THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.2.6 Simulated Maximum Deposit by a 20-Year Probable Flood in the Sto. Tomas River

ALTERNATIVE１ Maximum Deposit

ALTERNATIVE２ Maximum Deposit

ALTERNATIVE３ Maximum Deposit

m

Mesh (1 mesh = 80 m)

Mesh

m

Mesh (1 mesh = 80 m)

Mesh

m

Mesh (1 mesh = 80 m)

Mesh

IV-F22

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.1 Longitudinal Profile and River Width of the Bucao River

Bucao River

-2,000

-1,000

0

1,000

2,000

-4 -2 0 2 4 6 8 10 12

Sta. km

Riv

erbe

d W

idth

(m)

Balin Baquero River

-2,000

-1,000

0

1,000

2,000

12 16 20 24

Upper Bucao River

-2,000

-1,000

0

1,000

2,000

12 16 20 24

Bucao Bridge (Sta. 0.0 km)

Baquilan River(Sta. 5.5 km)

Upper Bucao River(Sta. 12.0 km)

Balintawak River(Sta. 13.0 km)

River Mouth(Sta. -2.4 km)

Malumboy(Sta. 10.0 km)

0

20

40

60

80

100

120

140

160

180

200

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta.km

Low

est R

iver

bed

(El.

m)

Bucao-Balin Baquero River

Upper Bucao River

1/280 1/180 1/90 Upper Bucao

1/95 Balin BaqueroRiverbed Gradient

IV-F23

Sto. Tomas River

-1,500

-1,000

-500

0

500

1,000

1,500

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Riv

erbe

d W

idth

(m)

River Mouth (Sta. -1.5 km)

Maculcol Bridge (Sta. 0.0 km)

Vega Hill (Sta. 10.5 km)

Santa Fe River (Sta. 11.5 km) Mapanuepe River

(Sta. 21.0 km)

Mt. Bagang (Sta. 21.5 km)

Paete Hill(Sta. 7.25 km)

0

50

100

150

200

250

300

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Low

est R

iver

bed

(El.m

)

1/310 1/130 1/60

Riverbed Gradient

1/40

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.2 Longitudinal Profile and River Width of Sto. Tomas River

IV-F24

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.3 Flow Duration Curve and Annual Hydrograph Pattern for Simulation

Flow Duration Curve

0.00

4.00

8.00

12.00

0 50 100 150 200 250

Days / Year

Dai

ly D

isch

arge

[m3/

s]

Original Data

Stepwise Approximation

Average Pattern of 1963 and 1984 in Bucao River

0200400600800

Jan

Mar

May Ju

l

Sep

Nov

Q(m

3/s)

01,0002,0003,0004,000

Rai

nfal

l(mm

)

Bucao Q(m3/s) Iba-Rainfall(mm)

Stepwise Flow DurationQ/Qmean (%)

Days PointQ StepQ0 11.991 11.99 11.992 11.992 6.99

10 6.99 6.9915 6.9915 4.3120 4.31 4.3125 4.3125 2.8030 2.80 2.8040 2.8040 1.6750 1.67 1.6775 1.6775 0.96

100 0.96 0.96125 0.96125 0.66150 0.66 0.66175 0.66175 0.25200 0.25 0.25225 0.25225 0.17250 0.17 0.17275 0.17275 0.13365 0.13 0.13365 0.00

Annual Hydrograph Pattern

0

10

20

30

40

50

60

0 30 60 90 120 150 180 210 240 270 300 330 360

Days

Q/Q

mea

n

Normal YearFlood Year

IV-F25

Riverbed Change in Bucao - Balin Baquero River after 20 Years

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. (km)

Cha

nge

of L

owes

t Riv

erbe

d El

evat

ion

(m)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)

Riverbed Movement in Bucao - Balin Baquero River after 20 Years

River Mouth(Sta. -2.4 km)

Baquilan River(Sta. 5.5 km)

Upper Bucao River(Sta. 12.0 km)

Bucao Bridge(Sta. 0.0 km)

Malumboy (Sta. 10.0 km)

0

50

100

150

200

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. (km)

Low

est R

iver

bed

(El.m

)

Original in 2002

Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.4

Simulated Riverbed Movement for 20 Years in the Bucao and Balin Baquero Rivers (Alternative-1)

IV-F26

Riverbed Movement in Upper Bucao River after 20 Years

Balin Baquero River(Sta. 12.0 km)

Balintawak River(Sta. 13.0 km)

0

50

100

150

-5.0 0.0 5.0 10.0 15.0 20.0 25.0Sta. (km)

Low

est R

iver

bed

(El.m

)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)

Riverbed Change in Upper Bucao River after 20 years

-20.0

-15.0

-10.0

-5.0

0.0

5.0

10.0

15.0

20.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. (km)

Cha

nge

of L

owes

t Riv

erbe

d E

leva

tion

(m)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.5 Simulated Riverbed Movement for 20 Years in the Upper Bucao River (Alternative-1)

IV-F27

Riverbed Movement for 20 Years in Bucao River (Alternative-1, Case-1)

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d (m

) after 20 yearsafter 10 yearsafter 5 yearsafter 1 yearOriginal in 2002

Riverbed Movement for 20 Years in Bucao River (Alternative-1, Case-2)

