Role of Roads and Water Control Structures on Polder Water Management

ROLE OF ROADS AND WATER CONTROL STRUCTURES ON POLDER WATER MANAGEMENT

MD. IBNUL HASAN

MASTER OF SCIENCE IN ENVIRONMENTAL ENGINEERING

DEPARTMENT OF CIVIL ENGINEERING BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY DHAKA, BANGLADESH

AUGUST, 2018

i ROLE OF ROADS AND WATER CONTROL STRUCTURES ON POLDER WATER MANAGEMENT

by MD. IBNUL HASAN

A thesis submitted for the partial fulfillment of the requirements for the Degree of

MASTER OF SCIENCE IN ENVIRONMENTAL ENGINEERING

DEPARTMENT OF CIVIL ENGINEERING BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY DHAKA, BANGLADESH

AUGUST, 2018

iii

Dedicated To My Loving Parents

v ACKNOWLEDGEMENT

First of all, the author likes to express his deepest gratitude to the gracious Almighty Allah for His unlimited kindness and blessings to fulfill the thesis work successfully.

The author wishes to express his heartiest gratitude and sincere thanks to his supervisor Dr. Rowshan Mamtaz, Professor, Department of Civil Engineering, BUET for her proper guidance, invaluable suggestions and continuous supervision at all stage of this research work. The author is indebted to her for his affectionate encouragement and endless contribution to new ideas and helpful co-operation throughout the thesis work. The author also appreciates her sincere effort, which came to a great help to write this thesis.

The author also likes to gratefully acknowledge the support and assistance provided by Dr. Cecilia Borgia from MetaMeta, Netherlands and Anika Tahsin from IWFM, BUET.

The author also likes to thank Mr. Rahul Dev Paul, Mr. Subrata Paul and Mr. Fahim Hasan for their assistance.

The author likes to express a very special indebtedness to his parents whose encouragement and support was a continuous source of inspiration for this work.

Finally, the author likes to thank all who helped him in making a successful and a productive completion of the thesis.

BUET, Bangladesh Md. Ibnul Hasan August, 2018

vi ABSTRACT

Bangladesh is a delta formed by the alluvial deposits of three mighty rivers the Ganges, the Brahmaputra and the Meghna. Bangladesh has been suffering from the twin problem of ‘floods and droughts’ for centuries and it’s also one of the most climate vulnerable countries in the world. From 1960, 19 big cyclones have hit the coast of Bangladesh. To protect the coast from recurrent natural disaster like floods, cyclones and storm surges along with salinity intrusion and sedimentation, the government of Bangladesh constructed 139 polders in the coastal area of Bangladesh. The immediate socio-economic consequences of these polders were very impressive and positive and that positive situation persisted for about two decades. But construction of embankments and unplanned roads within the polder disrupted the drainage system by blocking canals and rivers. This created a massive waterlogging problem within the polders.

This study was carried out mainly to find out the opportunity of roads and drainage structures in polder water management within the coastal polders of Bangladesh. To perform the study, two polders were selected. Polder 26 was selected for its massive waterlogging problem within the Polder. Polder 43/2F was selected because it has uneven land elevation within the polder, some areas are high and some low lands. The specific objective for polder 26 was to reduce waterlogging mainly by using roads and water crossing structures. And for polder 43/2F, the specific objective was to find out how roads and water crossing structures can be used to control water flow and store water in high lands for dry season irrigation.

A physical survey, several (around 60) House Hold Survey, 2 Focus Group Discussions (FGDs) and 2 Key Informant Interviews (KIIs) were carried out in each selected polder areas. The goals of these surveys were to find out the existing condition of the polders, impacts of waterlogging in farming and other activities, problems related to roads and water within the polder and possible solutions of those problems in priorities. A catalogue of issues and solutions related to road - water interactions is developed based on the survey findings and outcomes of FGDs and KIIs.

The study findings show that the overall scenario of road condition and water management within the two selected polders is not good. Most of the roads are earthen or broken. Both polders have waterlogging problem but it has become severe in polder 26. In polder 26, Farmers are facing crop failures (almost every year) and they have to abandon some portions of their cultivable land, in some cases up to 85 percent, because of waterlogging. To solve these problems, this study gives some recommendations such as improve the siting and size of water crossings, re-excavate khals to reconnect drainage ways, use (more) gated water crossings to retain and control water, improve the quality of roads and carpeting, improve collaboration between Bangladesh Water Development Board (BWDB) and Local Government Engineering Department (LGED), improve shelter function of embankments etc. Implementation of those recommendations will free a huge area from waterlogging and will improve the communication

vii system. As a result, there will be a positive change in farming activities. And the increased farmland and improved farming activity will increase amount of yields which will bring a big change in the local economy.

Finally, a simple design analysis (using rational method) was performed to calculate proper dimensions for internal culverts in polder 26. Rainfall data was collected from Bangladesh Metrological Department and Log Pearson Type III distribution was used to calculate rainfall intensity. From the recommended design dimensions (Table 6.3), it was found that three existing culverts (C2, C5, C7) are of inadequate sizes. To facilitate proper drainage in those locations, at least the recommended size (for 20 years return period and 3 days rainfall) should be provided. Moreover, the Polder needs at least 6 more culverts in stated locations to reduce waterlogging. Implementations of those recommended culverts will improve drainage in 5628 acre agricultural land. And if the improved drainage system can decrease 50% of the current cop loss then the total financial benefit will be USD 290, 823.

viii TABLE OF CONTENTS

Page No. ACKNOWLEDGMENTS vi ABSTRACT vii CONTENTS ix LIST OF TABLES xi LIST OF FIGURES xii LIST OF PHOTOS xiii LIST OF ABBREVIATIONS xiv

Chapter 1 : INTRODUCTION 1-4 1.1 Background 1 1.2 Objective of The Study 2 1.3 Scope of The Study 3 1.4 Organization of The Thesis 4

Chapter 2: REVIEW OF LITERATURE 5-33 2.1 Introduction 5 2.2 Polder 5 2.3 Polders in Bangladesh 6 2.4 Polder Water Management 10 2.4.1 Waterlogging problem in polders 11 2.4.2 Prevention and mitigation of waterlogging 12 2.4.3 Governance and water management structure of 13 polders in Bangladesh 2.5 Roads 14 2.5.1 National road classification 15 2.5.2 Role of LGED in road network development 16 2.5.3 Role Of LGIs in road network development 16 2.5.4 LGED road design standards 17 2.6 Water Crossing Structures 18 2.6.1 Factors influencing effective drainage through culverts 19 2.6.2 LGED design standards for culverts and bridges 22 2.6.3 Hydrological considerations for design of culverts 23 2.7 Role of Roads in Water Management 26 2.7.1 Opportunity of road designs in water management 28

Chapter 3: METHODOLOGY 34-39 3.1 Introduction 34 3.2 Site Selection 34 3.3 Data Collection 36 3.3.1 Primary data collection 36 3.3.2 Secondary data collection 38

ix 3.4 Design Adequacy Test of Culverts 39

Chapter 4: BASELINE STUDY OF POLDERS 40-48 4.1 Introduction 40 4.2 Polder 26 40 4.2.1 Environmental and social baseline 42 4.2.2 Water resources problems 43 4.3 Polder 43/2F 44 4.3.1 Environmental and social baseline 46 4.3.2 Water resources functions and problems 47

Chapter 5: RESULTS AND DISCUSSION 49-97 5.1 Introduction 49 5.2 Survey Findings 49 5.2.1 Polder 26 49 5.2.2 Polder 43/2F 61 5.3 Findings of FGD and KII 72 5.3.1 FGDs (Focus Group Discussions) 73 5.3.2 Findings from Key Informant Interview (KII) 79 5.4 Road – Water Management Issues and Solutions 80 5.4.1 Discussion on Polder 26 81 5.4.2 Discussion on Polder 43/2F 89

Chapter 6: DESIGN OF WATER CROSSING STRUCTURES 98-108 6.1 Introduction 98 6.2 Data Collection and Processing 98 6.2.1 Rainfall intensity 99 6.2.2 Catchment area 100 6.2.3 Runoff coefficient (C) 100 6.2.4 Culvert dimension calculation 101 6.3 Sample Calculation 102 6.4 Recommended Design Dimensions of Culverts 104 6.5 Financial Benefits of Recommended Culvert Implementations 105

Chapter 7: CONCLUSION 109-111 7.1 Conclusion 109 7.2 Recommendations 110

REFERENCES 112-117

ANNEX A Questionnaire (Physical Inventory) 118-126 ANNEX B Questionnaire (House Hold Semi-Structured Interview) 127-134 ANNEX C Questionnaire (Focus Group Discussions – UP/WMGs) 135-136 ANNEX D Questionnaire (Key Informant Interview- BWDB/BG) 137-138 ANNEX E Questionnaire (Key Informant Interview- LGED) 139-140

x LIST OF TABLES

Table No. TITLE Page No.

Table 2.1 National Road Classification (LGED, 2005) 15 Table 2.2 Bridge Carriageway Widths (LGED, 2005) 23 Table 2.3 RCC Box Culvert Carriageway Widths (LGED, 2005) 23 Table 2.4 Typical gaps by type of road, meters per kilometer (LGED, 23 2005) Table 2.5 Frequency factors to convert rainfall 26 Table 4.1 Water quality parameters of different water bodies in the 43 polder 26 Table 4.2 Water quality parameters of different water bodies in the 47 polder 43/2F Table 5.1 FGDs details for Polder 26, Dumuria, Khulna 73 Table 5.2 FGDs details for Polder 43/2F, Guilshakhali, Barguna 73 Table 5.3 Details of Key Informant Interviews (KIIs) 79 Table 6.1 Rainfall Intensity for different Duration and Return Period 99 Table 6.2 Runoff Coefficients for Rational Formula (From Michigan 100 State Administrative Rules R 280.9) Table 6.3 Recommended Design Dimensions of Culverts for Polder 26 104 Table 6.4 Land Use of Polder 26 105 Table 6.5 Benefits of Culvert Implementation 108

xi LIST OF FIGURES

Figure No. TITLE Page No.

Figure 2.1 Polders in Bangladesh 7 Figure 3.1 Location of two selected Polders 35 Figure 4.1 Topographic map of Polder 26 41 Figure 4.2 Topographic map of Polder 43/2F 45 Figure 5.1 Issues causing the drainage congestion (in %) in Polder 26 51 Figure 5.2 Impacts on property during flood 54 Figure 5.3 Present state of all the internal water crossing structures in 58 Polder 26 Figure 5.4 Present state of all the drainage slices with water flow direction 60 in Polder 26 Figure 5.5 Main issues related to water (in %) in Polder 43/2F 62 Figure 5.6 Causes of river flooding (in %) in Polder 43/2F 63 Figure 5.7 Irrigation water sources (in %) in Polder 43/2F 64 Figure 5.8 Present state of internal water crossing structures in Polder 70 43/2F Figure 5.9 Present state of Drainage Sluices in Polder 43/2F 71 Figure 5.10 Present state of inlet/outlet structures in Polder 43/2F 72 Figure 6.1 IDF curve for 20 years (1995-2014) rainfall in Polder 26 99 Figure 6.2 Catchment area calculation in Google Earth Pro 100 Figure 6.3 FHWA Design chart for culvert design 101 Figure 6.4 Location of culverts for Hydraulic design analysis 102 Figure 6.5 Land Use Map of Polder 26 106 Figure 6.6 Inundation Map of Polder 26 107

xii LIST OF PHOTOS

Photo No. TITLE Page No.

Photo 2.1 Waterlogged area in coastal zone of Bangladesh 12 Photo 2.2 A Water-crossing Structure in Polder 32 19 Photo 2.3 A Box Culvert in Polder 43/2F 22 Photo 2.4 Damage of roads due to inadequate drainage in Barisal, 28 Bangladesh Photo 2.5 An unplanned internal polder road causing waterlogging 29 Photo 2.6 A water crossing in a polder 29 Photo 2.7 A road side canal in Polder 26 in Bangladesh 31 Photo 2.8 A borrow pit in Ethiopia 32 Photo 2.9 Village road turfing by local grass in Polder 32 33 Photo 5.1 An inadequate culvert in Polder 26 50 Photo 5.2 Bad road condition in Polder 26 52 Photo 5.3 The Union road disrupting drainage of the Polder 55 Photo 5.4 A newly shaped embankment section of Polder 26 56 Photo 5.5 A location where a culvert is needed to connect khals 57 Photo 5.6 A totally damaged sluice in Polder 26 59 Photo 5.7 Bad road condition in Polder 43/2F 65 Photo 5.8 Broken part of embankment in Polder 43/2F 66 Photo 5.9 Muddy earthen roads in Polder 43/2F 67 Photo 5.10 Breaching of embankment near water structures is a common 68 problem in Polder 43/2F Photo 5.11 A blocked culvert in Polder 43/2F 69 Photo 5.12 FGD-1 in presence of local UP members (a) and FGD-2 in 75 presence of the representatives of local WMG (b) Photo 5.13 FGD-1 with the representatives of WMA and WMGs in polder 78 43/2F (a) and FGD-2 with local UP members (b) Photo 5.14 Waterlogged household in a polder area 81 Photo 5.15 Inadequate culvert on Kata Khal 82 Photo 5.16 Village road disrupting canal connectivity 83 Photo 5.17 A LGED road without water crossing structure 84 Photo 5.18 A silted canal in Polder 26 85 Photo 5.19 A model Gated Culvert 86 Photo 5.20 A muddy earthen road after rain 87 Photo 5.21 A broken road in Polder 26 88 Photo 5.22 Only gated culvert in Polder 43/2F 90 Photo 5.23 A defective sluice which can’t control water properly 91 Photo 5.24 A silted canal in Polder 43/2F 92 Photo 5.25 Road collapse near inlet structure 94 Photo 5.26 People using embankment as permanent shelter in Polder 32 95 Photo 5.27 LGED cut down embankment road to achieve their design top 96 width

xiii LIST OF ABBREVIATIONS

AEZ Agro-Ecological Zones BG Blue Gold BMD Bangladesh Meteorological Department BWDB Bangladesh Water Development Board CBOs Community Based Organizations CBR California bearing ratio DEM Digital Elevation Model EIA Environmental Impact Assessment EPWAPDA East Pakistan Water and Power Development Authority FCD Flood Control and Drainage FGDs Focus Group Discussions FHWA Federal Highway Administration GIS Geographic Information System GPS Global Positioning System IDF Intensity-Duration-Frequency IPSWAM Integrated Planning for Sustainable Water Management KIIs Key Informant Interviews LGED Local Government Engineering Department LGIs Local Government Institutes LLP Low Lift Pumps MDG Millennium Development Goal NCA Net Cultivable Area PIO Project Implementation Officer PSB Portable Steel Bridges SSWRDP Small Scale Water Resources Development Project UP Union Parisad WMA Water Management Association WMF Water Management Federation WMGs Water Management Groups WMO Water Management Organization RHD Roads and Highways Department

xiv Chapter 1

INTRODUCTION

1.1 Background

Roads are generally perceived as infrastructure to deliver transport services, but they are more than that. Roads have a major imprint on hydrology. They are a major human endeavor with a large impact on water management. Roads block water, guide water, concentrate the run‐off in limited drainage canals and affect sub‐surface streams. The impacts of roads on landscapes and surface hydrology are often negative. Roads cause erosion, trigger sedimentation and cause local flooding. Road bodies are a main reason for drainage congestion and water logging. There is a strong connection between roads and water management and flood protection in polders of coastal Bangladesh. Within the polders, rural transport structures such as roads, bridges and culverts strongly influence water flow and distribution (Borgia, 2017). This road-water interaction issue is getting more and more important in Bangladesh. Data from two coastal polders in Bangladesh show that 60% of farmers are affected by impeded drainage due to roads (Steenbergen, 2017) and this percentage is increasing with time.

