JICA Regional Focused Training on Flood Hazard Mapping
October 29, 2006 – December 02, 2006

CONCLUDING REPORT“Action Plan Towards Effective Flood Hazard Mapping in thePhilippines”

Ms. MA.LUISA O. ABAGAO
Flood Control Management Service
Metropolitan Manila Development Authority ( MMDA )Philippines
e-mail:mlabagao77@yahoo.com.ph

INTRODUCTION:
The Republic of the Philippines
is an island nation located in the Southeast Asia between the Philippine Sea andSouth China Sea and Manila as its
capital. It is made up of 7,107 islands
with a total land area of approximately
300,000squarekilometers(land=298,170 sq. km. and water=1,830sq. km.)
Philippines are divided into threegeographical areas: Luzon, Visayas andMinadanao. It has 17 regions, 80
provinces,117
cities,1,501
municipalities, and 41,982 barangays.
The Philippines is the world's
13th most populous country, with apopulation of 89,468,677 (as of July
2006, with ages 0-14 composes the 35%,
15-64 is 61% of the population andabout 4% of ages 65 or more). Manila
the capital is the eleventh most populous
metropolitan area in the worldThecountry
experiences
different natural hazard like typhoon,
land slide, active volcanoes, destructive
earthquake and tsunamis.

The Flood Status in the Philippines
Philippines is an astride typhoon belt, it is usually affected by 15 and struck by 5or 6 cyclonic storm per year. Tabulated below are the recorded annual flood damages in
the country starting from 1980 to 2003.

RECORDED ANNUAL FLOOD DAMAGES, PHILIPPINES, 1980-2003
YEAR

POPULATIONAFFECTEDCASUALTIESHOUSE DAMAGEDDAMAGEVALUE(millionpeso)

FAMILIESPERSONSDEADMISSING

INJUREDTOTALLYPARTIALLY

1980248,164

1,666,498

36

4

55

16,51051,101

1,472.00

1981

250,325

1,472,417

484

264

1,922

44,994

159,251

1,273.00

1982

266,476

1,569,017

337

223

347

84,027

97,485

1,754.00

1983

140,604

747,155

126

168

28

29,89285,072523.00

1984

741,510

4,048,805

1,979

4,426

732

310,646

313,391416.00

1985

318,106

1,643,142

211

300

17

8,204

211,151

3.00

1986

287,240

1,524,301

171

43

155

3,162

14,595

1,838.00

1987

464,1622,591,914

1,020

213

1,455

180,550

344,416

8,763.00

1988

1,173,994

6,081,572

429

195

468

134,344585,732

8,675.00

1989

501,682

2,582,822

382

89

1,088

56,473

184,584

4,494.00

1990

1,265,652

6,661,474

676

262

1,392

223,535

636,742

11,713.00

1991

150,894

759,335

5,201

4,278

357

15,45883,664

74.00

1992

418,964

2,097,693

145

95

51

3,472

8,342

7,359.00

1993

1,523,250

8,202,118

814

214

1,637

166,004

456,773

25,038.00

1994

670,078

3,306,783

266

54

260

58,869226,291

3,401.00

1995

1,710,619

8,567,666

1,255

669

3,027

294,654

720,50257,781.00

1996

260,5811,254,989

124

49

97

2,690

17,557

10,109.00

1997

777,997

3,954,175

199

28

66

13,22553,9804,842.00

1998

1,590,905

7,197,953

498

116

873

137,020

406,438

17,823.00

1999
2000
2001
2002
2003

270,424
1,426,965
756,938
538,600
702,223

1,281,194
6,852,826
3,629,295
3,546,469
3,362,991

56
338
431
169
139

3
59134
33
28

25
370
418
71
182

144
24,573
14,8992,980
12,306

687
195,536
54,422
15,94751,5791,555.00
7,217.00
6,924.00
829.004,567.00

TOTAL

16,456,353

84,602,60415,486

11,947

15,093

1,838,631

4,975,238

188,443.00

This year more than 12 typhoons visited the country and six of these typhoons caused
destruction to the country that result in loss of lives and properties as follows:
1. Tropical Storm Henry – make a land in the country last August 03, 2006, withaffected families total to 120,753 or 545,327 persons. With 2,860 of thisfamilies or 12,931 persons moved to 54 evacuation centers. 8 persons weredead, 1 injured 8 are reported missing. A total of 11 houses are totally
damaged and 30 houses is partially damaged. The amount of damage is equal
to 26,115,000 pesos worth in infrastructure and 101,575,057 pesos worth ofagricultural damage. Four hundred forty seven (447) barangays were flooded
in 33 affected municipalities with flood water ranging from 0.60 m to 1.20 m,
1 municipality with flood water reached up to 2.5 meters of flood water and 5
municipalities were declared under the state of calamity.
2. Tropical Storm Inday and Typhoon Juan – Tropical storm Inday passed thecountry last August 08, 2006 while Typhoon Juan landed on August 09.
Aside from flooding, flash floods and landslide, tornado and storm surge wereexperienced in some areas.
Flooding

