THE STUDY ON Fig. 2.5 COMPREHENSIVE FLOOD MITIGATION FOR LOWLAND AREA Flow Capacity of Rivers in the Study Area CTI Engineering International Co., Ltd (in Present Land Use Condition) Nippon Koei Co., Ltd F - 2 - 7

(Source: JICA Study Team) Reference: “CAVITE (No. 3163 II)”, “SILANG (No.3162 I)” and “MENDEZ-NUNEZ (No.3162 II)” published by published by MGS in 1982, and “CAVITE WATER SUPPLY DEVELOPMENT STUDY” conducted by JICA in 1995 (JICA, 1995) Note: Although the Taal Tuff (upper) is unexpressed on the geological map except for area, it is extensively and thinly distributed on almost all of the Study Area.

THE STUDY ON Fig. 2.6 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA CTI Engineering International Co., Ltd. Geological Map of Study Area Nippon Koei Co., Ltd

F - 2 - 8 Division Upland General Hilly Area Lowland Area Mountainous Area

Extremely Lowland Area

Schematic River Cross Section

(m) Tagaytay 600

Taal Tuff (upper)

400 Amadeo

Taal Tuff (lower) Silang

Groundwater surface 200 Trece Martires City Dasmarinas Rosario NIA Irrigation Guadulupe Formation Canal Guadulupe Alluvium (lower) Formation 0 (upper) 0 10 20 30 40 Taal Lake (km) Schematic Geological Profile

Upland General Hilly Extremely Division Lowland Area Mountain Area Area Lowland Area 1.Elevation (m) More than 400 30-400 2-30 Less than 2 2. Ground slope (%) More than 2 0.5-2 Less than 0.5 Almost flat 3.Topographic feature of Major Rivers Width of riverbed Little Medium Large Large Height of riverbank Low High Medium Medium 4. Geology Top layer Taal Tuff (upper) Taal Tuff (upper) Taal Tuff (upper) Alluvium Very soft Very soft Very soft loose Riverbed/Riverbank Taal Tuff (upper) Taal Tuff (lower) Guadalupe F. (upper) Guadalupe F. (upper) Very soft Moderately hard Moderately hard Moderately hard 5.Groundwater surface Low-medium Low-medium High High

(Source: JICA Study Team)

Reference: “CAVITE (No. 3163 II)”, “SILANG (No.3162 I)” and “MENDEZ-NUNEZ (No.3162 II)” published by published by MGS in 1982, and “CAVITE WATER SUPPLY DEVELOPMENT STUDY” conducted by JICA in 1995

THE STUDY ON Fig. 2.7 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Schematic Geological Profile and CTI Engineering International Co., Ltd. Cross Section of Study Area Nippon Koei Co., Ltd

F - 2 - 9

COMPREHENSIVE FLOOD MITIGATION FLOOD COMPREHENSIVE

CTI EngineeringInternational Co., Ltd. FOR CAVITE LOWLAND AREA Nippon Koei Co., Ltd THE STUDY ON F -210 Fig. 2.8

Regional Geology Pisolite (grey spots in this photograph) included in tuffaceous sandstone

THE STUDY ON Fig. 3.1 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA CTI Engineering International Co., Ltd. Existing Land Use in the Study Area Nippon Koei Co., Ltd

F - 3 - 1

THE STUDY ON Fig. 4.1 COMPREHENSIVE FLOOD MITIGATION

FOR CAVITE LOWLAND AREA CTI Engineering International Co., Ltd. Future land Use Plan Projected by City/Municipalities Nippon Koei Co., Ltd

F - 4 - 1 THE STUDY ON Fig. 4.2 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Proposed Land Use Plan CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd

F - 4 - 2

Soil Analysis Map: more than 15%, (NAMRIA) SAFDS Map (Office of the Provincial Agriculturist)

CARP Map (Agrarian Reform Office) NIA Map (National Irrigation Administration, )

THE STUDY ON Fig. 4.3 (1/2) COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA CTI Engineering International Co., Ltd. Area not Suitable for Future Built-up Area Nippon Koei Co., Ltd

F - 4 - 3

Inundation Map 2-yr, (JICA Study Team)

Map of Area not Suitable for Urban Use NIA Map (Overlay of above information) (National Irrigation Administration, Naic)

