The Preparatory Study for Sector Loan on Disaster Risk Management in the Republic of the Philippines
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DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS THE REPUBLIC OF THE PHILIPPINES THE PREPARATORY STUDY FOR SECTOR LOAN ON DISASTER RISK MANAGEMENT IN THE REPUBLIC OF THE PHILIPPINES FINAL REPORT PART II-C FEASIBILITY STUDY ON TAGOLOAN RIVER BASIN (TAGOLOAN) JANUARY 2010 JAPAN INTERNATIONAL COOPERATION AGENCY CTI ENGINEERING INTERNATIONAL CO., LTD. in association with NIPPON KOEI CO., LTD GED JR 10-012 DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS THE REPUBLIC OF THE PHILIPPINES THE PREPARATORY STUDY FOR SECTOR LOAN ON DISASTER RISK MANAGEMENT IN THE REPUBLIC OF THE PHILIPPINES FINAL REPORT PART II-C FEASIBILITY STUDY ON TAGOLOAN RIVER BASIN (TAGOLOAN) JANUARY 2010 JAPAN INTERNATIONAL COOPERATION AGENCY CTI ENGINEERING INTERNATIONAL CO., LTD. in association with NIPPON KOEI CO., LTD Exchange Rate used in the Report is: US$ 1.00 = PhP. 49.70 = JpY. 93.67 Jp¥ 1.00 = PhP. 0.5306 (as of 31st August 2009) LIST OF REPORTS Summary Part I : Main Report Part II-A : Feasibility Study on the Lower Cagayan River Flood Control Project for the Sector Loan Application Part II-B : Feasibility Study on the Ilog Hilabangan River Flood Control Project for the Sector Loan Application Part II-C : Feasibility Study on the Tagoloan River Flood Control Project for the Sector Loan Application Needs Assessment Study on Flood Disasters Caused by Typhoons No.16 (ONDOY) and No.17 (PEPENG) THE PREPARATORY STUDY FOR SECTOR LOAN ON DISASTER RISK MANAGEMENT IN THE REPUBLIC OF THE PHILIPPINES FINAL REPORT PART II-C: F/S ON TAGOLOAN RIVER BASIN (TAGOLOAN) LOCATION MAP COMPOSITION OF THE REPORT TABLE OF CONTENTS ABBREVIATION (REFER TO MAIN REPORT (PART-I)) TABLE OF CONTENTS Page CHAPTER 1 INTRODUCTION..................................................................................... 1-1 1.1 Background of the Study .......................................................................................... 1-1 1.2 Objectives of the Study............................................................................................. 1-2 1.3 Composition of the Final Report .............................................................................. 1-3 1.2.1 Objectives of the Sector Loan Project on Disaster Risk Management............. 1-2 1.2.2 Objectives of the Preparatory Study................................................................. 1-2 CHAPTER 2 NATURAL CONDITION OF THE STUDY AREA ............................... 2-1 2.1 Location ....................................................................................................................2-1 2.1.1 Topography....................................................................................................... 2-1 2.1.2 Geology and Soil.............................................................................................. 2-2 2.2 Meteo-Hydrology and River System of Ilog-HIlabangan River Basin..................... 2-5 2.2.1 Meteorology of Tagoloan River Basin ............................................................. 2-5 2.2.2 River System in Tagoloan River Basin............................................................. 2-7 2.3 Flood......................................................................................................................... 2-8 2.4 Related Information.................................................................................................. 2-8 2.4.1 Water Resources Development Plans ............................................................... 2-8 2.4.2 Actual Flood Mitigation Projects in the Past.................................................... 2-8 CHAPTER 3 SOCIO-ECONOMY ................................................................................. 3-1 3.1 The Population and Economy................................................................................... 3-1 3.2 Land Use Profile....................................................................................................... 3-2 3.3 General Economic Situation ..................................................................................... 3-3 3.4 Water Utilization and Wastewater Disposal.............................................................. 3-4 3.5 Public Hazards.......................................................................................................... 3-4 3.5.1 River Overbank Flow ....................................................................................... 3-4 3.5.2 Solid Waste....................................................................................................... 3-5 3.5.3 Water Pollution................................................................................................. 3-6 CHAPTER 4 ANALYSIS OF FUTURE LAND USE AND POPULATION................ 4-1 4.1 Future Land Use Conditions..................................................................................... 4-1 4.2 Population Projection (2005-2020)........................................................................... 4-1 4.3 Trends of Urban Development and Population Increase .......................................... 4-2 CHAPTER 5 HYDROLOGIC AND HYDRAULIC ANALYSIS ................................. 5-1 5.1 Approach................................................................................................................... 5-1 5.2 Hydrology................................................................................................................. 5-2 5.2.1 Rainfall Analysis .............................................................................................. 5-2 5.2.2 Runoff Analysis ................................................................................................ 5-8 5.3 Hydraulic Analysis.................................................................................................. 5-11 5.3.1 Target Area..................................................................................................... 5-11 5.3.2 River Cross-section Survey ............................................................................ 5-11 5.3.3 Initial Boundary Condition............................................................................. 5-11 5.3.4 Flow Capacity................................................................................................. 5-12 5.4 Flood Inundation Analysis...................................................................................... 5-13 5.4.1 General ........................................................................................................... 5-13 5.4.2 Flood Inundation Model................................................................................. 5-13 CHAPTER 6 PLANNING FRAMEWORK ................................................................... 6-1 6.1 Basic Concepts on Planning Framework .................................................................. 6-1 6.1.1 Summary and Outline of Current M/P ............................................................. 6-1 6.1.2 Core Areas to be Protected by Structural Measures in the Sector Loan Project .................................................................................... 6-1 6.1.3 Basic Concept for Flood Control...................................................................... 6-2 6.2 Planning Framework................................................................................................. 6-6 6.2.1 Target Project Completion Year........................................................................ 6-6 6.2.2 Social Framework............................................................................................. 6-7 6.2.3 Design Framework........................................................................................... 6-7 CHAPTER 7 STRUCTURAL FLOOD MITIGATION PLAN .................................... 7-1 7.1 Structural Flood Mitigation Plan against River-Overflow Flood ............................. 7-1 7.1.1 Maximum Design Scale Examined in the Study .............................................. 7-1 7.1.2 Potential Measures............................................................................................ 7-1 7.1.3 Alternative Flood Mitigation Plans against River-overflow and Tidal Floods...................................................................................................... 7-3 7.1.4 Flood Simulation Analysis ............................................................................... 7-4 7.1.5 Optimum Structural Mitigation Plan (Summary of Simulation Analysis)................................................................. 7-5 7.1.6 Preliminary Design of River Facilities ............................................................. 7-7 7.1.7 Construction Plan............................................................................................. 7-9 7.1.8 Cost Estimation .............................................................................................. 7-15 7.2 Economic Evaluation of Project ............................................................................. 7-19 7.2.1 Methodology................................................................................................... 7-19 7.2.2 Basic Unit for Estimation of Economic Benefit............................................. 7-20 7.2.3 Identification of Economic Benefit ................................................................ 7-24 7.2.4 Estimation of Economic Cost......................................................................... 7-25 7.2.5 Results of Economic Evaluation for the Project and Conclusion................... 7-27 CHAPTER 8 NON-STRUCTURAL FLOOD