The Feasibility Study of the Flood Control Project for the Lower Cagayan River in the Republic of the Philippines Final Report Supporting Report Annex VI: Flood Control

Figures Aparri Babuyan Channel Legend River course Diversion weir Lal-lo Dam Road Magapit Br. Magapit Basin boundary Sub-basin boundary Dummon River Nassiping Tupang Alcala Pared River Amulung

Iguig N Tug ueg Tuao arao Ri Cordillera Solana ver Chico River Buntun Br. Mountains Tuguegarao Enrile

Pinacanauan River Cabagan

r e iv Mallig Tumauini R ig ll Tumauini River a M

Ilagan Siffu River

Magat R r iver e Cauyan v i Ilagan River R

Magat Dam n a y a g a C

Santiago Echague

r Bayombon e iv Jones R t a g Sta Cruz River a M

Sierra Madre Addalam River Cagayan River Mountains

Caraballo Mountains Scale 0 10 20 30 40 50 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.1 in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY General Basin Map VI-F1 Babuyan Channel

Aparri

Zinundungan River Magapit

Dummon River Chico River

Nassiping Faire

Alcala

Pared River

Cagayan River Tuguegarao City

Tuguegarao River

Cabagan Pinacanauan River

Mallig Mallig River Tumauini River

Siffu River Roxas

Santa Cruz River Ilagan Ilagan River Magat River

San Mateo Naguilian

Cauayan Santiago City Note Ganano River Total Catchment Area : 27,300 sq.km Jones River Length : 520 km Legend Addalam River : City/municipality : Rivers San Agustin

Source : Topographic Maps

The Feasibility Study of the Flood Control Project Figure 1.1.2 for the Lower Cagayan River in the Republic of the Philippines Schematic River System of the Cagayan River JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F2

VI-F4

Elevation (EL m) 1,000 1,500 2,000 500 0

0 0 0 0 0 600 500 400 300 200 100 0 Aparri

Lal-lo Magapit Br. Gattaran Nassiping Alcala

Amulung Zinundungan R.(L) Iguig Dummon R.(R) Buntun Br. Tuguegarao Pared R.(R)

Cabagan

Tumauini

Distance from River Mouth (km) Mouth River from Distance Pinacanauan R.(R) Ilagan Tuguegarao R.(R) Gamu Br. Naguilian Br. Tumauini R.(R) Cauayan Chico R.(L)

Dalibubon Br.

Jones Siffu R.(L)

Ganano R.(L) Ilagan R.(R)

Addalam R.(L) Magat R.(L) /01/100 1/10 Source:Topographic Map Source:Topographic

Cagayan R. 1/200 1/2000 1/1000 1/500 Long itudinal Profile of the Cag ayan Ri ver 50

40 Alcala Aparri Cabagan Nassiping

Left Bank Br. Buntun Pared R.(R) Pared Chico R.(L) 30 Magapit Br. Sta. Maria Br. Sta. Maria Dummon R.(R) Dummon m Right Bank Tuguegarao R.(R) Tuguegarao Pinacanauan R.(R) Pinacanauan 20 R.(L) Zinundungan

10

0 Mean River Bed

Elevation (El (El Elevation De epes t R iv er Be d Mean River Bed slope -10

-20 Riverbed Slope=1/21,000Riverbed Slope=1/10,000 Riverbed Slope=1/9,000 Riverbed Slope=1/7,000

-30 0 20 40 60 80 100 120 140 160 180 VI-F5

5000 River Width of the Cagayan River

4000

3000

Width (m) 2000 River width including flood plain

Low Water Channel 1000

0 0 20 40 60 80 100 120 140 160 180 Distance from River Mouth (km) -20 i r r R g L r a R R n L R Aparr Alcal

-10 Cabaga Nassipin Buntun B Pared R.( Chico R.( Magapit B

Average River Bed Sta. Maria B 0 R.( Dummon T uguegarao R.( Pinacanauan R.( Zinundungan R.( Zinundungan ) 10

