the study of the Klohn-Crippen (2001), Upper Makulapnit Dam does not achieve

some of the accepted criteria for the stability analyses, and its spillway has an inadequate capacity to

handle the required of at least 50% of the probable maximum flood. These imply that the dam might be

under designed to accommodate earthquake loads and an overtopping of the dam could happen during

major storm events. But in spite of these, the structure is still standing. This maybe indicates that the

worst possible scenarios are not yet happening or maybe the assumptions used by the Clohn-Crippen in

the analyses were too small for those structure since according to the review, the analyses was performed

without benefit of the original design information. Until now, there is no clear report about the true status

of this structure.

All of the results and recommendations done to the studies conducted by the government and

other independent teams by which millions of pesos were spent were taken for granted. Until now, there

are no short or long term solutions done to the problems in this structure. There are no monitoring and

warning devices found in this structure or any maintenance done. According to D. Querijero the structure

is regularly inspected (personal communication, September, 2012), but this is useless since the results

were ignored by Marcopper and not given to public. If this situation continues, Upper Makulapnit Dam


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1.3.1 Dam

The dam is heavily vegetated with deep-rooted trees and brushes. No cracks or any visible

deformation were seen along the crest. The upstream and downstream slopes surfaces are irregular, since

a rockfill, so it is difficult to determine whether the slopes has crack or eroded. But still, there is no huge

erosion, cracking or any deformation found on the slopes. Both the left and right downstream abutments

show no signs of seepage. There is no standing water or seepage seen on the downstream toe of the dam.

But there is a drainage channel or canal found along it. According to M. Palomares, this channel carries

water coming from the mine waste dumps during heavy rains (personal communication, June 2, 2012).

The channel is dry during his visits. The reservoir banks were surrounded by vegetations which help in

the stability of the banks.

1.3.2 Spillway

The water in the spillway cannot flow easily because it is obstructed by weeds, brushes and debris

carried from the reservoir and eroded rocks. The spillway wall is underlain with solid rocks, only few

portion of it eroded. In June 2, 2012 the quantity of discharge of the spillway was measured to be

0.2758m3/s.

1.3.3 Diversion Tunnel

The diversion tunnel is leaking. The inspector failed to measure the quantity of leak because of

the fear of a burst but able to describe it. The water is clear, and it discharges small amount. There is no

monitoring equipment found to monitor this leak.

1.3.4 Access to the Site

The road is inaccessible to vehicles and heavy equipments due to the blocking of vegetation.

1.3.5 General Comments and Recommendations

The general comments stated below were based on the knowledge opinions of the inspector.

The presence vegetation on the Upper Makulapnit Dam is very harmful to the structure. It makes

difficult for the inspector to perform a thorough inspection. The roots can uplift to the materials on its

surface which can result erosion. The large trees could be uprooted during storm which will scour the

surface. This vegetation should be properly removed and disposed immediately.


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The drainage channel found along the downstream toe can pose threat to the structure. It could

possibly undercut the downstream slope of the structure, so this should be immediately diverted way from

the structure.

The debris that blocks the flow of water in the spillway should be immediately removed. This

debris can create serious problems such as overtopping.

The clear water leaking in the diversion tunnel signifies that there is no internal erosion on the

plug of the tunnel. The tunnel should be permanently sealed but if not, should be regularly monitored for

changes.

The access to the structure should be repaired. This road is important since it is the primary

means of accessing the structure for inspection and for emergency response.

The present defects found on the Upper Makulapnit Dam imply that there is no proper

maintenance done to this structure. This only proves the negligence of the concerned groups.

1.4 POTENTIAL ALTERNATIVES

1.4.1 Alternative 1: No Action

With this alternative, no restoration or maintenance will commence. The proponents expect that

doing nothing and leaving the dam as is will weaken the structure and will increase the threat to the lives

of the downstream people. The debris in the spillway will increase and will make the flow hard that may

lead to overtopping. The leak in the diversion tunnel will deteriorate its plug due to internal erosion that

will result to burst. This approach will eventually lead to failure and has a possibility to weaken the

structural integrity of the Lower Makulapnit Dam by which millions of cubic meters of mine waste are

stored. This option is not recommended.