THE STUDY ON Fig. 4.3 (2/2) COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Area not Suitable for Future Built-up Area CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd

F - 4 - 4

THE STUDY ON Fig. 4.4 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Principal Concept of Urbanization in the Study Area CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 4 - 5 Data Collection Field Inspection Flood Damage Survey

Rainfall Analysis

Runoff Analysis

Design Safety Level

Basic Flood Discharge

Flood Inundation Analysis (Reproduction)

Design of Control Flood Control yes Facility

No

Design Flood Discharge Flood Control Plan

River Channel Plan

Flood Inundation Analysis (Simulation)

Flood Mitigation Plan

THE STUDY ON Fig. 5.1 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Flowchart of Hydrological Analysis CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 1 N Port Area

Manila Bay

0 2 4 10 km

Sangley Point

Mabolo

Laguna de Bay

Alapan

S a n

J I u m a n u San Pedro s R R i v i Panaysayan e v r e r

P a n a y s a y a C n

a R n i v a Y e s l r a R n i g v

e Y r l a n g

R i v e r

Legend : Study Area : River Amadeo : Rainfall Gauging Station (Existing) : Rainfall Gauging Station (Closed) : Streamflow Gauging Station (Existing) Tagaytay : Streamflow Gauging Station (Abandoned)

Ambulong Taal Lake

THE STUDY ON Fig. 5.2 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Location of Rainfall and Streamflow Gauging Stations CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 2 Typhoon Reming in October 2000 Typhoon Gloria in July 2002

40 40 ) 30 30

20 20

10 10 Rainfall Intensity (mm/hr) Intensity Rainfall Rainfall IntensityRainfall (mm/hr

0 0 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 2000/10/27 2000/10/28 2000/10/29 2002/7/5 2002/7/6 2002/7/7

Philippine Standard Time (PST) PST

Typhoon Inday in July 2002 Typhoon Milenyo in September 2006

40 40

30 30

20 20

10 10 Rainfall Intensity (mm/hr) Rainfall Intensity (mm/hr)

0 0 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 02:00 08:00 14:00 20:00 2002/7/12 2002/7/13 2002/7/14 2006/9/27 2006/9/28

PST PST

THE STUDY ON Fig. 5.3 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Hyetograph at Sangley Point Station during Four Typhoons in 2000, 2002 and 2006 CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 3 Sangley Point (242.4 mm) Sangley Point (251.6 mm)

Mabolo (255.2 mm) Mabolo (247.2 mm)

Tagaytay (165.0 mm) Tagaytay (missing) Ambulong (227.1 mm) Ambulong (98.2 mm)

28-29 Oct. 2000 05-06 Jul. 2002 (Typhoon Reming) (Typhoon Gloria)

Sangley Point (139.4 mm) Sangley Point (407.2 mm)

Mabolo (172.6 mm) Mabolo (341.0 mm)

< 100 mm 100 - 200 mm

200 - 300 mm

300 - 400 mm

> 400 mm

Tagaytay (291.4 mm) Tagaytay (121.2 mm) Ambulong (196.2 mm) Ambulong (61.6 mm)

12-13 Jul. 2002 27-28 Sep. 2006 (Typhoon Inday) (Typhoon Milenyo)

THE STUDY ON Fig. 5.4 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Distribution of 2-day Rainfall during Four Typhoons in 2000, 2002 and 2006 CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 4 10,000 99.99 Plotting Method: Cunnane

1,000 99.9

100 99 50 98

20 95

10 90

5 80

2 50 Return Period (Year) Return Period Non-Exceedence Probability (%) Non-Exceedence 1.25 20

1.11 10 Sample 1.05 Gumbel 5 Log-Pearson III 1.02 2 Iwai 1.01 1

1.001 0.1 0 50 100 150 200 250 300 350 400 450 500 Rainfall (mm)

(Unit: mm) Return Period Gumbel Log-Pearson III Iwai (year) 2 184 191 188 3 216 224 221 5 251 258 255 10 296 295 296 20 339 326 333 30 363 342 353 50 394 360 378 80 422 376 400 100 436 383 411 150 460 395 430 200 477 404 443 Correlation 0.970 0.987 0.981