Polderisation started in Bangladesh in the sixties to protect the coastal zone from recurrent natural disaster like floods, cyclone and storm surges, salinity intrusion and sedimentation. This was a major landscape change that allowed the cultivation of wet season paddy, while protecting houses and property from the forces of nature (Steenbergen, 2015 and Rahman, 2015). So, people started to come and live in the flood protected polder areas. In 2008, the polders supported a total population of 8 million people living on 1.2 million hectares of land (BBS, 2010). The immediate socio-economic consequences of polders were very impressive and positive. This positive situation persisted for about two decades or so, but by the early 80s the secondary effects of polderisation in terms of sediment deposition began to be serious. Before establishing the embankment, boat was only the single mode of communication in the region. After polderisation, for the growing population, Local Government Institutes (LGIs)/the locals started to construct small earthen roads/pathways. Later Local Government Engineering Department (LGED) improved those earthen roads to asphalt or brick covered road. But both LGIs and LGED didn’t consider drainage system properly while constructing those roads (Onneshan, 2006). Additionally, maximum culverts didn’t construct with necessary height for water discharge. Moreover, foundation of bridges also escalates siltation. Therefore, problem arises for discharging the water from those regions. The slope of land in those regions is north- south oriented but maximum embankments are developed to east-west face. So rivers and channels lost their natural flow and create water logging at that region (Sarker, 2012). Besides, due to lack of repair and maintenance most of the water control structures got damaged, most of

1 the internal canals and surrounding rivers got silted. This changed the drainage pattern of most of the canals within the polder area and created waterlogging.

Further, roads also suffer from water-related damages. At present, water-related damage constitutes a major cost factor in road maintenance. For instance, 35 per cent of all road damage is caused by water all over the world (World Bank, 2006). Inadequate drainage not only leads to land degradation, but also jeopardizes road embankments, increases maintenance costs, and reduces road durability. There is a great potential to enhance road drainage with the focus on water storage, groundwater recharge, and retention. Optimized road designs are required better planning of alignments, making use of road drainage, road surfaces, and river crossings, but also capturing freshly opened springs and systematically including developing storage and enhanced recharge facilities in road-building programmes.

Therefore, both roads and polder water management are closely related to each other. Road design and design of drainage control structures must optimize the use of roads for local water management. A proper road design considering proper drainage system can help water management and can also reduce road maintenance cost. And to do so, it is important to find out the existing road and drainage condition of the polder as well as their impacts on firming, fishing and other daily activities.

In Bangladesh research works so far undertaken this direction was limited in scope and applicability. Most of the research works were done to prepare EIA report for different projects. Evidently there is a scope for undertaking such a study to develop a proper road and canal network for the polders by providing sufficient and adequate water crossing structures. The present study has been undertaken precisely with this objectives and its outcome was expected to have a lasting impact on future polder water management all over the coastal region of Bangladesh.

1.2 Objective of the Study

Internal roads, bridges, and culverts within the polders influence the water flow, the water distribution, and the water levels both in waterways (khals), around settlements, and on farmland. The network of different types of internal roads, including village feeder roads and pathways, interrupts the connectivity of the natural drainage system consisting of khals and divides the polder into disconnected compartments. Roads (both internal and embankment roads) have a great role to play in contributing to effective water management and reducing water logging. The main objective of this study is to optimizing the role of roads and drainage structures in polder water management. The specific objectives include:

- Prepare an inventory of in-polder road crossings and embankment roads in the study areas - Comprehensive assessment of road-water management interactions, problems and their impacts on farming activities, yields, and rural livelihoods - Make an assessment of the design adequacy of the existing drainage control structures within the polder area - Provide measures and options on a priority basis to improve the water logging problems in the study areas.

1.3 Scope of the Study

The following tasks will be carried out to achieve the objectives stated above: i) A physical survey of all the embankment roads, internal roads, water crossing Structures, water control structures and drainage system of each of the selected polder.

ii) Some Semi-structured Household Survey about water-roads problems, impacts of water management on farming, use of roads and mobility, flood protection, impacts of water management on property etc. in the selected polder areas.

iii) Several Focus Group Discussions with local representatives (UP, WMA, WMGs etc.) to find out road- water related problems within the polders and possible solution of those problems.

iv) Several Key Informant Interviews with key officials from related departments (LGED, BWDB, PIO etc.) to collect technical information and also to find out road- water related problems within the polders and possible solution of those problems.

v) Prepare a simple hydraulic model (Rational Formula) by using catchment area and rainfall data to find out proper dimension of all the internal water crossing structures.

vi) Develop a catalogue of issues and solutions related to road - water interactions and at the same time discuss about the feasibility and opportunities of different solutions.

1.4 Organization of the Thesis

This thesis presents the analysis, results and findings of the present research in 8 chapters and 5 appendices as shown below.

Chapter 1 presents a brief introduction of the study along with its objectives, justification and scopes.

Chapter 2 compiles all relevant literature and makes references to previous studies in related areas.

Chapter 3 provides a description of the methods adopted in this study.

Chapter 4 presents the baseline information of the two selected study sites.

Chapter 5 summarizes all the survey (Both Physical and Household) findings conducted within the polder areas.

Chapter 6 contains findings of FGDs and KIIs conducted within the polder areas.

Chapter 7 presents hydraulic design analysis of water crossing structures.

Chapter 8 summarizes a catalogue of issues and solutions related to road - water interactions with the feasibility and opportunities of different solutions. Additionally presents the conclusion of the study.

ANNEX A presents Questionnaire for Physical Inventory.

ANNEX B presents Questionnaire for House Hold Semi-Structured Interview.

ANNEX C presents Questionnaire for Focus Group Discussions – UP/WMGs.

ANNEX D presents Questionnaire for Key Informant Interview- BWDB/BG.

ANNEX E presents Questionnaire for Key Informant Interview- LGED.

Chapter 2

REVIEW OF LITERATURE

2.1 Introduction

The chapter focuses on the relevant information, literature regarding Polders in Bangladesh, its water management and the role of roads in water management. The chapter has been presented in five thematic areas to understand the whole matters in a sequential manner. At first, the background information of polders in Bangladesh was described. Then the current polder water management system and issues related to polder water management is discussed. Thirdly, LGED (Local Government Engineering Department) road design standards are thoroughly reviewed. After that the design standards of culverts and other water crossing structures are discussed. And at the end, the importance and opportunities of internal roads in polder water management is described.

2.2 Polder

A Polder can be defined as, a tract of low land reclaimed from the sea, or other body of water, by dykes, embankments etc. Polders can be found all over the world, where waterlogged lands or even lakes and estuaries have been reclaimed, mainly for agricultural purposes. In the polder, the runoff is controlled by sluicing or pumping and the water table is independent of the water table in the adjacent areas (International Commission on Irrigation and Drainage, 1996). Several definitions of polder exist. The most widely used ones are:

A polder is a level area, in its original state subject to high water levels (permanently or seasonally, originating from either ground water or surface water), but which through impoldering is separated from its surrounding hydrological regime in such a way that a certain level of independent control of its water table can be realized (Segeren, 1983).

A polder is a reclaimed level area, with an originally high groundwater table, that has been isolated from the surrounding hydrological regime and where the water levels (surface and ground water) can be controlled (Volker, 1982). There are three types of polder:

 Land reclaimed from a body of water, such as a lake or the sea bed  Flood plains separated from the sea or river by a dike/ embankment. Polders in Bangladesh fall in this category.

 Marshes separated from the surrounding water by a dike/ embankment and subsequently drained. The ground level in drained marshes subsides over time. All polders will eventually be below the surrounding water level some or all of the time. Water enters the low-lying polder through infiltration and water pressure of ground water, or rainfall, or transport of water by rivers and canals through regulating water control structures. This usually means that the polder has an excess of water, which is pumped out or drained by opening sluices at low tide. Care must be taken not to set the internal water level too low. Polders are at risk from flooding at all times, and care must be taken to protect the surrounding embankments. Embankments are typically built with locally available materials, and each material has its own risks: sand is prone to collapse owing to saturation by water; dry peat is lighter than water and potentially unable to retain water in very dry seasons. Some animals dig tunnels in the barrier, allowing water to infiltrate the structure; the muskrat is known for this activity and hunted in certain European countries because of it. Polders are most commonly, though not exclusively, found in river deltas, former fenlands and coastal areas.

2.3 Polders in Bangladesh

Bangladesh is an overpopulated country with limited resources. The present population is 166.37 million, having an area of 147,570 km2. The current population density is 1,115 people per km2 (World Population Review, 2018). The country is a delta formed by the alluvial deposits of three mighty rivers: the Ganges, the Brahmaputra and the Meghna. It has a complex river network of about 230 rivers occupying about 6% of the area (Ali, 2002). An important feature of the rivers is that 57 are cross boundary, coming from India and Myanmar. These river systems drain a catchment of about 1.72 million km2, out of which only 7% is located in Bangladesh (Ali, 2002).

For centuries, Bangladesh has suffered from the twin problem of ‘floods and droughts’. In the early 1950s, large-scale land and water development schemes began. A team of United Nations (UN) experts proposed the Ganges-Kobadak Project, lying in the greater districts of Khulna, Kushtia and Jessore after several years of studies. The country suffered from unprecedented floods in two consecutive years 1954 and 1955. As a result, a flood commission was constituted in December 1955 by the Government to look into the problems and to advice on remedial measures (East Pakistan Water and Power Development Authority, 1964). Besides, a team of experts on water resources management, known as the Krug Mission was formed in 1956 by UN. This Mission submitted the ‘Krug Mission report’ in 1957 after a detailed review of problems associated with the floodings (United Nations, 1957). In 1959, Based on the recommendations of the Krug Mission, the East Pakistan Water and Power Development Authority (EPWAPDA) was created for the unified and coordinated development of the water and power resources in the present Bangladesh.

Figure 2.1: Polders in Bangladesh

In 1964, EPWAPDA prepared a Master Plan for water resources development with the help of the International Engineering Company Inc. (IECO) (EPWAPDA, 1964). This was the beginning of the formulation of an integrated plan for flood control and water resources development of the country. The Master Plan organized the limited available hydrological data and recommended emphasis on systematic and scientific hydrological data collection and processing. The Master Plan included a portfolio of 58 land and water development projects including 3 barrages on

7 major rivers for implementation spread over 20 years, beginning in 1965 (Ali, 2002). Target area for these projects was for 5.8 million ha of land for flood protection. Three alternative options were proposed:

- Flood embankments with pump drainage

- Flood embankments with gravity drainage

- Flood embankments with tidal sluice drainage

Polderisation started in Bangladesh in the sixties to designate the reclaimed bodies of land in the coastal regions as shown in Figure 2.1. Its primary purpose was to increase agricultural productivity and reduce flood damages by constructing drainage sluices and embankments. The Coastal Embankment Project was conceived and initiated by the then East Pakistan Water and Power Development Authority in the early sixties. In 1967, it was proposed that the Coastal Embankment Project be divided into two phases and the first phase be expedited as part of the Grow More Food programme. And the first phase was approved in 1968 which consisted of 92 polders with about 4,022 km of embankments and 780 drainage sluices (Talukder, 1991). The gross polder area under phase-I was estimated to be 1.01 million ha and it was completed in June 1971 (Talukder, 1991). Since 1960 to early 1970 and to date, Bangladesh Water Development Board (BWDB) constructed 139 polders in the coastal region (BWDB, 2017).

Embankments were constructed at locations facing the Bay of Bengal, along the banks of the major or wide rivers, and at other places where high waves could be expected. Interior dikes were provided at more protected locations along major streams or along exposed sections of secondary streams or interior channels. Marginal dikes are located along interior channels where current and wave action is mild. For the construction of embankments, the return period for the design water level was about 20 years (Ali, 2002). Polders under phase-II included three categories of land areas, such as:

- Relatively non-saline areas;

- Off-shore islands which were vulnerable to erosion and sediment deposition;

- Partially reclaimed and unreclaimed areas of new land resulting from the construction of the Meghna Cross-Dam.

The emphasis on large scale works for high level flood control was dropped following the World Bank’s Land and Resources Sector Study in 1972. Instead, the development of minor irrigation through low lift pumps (LLP) and tube wells, to some extent supported by complementary low cost FCD (Flood Control and Drainage) schemes, was advocated. In 1974 Bangladesh experienced a devastating flood. And the government realized the need for quick implementable flood control and drainage improvement projects (Ali, 2002). The FCD Schemes were developed

8 in the lowlands of Bangladesh. The floodplain areas are diverse sub-systems of the main rivers that enable the temporary storage of excess water during floods. Before any intervention, flood control and drainage practices existed on the unprotected floodplains (Bangladesh Water Development Board, 1998) and people used to take initiatives to control water through the construction of small cross dams, embankments and drainage canals.

Initially Government took action to controlling floods from the river or from the sea to increase crop security in the floodplains. And it started with the construction of embankments (Bangladesh Water Development Board, 1998). Embankments solve the problem of flooding, but create other problems like obstructing the drainage of rainwater within the protected area. The engineering solution to this problem is the construction of sluices (in the main channel only) in the embankment equipped with flap gates on the riverside (Bangladesh Water Development Board, 1998). However, the area is definitely not flood free, because the first round of interventions also creates new problems like waterlogging problems during the post wet season. Prior to the construction of an embankment, the area would drain off almost as fast as river water levels fell, as water could drain from the area along the whole periphery. After completion of the flood control intervention, drainage was confined to the main arteries equipped with sluices, as smaller khals were often closed (Ali, 2002). The number of inhabitant started increasing in those flood protected areas and to facilitate communication and commerce, UP/LGED started constructing internal polder road. Most of those roads were constructed through khals but UP/LGED didn’t constructed structures (Culverts/ Brides) on each of those water crossings or constructed inadequate structures due to lack of funding. This created a massive waterlogging problem in most of the project areas. Moreover, in many locations water got trapped in local pocket areas behind the embankments. To evacuate the water trapped in low pockets, people have often cut the embankments (Bangladesh Water Development Board, 1998). In this phase, surface drainage outlets were constructed to evacuate accumulated water from low pockets behind the embankments. Often some re-excavation work to improve the conveyance capacity of the drainage channels (khals) was carried out (Bangladesh Water Development Board, 1998). This, however, was not the end of the development of the FCD schemes. As a result of the improved control over water, farmers saw new possibilities of high yielding varieties and changed cropping patterns and intensities. This lead to higher demands for water during the dry season. To meet this increasing demand for water, means were devised to retain water within the scheme at the end of the rainy season. During this phase, FCD schemes were remodeled to enable retention of water. The sluices, until then equipped only with flap gates, were modified by adding vertical lift gates on the countryside of the sluices. As water needed to be stored in the scheme for future use khals were deepened and widened to increase the storage capacity. With the possibility to retain water in the scheme, the need for devices to lift the water from the channels onto the land developed. Many traditional lifting devises were used, but this was also the moment when the low lift pumps (LLP) made their entry (Bangladesh Water Development Board, 1998). But most of these schemes didn’t cover all the polders. In addition BWDB didn’t

9 conduct regular maintenance of its water control structures, khals and rivers. As a result waterlogging is still a big issue in the polders especially in Khulna region.

2.4 Polder Water Management

Bangladesh is a country of limited resources. The country is basically a delta formed by the alluvial deposits of three mighty rivers: the Ganges, the Brahmaputra and the Meghna, it has a complex river network of about 230 rivers occupying about 6% of the country area (Hoque, 1997). These river systems drain a catchment of about 1.72 million km2, out of which only 7% is located in Bangladesh. Rests 93% of the catchment situated in China, India, Nepal, Bhutan and Myanmar (Ali, 2002). Bangladesh has been suffering from the twin problem of ‘floods and droughts’ for centuries.