1.4.2 Alternative 2: Removal of the Structure

This structure has potential uses that when utilized may contribute to the development of the

province. It is currently one of the sources of foods of the near-by Barangays such as Makulapnit,

Hinapulan, Kilo-Kilo. The UMD Reservoir is rich with fresh water foods such as Tilapia, Hito, and

Tulya, so its a big loss for the nearby people.Its lost will also greatly affect the unlikely resumption of

the Marcopper mining operation. It was discovered that the mining site has still an 18-year mine life.

UMD is their only source of water which is used in their industrial operation. Building this kind of

structure may cost billions of pesos, so it is a big waste if this structure will be decommissioned


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considering its potential uses and the nearby people whose livelihoods are dependent in this structure,

therefore the removal of this structure is not the option of the proponents.

1.4.3 Alternative 3: Rehabilitation and Utilizing the Structure

Upper Makulapnit Dam is currently holding back 34 million cubic meters of water (Querijro,

2011), and is located 275 meters above sea level (Klohn-Crippen, 2001). With these descriptions, this

dam has a potential to supply domestic water to the province. It can generate large amount of

hydroelectric power since it is located in a high altitude. It is also a good source of irrigation for the rice

fields of the province. The structure has a huge pond area which can be used in the production of fresh

water foods. This can also become a recreational area for Marinduqueos and tourists. This alternative

was chosen by the proponents.


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2.0 TECHNICAL STUDY

2.1 PROJECT PURPOSE

The purpose is to make a proposal for the Provincial Government of Marinduque about the

rehabilitation of Upper Makulapnit Dam. The rehabilitation only includes the solution to the present

problems in this structure which should be immediately remediated.

2.2 SCOPE OF THE PROPOSED REHABILITATION OF THE UPPER MAKULAPNIT DAM

The rehabilitation only includes the immediate solutions to the identified problems on the

structure. The proposed solutions composed of two phases, these are:

Phase I

Clearing and Repairing of Upper Makulapnit Dam Access Road (UMDAR),

Removal of the debris blocking the spillway,

Removal of the vegetations on the dam,

Installing water level sensing device in the reservoir, and

Installing surveillance camera in the structures Diversion Tunne l

Phase II

Monitoring, Inspection and Maintenance Program

2.3 SOURCE OF INFORMATION

No information about the structure is on public, it is kept private by the MR Holdings. The only

information used in this proposal was gathered from the copy of report of the University of Arizonas

Engineers entitled Engineering, Health, and Environmental Issues Related to Mining in Marinduque,

Final Report of the Independent Assessment Team: Engineering Assessment (2003). Other information

was based on personal interview made to the residence of Makulapnit and on the inspection made by the

inspector.

2.4 DESCRIPTION OF DEFECTS

The defects were described based on the results of inspection made on June 2 and September 1,

2012. Stated below are the parts which need immediate repair and their description and approximate

quantity of the defects which is needed in the technical and financial analysis of the proposal.


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2.4.1 Upper Makulapnit Dam Access Road

The road is block with small trees brushes, and branches of trees growing in the sides of the road.

The route was approximately traced by following the descriptions of the Makulapit residence. Using the

software Google Earth, the length and the location of the road was approximately measured and located.

From the accessible road, near the Tapian Pit, 132448.59 North 1215829.20 East, the route will go

towards the Lower Makulapnit Dam, will pass across it then will go up to the berm of the spillway wall

until the left side of the Upper Makulapnit Dam reached at 132426.14 North 1215842.32 East. The

length was approximately 1460 meters. The width of the road was actually measured on the site which is

5 meters.

2.4.2 Spillway

The spillway is approximately 400 meters and 14 meters wide. The debris blocking the flow was

estimated to be covering approximately 50% of the spillway surface.

2.4.3 Embankment Dam

The exposed surface of the dam was estimated using the Upper Makulapnit Dam Plan (see

Figure 1 at Appendix A). The surface was approximately 60,100 square meters. It is assumed that 100%

of the dam surface is covered with vegetation.

2.5 DETAILS OF ACTIVITIES

2.5.1 Phase I

Repairing and clearing of the UMDAR

This activity will be performed first to have an easy access to the different components of the

structure. Clearing involves the removal of trees and brushes on the road and trimming the branches that

are blocking the way. Then, after that is the resurfacing of the roadway.