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d (m

)

Riverbed Movement for 20 Years in Bucao River (Alternative-1, Case-3)

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d (m

)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.6 Chronological Riverbed Change for 20 Years in the Bucao River (Alternative-1)

IV-F28

Riverbed Change in the Bucao - Balin Baquero River after 50 Years(Alternative-1)

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d (m

)

after 50 yearsafter 40 Yearsafter 30 Yearsafter 20 years (Initial)

Riverbed Movement in the Bucao - Balin Baquero River after 50 Years(Alternative-1)

River Mouth(Sta. -2.4 km)

Bucao Bridge(Sta. 0.0 km)

Malomboy(Sta. 10.0 km)

Upper Bucao River(Sta. 12.0 km)

Baquilan River(Sta. 5.5 km)

0

50

100

150

200

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Riv

erbe

d (E

l.m)

after 20 Years (Initial)after 30 Yearsafter 40 Yearsafter 50 YearsAverage Riverbed in 1977

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.7

Simulated Riverbed Movement for 50 Years in the Bucao and Balin Baquero Rivers (Alternative-1)

IV-F29

Riverbed Change in the Upper Bucao River after 50 Years (Alternative-1)

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

2.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d (m

)

after 20 Years (Initial)after 30 Yearsafter 40 Yearsafter 50 Years

Riverbed Movement in the Upper Bucao River after 50 Years (Alternative-1)

Balin Baquero River (Sta. 12.0 km)

Balintawak River(Sta. 13.0 km)

50

100

150

-5.0 0.0 5.0 10.0 15.0 20.0 25.0

Sta. km

Riv

erbe

d (E

l.m)

after 20 Years (Initial)after 30 Yearsafter 40 Yearsafter 50 YearsAverage Riverbed in 1977

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.8 Simulated Riverbed Movement for 50 Years in the Upper Bucao River (Alternative-1)

IV-F30

Riverbed Change in the Sto. Tomas River after 20 years (Alternative-1)

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d El

evat

ion

(m)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)

Riverbed Movement in the Sto. Tomas River after 20 Years (Alternative-1)

River Mouth(Sta. -1.5 km)

Maculcol Bridge(Sta. 0.0 km)

Vega Hill(Sta. 10.5 km)

Santa Fe River (Sta. 11.5 km) Mapanuepe River

(Sta. 21.0 km)

Mt. Bagang(Sta. 21.5 km)

0

50

100

150

200

250

300

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Low

est R

iver

bed

(El.m

)

Original in 2002

Case 1 (No Flood in 20 Years)

Case 2 (Flood in 5th Year)

Case 3 (Flood in 15th Year)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.9 Simulated Riverbed Movement for 20 Years in the Sto. Tomas River (Alternative-1)

IV-F31

Riverbed Movement in the Sto. Tomas River after 20 Years (Alternative-2)

River Mouth (Sta. -1.5 km)

Maculcol Bridge(Sta. 0.0 km)

Vega Hill(Sta. 10.5 km)

Santa Fe River (Sta. 11.5 km) Mapanuepe River

(Sta. 21.0 km)

Mt. Bagang(Sta. 21.5 km)

Training Channel(Sta. 21.5 km - 25.5 km)

0

50

100

150

200

250

300

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Low

est R

iver

bed

(El.m

)

Original in 2002

Case 1 (No Flood in 20 Years)

Case 2 (Flood in 5th Year)

Case 3 (Flood in 15th Year)

Riverbed Change in the Sto. Tomas River after 20 years (Alternative-2)

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d El

evat

ion

(m)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)Alt-1 Case-1

Training Channel(Sta. 21.5 km- Sta. 25.5 km)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.10 Simulated Riverbed Movement for 20 Years in the Sto. Tomas River (Alternative-2)

IV-F32

Riverbed Movement in the Sto. Tomas River after 20 Years (Alternative-3)

River Mouth (Sta. -1.5 km)

Maculcol Bridge (Sta. 0.0 km)

Vega Hill (Sta. 10.5 km)

Santa Fe River (Sta. 11.5 km) Mapanuepe River

(Sta. 21.0 km)

Mt. Bagang(Sta. 21.5 km)

Consolidation Dam (Sta. 21.5 km)

0

50

100

150

200

250

300

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Low

est R

iver

bed

(El.m

)

Original in 2002

Case 1 (No Flood in 20 Years)

Case 2 (Flood in 5th Year)

Case 3 (Flood in 15th Year)

Riverbed Change in the Sto. Tomas River after 20 Years (Alternative-3)

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

-5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0

Sta. km

Cha

nge

of L

owes

t Riv

erbe

d El

evat

ion

(m)

Original in 2002Case 1 (No Flood in 20 Years)Case 2 (Flood in 5th Year)Case 3 (Flood in 15th Year)Alt-1 Case-1

Consolidation Dam(Sta. 21.5 km)

THE GOVERNMENT OF THE PHILIPPINES THE DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

The Study on Sabo and Flood Control for Western River Basins of Mount Pinatubo in

the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY

Figure 3.3.11 Simulated Riverbed Movement for 20 Years in the Sto. Tomas River (Alternative-3)

IV-F33