Initially the Zamindars constructed low dikes and wooden box sluices and maintained them for protection against saline water intrusion and floods. Unofficially the Zamindars have continued this maintenance job even though they were relieved from that duty when the British ruler abolished the Zamindary system. In absence of Zamindar’s initiative, the local farmers often started to make bunds themselves, which were technically poor and insufficient. After taking over the works by the Government more attention was given to the construction of polders. Lack of technical knowledge and financial constraints hampered the polderisation. Polder construction has increased the scale of production and introduced hopes for further development.

Large-scale land and water development schemes began in the early 1950s. At that time, huge investments have been made in flood protection, drainage and irrigation systems to reclaim and develop many polder areas. In these areas a holistic water management system is required to get optimal results from the investments in the physical infrastructure and enable the farmers to have a reasonable living. Finally, in 1959 East Pakistan Water and Power Development Authority (Now BWDB) were created for the unified and co-ordinated development of the water and power resources in the present Bangladesh. This authority, with the help of the International Engineering Company Inc. (IECO), prepared a Master Plan for water resources development in 1964. This plan marked the beginning towards the formulation of an integrated plan for flood control and development (FCD) of the water resources of the country. In the Master Plan the limited available hydrological data were presented and recommended actions were emphasizing on systematic and scientific hydrological data collection and processing. However, in many instances the actual water management in the FCD schemes has been below expectation, resulting in lower yields than were envisaged during the feasibility, design and construction stages. And that happen due to a variety of shortcomings. These include inadequate design, use of inappropriate technology, system layouts that do not adequately reflect existing conditions, inappropriate governance arrangements and poor management practices (Hofwegen and Svendsen, 2000). Injudicious planning of roads, canals and other infrastructure

10 blocking the natural drainage also cause many of the drainage problems, especially in low lying areas. There is considerable scope for preventing and alleviating drainage problems by more integrated planning and water management (Jansen, 1997 and Japanese Committee of the International Commission on Irrigation and Drainage, 2000).

The drainage condition plays an important role in defining agricultural and water management practices available to the farmers. The excess rains in wet season are normally drained through the hydraulic structures of the FCD schemes. Lowering of the water level by drainage should be realized in such a way that fish culture and environmental issues are also properly taken into account. The drainage criteria of the FCD schemes should be developed on the basis of the inundation depth that may occur during heavy rains in the wet season. A water depth greater than 0.3 m for three days or more is not suitable for cultivation of any Rice crops (Rice knowledge Bank, 2018). So lowering of the water level by operating the hydraulic structures must depend on achieving the 0.3 m depth within three days.

An effective and sustainable water management scheme requires an institutional framework, which can ensure the democratic representation of the various water users and their interests. The set-up of the framework should be such that it can accommodate various interests of the different users. Efforts should be made to create opportunities for various users to participate in different stages of the scheme cycle.

2.4.1 Waterlogging problem in polders

An area may be regarded as waterlogged in this study when the water level above the ground is too high that does not permit an anticipated activity, like agriculture. For example, a water depth greater than 0.3 m for three days or more is not suitable for any Rice crop. It occurs when the rate of accumulation of water through rainfall or some other means exceeds the combined rates of drainage, percolation and evapotranspiration of a catchment or when flood water submerges an area (Mancuso, 2010). Water logging may differ from flood situation in such a way that the flow of water is almost nil in former case as the water body is arrested by a boundary (like polder). An area may be affected by both water logging and flood concurrently; however, the later may not persist to a long time.

Photo 2.1: Waterlogged area in coastal zone of Bangladesh

Waterlogging is an acute problem in the southwestern region of Bangladesh (Photo 2.1), especially Jessore, Khulna and Satkhira districts, causing severe damage to people’s livelihoods and often creating social unrest (Rahman, 1995; Lázár et al., 2015; Bernier et al., 2016). Construction of polders in the 1960s and 1970s restricted water flow into the settlement areas and consequently restricted sedimentation to polders, which have no connection with outside water sources other than through manually operated devices. The special nature of soil in the coastal areas is causing subsidence at the rate of 6 mm/year (Brammer, 2013). In addition, the level of sedimentation in riverbeds outside the polders is increasing the gap between the levels of ground surface in and outside the polders. The difference in elevation of land surfaces is the main reason for differential water level, which is ultimately causing waterlogging. Besides, construction of internal polder roads without giving sufficient water crossing structures also creating severe waterlogging problems in the polder areas.

2.4.2 Prevention and mitigation of waterlogging

Waterlogging is one of the biggest problems in the polder areas of Bangladesh, but the way of its prevention and mitigations to date have received little attention. The problem is very much site specific, nevertheless some methods for preventing and mitigating the drainage congestion due to water logging can be mentioned from the literature like establishment of shallow interceptor drains (Hatton,2002), discharging the congested water by installation of drainage pump (Chandio, 2012), minimizing the accumulation of congested water through rain water

12 harvest (Li, 2012), downing water table by groundwater recharge (Singh, 2012), lowering groundwater levels through deep tube wells (Qureshi, 2008), subsurface drainage systems that consisting of open and pipe drains (Ritzema, 2008), dry drainage that involves the allocation of areas of fallow land, which operate as evaporative sinks drawing a stable flux of water (and salt) from irrigated areas (Konukcu, 2006), plantation or stands of halophytes (salt-loving plants) those can transpire sufficient water to lower water tables, thereby ameliorating water logging and presumably inundation (Barrett-Lennard, 2002). Interestingly, in some European countries windmills are also used to pump water into the embanked river to prevent water logging of the lowlands (polders) behind them. In some cases, drainage with or without raised beds are the best way to overcome water logging and inundation in most areas.

Another approach performed by BWDB is Tidal River Management (TRM). Its principal is to flush away the silt from reservoirs to keep them functioning, to improve the natural flow of river water, to increase flood protection capacity, formation of new alluvial land in tidal wetland through silt deposition, mitigate climate change induced sea level rise. At last it can be called as sustainable solution to water logging and drainage congestion. TRM prevents silt deposition on the riverbed and ensures the drainage and smooth navigation in river channels.

Due to special geographical location and climate, the water logging is one of the most serious hazards now-a-days in southwest coastal region of Bangladesh. The zone is too fragile under storm surge due to tropical cyclone, sea-level rising, tidal excursion and back water effect, thus intrusion of saline water from the Bay of Bengal is common. Therefore, exploring the best adaptation practices is time demanded with the prevention and mitigation of water logging in the region.

2.4.3 Governance and water management structures in polders

The responsibility of water management in polders lies with BWDB. BWDB has adopted integrated participatory approaches in governance and management of water within the polders. However, Local Government Engineering Department (LGED) managed Small Scale Water Resources Development Project (SSWRDP) polder having water management organization (WMO). The categorization is based on the size of the polder; i.e. Polders having area ≤ 1000 ha are under LGED and polders having area > 1000 ha are under BWDB.

2.4.3.1 Community Participation through WMO/ CBO

In some polders, BWDB has active Water Management Organization (WMO) and Community Based Organizations (CBOs) to ensure sustainable operation of the projects. Therefore, a three tier organizational structure comprising of Water Management Groups (WMGs) at the lowest level, Water Management Associations (WMAs) at the mid-tier and Water Management Federation (WMF) at the apex are in place. These groups, associations and federations in a

13 particular sub-project are together termed as the Water Management Organizations (WMOs) which has been considered in the polder projects.

2.4.3.2 Water Management Committee (WMC)

For operation of water control structures i.e. flushing inlets, drainage outlets and drainage sluices a separate group would be acting locally, termed as WMCs formed by BWDB. The responsibilities of maintaining water control structures at their best condition are down to the WMCs. Each WMC would comprise of 5 to 11 members, depending on the significance of the intervention.

2.5 Roads

A road is a thoroughfare, route, or way on land between two places that has been paved or otherwise improved to allow travel by foot or some form of conveyance, including a motor vehicle, cart or bicycle. Roads consist of one or two roadways, each with one or more lanes and any associated sidewalks and road verges. Roads available for use by the public may be referred to as parkways, avenues, freeways, interstates, highways, or primary, secondary, and tertiary local roads. Bangladesh has characteristics of high population density, high productivity of land, intensive cultivation, small-scale farming and marketing of its production and diversified non-farm activities. All these together generate intensive trading of goods and services in the rural areas and a high level of demand for movement of goods and people, which results the level of traffic in the rural areas of Bangladesh comparatively high.

The Roads and Highways Department (RHD) and the Local Government Engineering Department (LGED) share responsibilities for the entire road network of the country. While the former is to manage the National, Regional and Zila Road, the latter is to focus on the Upazila Road, Union Road and Village Road.

Establishing road communication network in the rural areas has become the dire necessity of the time with the ardent objective of stimulating trade and commerce in the rural areas- an inalienable area of the national economy. This paramount responsibility has been bestowed upon LGED, which is one of the largest and well-structured organizations in Bangladesh. As a matter of fact, all implementation responsibilities related to rural infrastructure development are vested with the functionaries of LGED at the Upazila and the District levels.

2.5.1 National road classification

Higher Road System and Rural Road are two broad classifications for which agencies responsible are RHD and LGED/LGI respectively. National Road Classification is shown in Table 2.1. LGED and LGI both belong to the Local Government Division under the Ministry of Local Government, Rural Development and Cooperatives (LGRDC). LGED's one of the mandates is to provide technical support to the LGIs. LGED takes the responsibility to construct/re- construct, rehabilitate and maintain roads in conjunction with LGIs under the purview of Local Government Division.

Table 2.1: National Road Classification (LGED, 2005)

Sl. Road Class Definition Design Ownership No Type and . Responsibility 01. National Highways connecting National - RHD* Highways Capital with Divisional HQ/s or seaports or land ports or Asian Highways. 02. Regional Highways connecting District - RHD Highways HQ/s or main river or land ports or with each other not connected by National Highways. 03. Zila Road Roads connecting District - RHD HQ/s with Upazila HQ/s or connecting one Upazila HQ to another Upazila HQ by a single main connection with National/Regional Highway, through shortest distance/route. 04. Upazila Road Roads connecting Upazila HQ/s 4,5,6 LGED*/LGI with Growth Center/s with * another Growth Center by a single main connection or connecting Growth Center to Higher Road System**, through shortest distance / route. 05. Union Road Roads connecting Union HQ/s 7,8 LGED*/LGI with Upazila HQ/s, Growth * Centers or Local Markets or

with each other.

06. Village Road a) Roads connecting - LGED*/LGI Villages with Union * HQ/s, local markets, farms and ghats or with each other. b) Roads within a Village.

*RHD-Roads and Highways Department, LGED - Local Government Engineering Department, LGI - Local Government Institutions. ** Higher Road System - National Highway, Regional Highway and Zila Road.

Rural road comprises of Upazila roads, Union roads and Village roads in the rural areas of Bangladesh.

2.5.2 Role of LGED in road network development

Local Government Engineering Department is the prime engineering organization in pursuing rural development programme. LGED’s main functions are planning and implementation of infrastructure development projects mostly in rural areas to improve transport network, in order to facilitate employment generation, poverty reduction, and to provide technical support to the Local Government Institutions. Additionally, LGED also responsible for construction and maintenance of water crossing structures on all of the rural roads under LGED.

Reflecting strong initiatives of Government for pursuing rural prosperity, the total volume of investment program on rural infrastructure has been continuously increasing. In addition, the better and reliable quality of development rural infrastructures is requested to meet the social demand for efficient use of public investment, LGED has been playing a key role in this respect with high performance and flexibility on each project component.

2.5.3 Role of LGIs in road network development

Local Government Engineering Department is the prime responsible department for rural road development. But sometimes Union Parisad/ Upazilla Parisad which are part of LGIs conduct some road construction/ development works in the polder area. Union Parisad/ Upazilla Parisad mostly construct new village roads which have a little economic value. The local LGIs don’t have any technical section for the design of road/ water crossing structures. They are instructed to follow LGED design guidelines for rural roads.

2.5.4 LGED road design standards

As described above, LGED is responsible for planning and implementation of infrastructure development projects mostly in rural areas. And LGED has a design manual (Road Design standards’ 05) for geometric design of roads and bridges and pavement design configuration defined in the National Road Design Standards, 04 which will serve as an ease handbook on road pavement.

The features of Road Design Standards’05 by LGED (LGED, 2005) are as follows:

 Pavement cross-sections of Upazila Roads (Type 4, 5 & 6) with projected traffic of 600, 300 and 200 commercial vehicles (axle load 8.2 ton) and Union Roads (Type 7 & 8) with projected traffic of 100 and 50 commercial vehicles (axle load 8.2 ton).

 Road Geometry of Upazila and Union Roads as per National Road Design Standard, 04.

 Road Pavement Design criteria of Upazila and Union Roads as per National Road Design Standard, 04.

 Bridge Geometry of Upazila and Union Roads as per National Road Design Standard, 04.

 Bridge Approach Planning of Upazila and Union Roads as per National Road Design Standard, 04.

 Shoulder treatment when roads passing through built-up or market areas.

 Road Junction, Road Intersection and Road Widening for Bus Stop and rural traffic stand.

 Pavement cross-sections for Upazila Roads and Union Roads along with shoulder and drainage facilities in Hilly ar eas.

 Relevant information on for Gradients and Super Elevation of roads and extra width of pavement required at horizontal curves.

 Protective measures to road embankment vulnerable to erosion from wave action of floodwater in Char and Haor areas.

2.5.4.1 Road Network

For an effecting road network, many factor and criteria should be considered. These are as follows:

 Traffic and transport need;

 Improvement of accessibility to the poorer sectors of society;

 Contribution to strategic economic growth targets

 Projects should provide links with the paved network;

 Roads should be implement able over a reasonable time period so as to bring benefits quickly (6 years maximum);

 Phased projects should provide staged benefits;

 Connections to the paved road network for growth centres and Union Parishads.

2.5.4.2 Road Widening

The criteria for road widening should be traffic. Road widening should not necessitate re- classification. Road Types 5 and 6 all have 7.3 m (24 feet) crest widths. Widening of Feeder Roads to Type 5 and widening of a Type 6 to a Type 5 do not involve any increase in the size of the embankment. All other widening requires embankment widening.

2.5.4.3 Road Strengthening

The CBR value of the sub-base/base of the existing pavement form the survey indicates the necessity of road strengthening. CBR value indicates where removal of the surfacing would be necessary and a new base layer with bituminous surfacing may be provided.

2.6 Water Crossing Structures

Road Construction unavoidably obstructs and interferes with the natural overland flow and flow through the natural channels e.g. rivers, nallas, canals, drains etc. Suitable water crossing under the road should, therefore, be provided across these channels with a view to pass the peak discharge through the channels without causing harmful afflux and disturbing the natural flow. Provision of adequate numbers of culverts of appropriate size is a prerequisite for a healthy road. Submergence and overtopping of road not only causes damage to the road and road structures, it results in disruption of traffic, creates waterlogging, damage crops and miseries to many of the poor people who take shelter on roads during floods in many parts of our country.

Photo 2.2: A Water-crossing Structure in a Polder Bridges or culverts are often used by local people and livestock to cross the busy roads or embankments (Figure 2.2). They also act as passage of fish and other aquatic species. Sediments and debris carried by the stream, especially during floods, must freely move downstream through these openings to avoid aggradations and other interrelated problems. For existing roads, it is not uncommon to find silted barrels of existing culverts and culverts having inadequate capacities causing overtopping of the road embankments.