This activity is proposed to be done by the DPWH. They are the only government agency that has

the most experience in doing such activity. They have the most knowledge and experienced manpower

and have the necessary equipments and tools need.

A more detail of this activity should be made by DPWH such as the accurate survey of the site,

the necessary treatment to the road, etc.


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Removal of the Debris Blocking the Spillway and Vegetations on the Dam

Removal of debris in the spillway is important in the continuous flow of water to prevent the risk

of overtopping. This involves removing of the weeds and brushes growing in the spillway, eroded rocks,

logjams, and other debris blocking the spillway.

In the dam, there are two activities involve. The first is the removal of all vegetation such as

deep-rooted trees, brushes and other unlikely vegetations which are affecting the access and stability of

the dam. The second is planting vegetation such as Bermuda grass that will help in blocking the growth of

unwanted vegetation.

After the removal of vegetation, the cuttings should be hauled off the dam to allow for a clear

view of the embankment. Its disposal should be properly planned to eliminate any risk it may cause.

The most crucial part of this activity is the removal of deep-rooted tress. Its removal might uplift

the surface that will cause the weakening the slope also, it will cause hole on the surface. This part should

be planned well to eliminate any risk that will affect the dam.

This activity is proposed to be performed by an experienced contractor. In Marinduque, there are

no contractors who have experience and specialty in doing this activity, so it will came from other place.

The contractor must have experience and specialty in the said activity and must have the appropriate tools

and equipments.

A more detailed plan should be made by the chosen contractor.

Installing water level sensing device and Surveillance Camera

It is proposed to put monitoring devices on the critical parts of the structure as was identified

during the visits. These devices are the water level sensing device to monitor the water level in the

reservoir and a surveillance camera to monitor the leakage in the diversion tunnel. The proposed two sites

are most critical part which needs to be monitored at any time by the downstream people.

The proposed water level sensing device will serve as eye of the downstream people to warn them

in case the water level is in critical during heavy rains. The sensing device will automatically report or

warn the concerned people when the critical level has reached by transmitting it to computers or

cellphones.

The proposed surveillance camera will be the eye of the concerned inspector in the UMD

Diversion Tunnel to monitor the leak. An increase in the quantity or changes in the turbidity of the leak


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might indicate a problem in its plug. So this should be monitored more often by the inspector. This

proposed device is wireless and remotely controlled so that it can be monitored at any time and place.

The proposed devices will be powered by solar energy and battery at night which is charged by

solar energy during days.

Details such as the critical water level, the type of devices should be determined and planned.

2.5.2 Phase II (Monitoring, Inspection and Maintenance Program)

Monitoring Program

Since Upper Makulapnit Dam is located in a very remote place, it is difficult to visit, especially

when there is storm. Some critical things such as the water level of the reservoir that needs to be regularly

monitored were difficult to do. Using the proposed devices, monitoring the critical part would be easy.

These parts should be monitored as often as possible to immediately inform the concerned individual.

Inspection Program

The proposed inspection plan should be regularly done three times a year and every after a storm,

heavy and long duration rains and seismic events. The reports of the proposed inspection will be regularly

send to the concerned groups such as the DENR, Provincial Government and the Municipality of Boac, to

have a regular update to the structure.

The inspection will be made by expert from the Mines and Geosciences Bureau. They should use

the standard way of inspecting a rock-field dam.

Maintenance Program

The proposed maintenance program involves the maintaining the Upper Makulapnit Dam Access

Road passable, removal of the unwanted vegetation on the dam, repairing for the seen defects during

inspection such as spillway blockage, erosion, etc. and the monitoring devices.

The maintenance of the roadway will be made three times a year to assure the structure willalways be accessible especially during emergencies. This is proposed to be managed by the DPWH

Marinduque District.

The vegetation control will also be done regularly to the dam three times a year to assure an easy

access for the inspector and the stability of the dam. Repairs on seen defects on the dam should be done


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immediately after discovered. The maintenance done to the monitoring equipments is indicated to its

manual and should be followed. This is proposed to be managed by the DENR.