THE STUDY ON Fig. 5.5 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Results of Frequency Analysis on Basin Mean 2-day Rainfall CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 5 2-year Return Period 3-year Return Period 100 100

r 80 r 80

60 60

40 40 Rainfall (mm/h Rainfall Rainfall (mm/h 20 20

0 0 0 4 8 12162024283236404448 0 4 8 12162024283236404448 T (hour) T (hour)

5-year Return Period 10-year Return Period 100 100

r 80

r 80

60 60

40 40 Rainfall (mm/h Rainfall 20 (mm/h Rainfall 20

0 0 0 4 8 12162024283236404448 0 4 8 12162024283236404448 T (hour) T (hour)

20-year Return Period 30-year Return Period 100 100

r) 80 r) 80

60 60

40 40

Rainfall (mm/h 20 Rainfall (mm/h 20

0 0 0 4 8 12 16 20 24 28 32 36 40 44 48 0 4 8 12162024283236404448 T (hour) T (hour)

50-year Return Period 100-year Return Period 100 100

r 80 r) 80

60 60

40 40 Rainfall (mm/h Rainfall 20 Rainfall (mm/h 20

0 0 0 4 8 12162024283236404448 0 4 8 12162024283236404448 T (hour) T (hour)

THE STUDY ON Fig. 5.6 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Design Storm of Long Duration Rainfall CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 6 2-year Return Period 3-year Return Period

30 30 25 25 20 20 15 15 10 10 Rainfall (mm) Rainfall 5 (mm) Rainfall 5 0 0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 T (min) T (min)

5-year Return Period 10-year Return Period

30 30 25 25 20 20 15 15 10 10

Rainfall (mm) Rainfall 5 (mm) Rainfall 5 0 0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 T (min) T (min)

20-year Return Period 30-year Return Period

30 30 25 25 20 20 15 15 10 10 Rainfall (mm) 5 (mm) Rainfall 5 0 0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 T (min) T (min)

50-year Return Period 100-year Return Period

30 30 25 25 20 20 15 15 10 10

Rainfall (mm) 5

Rainfall (mm) Rainfall 5 0 0 0 20406080100120 0 20 40 60 80 100 120 T (min) T (min)

THE STUDY ON Fig. 5.7 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Design Storm of Short Duration Rainfall CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 7 IM-11 BC-05 SJ-10L SJ-10R BC-03

IM-10 BC- SJ-07 SJ-09 04 IM- BC-02 06 IM-09 SJ- YY-06 08L IM-08

SJ-08R CN-12 SJ-06 BC-01 YY-04

NIA Irrigation Canal IM-04 SJ-04 CN-11

IM-05

CN-10 YY- 03 IM-07 CN-09 SJ-04 SJ-05

CN-05

CN- 06 SJ-03 IM-03 IM-02

CN-08 CN-02

SJ-02 YY-01 YY-02

CN-04

CN-07 N

CN-03

SJ-01

IM-01

0 2 4 10 km CN-01

Legend : River : Basin Boundary : Sub-basin Boundary

THE STUDY ON Fig. 5.8 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Basin Subdivision for Three Major Rivers CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd. F - 5 - 8

THE STUDY ON Fig. 5.9 COMPREHENSIVE FLOOD MITIGATION

FOR CAVITE LOWLAND AREA CTI Engineering International Co., Ltd. Basin Subdivision for Drainage Area Nippon Koei Co., Ltd

F – 5 – 9 Bay Bacoor Bay

Daan Bukid 13 12 SJ-10R 11 SJ-09 Creek IM-11 11 BC-03 SJ-10 BC-05 L CN-12 8 9 10 8 10 SJ-08 SJ-08 SJ-07 8 L R Bacoor 9 Palamitan River