2.6.1 Factors influencing effective drainage through culverts

Design of an efficient cross-drainage system is a prerequisite for a sustainable road project. Design and planning of water crossings (specially culverts) is very important for road design from the point of view of durability of the road (new or existing one) as well as for the drainage condition of the area. Planning of culverts generally covers selection of location, type, numbers and size of culverts.

2.6.1.1 Role of culvert location

To be most effective, location of culverts have to be very carefully decided after studying the terrain and collecting relevant information from toposheets and other sources. Field visit and consultation with local people and local authorities conversant with local topography and drainage problem of the area is extremely useful.

a) Location of culverts for new road projects

A drainage culvert should be placed in a natural depression or valley points. These locations are easily identifiable in hilly / rolling terrains but very difficult to be identified in plains. An easy method of identifying the depression / valley and direction of flow is contour study of the project road corridor and a site visit to study drainage pattern of the area. The ground level elevations along the toe of the road on upstream and downstream (L-Profile) should identify the natural dips and thus suitable culvert locations and direction of flow. It is mandatory to ensure a path for the runoff to reach the outfall point from culvert outlet either through existing channel or roadside ditches or by overland flow. Flow coming out of the culvert must not get accumulated at its outlet jeopardizing the safety of the road embankment. Downstream canalization, wherever feasible, may also be thought of to avoid such accumulation of water.

b) Location of culverts for road up gradation projects

For a road up-gradation project, the task of selecting culvert locations reduces to selection of locations for additional culverts only. Even if the conveying capacity of some of the existing culverts is not hydraulically adequate, replacement of such culverts by a bigger size culvert or a small bridge shall be made in the existing locations only. For additional culverts, the locations shall be based on the natural dips along the stretches of existing road vulnerable to overtopping. An inventory of existing culverts has to be prepared indicating chainage, type and size of culverts, invert levels at entry and exit of culverts, ground level and stream bed level, condition of culverts, ponding level, submergence of land, overtopping of road and extent of overtopping etc. Such detailed inventory of culverts is very helpful in preparing an adequacy statement and deciding which of the existing culverts require replacement by larger size culverts or small bridges and to decide whether additional culverts will be needed or not.

2.6.1.2 Types and size of culverts

Culverts may be of several types and geometry, namely, Pipe Culverts (circular and elliptic), Box culverts (square and rectangular), Slab and Arch culverts (with or without bottom slab) etc. Selection of type and geometry of culverts inter alias depends on the required width and area of opening, height and vertical clearance required, length of culvert and height of embankment decided from geometrics of road design. While it is easier to decide between a pipe culvert and box / slab culvert, selection between box and slab culvert is a matter of cost optimization.

a) Pipe culverts

For minor crossings, circular pipe culverts suffice hydraulically. However, a pipe culvert has more joints owing to smaller length of precast pipe units manufactured in the market. The more the carriageway width of the road, more will be the length of culvert and consequently more will be the number of joints. As such it has now become a common practice for the major concessionaires to avoid pipe culverts for new major projects like Ganga/Yamuna expressway. However, for many other new projects in India, pipes having minimum diameter of 1200 mm are being used. For mountainous regions, the culverts are generally provided at frequent interval. Pipe culverts are, therefore, very common in hilly stretches of roads. However, in stretches where the streamlets carry large size cobbles and boulders, there is a fair possibility of pipes getting damaged / choked. Pipe culverts are, therefore, avoided in such stretches and either slab type or box type culverts are preferred.

b) Box and slab culverts

For crossings where pipe culverts may not be feasible from hydraulic point of view, box or slab culverts are chosen for installation. From structural definition, a box culvert is a reinforced box structure with rigid joints whereas a slab culvert is one where a simply supported reinforced slab is placed over abutments (Photo 2.3). Generally, for medium height of embankments, both of the options viz., box culverts with road embankment supported on roof slab and slab culvert with roof slab directly supporting the wheel loads, are feasible. One of the options is chosen on the basis of LTEC (Least Total Expected Cost) method. For high embankments (for example near approach of bridges), however, box culverts are preferred to slab culverts from both structural and economic considerations.

Photo 2.3: A Box Culvert in Polder 43/2F

Box and slab culverts are suitable for mountainous reaches where the streamlets carry large sized cobbles and boulders. To avoid excessive scour in slab/Arch culverts, bed may be lined or unlined depending on flow velocity and type of bed materials. Lining of bed helps in preventing growth of weeds which drastically reduces the conveying capacity of culvert due to high resistance offered by such weeds and jungles.

2.6.2 LGED design standards for culverts and bridges

Culverts should normally be no longer than 6m spans. Bridges should be used if the gap exceeds 6m spans. Culverts and bridges shall be designed with H20S16 loading. Table 2.2 lists approved bridge widths. Table 2.3 lists recommended RCC Box Culvert carriageway widths. Guard Post shall be provided if carriageway width of Box Culvert is less than crest width of the road. Cut-off Wall of RCC Box Culvert shall be provided at upstream and downstream away from Box by at least two-third of Box height.

Portable Steel Bridges (PSB) may be proposed with narrower carriageways, as emergency measures. Brick Arch Culverts may be proposed on Union and Village Roads with 3.7m carriageway width, where length is <= 4.5m and height is limited to maximum of 4m. On higher roads wider Brick Arch Culverts with 5.5m and 7.3m width and a maximum of 4m heights could also be considered. This practice should be encouraged as steel reserve is gradually diminishing and if this alternative is found cost effective.

Table 2.2: Bridge Carriageway Widths (LGED, 2005)

Design Class Length less than 30m Length greater than Type (100') 30m (100') 8, 7 Union 3.7 (12') 5.5 (18') 6,5,4 Upazila 5.5 (18') 5.5 (18')

Table 2.3: RCC Box Culvert Carriageway Widths (LGED, 2005)

Design Type Class Standard Optional* Carriageway Carriageway width width 8, 7 Union 5.5 (18') Crest Width 3.7 (12') 6,5,4 Upazila 7.3 (24') Crest Width 5.5 (18')

*To be determined by the authority with justification

Table 2.4 lists typical gap requirements for cross drainage by type of road. All roads should be provided with appropriate gaps, irrespective of road building agency, according to the design type and geographical location. Table 2.4: Typical gaps by type of road, meters per kilometer (LGED, 2005)

New Class Road Design Type Geographical location Swampy Hilly Haor Plane * Upazila Type 6, 5, 4 10-15 7-15 10-15 6-10 & Union Types 8, 7

*To be determined case by case

2.6.3 Hydrological considerations for design of culverts

Main objective of hydrologic investigation is to determine the peak design flood discharge which the culvert is to carry across the road during flood season. The methodology of flood estimation for culverts is well explained in (RDSO, 1990; AASHTO, 1975), text books (Raghunath, 1985; Kings & Brater, 1976) and Design Manuals (AASHTO, 1975; WSDT, 1997). However, some of the important aspects are briefly mentioned underneath.

2.6.3.1 Estimation of design peak flood by rational formula

The hydrological design of a culvert is governed by the hydrological response of a catchment to the design rainfall over it. Various factors which affect the peak run-off from a drainage basin are  Physiographic parameters affecting runoff from catchments e.g. size, shape, slope, cover conditions, permeability, antecedent moisture condition etc.  Rainfall- its magnitude, intensity, duration and frequency (or return period)  Time of concentration i.e. the time of overland flow and flow through channel from the hydrologically most distant point in the catchment  Determination of storm duration to be considered depending upon concentration time  Movement of storm towards or away from the outfall point

Since the catchment area of culvert is small, peak flood for culvert is usually calculated by using rational formula:

Q = 0.0028CiA

Where,

A = the area of the watershed (drainage area) that drains to the point for which the peak runoff rate is needed (ha)

C = Runoff coefficient for drainage area A. A physical interpretation is the faction of rainfall landing on the drainage area that becomes storm water runoff. i = the intensity of the design storm for peak runoff calculation (mm/hr)

Q = the peak storm water runoff rate from the drainage area, A, due to the design storm of intensity, i. (m3 /s).

2.6.3.2 Determination of catchment area

For mountainous regions, delineation of catchment area may be done either with the help of available toposheets of 20m contour interval or with the help of Google Earth Images. 1:50,000/1:25,000 toposheets are registered in AutoCAD or ArcGIS platform and the ridges can be plotted on it. The Channel length and slope can also be estimated from the available map. Delineation of catchment can be done with more precision with the help of Google Earth images. Polygons can be drawn along the ridges for delineation of catchments with naked eyes with reasonable accuracy. Properties of these polygons can be ascertained either directly (for Google Pro) or by exporting these polygons into AutoCAD / ArcGIS platform. The fall (difference in height) of channel can be ascertained directly from Google Earth image at any desired point with 24 respect to the outfall point at culvert. For plain regions, toposheets having 20m contour interval may not be at all useful in delineating catchment or determination of fall of the channel. However, the artificial ridge lines like roads, canals etc can be easily traceable on the toposheet/ map and these ridges can be considered as catchment boundary for a particular culvert. For plain regions, most of the culverts are designed as balancing ones and do not span any distinct channel. As such, area of catchment applicable for any particular point is governed by the countryside length discharging towards the culvert and the distance between two consecutive cross ridges (natural or artificial) on either side of it. The countryside length may be taken as the distance between the proposed alignment and existing artificial ridges (roads, canals etc), if any, running parallel to it. The distance between the existing cross ridges (running perpendicular to the proposed alignment) can be measured from toposheets or the survey data of the road corridor. However, if the distance between two consecutive cross ridges is so large that it entails unreasonable size of the roadside ditches, the acceptable size of the roadside ditches shall limit the spacing of the culverts. In such cases, group of culverts at available dips may be required between two cross ridges.

In practice, delineation of catchment is really a problem in plain regions. Delineation of the catchments of rivers is comparatively easier from Toposheets / ArcGIS tools. An innovative method of estimating the catchment for a group of culverts may be as follows:

 Delineate the catchments of the major rivers / streams / streamlets to the extent feasible from ArcGIS or study of Toposheets.

 Measure the area entrapped between two consecutive outfall points of the adjoining streams, which is not a part of the catchments already delineated for the streams.

 Try to plot the artificial ridge lines, if any, running parallel to the proposed alignment within the entrapped area not included in the delineated catchments of the adjoining streams.

 The peak run-off from the area in between the catchments of identifiable streams, will have to be evacuated through the culvert openings to be proposed at natural dips between the two consecutive stream outfall points where bridges are recommended.

2.6.3.3 Rainfall analysis

The runoff from a catchment is heavily dependent on the design rainfall. As the catchment area of a culvert is considerably small, the spatial distribution of rainfall over a particular catchment area can be reasonably considered as uniform. However, the times of concentration for such catchments vary widely from as low as 5 minutes (roads on hill cuts) to a few hours (flat terrains). The design intensities of rainfall (corresponding to these varying durations), which are inversely proportional to the time of concentration and directly proportional to the peak discharge, require to be determined with reasonable accuracy.

Determination of Intensity-Duration-Frequency (IDF) curves requires continuous rainfall data for a reasonable length of time. Again, as a road traverses a long distance, different sets of curves may be required to be prepared for different stretches of the roads, depending on the likely variation of rainfall characteristics over varying stretches. In most of the cases, continuous records of rainfall for a reasonably long period are not readily available for carrying out frequency analysis by extreme value distribution method like Gumbel’s method, Log Pearson method etc. (Raghunath, 1985).

A recommended return period of 25 years for important roads like National and State highways (50 years for depressed sections) and 10 years for lower category roads (IRC:SP:42, 1994). The same may be adopted for the hydrologic design of culverts since culverts are an integral part of road drainage system. Different return periods for different purposes e.g.10 year peak where there is fish movement, 25 year peak for finding maximum head water elevation and 100 year peak to check overtopping of road surface (WSDT, 1997). Approximate values of rainfall frequency factors to convert rainfall of 10 year return period to higher return periods are as follows (Table 2.5):

Table 2.5: Frequency Factors to convert rainfall

Return Period (Years) Frequency Factor 10 1.0 25 1.10 50 1.20 100 1.25

2.7 Role of Roads in Water Management

Roads are generally perceived as infrastructure to deliver transport services, but they are more than that. They pose major interventions in the hydrology of areas where they are constructed – concentrating runoff and altering subsurface flows. At present, water-related damage constitutes a major cost factor in road maintenance. But a research from Ethiopia, argues to reverse this and turn water from a foe into a friend and integrate water harvesting with road development. Optimized road designs are required better planning of alignments, making use of road drainage, road surfaces, and river crossings, but also capturing freshly opened springs and systematically including developing storage and enhanced recharge facilities in road-building programmes. Equally important are inclusive planning processes that are sensitive to the multi-functionality of roads but also to the potentially uneven distribution of benefits and the diverse livelihood impacts. There is a need for closer integration of watershed and road-building programmes. With 5.5 million kilometers of roads in sub-Saharan Africa alone, and road building continuing to be one of the largest public investments, the potential of roads for water harvesting is great.

The basic idea of ‘roads for water’ is to make roads instruments of beneficial water management and resilience. Roads have a major imprint on hydrology. They are a major human endeavor with a large impact on water management. Roads block water, guide water, concentrate the run‐off in limited drainage canals and affect sub‐surface streams. (Ibisch, 2016) have described the fragmentation of landscapes (and as well as the drainage basins) that has come with road development. They further established that by now 20% of the global land surface is within one kilometer of a road. The remaining 80% is divided into approximately 600,000 patches - more than 50% of which are less than one 1 km2 and only 7% of which are larger than 100 km2. To manage surface and sub‐surface hydrology hence means increasingly managing roads (and to safe guards the remaining ‘road‐less’ areas) (Steenbergen, 2017).

The impact of roads on landscapes and surface hydrology is often negative. Roads cause erosion, trigger sedimentation and cause local flooding. Road bodies are a main reason for drainage congestion and water logging. They disturb wetland hydrology and interfere with fish movement in flood plains. Roads could also initiate landslides. Transect surveys along roads undertaken in upland Ethiopia and Uganda showed that in every 10 kilometer of roads there are between 8 to 25 problem spots. Data from two coastal polders in Bangladesh show that 60% of farmers are affected by impeded drainage due to roads ( Steenbergen, 2017).

This impact of roads on the surrounding landscape is not going to diminish. An estimated 900 Million rural people still did not have access to roads and transport infrastructure in 2006, defined as the population living with 2 kilometers distance from an all‐weather road. Sub Saharan Africa scored particularly low with the rural access index standing at 30% (Roberts, 2006). It is predicted that roads and railways in all continents will increase significantly to 2050. One estimate is that nearly 25 Million paved road lane‐kilometers and 335,000 rail track kilometers will be added from 2010 to 2050 a 60% increase (Dulac, 2013).The cost of this infrastructure will be approximately $45 Trillion USD over the period. To this the expansion of unpaved road network may be added. When combined with reconstruction/upgrade costs and annual operation and maintenance spending, global transport expenditures are expected to approach USD 3 Trillion per year over the next 40 years. Roads are also essential for improved rural transport and this drives inclusive growth. Rural road infrastructure promotes social cohesion and connectivity and has key links to meeting the challenge of the Sustainable Development Goals in trade, education, health and jobs.

Photo 2.4: Damage of roads due to inadequate drainage in Barisal, Bangladesh

Further, roads also suffer from water-related damage. Inadequate drainage not only leads to land degradation, but also jeopardizes road embankments, increases maintenance costs, and reduces road durability (Photo 2.4). There is great potential to enhance road drainage with the focus on water storage, groundwater recharge, and retention. The win–win case is substantial; in Ethiopia, for instance, 35 per cent of all road damage is caused by water (World Bank, 2006).

Both road design and road-design processes must optimize the use of roads for local water management. In general, roads need to serve not just mobility but inclusive and balanced growth, which requires a rethink of the design and development process.