Depth (m 20 Deepest River Bed

30

40 Channel Depth below Riverbank Elevation

VI-F6 50

25000 Bankful Carrying Capacity 20000 /s) 3

15000

10000

Carrying Capacity (m Capacity Carrying 5000

0 0 20 40 60 80 100 120 140 160 180 Distance from River Mouth (km) 40 Longitudinal Profile of the Chico River

30 Right Bank Left Bank 20

10

Elevation (El m) (El Elevation 0 Deepest River Bed Average River Bed -10 Riverbed Slope=1/2,800 -20

1000 River Width of the Chico River 800

600 Law Water Channel

400

200

0

0

2 Channel Depth below Riverbank Elevation

4 Average River Bed 6

8

10

12

14 Deepest River Bed

16

18

20

12000

10000

8000

6000 Width (m) Width 4000

2000 Bankful Carrying Capacity 0 0 2 4 6 8 10 12 14 Distance from River Mouth (km)

The Feasibility Study of the Flood Control Project Figure 1.1.6 for the Lower Cagayan River in the Republic of the Philippines Characteristics of Existinng River Channel JAPAN INTERNATIONAL COOPERATION AGENCY ( Chico River)

VI-F7 80 Longitudinal Profile of the Tuguegarao River 70

60 Left Bank 50 Right Bank 40

30

Elevation (El m) 20

Average River Bed 10 Deepest River Bed

0 Riverbed Slope=1/800 -10

1200 River Width of the Tuguegarao River 1000

800 Law Water Channel 600

400

200

0

0 Channel Depth below Riverbank Elevation 2 Average River Bed 4

6

8

10 Deepest River Bed 12

14

16

16000

14000 Bankful Carrying Capacity

12000

10000

8000

Width (m) Width 6000

4000

2000

0 02468101214 Distance from River Mouth (km)

The Feasibility Study of the Flood Control Project Figure 1.1.7 for the Lower Cagayan River in the Republic of the Philippines Characteristics of Existinng River Channel JAPAN INTERNATIONAL COOPERATION AGENCY (Tuguegarao River)

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The Feasibility Study of the Flood Control Project Figure 1.1.8 for the Lower Cagayan River in the Republic of the Philippines Geomorphological Survey Map JAPAN INTERNATIONAL COOPERATION AGENCY of the Cagayan River (1/3)

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The Feasibility Study of the Flood Control Project Figure 1.1.8 for the Lower Cagayan River in the Republic of the Philippines Geomorphological Survey Map JAPAN INTERNATIONAL COOPERATION AGENCY of the Cagayan River (2/3)

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The Feasibility Study of the Flood Control Project Figure 1.1.8 for the Lower Cagayan River in the Republic of the Philippines Geomorphological Survey Map JAPAN INTERNATIONAL COOPERATION AGENCY of the Cagayan River (3/3)

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l l h a a g r i i u v t H u l a l N A n i a l P

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n A l i w a a i l o v P L u

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The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.9 in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY Typical cross-section of alluvial plain Babuyan Channel

Aparri

A

A

N

B

B

Legend C C Topographic map (1947 - 1953)

Aerial photographs (1979)

Aerial photographs (1996)

Aerial photographs (2000)

Road

D D Lal-lo

Magapit

Scale 0 1 2 3 4 5 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.10 in the Republic of the Philippines River Course Shifting (1/5) JAPAN INTERNATIONAL COOPERATION AGENCY VI-F13 Legend Gattaran E Topographic map (1947 - 1953)

Aerial photographs (1979)

Aerial photographs (1996)

Aerial photographs (2000) E

Road

N

Nassiping

Alcala

Amulung

Scale 0 1 2 3 4 5 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.10 in the Republic of the Philippines River Course Shifting (2/5) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F14 Legend

Topographic map (1947 - 1953)

Aerial photographs (1979)