Imus River 7 BC-02 River IM-10 6 7 BC-04 IM-09 5

BC-01 CN-11 7 YY-06 3 IM-06

SJ-06 River San Juan 4 YY-05 IM-05 IM-08 4 Canas River Canas

CN-10 6 YY-04 SJ-04 3 6 2 IM-04 Pason Cama Chile River Julian River NIA Canal

Matangilan SJ-05 IM-07 River CN-09 5 CN-08

IM-03 4 5 YY-03 Baluctot River

CN-06 Ylang Ylang River Ylang Ylang San Juan River San Juan Imus River IM-02

Canas River Canas 1 Panaysayan River Panaysayan 2 SJ-03 CN-07

CN-05 3 Dasmarinas River Dasmarinas

YY-02 IM-01

2 CN-04 Legend 1 SJ-02 CN-02 1 Sub-basin

YY-01 River Channel

CN-03Pulonan River Distributed SJ-01 CN-01 Source Point Source

THE STUDY ON Fig. 5.10 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Schematic Diagram of Flood Routing Model CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 10 COMPREHENSIVE FLOOD MITIGATION FLOOD COMPREHENSIVE Malimango Drainage Rosario-Poblacion CTI EngineeringInternational Co., Ltd. Malamok River FOR CAVITE LOWLAND AREA Sta. Isabel E Isabel Sta. Tirona River Sineguelasan San Rafael Binakayan Wakas N Silangan Ligtong Nippon Koei Co., Ltd Bacao THE STUDY ON Sapa -Poblacion Sta. Isabel W Pulvorista S6 Calero River Calero

S5 S5 S11 Banalo F -511 S4 S3 S4 S10 Fig. 5.11 Mabolo Salinas

S3 S2 S3 Schematic DiagramofDrainage Area Wakas S Wakas

S2 S2 S5 S9 San Juan

S1 Daan Bukid Creek

S4 S8

S1 S4 S2 S1

S3 S7 BACOOR S3 S1

Panamitan S2 S6 SAN JUAN CANAS

S1 IMUS

36 0 35 Rainfall 34 40 33 Calculation 32 Flood Mark 80 31 30 29 120 28 Rainfall (mm/hr) Water Level (El.m) Level Water 27 160 26 25 200 9/27 08:00 9/27 20:00 9/28 08:00 9/28 20:00 9/29 08:00 9/29 20:00 (1) Imus River (at NIA Canal) 36 0 35 Rainfall 34 40 33 Calculation 32 Flood Mark 80 31 30 29 120 28 Rainfall (mm/hr)

Water Level (El.m) Level Water 27 160 26 25 200 9/27 08:00 9/27 20:00 9/28 08:00 9/28 20:00 9/29 08:00 9/29 20:00 (2) Ylang Ylang River (at NIA Canal) 36 0 35 Rainfall 34 40 33 Calculation 32 Flood Mark 80 31 30 29 120

28 (mm/hr) Rainfall Water Level (El.m) 27 160 26 25 200 9/27 08:00 9/27 20:00 9/28 08:00 9/28 20:00 9/29 08:00 9/29 20:00 (3) San Juan River (at NIA Canal)

31 0 30 Rainfall 29 40 28 Calculation 27 26 Flood Mark 80 25 24 120 23

22 (mm/hr) Rainfall Water Level (El.m) 160 21 20 19 200 9/27 08:00 9/27 20:00 9/28 08:00 9/28 20:00 9/29 08:00 9/29 20:00 (4) Canas River (at NIA Canal) THE STUDY ON Fig. 5.12 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Verification Results of Flood Runoff Model orf the 2006 Flood CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 12 Daan Bukid Creek

Habay Bridge Palico Bridge 8 7 Bacoor River

Muntino Bridge Triburary NIA Canal

Island Cove Banalo Bridge Triburary Bridge 9 Anabu Balsahan Bridge Imus Bridge Dam

10 6 2 1

Imus River 4 3 Bacoor Bay 5 Bucandala Dam Julian River Taclong II Bridge Triburary

Present Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 200 240 310 420 550 600 650 700 2 270 320 430 600 750 750 850 950 3 80 90 100 120 150 160 170 180 4 130 150 170 210 240 250 280 300 52530304045455050 6 400 470 600 750 950 1,000 1,100 1,200 7 65 75 85 100 120 130 140 150 8 130 150 170 190 230 240 260 270 9 140 160 180 210 240 250 270 290 10 550 650 750 950 1,200 1,200 1,400 1,500 Future Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 310 370 430 500 600 650 700 800 2 410 470 600 700 800 850 950 1,000 3 130 140 160 170 190 190 200 210 4 200 230 260 280 310 310 330 350 54045505055606065 6 650 750 850 1,000 1,200 1,200 1,300 1,400 7 80 90 110 120 130 140 150 160 8 150 170 190 220 250 260 280 290 9 160 180 210 230 270 280 300 320 10 750 900 1,100 1,200 1,400 1,500 1,600 1,700