2.7.1 Opportunity of road designs in water management

2.7.1.1 Planning road alignments

Road alignments should be carefully planned. They determine the pattern of runoff and determine which areas are served by water harvesting and recharge. The slope of the road affects the speed of surface runoff and the sediment load it can carry. There are several variables to take into consideration: topography, soil structure, and local rainfall patterns all determine runoff behaviour. Often roads are placed in valley bottoms for reasons of easy access and construction. Flat valley bottoms are more difficult to drain. Roads placed at the lowest point in a valley also cannot harvest water or route runoff to storage or recharge areas. Instead, it is recommended to build roads, if feasible, at the toes of hills, as slopes ranging between 5 and 40 per cent gradient are easier to drain and thus maintain (Zeedyk, 2006). The runoff, moreover, can be reused in a lower-lying area.

Photo 2.5: An unplanned internal road causing waterlogging in a Polder

The land level is not same within the polders. Some areas are high and some are low. In those cases, road alignments can perform a great role. If road constructed in a way that it separated high and low lands. Then that road can be used to store water in the high land and that water can be used for irrigation in dry season.

2.7.1.2 Cross-drainage and culverts

While road embankments concentrate runoff, the location and number of cross drains determines how and where the runoff is redistributed. A large number of smaller cross-drainage structures will spread the runoff more evenly, but will also come at a cost. Furthermore, the dimensions of the cross-drainage structures determine the velocity of the runoff. Smaller orifices may slow down the volume released but will also cause impounding on the higher side of the road, with the risk of waterlogging of adjacent farmland.

Photo 2.6: A water crossing in a polder

Cross-drainage and lateral drains can be planned to direct upstream runoff to recharge zones and prevent gullying on the downstream side of the road. Cross drainage can go either under the road pavement by culverts (mandatory for tarmac roads) or over it (in dirt roads). Culverts are structures that drain runoff under road pavements (Photo 2.6). Their setup is critical, as incorrect placement or undersized culverts can cause gullying or trigger sediment deposition. Lead-out drains have the same function as culverts; however, they drain the flow over the road pavement and are common in dirt roads.

Grade reversals is another simple technique which can be used to improve road drainage (Zeedijk, 2006). It is the frequent use of different grades, uphill and downhill, to drain out runoff. Sloping of the road profile, alternating out-sloping (tilting the road outwards, towards the road fill) and in-sloping (tilting the road inwards, towards the fill slope) are other techniques to drain road surfaces.

All road drainage structures can be used not only for cross-drainage but also as the water source for borrow pits and storage ponds or for enhanced recharge areas. In steep areas check dams or armouring may be provided on the drains leading from the road to avoid stream scouring and gully formation.

2.7.1.3 Roadside drains

Besides culverts and cross-drains, roadside drains are important sources for water (Photo 2.7). The shape of the road is important – in particular the presence of a berm. The road template may be either in-sloped with water draining into an uphill side drain, or they may be out-sloped shedding water on the down-slope side, either continuously or into a side drain. A berm may place on an out-sloped road profile - it will keep water longer on the road surface, which may not necessarily be desirable. Crowned or elevated road cross-sections drain water on both sides of the road.

Photo 2.7: A road side canal in Polder 26 in Bangladesh

It is the water from down-slope drains that can be used for water harvesting directly along the stretch of the roads. The water from the road drain may be routed directly to the land (a practice that is common but not universal) or to soak pits, small reservoirs or ditches or other improved structures (Kubbinga, 2012). The advantage of using such recharge and storage systems along the road drain is that they help accommodate and store peak discharges. When the water is applied to the field directly, moisture storage techniques common in spate irrigation are most appropriate: mulching and deep ploughing in semi-arid areas will ensure the availability of water later in the growing season (Steenbergen et al., 2010).

Scouring of roadside drains needs to be avoided. This can be done by creating regular lead-offs or escapes and by paving the drain with rip rap for instance in steep sections or by planting vegetation.

2.7.1.4 Borrow pits

Borrow pits can be systematically used as recharge, storage or seepage ponds. Borrow pits are excavations done to collect materials – sand, gravel, soil – for road construction and are usually located very near to the road itself (Photo 2.8). After the road is finished, if not refilled, borrow pits are left unused. However they may be filled with water after rains. Thus they can act as water storage if properly combined with road drainage, leading runoff to the storage ponds. The shape and size of the ponds are relevant: round shapes maximize effective storage; deeper ponds have less evaporation loss. Access ramps will facilitate the collection of water.

Photo 2.8: A borrow pit in Ethiopia

Depending on the soil conditions and geology, borrow pits can also be used as recharge ponds. The charm of these uses is that the additional storage is created at no additional cost (Nissen- Petersen, 2006).

In areas with permanent shallow groundwater the borrow pits also serve as dug-out ponds, filled with the water seeping in from the adjacent shallow aquifers. Such ponds have become an important source of water for irrigation or livestock in dry flood-plain areas, in Ghana and South Sudan.

2.7.1.5 Use roadside vegetation/ Turfing

Roadside vegetation will help slow down runoff, capture sediment, and fix pollutants. Vegetation is a natural barrier against runoff and erosion and will help increase infiltration (Bender, 2009). Moreover, soils with good structure are more resilient to land degradation. Vegetation is thus relevant to control runoff and stabilize land surrounding the road.

Photo 2.9: Village road turfing by local grass in a Polder

Additionally, vegetation fixes pollutants carried by the water. Rock bunds can be combined with planted vegetation. Side drains can also be designed in combination with vegetation to favour infiltration.

Chapter 3

METHODOLOGY

3.1 Introduction

The main objective of this research was to find out the opportunity of internal roads and drainage control structures in polder water management. To achieve this goal, two polders were selected in south-west coastal regions of Bangladesh as study sites (Figure: 3.1). In these selected polders, several house hold semi structured interviews, physical survey of road and drainage structures, focus group discussions and some key informant interviews were carried out. This Chapter presents the methodology adopted and setup used in this research to carry out the data collection and analysis. Furthermore, this chapter describes the methods used for assessment of the design adequacy of the existing drainage control structures within the polder areas.

3.2 Site Selection

In the present study, Polder 26 and Polder 43/2F were selected as study sites. Waterlogging is an acute problem in the southwestern region of Bangladesh, especially Jessore, Khulna and Satkhira districts, causing severe damage to people’s livelihoods and often creating social unrest (Rahman, 1995; Lázár et al., 2015; Bernier et al., 2016). Waterlogging problem is severe in Polder 26. This polder was selected for this study to find out the opportunity of internal roads and water control structures to solve the waterlogging problem in the polder area.

Polder 26

Polder 43/2F

Figure 3.1: Location of two selected Polders

Polder 43/2F was selected because there exists a difference in land elevation in different part of the polder. Some areas are high and some are low. High areas are facing irrigation water scarcity problem in dry season and the low areas are facing wet season crop damage due to waterlogging. With an objective in mind that roads can play an important role to solve this water management problem, Polder 43/2F was chosen as another study site.

3.3 Data Collection

3.3.1 Primary data collection

The fieldwork (Physical Survey and HH Survey) was conducted during a period between January and March, 2017. The fieldwork comprised of a physical survey of the state of road- water infrastructures (internal roads, embankment sections, culverts, bridges, sluice gates, inlets and outlets), focus group discussions with UP and WMG members, as well as KII with local staff of BWDB, LGED, and BG. The aim was to develop a catalogue of road-water issues, understand the nature and magnitude of these issues, and also to identify possible improvements to polder infrastructures and solutions to these issues. Household surveys (Semi-structured interviews) were conducted with 52 households in Polder 26 and 59 households in Polder 43/2F to understand how challenges created at the road-water interface (e.g. waterlogging, flooding, bad quality of roads, defective and damaged road-water crossings etc.) affect people’s livelihoods, productive activities, and socio-economic development. Through this combination of methodological tools, it was possible to cover the majority of polder area and almost all physical structures (i.e. sluice gates, inlets and outlets, bridges and culverts) within the polders.

3.3.1.1 Household surveys (Semi-structured interviews)

Semi-structured interviews were conducted in the house-holds all along the polders. A questionnaire was prepared based on the issues related to roads and water management (Annex A). The questionnaire was subdivided in 6 parts-

A. General information B. Water-roads problems C. Impacts on farming D. Use of roads and mobility E. Flood protection F. Impacts on property

The sample size was selected randomly (around 60 for each polder). And the researcher tried his best to interview people from all part of the polder but focused mostly on the waterlogged areas. During the interviews, people’s feedback about the problem they are facing related to water and road management and their suggestions about ways to mitigate the problems were considered.

3.3.1.2 Physical survey

Physical survey was conducted in each polder to find out the location, dimensions, information on construction, maintenance/repair, current condition and problems related to water management of all the roads, embankments and water structures within the polder. The physical

36 survey was conducted following a structured format (Annex B) including the information and data of the following elements- – Internal Road – Embankment Road – Culverts – Bridges – Sluices – Inlets/Outlets – Water Issues

During the physical survey, roads/ embankments were divided into segments (1-3 km each) depending on number of structures on it. The location, data and current condition of the structures was collected using a GPS camera. The dimensions of the structures were measured using a measuring tape. Information on construction, background history of maintenance/ repair and challenges related to water management was collected by interviewing local people.

3.3.1.3 Focus group discussion

Two FGDs were conducted in each polder, one with the UP members and the other one with the WMA & WMGs members. A questionnaire was prepared based on the important issues related to roads and water management (Annex C). In the FGDs, an effort was made to invite all the people who are directly involved with the water management of the polder area. During the FGDs, efforts were also made to get feedback from the participants on the problem they are facing related to water & road management and their suggestions about ways to mitigate the problems. At first, various options to solve waterlogging based on findings of physical inventory, HH surveys and KIIs were presented to the groups. Potential drainage pattern and other options were indicated on a map to visualize better Social - political feasibility of the various options:

1. Option to re-shape existing but silted khals? 2. Options to excavate new khals to reconnect drainage network? Is there land that could be acquired with fair compensation? 3. Discuss what could be the challenges? 4. Discuss how to overcome those challenges?

In addition to the FGDs, a number of informal meetings with local stakeholders were carried out in the polder area. Moreover, two key informant interview (KII) sessions have also been conducted with important relevant person from BWDB and LGED.

The following issues were addressed during the FGDs:

1. What are the roles and responsibilities of the WMG?

2. Are WMGs also responsible for constructing/maintaining lower level khals? 3. Are WMGs responsible for maintenance of internal structures (culverts and bridges) and field outlets within the polder? 4. What are the roles and responsibilities of UP in relation to water management and drainage? 5. What are the roles and responsibilities of UP in constructing and maintaining village roads? 6. Is the UP responsible of constructing/maintaining drainage structures along village roads?

3.3.1.4 Key informant interview

To collect all the required information from the local representatives and to validate the information collected from surveys, key informant interviews with some key personnel from the organizations (LGED, BWDB & BG) that directly involved with the roads and water management in the two polders were performed.

Two common techniques have been used to conduct key informant interviews:

– Telephone Interviews – Face-to-Face Interviews

Face-to-Face Interview technique was selected for the KII. At first, all the existing data was gathered and reviewed. Then it was found what further information is needed. Some District/Upazilla level officials from LGED, BWDB & BG were selected for the interviews. Depending on the required information three questionnaires (Annex D) were prepared, one for LGED, one for BWDB and the other one was for Blue Gold. Finally, two KIIs were conducted in polder 26 with BWDB and LGED personnel, and three KIIs were conducted in polder 43/2F with BWDB, LGED and BG personnel.

3.3.2 Secondary data collection

3.3.2.1 Baseline Study of Selected Polders

A baseline study was done for each selected polders before starting the survey. Environmental and social baseline information was collected from government report, guidelines, EIA reports publications etc. In addition, information related to water management and drainage congestion also collected from those resources. Later this information was used to prepare questionnaire for survey and also used to support the study findings.

3.3.2.2 Rainfall Data

The rainfall data was collected from Bangladesh Metrological Department. Daily rainfall data of Khulna BMD station for 20 years (1995-2014) was collected to perform the design analysis of culverts.

Additionally, some secondary data was collected from LGED, BWDB and BG during the KIIs. And those secondary data was mainly polder maps, DEMs, GIS shape files and different guidelines of those organizations.

3.4 Design Adequacy Check of Culverts

In polders of Bangladesh, waterlogging occurs mainly because of excessive rainfall and poor drainage system. To validate this, an assessment of the design adequacy of the existing drainage control structures within the polder area was done in Rational formula using rainfall data, maps, DEMs, shape files and Physical survey data (Location data, dimensions, background history of construction, background history of maintenance/ repair, current condition and challenges related to water management of all the roads, embankments and water structures).

Chapter 4

BASELINE STUDY OF POLDERS

4. 1 Introduction

Two BWDB polders (Polder 26 and Polder 43/2F) were selected for this study. The baseline information (Environmental and Social) of these two polders is described in the following sections.

4. 2 Polder 26

Polder 26 is located in Shovna union of Dumuria Upazila in Khulna district. Bangladesh Water Development Board (BWDB) constructed this polder back in 1967-68. The gross area of the polder is about 2,664 ha of which net cultivable area (NCA) is about 1,993 ha. Recently its water management system was rehabilitated under the Integrated Planning for Sustainable Water Management (IPSWAM) project from 2003-11. The polder is located in the South-West hydrological region of Bangladesh and it is under the administrative jurisdiction lying within the Khulna O&M Division-1, BWDB, Khulna regarding the water management system within the polder. This polder is surrounded by the Teliganga River in the west and Mora Bhadra River in the east.

The polder is surrounded by a 20 km long embankment which providing protection against tidal and storm surges and salinity intrusion. There are three active drainage sluices in addition of one blocked and two damaged sluices. Around 20 drainage khals is there but most of them are almost silted. The existing condition of the embankment is good in most of the portion; only 5% of the peripheral embankment is paved, which allow vehicular movements in dry season. Drainage sluices of this polder became redundant as the surrounding rivers have nearly been silted up. Only the Teliganga River which is in the west side is in good condition. Out of the three active drainage sluices, one is now under-construction and another one needs repairing. As a result, these cannot fulfill the public needs. Unauthorized public cut of embankment is injurious and threat to the polder area. The overall condition of the internal drainage channels of polder 26 is pretty good except the connectivity and siltation problem of the khals namely; Baorer khal, Shakha Bai, Dangar khal etc.

Figure 4.1: Topographic map of Polder 26

4.2.1 Environmental and social baseline

A total of 15,175 people are living in this polder. Average literacy rate is 60%. About 100% household drink tube well water and about 40% of household use water sealed sanitary latrine. It is reported that about 55% of households are in the balance or breakeven poverty status (Blue Gold Program, 2016). However, the gross area of the polder is about 2,664 ha of which net cultivable area (NCA) is about 1,993 ha (Blue Gold Program, 2016). About 67% of NCA exists in “Non saline with very slightly saline (S1)” soil salinity class and 94% NCA characterized in poorly drainage. Most prominent cropping pattern of this polder is “Fallow - HYV T Aman - Boro”, which is practiced in 40% of the NCA and cropping intensity is about 143%. Annual total crop production stands at about 9,637 tons of which 8,552 tons are rice and 1,085 tons are nonrice (Blue Gold Program, 2016).

The Polder is within an aerial distance about 85 km from the coast of the Bay of Bengal. The polder is surrounded by a tidal river namely, Mora Bhadra River in the north and east and the Teliganga River in the west. Mora Bhadra River has completely been silted up and converted into an agricultural field while the Teliganga River is the properly functioning as a peripheral river. Water levels during high tide ranges from 1.7 to 2.3 m +PWD, during the low tide water levels range from 0.7 to 1.2 m below the MSL (Blue Gold Program, 2016). Elevation of about 48% of the land inside the polder is in between 1.26 and 1.73 m +PWD, while 43% lands below 1.26 m, PWD (Blue Gold Program, 2016). The polder is covered by two Agroecological Zones (AEZ) i.e. High Ganges River Floodplain (AEZ-11) and Ganges Tidal Flood Plain (AEZ-13).