Aerial photographs (1996)

Aerial photographs (2000)

Road Iguig

N

Solana

Tuguegarao F

G

G F Enrile H Namabbalan Scale 0 1 2 3 4 5 km H

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.10 in the Republic of the Philippines River Course Shifting (3/5) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F15 Legend

Topographic map (1947 - 1953)

Aerial photographs (1979)

Aerial photographs (1996)

Aerial photographs (2000)

Road

D

D Cabagan

N

Tumauini

Scale 0 1 2 3 4 5 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.10 in the Republic of the Philippines River Course Shifting (4/5) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F16 N

Ilagan

Legend

Topographic map (1947 - 1953)

Aerial photographs (1979)

Aerial photographs (1996)

Aerial photographs (2000)

Road

Scale 0 1 2 3 4 5 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.10 in the Republic of the Philippines River Course Shifting (5/5) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F17 40

30

20

10 Mean River Bed ('00) Mean River Bed ('86)

0

-10 Deepest River Bed ('86) Deepest River Bed ('00) -20 Variation of River Bed Elevation (Mean/Deepest) -30 VI-F18 20

15 13.0m ('00) 13.0m ('86) 10 6.8m ('00) 5 6.6m ('86)

0 -2.4m ('00) -1.7m ('00) -2.1m ('86) - -2.6m ('86) 5 Variation of Average River Bed Elevation (Mean) for the Past 14 years - 10 0 20 40 60 80 100 120 140 160 180 Distance from River Mouth (km)

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.12 in the Republic of the Philippines JAPAN INTERNATIONAL COOPERATION AGENCY Cross-Sectional Variation (4/4)

VI-F22 Linao Babuyan Channel

Aparri

Macanaya

Tallungan

Bisagu

Zanja

Legend

Topographic Map (1979) Paruddun Sur

Aerial photographs (1996)

Aerial photographs (2000)

Mbangug

Scale 0 0.5 1 2 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.13 in the Republic of the Philippines Variation of Sandbar near River Mouth JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F23 Erosion and Sedimentation Process due to River Meandering

River bank consists of coarse sand with small stones Erosion

Erosion

Sedimentation Sedimentation

Flow direction

Track of natural levee/sand dune

Process of Erosion and Sedimentation at Bending Sections

2 `3H 2 `3H

H

Sedimentation

Erosion

Source: Yamamoto,1989: Chuuseki Kasenngaku, pp 183 and 184

The Feasibility Study of the Flood Control Project Figure 1.1.14 for the Lower Cagayan River in the Republic of the Philippines Erosion and Sedimentation due to River JAPAN INTERNATIONAL COOPERATION AGENCY Meandering

VI-F24 Nassiping

N Meandering rate Alcala Meandering rate (S) = AB / CD AB : Channel length CD : Straight line length

Channel

C D Amulung A B

Meandering rate (S) Year AB CD S (km) (km) (AB/CD) 1953 87.0 41.0 2.12 1979 78.0 41.0 1.90 1996 74.8 41.0 1.82 2000 74.4 41.0 1.81 m k

0 . Iguig 1 4

=

h t g

0 10 20 30 40 50 60 n e l

20.48 0.8 e n i l

t h

20.26 0.6 g i

Meandering rate a ) r

t D S C / 20.04 0.4 B

A ana = Sol S

( 10.82 0.2

10.60 0.0 19050 191600 129070 139080 149090 25000 260100 Meandering rate (S) Tuguegarao

Legend Enrile Topographic map (1947 - 1953) Aerial photographs (1979) Aerial photographs (1996) Aerial photographs (2000) Scale Road 0 2 4 6 8 10 km

The Feasibility Study of the Flood Control Project for the Lower Cagayan River Figure 1.1.15 in the Republic of the Philippines Meandering Rate in the Reach JAPAN INTERNATIONAL COOPERATION AGENCY from Alcala to Tuguegarao VI-F25 (A) : Development Process of River Meander