Point Peak Discharge for Each Return Period (m3/s) Future Land Use No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year (with on-site flood 1 250 290 350 430 550 650 700 800 2 320 380 480 600 750 850 950 1,000 regulation pond) 3 90 100 120 140 160 190 200 210 4 140 170 200 240 230 310 330 350 52530354045606065 6 470 550 700 850 1,000 1,200 1,300 1,400 7 70 80 90 110 130 140 150 160 8 130 150 170 200 230 260 280 290 9 140 160 190 210 250 280 300 320 10 600 700 850 1,000 1,200 1,500 1,600 1,700

THE STUDY ON Fig. 5.13 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Probable Discharge Distribution of Imus River Basin CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 13 NIA Canal

Ylang-Ylang River Pasong Kastila Bacoor Bay Dam Panamitan Bridge 3

Panamitan River San Juan Ilang-Ilang Bridge Bridge 4 Bayan Diversion Dam 6 5 2 1 Diversion San Juan River point

Present Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 120 150 220 330 450 500 600 650 2 180 220 320 440 600 650 750 800 3 190 230 280 410 600 650 700 800 4 190 230 290 420 600 650 700 800 5 320 400 600 800 1,100 1,200 1,300 1,500 6 270 330 470 650 850 900 1,100 1,200

Future Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 160 190 230 350 470 550 600 700 2 220 270 340 460 600 650 750 850 3 270 320 370 490 650 700 750 850 4 270 320 380 490 650 700 750 850 5 410 500 650 850 1,100 1,200 1,400 1,500 6 340 410 550 700 850 950 1,100 1,200

Future Land Use (with on-site flood regulation pond) Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 130 160 220 340 460 550 600 700 2 190 240 320 450 600 650 750 850 3 220 250 300 430 600 700 750 850 4 220 260 320 440 600 700 750 850 5 340 420 600 850 1,100 1,200 1,400 1,500 6 290 350 480 650 850 950 1,100 1,200

THE STUDY ON Fig. 5.14 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Probable Discharge Distribution of San Juan River Basin CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 14 Tejero Bridge Plucena Dam

4 2 1 3 Canas River NIA Canal Bridge

Present Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 210 270 430 700 950 1,100 1,200 1,300 2 230 290 470 700 1,000 1,100 1,300 1,400 33035405575808595 4 240 320 500 750 1,100 1,200 1,300 1,500

Future Land Use Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 310 380 480 750 1,000 1,100 1,200 1,400 2 330 400 550 750 1,000 1,100 1,300 1,400 3455055708590100110 4 350 440 600 800 1,100 1,200 1,400 1,500

Future Land Use (with on-site flood regulation pond) Point Peak Discharge for Each Return Period (m3/s) No. 2-year 3-year 5-year 10-year 20-year 30-year 50-year 100-year 1 240 300 440 700 950 1,100 1,200 1,400 2 250 320 480 750 1,000 1,100 1,300 1,400 3303540607590100110 4 270 340 550 800 1,100 1,200 1,400 1,500

THE STUDY ON Fig. 5.15 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Probable Discharge Distribution of Canas River Basin CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 15 100

Envelop Curve 2

10 q: Specific Discharge (m3/s/km Discharge Specific q:

1 10 100 1,000 10,000 A: Catchment Area (km2)

Imus (Future Land Use) Imus (Present Land Use) San Juan (Future Land Use) San Juan (Present Land Use) Canas (Future Land Use) Canas (Present Land Use) Basins in and around Manila Agno Sacobia-Bamban-Abacan Bicol

Source: 1) Basins in and around Manila: The Study on Flood Control and Drainage Project in , Vol. 2, Supporting Report, 1990, JICA 2) Basins in the Island: Study for the Preparation of Flood Control Manual for Department of Public Works and Highways Technical Standards and Guidelines, Final Report, Main Report, Vol ume I, March 2003, JICA, DPWH THE STUDY ON Fig. 5.16 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Comparison of Specific Discharge with Other River Basins in the Luzon Island CTI Engineering International Co., Ltd. (5-year probable flood) Nippon Koei Co., Ltd F - 5 - 16 100