The project area experiences tropical climate. The average temperature ranges from 19°C (January) to around 29°C (April). The maximum rainfall recorded (from 1978 to 2013) in the area is 343 mm in the month of July and lowest 7 mm in the month of December. The monthly average relative humidity of the Khulna BMD station varies from 73% to 88%. Daily average sunshine hours are more than 7 hours which reduces to 5 hours from June to September. Wind speed of the polder area is highest in April (around 160kph) and lowest in November (around 40 kph) (Blue Gold Program, 2016).

Table 4.1: Water quality parameters of different water bodies in the polder 26

Water Bodies Parameters Temp in © pH DO (mg/l) TDS (ppm) Salinity (ppt) Internal Khal 30.0 8.1 4.9 245 0 Periphery 32.0 7.9 5.3 1265 8 River Standard (28-34)** 6.5-8.5 (4.0-6.0)* 1000 (0-4) for prawn Values for and (5 -35) for Fish shrimp*

Source; Field test, March 2015 (*M A Mazid 2002 ** Jack M. et al, 2002)

The polder area is diversified with brackish and fresh water environment containing about 245 ha. of fish habitat. Rice-Prown are mainly is cultured in the polder area. Total fish production is about 103 M. Ton, half of which comes from Rice-Prown cultivation (Blue Gold Program, 2016). One of the Bio-ecological zones namely the Saline Tidal Floodplain falls inside the polder. Homestead and Crop field vegetation are the main floral pattern of the polder which performs major ecosystem services. Soil salinity and internal canal bed siltation are the main threats on ecosystems of this polder. More than 60% households of the polder are rearing cattle and chicken and having 50-70 poultry farmers inside the polder. The surface water quality of both Periphery Rivers and internal khals has been measured (Table 4.1). The pH values at different locations are higher than neutral scale and measured highest in Barobeeler Khal inside the polder. Average Salinity of the river systems in dry season about 8 ppt (Blue Gold Program, 2016).

4.2.2 Water Resources Problems

4.2.2.1 Tidal and storm surge flooding

Local people in Polder 26 opined that the peripheral embankment effectively offers protection from regular tidal flooding in the area. Even though very minor flow leakage is occurring through some of the water control structures, the amounts of flow entering the polder are minimal. As such, no tidal flooding takes place inside Polder 26. Local people also alleged that there were no storm surge flooding in during Aila (2009) and Sidr (2007).

4.2.2.2 Water logging and drainage congestion

Drainage congestion has been the most prominent water related issue inside the polder. At present, only two sluice gates (Baloijakin 1-V Sluice and Zialtola 3-V Sluice) are located along the side of Teliganga River, and only one sluice gate (Kakmari 3-V Sluice) exists along the Mora Jaykhali River. The Mora Jaykhali River has lost its major share of flow over the years, but the Teliganga River is still functional, and offers an indespensible source of drainage within the polder. However, with only two sluice gates in place, the polder suffers from tremendous 43 drainage congestion problems after any major rainfall events. Water cannot drain out from the internal Khals timely, and it sometimes takes more than a week to drain water out from the polder through the Teliganga River. Furthermore, the siltation of some of the khals inside the polder also aggravates the drainage congestion problems. From field observations and spatial studies, it can be inferred that around 70% of the internal water courses (Barobeeler Khal, Sakha Bai Khal, Zialtola Khal etc.) of the polder suffer from drainage congestion problems. The drainage congestion problems mostly originate from the khal openings and gradually spread inside the polder. Such problems induce minor short term flooding in nearby areas, but no long term water logging occurrences takes place inside the polder.

4. 3 Polder 43/2F

Polder 43/2F is located in Gulishakhali union of Amtali upazila, Barguna district. The polder is surrounded by Gulishakhali and Payra rivers in the west and the Kukua River (in the east). The polder covers an area of 4,130 ha, with a Net Cultivable Area (NCA) of 2,590 ha (63%). The polder area is bounded by a 33 km embankment that protects the area against tidal and storm surges as well as salinity intrusion (Blue Gold Program, 2016). Besides, there are 16 drainage sluices, 4 drainage outlets and a number of flushing inlets within the area. The existing situation of the embankment in most parts is good, offering protection against tidal and storm surges and facilitating the communication system as well. The exception is the Katakhali outlet, where the road width has decreased by around 5 feet since the construction of the structure beneath the embankment. The embankment beside the Payra River at Angulkata, Gulishakhali, Dalachara and Naiapara is vulnerable to erosion and tends to be eroded whenever a moderate flood occurs. The existing water control structures are not functioning up to the desired level due to damages in the wheels and shafts. There are also severe mismanagement issues regarding the water control structures. The number of inlets is also not sufficient to meet the flushing requirements. Among the 93.5 km of internal drainage channels, some were very shallow due to topsoil erosion and other land filling activities. Moreover, public encroachments were also observed, e.g.in Koromjabunia khal, local fishers have formed ghers, obstructing the khal at multiple locations (Blue Gold Program, 2016).

Figure 4.2: Topographic map of Polder 43/2F

4.3.1 Environmental and social baseline

The total population of Polder 43/2F is more than 28,000 consisting of 6,400 households. The density of population is about 563 persons per sq. km. The average household size is 4.39. On average, about 45% of the households are in the „deficit‟ category. In the polder area, about 35% of the total population is employed, 47% is engaged in household work and about 18% is unemployed. At present, most of the population is engaged in the agriculture sector (83%). The average literacy rate in the study area is 50%. There are 56 primary schools, 14 high schools and 22 ebtedaye/ Dakhil Madrashas as well as five Union Health Complexes and 13 Community Clinics in the polder area. Tidal flooding, erosion, water logging and cyclones are the major natural disasters occurring in this area ( Blue Gold Program, 2016) .

The polder covers an area of 4,130 ha, with a Net Cultivable Area (NCA) of 2,590 ha (63%). Total cropped area is about 2,590 ha of which the coverage of rice is 63%. Cropping intensity of the project area is about 166%. Surface water is the only source of irrigation water. The annual total crop production stands at about 10,212 tons of which about 6,162 tons of rice is produced and 4,050 tons non-rice is produced. Total loss of rice production is about 54 tons in 2,720 ha and loss of non-rice production is about 52 tons in 1,580 ha (Blue Gold Program, 2016). Polder 43/2F lies in the Ganges Tidal Flood Plain (AEZ-13). The most prominent cropping pattern is Fallow-Lt Aman- Fallow which covers about 34% of the NCA and Fallow – Lt Aman – Sesame which covers about 25% of the NCA.

The project area experiences tropical climate where monthly maximum temperature varies from 29°C to 36°C and monthly minimum temperature varies within the range of 10.3°C to 24°C. The maximum rainfall ever recorded in the area is 590 mm in the month of July and lowest rainfall is observed in the month of December which is 7 mm. The monthly average relative humidity of the Patuakhali BMD station varies from 74 to 90%. Daily average sunshine hours are higher than 6 hours (August-March) which reduces to 3 hours from April to July (Blue Gold Program, 2016) .

In measuring the water quality, TDS values were found to be 683 to 1238 for different locations inside the polder. Values of DO were mostly found close to the standards set by the DoE for both irrigation (5 to 6 mg/l) and fishing (5 mg/l). On the other hand, almost all the surface water samples were found having no salinity during field measurement in the month of May. About 81% of land in the area has elevation between 1.4 and 1.61 m +PWD. Wind speed of the polder area is the highest in April (around 167kph) and the lowest in December (around 50 kph) (Blue Gold Program, 2016) .

Table 4.2: Water quality parameters of different water bodies in the polder 43/2F

Water Bodies Parameters Temp in © pH DO (mg/l) TDS (ppm) Salinity (ppt) Internal Khal 31.1 7.6 5.4 697 0 Kakua River 31.8 8.0 7.9 1275 0 Pond 33.3 7.9 5.9 0 Standard (28-34)** 6.5-8.5 (4.0-6.0)* 1000 (0-4) for prawn Values for and (5 -35) for Fish shrimp*

Source; Field test, March 2015 (*M A Mazid 2002 ** Jack M. et al, 2002)

Polder 43/2F is 33 km away from the Bay of Bengal and undergoes diurnal tidal influence. It is surrounded by the Gulishakhali River in the north and north-west directions, the Payra River in the south-west, and the Kukua River on the eastern side. Surface water levels during high tide range from +1.14 m PWD to +2.22 m PWD (above MSL), and the low tidal water levels range from 0.1 to 0.3 m below the MSL. Average daily use of water is around 25 lpc for domestic use. 30% of the polder population suffers from water deficiency (daily consumption as low as 10 lpc) for domestic use as reported by local people. The existing surface water irrigation coverage is only 5% of the Net Cultivable Area (NCA) of the polder (Blue Gold Program, 2016). The estimated fish habitat area is 309 ha where capture fishery contributes the major share (214 ha) and the culture fish habitat shares the rest. The estimated total fish production of the polder area is more than 191 tons. The bulk of the fish production (about 76%) comes from culture fisheries and the rest is contributed by capture fishery (Blue Gold Program, 2016) . The project area is moderate in fish biodiversity although the biodiversity of fishes has shown a declining trend over the years. About 100 fish species are available in the area. The dominant cultured fish species are Tilapia, Silver carp, Sarpunti, Prown etc. Gulisakhali Khal, Chunakhali khal, Mothbari khal, West Kolagachia khal etc and other peripheral water bodies serve as feeding and spawning grounds of most of the open water fishes.

4.3.2 Water resources functions and problems

The water resources functions and problems in and around the polder area are described in the following sections:

4.3.2.1 Tidal and storm surge flooding

Local people in Polder 43/2F opined that the peripheral embankment at most locations effectively offer protection from regular tidal flooding. However, there are some locations along the peripheral embankment which are inundated during major rainfall events. During public consultation it was found that a minor portion of the embankment crest gets submerged at some damaged spots of Khekuani and Solohawlabar to a depth of 1~2 feet. The adjacent low lying

47 lands also get flooded during the period. However, water does not usually inundate the polder during a typical high tide and in general the tidal flooding situation can be considered as nominal for the entire polder.

4.3.2.2 Drainage congestion and water logging

From field investigation it was found that the polder suffers from drainage congestion issues at several low lying places. GIS-based spatial analysis and field investigations have revealed that approximately 37 km of water courses within the polder suffer from drainage congestion issues. The phenomenon is prominent in the north, south and eastern ends of the polder with around 7.5 km of khals (Motbari, Bazarkhali, Solohawlabar and Purbo Kalibari khals) affected by high drainage congestion problems. The distributaries of these khals also suffer from low to medium drainage congestion problems. As a consequence of this issue, almost 44 ha of area near Kolagachia, Khekuani and Purbakalibari remain water logged during the post monsoon season, hampering post monsoon production.

Chapter 5

RESULTS AND DISSCUSSION

5.1 Introduction

During a period of 6 months (December 2016-May 2017), a comprehensive assessment of road- water issues and impacts has been carried out in Polder 26 and 43/2F for this study. Practical solutions have been identified, validated, and ranked with main actors (BWDB, BG, LGED, UP, WMGs, WMAs) by conducting some FGDs, KIIs, House Hold Survey and Physical Survey. The main focus of this chapter is to present the summary of House Hold Survey, Physical Survey, FGDs and KII findings from the two selected polder areas. Later a catalog of issues and solutions related to road - water interactions is discussed based on the study findings.

5.2 Survey Findings

Around 60 HH Survey (52 in Polder 26 and 59 in Polder 43/2F) were conducted in each study area. Road-water issues, its impacts on farming, fishing and other daily activities and possible solution of those issues were identified in HH Survey. Additionally, a Physical Survey was conducted along the entire embankment and internal roads in each study areas to find out the current state of embankment, roads, water crossing structures, sluices, inlets-outlets etc. and challenges related to those structures.

5.2.1 Polder 26

Polder 26 is divided into two parts (East Part and West Part) by a Union Road aligned along the North - South axis and crossing several large khals flowing from the East to the West of the polder. Almost all (except a privet outlet) the functioning sluices/ outlets are located on the West Part of the polder. Since connectivity between khals on the East of the polder and those on the West is partly interrupted by the Union Road. As a result, a lot of water accumulates on the East side of the polder. Although baseline information shows, there are only two working sluice on the West side but during physical survey 4 working and another under construction sluices was found in the West side. Sluices on the North-East of the polder are almost damaged/ blocked and are no longer used because the peripheral river flnking the polder on the East side has completely silted up. The only functioning sluice gate in the South-East side is Kadamtola Private Outlet which can drain out water from one Khal only. As a result of few functioning sluice gates, siltation of khals, and insufficient water crossings along roads, waterlogging is widespread: it constitutes a major problem in Polder 26. BG is currently constructing 2 additional outlets to improve drainage in the polder. Another challenge in the polder is the poor quality of internal

49 roads, particularly earthen village roads, which deteriorate rapidly and become inaccessible during the rainy season, which is partly due to inadequate road drainage.

5.2.1.1 Findings of house hold survey

The selected sample size for HH Survey was around 60 but finally 52 HH Survey were conducted in Polder 26. A strong effort was made to cover all part of the polder but at the same time a bit more priority was given to the problematic areas (mainly waterlogged areas). Among the 52 HH Survey, 32 was conducted in houses near the Embankments and 20 was conducted in houses near the internal roads. Almost 75% of the respondent was male and the rest 25% was female. Among the 52 respondent, 50% was farmer, 8% was fisherman, 21% of them was involve in both farming & fishing and the rest are businessman, daily labour, teacher etc.

a) Water-roads problems

Around 85% of the respondent mentioned waterlogging as the main problem related to water in the polder area and the rest mentioned drinking water scarcity and irrigation water salinity as main problem related to water. Those who mentions waterlogging as the main problem related to water, thinks poor drainage of excess rainwater mainly causes waterlogging.

Photo 5.1: An inadequate culvert in Polder 26

They also mentioned some specific issues (Fig: 5.1) that causing the drainage congestion and 75% of them think inadequate/ insufficient water crossing on internal roads are causing this

50 waterlogging problem (Photo: 5.1). According to the survey findings, the polder is facing waterlogging every year and it happens mainly in the rainy season.

Percentage (%) 40

0 Insufficient/ River/Canal Damaged/Inactive A & B A & C Inadequate Siltation (B) Sluices (C) Watercrossing (A)

Figure 5.1: Issues causing the drainage congestion (in %) in Polder 26

Around 87% of the respondents think they need new culverts to solve their waterlogging problem and the other 13% have an opposite thinking. Only 23% of the respondents got affected by river flooding and those happened during the big cyclones like Sidr.

b) Impacts on farming

In Polder 26, almost all the farmers grow mainly paddy in the wet season but they grow jute also in some of their lands. In the dry season, farmers grow different types of vegetables like Cauliflower, Potato, Tomato, Bitter Gourd, Cucumber, Red Lentil etc. Around 65% of the respondents mentioned that their farming activities got affected due to waterlogging and it happens almost every year. Half (Exact 50%) of the respondent told that most severely affected crop by waterlogging is Paddy and it happens mostly in the sapling stage. Around 29% of them answered vegetables as the most severely affected crop by waterlogging. According to the survey data, the farmers used to lose 25-80% (5k to 300k in taka) of their crops due to waterlogging in every year. Around 65% of the respondent claimed that they abandon their cultivable land (Up to 85%) due to waterlogging. Most of the respondent experience delays/constraints in carrying out

51 farming activities as well as marketing farming products because of waterlogging. Some fisherman also claimed that flood due to excess rainfall and poor drainage affects their fish farming activities. Sometimes ponds overtop during flood and flood water wash out all the fishes.