StormSurge

TornadoFlash Floods
and Land slides

Affected Populations:
Affected Persons
Affected Families
No. of families Evacuated
No. of Persons Evacuated
No. of Evacuation CenterNo. of Dead
No. of affected Barangays

62,28013,158
286

102-

6,540
1,441

15,877
2,987
463
2,152
3
7

114

1
1
35,000174
15-----

Damage Properties:
Partially Damage Houses
Totally Damage Houses
Amount of Damage
Agriculture
Amount of Damage
InfrastructuretotoP

1718
290
4,726,183 P-3. Typhoon Milenyo (Xangsane) – it is the biggest and most destructive theseyear. It landed the Philippines last October 12, 2006. The affected areas were
4,435 barangays of 32 cities and 235 municipalities of 21 provinces from 7regions. The affected population is equal to 825,493 families or 4,022,603
persons with a total of 2,524 families or 15,711 persons evacuated to 96
designated evacuation centers. The casualties are 184 dead, 536 injured and47 are reported missing. The amount of damages to infrastructures andagriculture are worth 2.6 and 4.0 billion pesos respectively, with a tally of117,429 totally damaged houses and 378,896 partially damaged houses.
Declaration of State of Calamity was made in the following places; Metro

Manila, Province of Cavite, Province of Antique, and Municipality of San
Roque and Northern Samar
4. Typhoon Paeng ( Cimaron ) – it landed last October 29, 2006 with a total of68,783 families or 309,606 persons are affected. The barangays that aresubmerged to water have a total of 830 from 6 cities and 77 municipalities of12 provinces. A total of 1,504 families or 6,790 persons were moved toevacuation centers. The casualties are as follows; 23 dead, 65 injured and 15
were reported missing. The results of damages are as follows; 963 totally
damaged houses and 7,030 partially damaged; an amount of 155,313,495
estimated damaged to structures and 384,686,297.33 in agriculture. Landslide
occurs in 7 areas from different provinces, and electric and communication
powers were interrupted in 3 provinces.
5. Typhoon Quennie – made a landfall in the country last November 09, 2006
with affected families of 3,958 or 21,250 persons, there are 38 barangays from
7 municipalities and 1 city that suffer from flood. The number of casualty are
as follows; 1 dead, 10 persons injured and 228 houses were totally damaged
and 1449 were partially damaged due to these flood.

At present the country is flood prone and suffering from this disaster. In Metro
Manila, the National capital Region of the country more than 10% of the land area isflood prone, but these was decreased to 50% because in year 2002 around 13,100
hectares or 20 % of the land area is flood prone but due to massive clean up andinformation campaign we decreased it to 6,500 hectares, but these remaining flood needs
structure because we already meet the maximum capacity of the drainage system. Floods
do not spare Metro Manila, it occur frequently during the southwest monsoon season
causing loss of lives and properties. Topographically, a large portion of Metro Manila isbelow sea level these are the city of Manila, Valenzuela, Parañaque, Las Piñas, Pasig andMuntinlupa and the Municipalities of Malabon, Valenzuela, Navotas and Pateros. Thelow lying areas are affected by the rise of water at Laguna Lake and Manila Bay.
Flooding in Metro Manila is caused by two types such as follows;
1. Overflow Flooding – caused by in adequate capacity of waterways.
2. Inland Flooding – caused by inadequate drainage or high water in the mainchannel.
To mitigate flood damages in the country priority programs are implemented by
the Philippine government to attain the development goals and minimize loss of lives andproperty caused by flooding. In Metro Manila the Flood Control Management Service ofMetropolitan Manila Development Authority (MMDA), perform a massive clean-up;
information campaign and development of infrastructure projects that prioritize floodprone areas that are designated to provide public welfare and safety as well as to improvethe health and sanitation of the people in the flood affected areas; also support the landconservation and economic development of the regions.
Metro Manila have 41 rivers (length=155,144 m); 125 creeks (length=318,622m);
and 30 esteros (length=40,765m) all are under MMDA jurisdiction, in order to mitigate
flooding in Metro Manila, the MMDA enhances its capacity to address this issue toprevent and mitigate flooding within the Metropolis, these involves activities that areboth structural and non-structural as enumerated:
Structural Measures:• Construction of Pumping Station• Drainage Improvement (construction of drainage lines and manholes)• Bank Improvement ( riprapping,)• Napindan Hydraulic Control Structure• West Mangahan Floodway Project and construction of revetment wallalong major rivers• KAMANAVA Projects (Construction of dikes within the Kaloocan,Malabon, Navotas and Valenzuela boundary from bodies of water)
Non-Structural Measures:•••••••••

Declogging of drainage laterals by the use of mechanical scraper, SRECO
machine, vacuum, sewer jet and flushing machine;
Desilting of Drainage Mains done by crawler crane and scraper;
Dredging of open waterways using backhoe and crane;
Demolition of informal settlers along the open waterways;
Hydrological data acquisition and operation of Effective Flood Control
Operation System (EFCOS);
Operation of the existing Rosario weir flood control structure and its
related facilities;
Close supervision and effective management of the pumping stations,floodgates and automatic trash screen; quick response operation;
flood watch on a round-the-clock basis during times of calamities; studies
and researches and;FLOOD HAZARD MAP production and dissemination.