Envelop Curve 2

10 q: Specific Discharge (m3/s/km Discharge Specific q:

1 10 100 1,000 10,000 A: Catchment Area (km2) Imus (Future Land Use) Imus (Present Land Use) San Juan (Future Land Use) San Juan (Present Land Use) Canas (Future Land Use) Canas (Present Land USe) Basins in and around Manila Laoag Cagayan Agno Sacobia-Bamban-Abacan Pampanga Bicol

Source: 1) Basins in and around Manila: The Study on Flood Control and Drainage Project in Metro Manila, Vol. 2, Supporting Report, 1990, JICA 2) Basins in the Luzon Island: Study for the Preparation of Flood Control Manual for Department of Public Works and Highways Technical Standards and Guidelines, Final Report, Main Report, Vol ume I, March 2003, JICA, DPWH THE STUDY ON Fig. 5.17 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Comparison of Specific Discharge with Other River Basins in the Luzon Island CTI Engineering International Co., Ltd. (100-year probable flood) Nippon Koei Co., Ltd F - 5 - 17 Imus River (River mouth) Imus River (River mouth, 5-year probable flood) 1,800 1,200 1,600 1,400 1,000 1,200 800 1,000 800 600 600 400

400 (m3/s) Discharge Peak Discharge(m3/s) 200 200 0 2 3 5 10 20 30 50 100 0 0 6 12 18 24 30 36 42 48 Return Period (Year) Hour Future Land Use Present Land Use Future Land Use Present Land Use

San Juan River San Juan River (Diversion Point) (Diversion Point, 5-year probable flood) 1,800 1,200 1,600 1,400 1,000 1,200 800 1,000 800 600 600 400 Discharge (m3/s) Discharge

Peak Discharge (m3/s) 400 200 200 0 0 2 3 5 10203050100 0 6 12 18 24 30 36 42 48 Return Period (Year) Hour

Canas River (River mouth) Canas River 1,800 (River mouth, 5-year probable flood) 1,200 1,600 1,400 1,000 1,200 800 1,000 600 800 600 400 Discharge (m3/s)

Peak Discharge (m3/s) 400 200 200 0 0 0 6 12 18 24 30 36 42 48 2 3 5 10203050100 Return Period (Year) Hour

THE STUDY ON Fig. 5.18 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Increase in Runoff Discharge by Urbanization CTI Engineering International Co., Ltd. Nippon Koei Co., Ltd F - 5 - 18 µ

Legend Project Area less than 0m 0 - 1m 1 - 2m 2 - 3m 3 - 5m 5 - 10m 10 - 15m 15 - 20m 20 - 25m 25 - 30m 30 - 35m 35 - 40m out of target area

0241 km

THE STUDY ON Fig. 5.19 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Generated DEM by 100m Scaled Mesh JAPAN INTERNATIONAL COOPERATION AGENCY

F - 5 - 19 Typhoon Milenyo Legend in 2006 Inundation Depth No Flood 0.01 - 0.25m 0.25 - 0.5m µ 0.5 - 1.0m 0120.5 km 1.0 - 2.0m More than 2m

Alapan )"

Julian )")" Bucandala Bukol Bago-D )" )" Balbakin )" )" Siroy Bilad )" Ragatan )" )"

Kaliwa )" Anabu Bayan )" )" Calubcub )" Cosme Bago-U )" Buyang )" )" Pasong Buaya Camatchile )" )" Plucena )" SalaanTapun )" )" )" Pasong Kastila San Gabriel )" Hari Anton )" Ang Baluctot )" )" Emong )" Escribiente I )" Palindong )" Salitran Man)" )" )" Engue Escribiente II Abubot )" )" )"

Igme Maculing )" )" Kasundid )" Pari )" Menes Matanda )" Marcelo )" )" Danayan )"Hasaan 1 )" Kambing )" Saulog )" )" THE STUDY ON Fig. 5.20 COMPREHENSIVE FLOOD MITIGATION FOR CAVITE LOWLAND AREA Reproduction of Flood of Typhoon Milenyo in 2006 JAPAN INTERNATIONAL COOPERATION AGENCY

F - 5 - 20