: Pool (Deep) : Erosion

Data @Source : Yamamoto, 1994 : The Kado Tokuseironn, Japan, Public Works Research Institute Paper Vol. 2662, pp.80-109 and Kondrat'yev, N.Y

(B) : Relationship between Meandering Rate (S) and (B/Hmax) for Various Rivers

3.0

2.5

2.0 Cagayan River I= -1/1800 I=1/ 800-1/1200 I=1/1200-1/1600 1.5 I=1/1600-1/2500 I=1/2500-1/5000 I=1/5000- 0 1.0

0.5 B: River width (m) Hmax.: Max. water depth (m)

0.0 1 10 100 B/Hmax Data Source: Yamamoto, 1989 : Study note on influence on river channel characteristics by climatis, topography and soil conditions,Japan, Pulic Works Research Institute Paper Vol.2795, pp.88-124 and Schumm, S.A., 1960 : The shape of alluvial channels in relation to sediment type,U.S. Geological Survey Professional Paper 352-B The Feasibility Study of the Flood Control Project Figure 1.1.16 for the Lower Cagayan River in the Republic of the Philippines River Meandering Characteristics (1) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F26 (A): Relationship between Meandering Rate (S) and (B/R) for Various Rivers in Indonesia

2.5

Ib=1/ 800-1/1200 Cagayan Ib=1/1200-1/1600 Ib=1/ (Ib=1/River 2.0 3000 9000) Ib=1/1600-1/2500 Ib=1/2500-1/5000 Present condition Ib=1/ Ib=1/9000 2000

1.5 Ib=1/ 1000 after construction of cut-off channel

1.0

0.5 B: River width (m) R: Hydraulic mean depth (m)

0.0 1 10 100170 1000 B/R Data Source: Yamamoto, 1989 : Study note on influence on river channel characteristics by climatis, topography and soil conditions, Japan,Pulic Works Research Institute Paper Vol.2795, pp.88-124

(B): Relationship between Meandering Rate (S) and (B/R) for Various Rivers in India and Pakistan

2.4

d50=0.01- 0.02 2.2 d50(cm) 0.004 - 0.01 2.0 0.01 - 0.02 d50=0.02- 0.021 - 0.05 0.05 Cagayan River 0.051 - 0.1 1.8 0.11 - 0.48

1.6

Grave 1.4 l B: River width (m) R: Hydraulic mean depth (m) 1.2

1.0

0.8 10 100 1000 10000 B/R

Data Source: Yamamoto, 1989 : Study note on influence on river channel characteristics by climatis, topography and soil conditions, Japan, Pulic Works Research Institute Paper Vol.2795, pp.88-124

The Feasibility Study of the Flood Control Project Figure 1.1.17 for the Lower Cagayan River in the Republic of the Philippines River Meandering Characteristics (2) JAPAN INTERNATIONAL COOPERATION AGENCY

VI-F27 Floodway with Floodway with Japan Sea a length of 4 km Japan Sea a length of 4 km (Completed in 1730) (Completed in 1730)

Niigata Niigata City Agano RiverCity Agano River

N N

Present River Course Present River Course confined by Dike confined by Dike

Diversion Channel Diversion Channel VI-F28

Old River Course Old River Course in 1762 in 1713

River Course in 1713 River Course in 1762

03 km 03 km

Data Source: Oya and Kato, 1984 : Agano River Geomorphologic Map Legend Historical River Course Shifting 1644 Sakata City 1649 Mogami River in the Mogami River 1660~167 2 1672~182 2 River courses reproduced Japan Sea ? 1823? based on old maps and 1823 ? topographic maps 1913 1934 1953

.

Mogami River

VI-F29 Present River Course Present River Course

River courses scattered in the past were finally confined to the present one by continuous earth dike throughout historical river improvement works

0 1 2 3 km

Sourse: Ohya, Kotouda, Wakamathu and Kubo,1982: River course shifting of the Mogami