Flood hazard map is very useful in the Philippines because the country lacks offunds to provide all structures needed in mitigating flood. In Metro Manila we use this as
guide to choose and decide for the area is to be given priority when funds are available.
We also use this in land use; and most of all the concept to use this as basic but powerfultool in evacuation during disaster. Through this map we will be able to minimize loss ofhuman lives and properties and to be able to have a smooth, safe and easy evacuation thiswill serve as guide. We also used this map to know if the measures/project that wasmade was effective by comparing the status of the area after a big flood before and after
the construction of the structures and the most important is in times of flooding for theresidents to know were to go through and what path to used.

Organization involved and responsible in making and disseminating inundation andFlood Hazard MapIn the Philippines NAMRIA is in-charge in producing map, topographic map,
land use map and many other kinds of map but due to lack of resources and funds toupdate the existing data we have in the country they cannot be able to provide an accurate
data. In Metro Manila we used an electronic map that came that is used in 2000 project
the MMEIRS, this is a study about earthquake status in the region, from the study they
have to make survey and aerial data of the area for them to be able to used in plotting thescenario needed, we used this base map and other information like elevation , land use,
and other making as the basic map in the agency in producing other map like road guide,for inputting the on-going project, and others because it is more accurate than the one
existing in NAMRIA.
Based from my knowledge and work, the MMDA is also the one responsible inmaking inundation and flood hazard map. At present we already have the inundation
map in the region, it based on the observed data and computed from the banks.
The agency the will be involved in disseminating inundation and flood hazard
map aside from my department are the local government from different cities andmunicipalities, barangay officials, academe/university/school, we can also used theinternet and media like TV and radio.

My Target Area to make Flood Hazard Map
I choose the San Juan River Watershed/Catchment Area because every time
typhoon visited the country and hits the area flooding occurs due to inadequate capacityof the waterways. The water system can only accommodate a maximum rainfall of
50mm/hr rainfall so an increased in this rainfall will cause the area to be flooded. Thetotal length of the river is 10.20 km with a drainage area of 8,938 hectares, 8 percent of
this area is flooded and a total of more than 4,000 families is affected every time flooding
occurs in the area. It covers 6 cities and 1 municipality in the region. The river has 8
tributaries which comes from different cities and municipalities. The area is basically anurban ecosystem, at present, approximately 90.5% of the total land area is utilized forresidential, 6% for commercial and 3.5% for park and open spaces.

San Juan River Catchment Area

What is necessary to make Flood Hazard Map
The resources we have and necessary to make Flood are electronic map needed tomake FHN like DEM map, the aerial photo, base map and others, We also have thesoftware like GIS in production of maps; inundation map ( but based only on survey,
observed water elevation during flood; and data computed manually); the number offamilies that will be affected; evacuation area already identified; critical area/spots
already identified ( like open manhole/drainage); and location of hospitals and training
centers.
The most important that needed to be sourced out is the funds needed in theproduction of maps and other necessary materials and data and the lack of humanresources and experts that have knowledge in making the maps.
My Action Plan within the Next Five Years
Activities
2007 2008
Presentation of the result of my training to myoffice (December, 2006)
Enhance my knowledge and continue
practicing on using the computer software(starting Dec. 2006)
Proposed and request for budget for the
production and dissemination of FHM
Train engineers and computer operator frommy department on the process and method ofproducing accurate, simple, reliable andeffective FHMContinues update of existing data
Continues Preparation and updating of FHM(start Dec., 2006)
Conduct training/giving information tomunicipalities/cities/and barangay officialsthat will be involved in producing anddisseminating FHM
Dissemination and information campaign ofFlood Hazard Map to affected areas but only
through internet (but maybe just my target
area for now then followed by the next
problematic area,) and using the radio station
to invite people to access internet or visit us in
the office
Production of Flood Hazard Map to be used as
signages in public places that can haveinundation and near the inundated area

20092010 2011

My own Flood Hazard Map in Ise City

This is my Flood Hazard Map in ISE City, I added the evacuation route, floodgates and pumping stations, hospitals which is necessary in casualties; and danger area
like open manhole which will make the people in danger during flooding.
Conclusions:
Flood Hazard map is an effective tools in minimizing the flood disaster in thecountry, it is very useful to minimize loss of human lives and properties and the smooth ,safe and fastest way to move to evacuation area can be attain by using flood hazard map.
It is also effective in using this to decide for the flood control structure to be used indifferent area.
Having one month of stay in japan and focusing on the training of flood hazard
mapping is a big help that I gained so much knowledge and friends and enhance mycapability in producing effective, simple and informative FHM.