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3.0 FINANCIAL ASPECT

3.1 COST

3.1.1 Phase I

Clearing and Repairing of Upper Makulapnit Dam Access Road (UMDAR),

The estimation of clearing and repairing of UMDAR was based on the following information:

Approximate length: 1460 m

Approximate width: 5 m

Description: Block with small trees brushes, and branches of trees growing in the sides of the road.

There are portion needs to be resurfaced.

The standards used by the DPWH - District of Marinduque in road maintenance were used in the

estimation.

Table 1 - Removal of Vegetation

QUANTITYDURATION

(days)

UNIT

PRICE

AMOUNT

(Php.)

1 12 506.16 6073.92

20 12 283.36 68006.4

6800.64

Rent of Service Vehicle

(transportation of workers)1 12 505.87 6070.44

Diesel 10 L 12 54 6480

Rent of Loader (disposal of cut

vegetation)1 5 833 4165

Operator 1 5 366.48 1832.4

Diesel 15 L 5 54 4050

16178.88

119657.68TOTAL

DESCRIPTION

Other Cost 10% of Total Cost

10 % of Labor CostTools

Laborers

Foreman


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Table 2 - Resurfacing of Roadway

QUANTITYDURATION

(days)

UNIT

PRICE

AMOUNT

(Php.)

1 5 506.16 2530.80

1 5 366.48 1832.403 5 283.36 4250.40

Rent of Road Grader 1 5 833 4165.00

Diesel 80L 5 54 216.00

1116.22

12278.42TOTAL

DESCRIPTION

10% of Total Cost

Foreman

Laborer

Other Cost

Heavy Equipment Operator

The estimated cost of repairing the UMDAR is Php. 131,936.10.

Removal of the Debris Blocking the UMD Spillway and Removal of Vegetations on the UMD

The estimation was based on the following information:

Approximate area of the spillway:(14m x 400m) = 5600 m2

Description of the debris:Blocked with debris such as brushes, weeds, logs, and eroded rocks and it

is assumed that 50% of the spillway is covered with it.

Approximate exposed surface area of the UMD:60100 m2

Description of the Vegetation:Vegetated with deep-rooted tress and brushes, and it is assumed that

100% of the dam surface is covered with it.

There is no information found about the estimation of this activity, so to have a close to reality

estimation, the estimates used in the removal of vegetation on a roadway was used as a basis of this

estimation. Because the activity involved in the dam is more complex than in the road, since it requires

more equipment and more details in work, an additional of 20% of the cost in the roadway repair will be

added in the dam works and 10% will be added in the spillway works.

The estimated cost in repairing the UMDAR is Php 16.4/m2.

Estimated cost in vegetation removal of UMD

= (60100m2x Php 16.4/m2x 1.2) = Php 1,182,768.00

Estimated cost in debris removal of UMD Spillway

= (5600 x .5 x 16.4/m2x 1.1) = Php 50,512.00


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4.0 ECONOMIC ASPECT

Since the Marcopper Mining Company seized their operation, UMD has not been properly

maintained. This causes fear and threat to the lives and livelihood of people living in the downstream

areas. This structure is holding back 34 million cubic meters of water that if happen to fail will bring

severe flash floods on the affected areas.

According to Magalang, (2011), the collapse of this structure will be a major catastrophe, with a

very large magnitude of devastating effects in crops and lives of almost 50% of the population of Boac.

Boac is an agricultural land with 16,208 hectares of its 21,272-hectare land area devoted to agriculture.

Any disaster it could cause will greatly affect its economy as a whole.

Upper Makulapnit Dam has potential uses, that when utilized, might contribute to the

development of Marinduque. Of all the Marcopper dams, only this dam does not retain mine wastes. It

was built to impound storm water originating from Makulapnit River. According to Querijro (2011), it

carries 34 million cubic meters of water or more. It has an elevation of 275 meters above sea level and a

catchment area of approximately 11 square kilometres. Klohn-Crippen (2001) With these descriptions,

this dam has a potential to supply domestic water to the province. It can generate large amount of

hydroelectric power since it is located in a high altitude. It is also a good source of irrigation for the rice

fields of the province. The structure has a huge pond area which can be used in the production of fresh

water foods. This can also become a recreational area for Marinduqueos and tourists. Building this kind

of structure may cost billions of pesos, so it is a big waste if this dam will be decommissioned or

destroyed and end up with nothing.