Almost all the farmers (65% of total respondent) mentioned that they have canals near their cultivable land and they have access to those canals. But most of the canals are silted and gets dry in the dry season. That’s why they are using ground water for irrigation but they used to pay 1/3 of their crops for that water to the deep tube well owner. They like to have BWDB to dredge the canals so that they can extract water from those canals for irrigation in the dry season. Almost half of the respondent has access to pond water but they use that water either in household works or for fish cultivation.

c) Use of roads and mobility

A pucca (asphalt concrete) Union Road aligned along the North - South axis divided the polder into two parts and that road is the mostly used road within the polder. This road connects the polder with the upazila road. Moreover, there are several village roads which are so important for the people living in the polder. People use roads mainly for access and transportation/ marketing of goods. They use heavy vehicle like track only on the main Union road. On the other roads they use light vehicles like Bicycle, Van, Motorcycle, Three Wheeler etc.

Photo 5.2: Bad road condition in Polder 26

Only 15% of the respondents are satisfied with the current road condition and the rest wants improvement in road condition. And almost all of them mentioned that lack of repair and maintenance is the main cause of bad road condition (Photo: 5.2). Most of them don’t want any new road but almost 92% of them want road repairing. People want to increase the width of the roads and to cover the earthen roads by bricks or asphalt. Almost all the respondent think that the current road condition affecting their mobility and daily life badly. Mainly in the rainy season, the earthen roads get inaccessible. So people can’t take their crops easily in the market, children can’t go to school; even it’s become very tough to hospitalize an emergency patient.

d) Embankment for flood protection

Around 75% of the respondents are satisfied with the height of the embankment and they think the existing embankment is enough to protect them from flood. But the other 25% opined that embankment height needs to be increased (1-2 feet). Around 42% of the respondents mentioned that there are effective sluices for flood control in their part of the polder. And another 27% mentioned that there are sluices in their part of the polder but those are too old/ blocked/ damaged. Around 52% of the respondent claim that their life being endangered by floods and one of them lose his daughter back in 2004. Around 25% respondents took shelter on the embankments during flood and another 13% took shelter in the local primary school/ UP complex. People took shelter on embankments for 2/3 days to 3 months. And that time they faced a lot of challenges like drinking water problem, food, disease etc. The researcher found a few families living on the embankment permanently in the northern part of the polder.

During flood, around 63% of the respondents experienced damages or loss of house (Figure: 5.2). Furthermore 71% and 37% of the respondents experienced damages or loss of goods and storage equipment respectively (Figure: 5.2). Half of the respondents said that they do take a lot of actions like repairing base or poles of kacha house, elevating house by earth filling, taking valuable goods and livestock’s into higher & safe places etc. to protect their house and property. And the rest normally don’t take any actions to protect their house and property. Only 5 respondents (around 10%) mentioned that they used embankments as post-flood shelter and 2 of them used the embankment as permanent shelter.

120

100

80 Percentage (%)

60 No Yes 40

0 Damages of your Damages of Damages of storage house equipment and goods facilities

Figure 5.2: Impacts on property during flood

5.2.1.2 Findings of physical survey

To make the physical survey easier, the internal polder roads were divided into 11 small road segments (1-4 km) and the embankment was divided into 9 small embankment segments (1-4 km). So, total 20 (11 for roads +9 for embankments) physical survey questionnaires were filled during the physical survey. Furthermore, 3 bridges and 10 culverts along the internal road and 2 inlets and 12 sluices/ outlets along the embankment were physically visited to investigate the actual condition of these drainage control structures.

a) Internal roads

All the internal roads are used mainly for access and transport of goods. Almost half of them (4/11) are asphalt road and is in good condition. LGED constructed these roads and LGED is responsible for operation and maintenance of these roads. There was 4 brick covered road segments and those also constructed by LGED. Two of the brick layered roads are in good condition but the other two brick covered roads are broken in many places and bricks are missing in some places (Photo: 5.2) . The last three roads are earthen village roads and were constructed by UP. These roads are not important regarding economic point of view. Usually these are roads mainly used for only communication purposes.

Photo 5.3: The Union road disrupting drainage of the Polder

The conditions of the earthen roads aren’t good and they become muddy and inaccessible during the rainy season. According to survey findings, none of the internal roads went underwater during flood in the last 50 years. The frequency of road maintenance isn’t good (around 10-15 years). Only three road segments were repaired in last 5 years. For almost all the road segments, last major repair was done 12- 20 years ago. Most of the roads (5/11) don’t have sufficient water crossing structures to drain out rain water during the rainy season which causes waterlogging. For example, the main union road gone through a river (Shakha Bai river) (Photo: 5.3) and a Khal (Kata Khal). LGED constructed two single vent culverts on those two water crossings but those culverts are inadequate because all the water from the east part of the polder goes through these two paths.

b) Embankment roads

Most part of the embankment is earthen. Only a small segment (around 2 km) of the embankment has been covered (Asphalt) by LGED around 3 years ago. So, this part of the embankment is in very good condition. Most of the earthen part (around 70%) of the embankment has been reshaped by Blue Gold in last two years and that part of the embankment is also in good condition.

Photo 5.4: A newly shaped embankment section of Polder 26

The rest 20-30% of the embankment is uneven, narrow and insufficient in height (around 1- 1.5m). This part of the embankment needs to be repaired. Normally people are using the embankment as road. But the earthen embankment gets muddy in rainy season and become difficult to use. The embankment never overtopped in the last 50 years due to river flood. But in the western part of the embankment, in some points the embankment used to get eroded due to river erosion. In those points, reinforcement is needed to protect the embankment.

c) Bridges and culverts

During the physical survey, 3 bridges and 6 culverts were found on the internal polder roads. Two of the bridges are functioning well but old. The third one is blocked and too old to function and it need to be replaced by a new one. Among the 6 culverts 2 are functioning well, 3 of them are inadequate in size and the 6th one doesn’t have any connection with any khals.

Photo 5.5: A location where a culvert is needed to connect khals

Besides, there are 4 more important location where roads go through obstructing an important khal or roads go through a connection point of two important khals (Figure: 5.5). Those points interrupting the overall drainage system of the polder. For a proper drainage system, connections between khals are so important. That’s why culverts in those 4 points are badly needed to solve the waterlogging problem. The elevation of north-east part of the polder is higher than the other parts. So canals get dry during the dry season in the north-east part but according to the local people a gated culvert on chingra-kodalkata khal (Figure: 5.3) can solve this problem. This gate will help to store some water for irrigation in the dry season.

Figure 5.3: Present state of all the internal water crossing structures in Polder 26

d) Drainage sluices

When this polder was constructed then there were 6 sluices (Two 3 vent and four 1 vent) all around the polder and those were sufficient enough to drain out water from the polder. But with time going, the surrounded rivers got silted and now there is river only in the western side of the polder. Among the 6 initial sluices, the entire four 1 vent sluices are already damaged, a 3 vent sluice is still active and the other 3 vent sluice is in good condition but that has no connection with the river. In the meantime, the local people constructed two 1vent outlets (One made by concrete and another made by wood) and each of those outlets can drain out water only from a single khal.

Photo 5.6: A totally damaged sluice in Polder 26

Recently, BG started some development work in this polder. BG already constructed two 1 vent outlets and another two outlet (One 1 vent and one 2 vent) is under construction.

Figure 5.4: Present state of all the drainage sluices with water flow direction in Polder 26

5.2.2 Polder 43/2F

Polder 43/2F is surrounded by rivers, one being a large river (Payra River), and it is crossed by many khals, several of them as wide as rivers. Compared to Polder 26, waterlogging is much less severe because drainage and water infrastructures are more extensive and functional. There are 19 sluice gates and 28 inlets/outlets along the embankment and a high number of internal water- crossings. Moreover, the system of khals is better interconnected than in Polder 26. Overall sluices and outlets are functioning well and even during monsoon, water can be drained off the polder during low tide. Waterlogging occurs mostly around settlements and in low lands.

Whereas in Polder 26 drainage and waterlogging were the main constraints, in Polder 43/2F water control for irrigation emerged as a pressing issue. Overall water supply for irrigation through the khal system is sufficient to achieve two harvests per year: one paddy crop during the rainy season and a system of mixed dry crops during the dry season (e.g., potato, chili, nuts, sunflower, and beans). However, due to the irregular topography and the presence of scattered pockets of higher elevated lands, it is difficult to control and retain water when and where it is most needed. Similar to Polder 26, bad quality and conditions of roads features as a main problem in Polder 43/2F. Moreover, there is a prevalent safe drinking water scarcity in this polder because there are no sufficient boreholes. Drinking water availability was highlighted as the main water-related problem in the polder.

5.2.2.1 Findings of house hold survey

The selected sample size for HH Survey was around 60 but finally 59 HH Survey was conducted in Polder 43/2F. A strong effort was made to cover all part of the polder but more concentration was given in the problematic areas. Among the 59 HH Survey, 30 was conducted in houses near the Embankments and 29 was conducted in houses near the internal roads. Almost 76% of the respondent was male and the rest 24% was female. Among the 59 respondent, 59% was farmer, 14% has small business, 5% of them was daily labour and the rest are fisherman, teacher and other job holders.

a) Water-roads problems

Around 61% of the respondent mentioned drinking water scarcity as the main problem related to water in the polder area. Another 25% and 22% of the respondent mentioned waterlogging and irrigation water scarcity as main problem related to water respectively. This polder is much closer to the Bay of Bengal than Polder 26 and that is why groundwater of this region is saline. Only deep tube well water is drinkable here but construction of a deep tube well is costly for the village people. Government of Bangladesh/ BADC has constructed some deep tube well in the polder but those are small in numbers and far from most of the people’s house. Those who mentioned waterlogging as the main problem related to water, thinks poor drainage system cannot drain excess rainwater from the polder area which causes waterlogging. People also

61 mentioned some specific issues like inadequate/ insufficient water crossing structures on internal road, canal siltation, inefficient sluice gates etc. According to the survey findings, almost 71% of the respondent is not satisfied with the current drainage condition and the polder is facing waterlogging every year in the rainy season.

40 Percentage (%) 30

0 Waterlogging Problem Drinking Water Scarcity Water Scarcity for Irrigation

Figure 5.5: Main issues related to water (in %) in Polder 43/2F

Around 71% of the respondents asked for new culverts to solve their waterlogging problem and the others have an opposite opinion. Around 31% of the respondents got affected by river flooding in every rainy season. Another 53% of the respondents got affected by river flooding but only during the big cyclones like Sidr and Aila. And the rest never affected by river flooding in the last 50 years. Those who mention that they got affected by river flooding also mentioned some specific causes like inefficient sluice gates, excess water in the river due to big cyclones, heavy rainfall, height of embankment is too small etc.

34 31

Percentage (%)

8 7 5

Heavy rainfall Insufficient Excess water in Inefficient Poor drainage embankment the river due Sluice gates system height to big cyclones

Figure 5.6: Causes of river flooding (in %) in Polder 43/2F

b) Impacts on farming

In Polder 43/2F, almost all the farmers grow mainly paddy in the wet season. In the dry season, they grow different types of vegetables like Mug, Potato, Nuts, Chili, Bitter Gourd, Cucumber, Mustard etc. Most of the respondent mentioned that their farming activities got affected due to waterlogging and it happens almost every year. Around 51% of the respondent told that most severely affected crop by waterlogging is Paddy and it happens mostly in the sapling stage. Around 32% of them answered vegetables (mainly Chili and Potato) as the most severely affected crop by waterlogging. According to the survey data, the farmers used to lose 20-90% (5k to 200k in taka) of their crops due to waterlogging in every year. Around 61% of the respondent claimed that they abandon their cultivable land due to waterlogging. Around 78% of the respondent experience delays/constraints in carrying out farming activities as well as marketing farming products because of waterlogging.

Percentage (%)

15 15

Deep tubewell Canal water River water

Figure 5.7: Irrigation water sources (in %) in Polder 43/2F

Almost half of the farmers (54% of total respondent) mentioned that they have canals near their cultivable land and they use canal water for irrigation. Additionally, 15% of the respondent takes river water by inlets for irrigation (Fig: 5.7). Now almost all of them are growing Rabi grain (This crops need less water) in dry season but they want to grow paddy in the dry season also which will be beneficial for them. But they can’t grow paddy because the canals and rivers became shallow and can’t store enough water for growing paddy. Around 88% of the respondent are facing irrigation water scarcity problem every year and all of them thinks canal & river dredging can solve this problem. Almost half of the respondent has access to pond water but only a few of them use that water either in household works or for fish cultivation.

c) Use of roads and mobility

The pucca (asphalt concrete) Union Road (Goskhali to Gulishakhali) which is actually the part of the embankment is the mostly used road within the polder. That road connects the polder with the upazila road. Moreover, there are several village roads which are so important for the people living in the polder and most of the roads are asphalt road. People use roads mainly for access and transportation/ marketing of goods. They use heavy vehicle like track only on the main Union road. On the other roads they use light vehicles like Bicycle, Van, Motorcycle, Three Wheeler etc.

Photo 5.7: Bad road condition in Polder 43/2F

Only 24% of the respondents are satisfied with the current road condition and the rest wants improvement in road condition. Half of them think heavy loaded vehicle damages the roads and the other half thinks lack of repair work and maintenance damages the roads (Figure: 5.7). Most of them don’t want any new road but almost 92% of them want road repairing. They want to increase the width of the roads and to cover the earthen roads by bricks or asphalt. Almost all the respondent think that the current road condition affecting their mobility and daily life badly. Mainly in the rainy season, the earthen roads get inaccessible. So people can’t take their crops easily in the market, children can’t go to school; even it’s become very tough to hospitalize an emergency patient.

d) Embankment for flood protection

Around 42% of the respondents are satisfied with the height of the embankment and they think the existing embankment is enough to protect them from flood. But the other 58% opined that embankment height needs to be increased (0.5-1 feet). Around 40% of the respondents mentioned that there are effective sluices for flood control in their part of the polder. And another 25% mentioned that there are sluices in their part of the polder but those are too old and need to repair the gates. Around 71% of the respondents claim that their life being endangered by floods and that happened mainly during the big cyclones like Sidr.

Photo 5.8: Broken part of embankment in Polder 43/2F

Only 20% respondents took shelter on the embankments during flood and another 20% took shelter in the cyclone shelter and the others stay at home to protect their properties. They took shelter on embankments for 2/3 days to 2 weeks. And that time they faced a lot of challenges like drinking water problem, food, disease etc.

All the respondents experienced damages or loss of house because of flood but it happens only in 2007 by Sidr. Furthermore the respondents experienced damages or loss of goods and storage equipment (10k to 300k in taka) respectively. Only 17% of the respondents said that they do take a lot of actions like repairing base or poles of kacha house, elevating house by earth filling, taking valuable goods and livestock’s into higher & safe places etc. to protect their house and property. And the rest normally don’t take any actions to protect their house and property. Around 30% respondent mentioned that they used embankments as post-flood shelter and only one of them using the embankment as permanent shelter.

5.2.2.2 Findings of physical survey

To make the physical survey easier, the internal polder roads were divided into 10 small road segments (1-4 km) and the embankment was divided into 11 small embankment segments (1-4 km). So, total 21 (10 roads +11 embankments) physical survey questionnaires were filled during the physical survey. Furthermore, 10 bridges and 28 culverts along the internal road and 28 inlets/ outlets and 19 sluices along the embankment were physically visited to investigate the actual condition of these drainage control structures.

a) Internal roads

All the internal roads are used mainly for access and transport of goods. They use mainly light vehicles like Bicycle, Van, Motorcycle, Three Wheeler etc. on these roads. Half of the roads (5/10) are asphalt road and is in good condition. LGED carpeted these roads in the last 5 years and LGED is responsible for operation and maintenance of these roads. The other roads are earthen village roads and were constructed by UP. These roads are not important regarding economic point of view. Usually these are roads mainly used for only communication purposes.