The loss of this structure will greatly affect the unlikely resumption of the Marcopper mining

operation. It was discovered that the mining site has still an 18-year mine life. UMD is their only source

of water which is used in their industrial operation.

This structure is also one of the sources of foods of the near-by Barangay such as Makulapnit,

Hinapulan, Kilo-Kilo. The UMD Reservoir is rich with fresh water foods such as Tilapia, Hito, and

Tulya. This structure is a big lost for them.


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5.0 SOCIAL IMPACT ANALYSIS

The proposed maintenance and monitoring of Upper Makulapnit Dam is essential and will greatly

affect the society. Without this project, there is a great chance that the Upper Makulapnit Dam will

collapse due to rapid deterioration. When this eventually happen, much of the surrounding villages will be

inundated by flash floods.

With the proper maintenance of the dam, the water will flow freely reducing the pressure develop

in the dam that increase its risk of failure and through monitoring, the residents, young or adult, will be

inform on its condition regularly resulting to ease their worries.

But the access to the dam is difficult and needs further improvement. On the process of cleaning

the structure and its access, trimming, cutting and uprooting bushes, weeds and trees will be conducted. In

doing these preliminary activities in the maintenance of the structure, several equipments will be use

which may bring noise pollution. But since the location of the structure is far from the neighbouring

houses, the residents will not be affected by the use of these equipments.

But Upper Makulapnit Dam is owned by Marcopper Mining Company who abandoned it after

their operation and denying their responsibilities on the structures left at the site without considering its

dangerous effect not only to the residents but also to environment. If the ownership of this structure was

transferred to the local government, everyone will be benefited.

Marcopper Mining Companys responsibility with the structure will gone. The govern ment can

utilize and use the potential of the dam as a source of hydroelectric power and water supply. The

proponents will be able to maintain and monitor the structure and inform the residents with its condition

regularly.


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6.0 ENVIRONMENTAL IMPACT ANALYSIS

Maintaining and monitoring of the Makulapnit Dam in Sta. Cruz is not hazardous to the

environment and the community near the project site in such a way that it sustained the impacts examined

by the Environmental Impact Assessment (EIA) which are the biological, socio-economic, human health,

geophysical impacts, and the risks it may take.

The maintenance and monitoring of the Makulapnit Dam will not emit any pollution because

removal of deep rooted vegetation and organic debris from the spillway, installing of monitoring devices

and regular inspection are the only to be done.

Removing of deep rooted vegetation with the use of power saw can emit a minimal amount of

smoke and chemical reaction to air. But the other trees can resist it all to prevent air pollution. Marine,

terrestrial animals and even the endangered species near the project site will not be affected by the

proposed activities in a way that no chemical will penetrate and flow with the water. The trees that will be

removed are only those trees located near the dam that affect the strength of the dam and approve by the

DENR.


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REFERENCES

Dioceses of Boac (2008 Febuary 28), Pahayag ng Pagkabahala at Panawagan Para sa mga Kongkretong

Aksiyon Hinggil sa mga Panganib na Maaaring Idulot ng mga Malalaking Dams ng Marcopper

Mining Corporation sa Kabundukan ng Lalawigan ng Marinduque from (internet, failed to show)

Klohn-Crippen (2001). Engineering, Health, and Environmental Issues Related to Mining in Marinduque,

Final Report of the Independent Assessment Team: Engineering Assessment. The only copy

available on public is at MACEC, Boac, Marinduque.

Magalang, M., (2011 November 21), Leak at Marcopper Mine Site again Raises Fears. Retrieved May 8,

2012, from http://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fears

Padolina, M. R., & Ordillano, S. D., (2003). Physical Condition of Marcopper Dams

Querijro D., (2011 November 21), Leak at Marcopper Mine Site again Raises Fears Retrieved May 8,

2012, from http://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fears
http://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fearshttp://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fearshttp://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fearshttp://newsinfo.inquirer.net/97513/leak-at-marcopper-mine-site-again-raises-fears

Documents

Rehabilitation of Upper Makulapnit Dam Proposal