Photo 5.9: Muddy earthen roads in Polder 43/2F

The conditions of the earthen roads are not good and they become muddy and inaccessible during the rainy season. According to the survey findings, none of these earthen roads are repaired in last 10-15 years. None of the internal roads (Both asphalt and earthen) went underwater during flood in the last 50 years. The frequency of major road maintenance is not good (around 10-15 years). Only the asphalt roads were repaired in last 5 years.

b) Embankment roads

Almost half of the embankments (5/11) has been covered (Asphalt) by LGED around 2/3 years ago. This part of the embankment is almost in good condition, just broken in some places. Most of the earthen part (around 80%) of the embankment is also in good condition. The rest 20% of the embankment is too narrow and insufficient in height. This part of the embankment needs to be repair. Normally people are using the whole embankment as road. But the earthen embankment gets muddy in rainy season and become difficult to use.

Photo 5.10: Breaching of embankment near water structures is a common problem in Polder 43/2F The UP used fill up the broken part of the embankment once in 2/3 years. Some part of the embankment got overtopped during Sidr. The height of most of the embankment isn’t satisfactory. Especially the carpeted part of the embankment isn’t enough; it can be easily overtopped during big floods. Part of the embankment near the big river (Payra) needs to be protected by reinforcement.

c) Bridges and culverts

During the physical survey, 10 bridges and 28 culverts were found on the internal polder roads. Most of the bridges are old but functioning well. Two of those are too old to function and need to be replaced by new ones.

Photo 5.11: A blocked culvert in Polder 43/2F

Among the 28 culverts 21 are working well, 2 of them are inadequate in size and another culver is totally damaged. So, the overall internal drainage situation of this polder is much better than polder 26 but routine maintenance of these structures is so important.

Figure 5.8: Present state of internal water crossing structures in Polder 43/2F

d) Drainage sluices

There are 19 sluices all around the polder and those were sufficient enough to drain out water from the polder. But due to saline water, gates got eroded very easily. 12 out of 19 sluices are not

70 working properly. Besides, another two sluices are almost damaged and need to be replaced. The other five sluices working properly. So, to maintain the drainage system of the polder, BWDB should repair the damaged gates as soon as possible.

Figure 5.9: Present state of Drainage Sluices in Polder 43/2F

e) Inlets/Outlets

There are around 28 inlets in this polder to take river water into small catchments for irrigation. These are so important because here ground water is saline; river/canals are only source of

71 irrigation water. Most of the structures (25 out of 28) are in good condition but only few of them have gates. All the gates have been stolen or damaged. Farmers are using earth to stop the water flow but it does not work well always. So, BWDB should provide new gates for these structures and WMGs should take care of those. Besides, Inlets and outlets are designed to pass water in one direction only, yet farmers usually use inlets also to drain out water, which damages the structure.

Figure 5.10: Present state of inlet/outlet structures in Polder 43/2F

5.3 Findings of FGD and KII

As a part of the study, Focus Group Discussions (FGDs) and Key Informant Interviews (KIIs) were carried out for documenting the existing problems related to roads & water management in the study areas and for assessment of the possible solutions of the problems. Two Focus Group

Discussions (FGDs) and two Key Informant Interview (KII) sessions and a number of informal public consultations were carried out for each of the selected locations. The summery of findings from Focus Group Discussions (FGDs) and Key Informant Interview (KII) sessions for each of the study areas are given below.

5.3.1 FGDs (Focus Group Discussions)

In the FGDs, an effort was made to invite all the people who are directly involved with the water management of the polder area. During the FGDs, Outmost efforts were made to get feedback from local community about the problems, they are facing which is related to roads and water management, and their suggestions about the way to mitigate or solve the problems. People who participated in the public consultations were found enthusiastic in sharing their views.

Table 5.1: FGDs details for Polder 26, Dumuria, Khulna

SL No. Date Venue Time Participants Number of Participants FGD 1 02-02-2017 Shovna Union 09:30am- UP Members 07 Parishad Complex, 11:00am in Polder 26 Dumuria, Khulna FGD 2 02-02-2017 Shovna Union 03:00pm- WMG 14 Parishad Complex, 04:30pm Representative Dumuria, Khulna s in Polder 26 Total 21

Table 5.2: FGDs details for Polder 43/2F, Guilshakhali, Barguna

SL No. Date Venue Time Participants Number of Participants FGD 1 14-03-2017 Guishakhali 10:00am- WMA 15 UP Complex, 11:30am Representatives Barguna. in Polder 43/2F FGD 2 14-03-2017 Guishakhali 12:00pm- UP Members in 9 UP Complex, 01:30pm Polder 43/2F Barguna. Total 24

5.3.1.1 Common findings from the FGDs

Every Union Parisad (UP) has 9 wards. UP have a working committee of 1 chairman, 9 members (one form each wards) and 3 female members (one from each 3 wards). This committee is elected by people for 5 years. UP is mainly responsible for construction and maintenance of most internal village roads and water crossing structures on village roads. Besides, as people’s representative they can do any kind of development work upon necessity.

There is a Water Management Association (WMA) in each polder. And there are several WMGs (mainly for each sluice) in a polder. These WMA and WMGs are also elected committee but they work for BWDB. The WMA and WMGs are mainly responsible for operation and maintenance of BWDB’s property like embankments, sluices, inlets, outlets etc.

So the work place of this two key organization is separate. UP works mainly inside the polder while WMA/WMGs work mainly on the embankment. Normally UP/ PIO constructs a new village road upon people demand. UP does it under the ‘Food for work’ project and sometimes UP also constructs small culverts under this project depending on the fund availability. When PIO office constructs a new village road or water crossing, they do it by consulting with the UP. Besides, LGED also consult with the local UP members before doing a development work. So before constructing or developing a road, the responsible organizations consult with locals or their representatives (like UP) about the road alignment, importance of road, water crossing structures etc. But sometimes the responsible organizations can’t follow all the suggestions because of insufficient funding. This happens mostly for water crossing structures. Normally, UP/PIO office doesn’t get sufficient fund to construct sufficient water crossing structures on the newly constructed road. But UP chairman always can inform LGED/PIO about any problem related to roads/ water crossing in the Upazila Parisad Monthly meeting and later LGED/PIO can solve that problem by yearly maintenance fund/ other funds.

BWDB/BG forms WMA to take care and to take decisions related to water management inside the polder. Before doing any development work, BG/BWDB takes proposals (like list of Khals for re excavation) from the WMA. Besides, BG/BWDB subdivided the polder into several parts and forms WMGs for each part. WMGs are responsible for operation and maintenance of embankment and water structures on embankment on those specific areas. WMA & WMGs also supervise the development works (outlet construction, khal re-excavation etc.) done by BG/BWDB.

But there are some co operational gaps between these two organizations. Normally UP members are more powerful then WMGs because UP is a part of Local Government. That’s why WMGs need help from UP during khal re-excavation for land requisition (people started farming on the silted khals). Besides, people are not getting benefits of khal re-excavation due to some insufficient water crossing structures. Here, UP can perform a great role to improve the water

74 management. They can try to collect some fund for improving those structures from local MP (Member of Parliament)/ LGED/ PIO/ Upazilla Parisad. UP also can take action to remove net pata and other blockage to maintain the connectivity of the khals.

5.3.1.2 FGD findings for Polder 26

More culverts needed to maintain the proper flow of water. BG is dredging some khals but there are not sufficient culverts for the local people to use these. As a result people will again fill up the dredged khals to make roads for communication. The list of culvert location from the FGDs is given below- 1. The main UP road has separated the Shakhabai River, this river used to pass most of the water. So a culver (Wider than 15 feet) is needed to maintain the flow of the river. And it needs to be gated. So that it can control the flow of water which will be helpful for irrigation for the entire east part of the polder (high land). 2. A culvert needed near the new sluice (Baloijakhi Sluice). People use bamboo culvert to transport goods. They have no other way. 3. A gated culvert is needed near Modhu’s House (In the middle of a bill). Some part of this area is high and some is low. So it’s very difficult to store water for irrigation in high lands. For this reason a culvert is must needed for irrigation water storage. 4. A culvert needed near agar bill. 5. A culvert needed on Bujhtola khal. 6. A culvert is needed on Kakmari purbopara road. 7. A Culvert on Boyersing khal needs improvement (Inadequate in size).

(a)

(b) Photo 5.12: FGD-1 in presence of local UP members (a) and FGD-2 in presence of the representatives of local WMG (b). Both FGDs was organized at the meeting room of Shovna UP Complex, Dumuria, Khulna.

They also mentioned some problem related to sluices. The Kodomtola privet sluice isn’t working properly. Gate of this sluice is made of wood and too old. So it needs to be replaced. Another 2 damaged sluice in the northern side need to be replaced. Besides, it is very important to dredging the both side of each sluice at least 1 in every 2 years. But BWDB didn’t conduct this type of maintenance work. Local people do this by their own labor.

Most of the polder roads are earthen roads. These roads become muddy and inaccessible during rainy season. Farmers can’t take their crops in the market in time due to poor road condition and as a result they don’t get the right price of the crops. Besides, children also can’t attend school regularly in the rainy season. Additionally, the participants mentioned that the main UP road isn’t wide enough for heavy vehicle and need to improve.

The FGD participants also mentioned some Khals name which need re-excavation.

- Zhilla khal - Kaliduhar Khal - Bujhtola khal - Shakhabai Khal - Kodomtola- Chingra khal

5.3.1.3 FGD findings for Polder 43/2F

Water logging problem exists in this area. Water logging occurs during rainy season. Seeds and crops get damaged due to waterlogging. And in the dry season, people face water scarcity problem. The ground water is saline here. So, surface water (Canal & river water) is the only source of water for irrigation. But the existing system can’t supply sufficient water for rice cultivation. Basically, both of these problems happen due to poor drainage system. Most of the Khals (canals) are not dredged properly and need to be excavated. The participants mentioned some khals which need re-excavation. Those are given below-

- Khekuani khal - Horidrabaria khal - Dalachara khal - Chandra khal - Patabuniya khal - Dhupaihuta khal - Shoilabunia khal - Dhupaihuta khal - Gunachonda khal

In some areas, Drainage system is good but need water pump to get canal water into the lands for irrigation. Due to water problem in Khekuani, deep tube well should be installed for supply of drinking water.

Most of the Existing sluices are not in good condition. Gates are damaged in 16 sluices and need to be repaired. The main 3V sluice in Ghojkhali isn’t working properly and need to repair. In South Khekuani, two sluice gates remain damaged for last three years which need to be replaced. Although there exist a big sluice gate in North Ghojkhali, it does not work properly for being damaged. Existing sluices can’t supply enough water for irrigation in North Dalcara. River’s side slope is damaged, at any time embankment may collapse. River bank needs to be protected using concrete blocks along the embankment. Blocks should also be provided beside the under constructed sluice gates to protect it from river erosion. Embankment height should be increased from Forkan’s house to Mujibur Hawlader’s house.

(a)

(b) Photo 5.13: FGD-1 with the representatives of WMA and WMGs in polder 43/2F (a) and FGD-2 with local UP members (b) at Guishakhali UP Complex, Barguna.

Most of the roads (both internal road & embankment road) are carpeted (Asphalt or concrete) in this polder. But almost all of those roads are broken near most of the water crossing structures like inlets/ outlets/ culverts. The reason behind this is the soil property (Clay) and soil compaction. Design should be changed to the under constructed roads. Here road should be a little wider due to poor soil properties. And the pot holes should be repaired immediately. Internal Roads of Bajarkhali to Majid master house need to be carpeted. People facing transportation and communication problems during rainy season due to muddy roads. There are a lot of brick fields beside the main UP road and people use trucks to transport bricks. Those overloaded trucks damaging the embankment and roads.

The participants give an idea of creating sub-polder. They need embankment between low laying land and high laying land so that they can store water in the high land in the dry season for irrigation. It will also solve the waterlogging problem in the low land during rainy season. Beside

78 the sub-polder, they also need gates in the culverts for water storage. And there is only one gated culvert in the polder area.

UP members should be in the WMG/WMA group to serve better in water management sector. BG/BWDB usually starts their work in rainy season; they should start their work before starting of rainy season.

5.3.2 Findings from Key Informant Interview (KII)

Two KII sessions have been organized for this study with relevant officials of BWDB & LGED local institutions for each of the study area. The BWDB participants in the KII session provided valuable opinion about the project and also give some information about the development, future plan and responsibility of BWDB for the polder areas. Similarly, the LGED participants in the KII session provided some valuable information about the history and current category of roads in the polder areas. He also provided some information about the responsibility and future plan of LGED for the polder areas.

Table 5.3: Details of Key Informant Interviews (KIIs)

Polder No. Organization Name Designation 26 LGED Mr. MMA Bakr Sub-Assistant Engineer 26 BWDB Mr. Akram Sub-Divisional Engineer 43/2F LGED Md. Nazrul Islam Upazilla Engineer 43/2F BWDB Aminul Islam Sohag Sub-Assistant Engineer

5.3.2.1 KII findings from BWDB

BWDB is responsible for dredging and maintenance of most of the khals. BADC (Bangladesh Agricultural Development Corporation) is responsible for some of the khals. But now BG is working on the khals on behalf of BWDB. The local DC office is responsible for leasing khals to individuals. BWDB reshapes the embankment in every 2 years. Currently BG is reshaping the embankment (Except North part) in polder 32. And in polder 43/2F, BG reshaped the whole embankment 3 years ago. Bu t no reinforcement was given in the river side in both of the polders.

Design specification of embankment-

R: S= 1:3, C: S=1:2, Top width= 4.27m, Design level=4.5m.

BWDB repairs field outlets when needed but now BG is maintaining those. BWDB isn’t involved with any new construction (BG does). BWDB is just responsible for emergency

79 maintenance. BG is working on some intake/outfall structure. Sluices are operated by local people. Every sluice has a committee which controls it. All sluice function both ways. Sluices can drain water out of the polder area during monsoon in low tides.

BG has prepared a polder map which contains Design approach and specifications for field outlets/ sluices, current status of water structures and details about future development plans of BG. LGED doesn’t seek permission from BWDB before carpeting or repairing an embankment. Sometimes they carpeted low lying section of the embankment.

5.3.2.2 KII findings from LGED

LGED is responsible for maintaining most of the roads in the polder area in every four years. They repair roads when they get budget from the local government (mostly it’s not pre planned) and the repair works are held in the specific area where local MP/Minister suggested. LGED has three types of roads in the polder area (Union road, Village road type- A and B) and each of those roads has a road ID in LGED database. For each type of road LGED has specific design guidelines and those guidelines are available in LGED website. Normally LGED makes carpeting roads but where roller cannot be used, there LGED uses brick soling.

LGED has guideline for design of cross-drainage structures also. If length of the water crossing structure is greater than 12 m then it is called bridge and if it is less than 12 m then it is called culvert. According to the guideline, LGED have to provide at least 15m opening for water passage in each Km of road.

Construction of new roads or water crossing structures depends on peoples demand. Normally LGED does not construct new roads. But Sometimes LGED does it on the request of local MP/Minister. LGED conduct a yearly survey on all of theirs roads. And depending on the survey data LGED makes a priority list for repair or maintenance of roads and water crossing structures. LGED district office gets a yearly budget for repair or maintenance from the government. Improvement/ repairing are carried out from the budget allocated for them.

5.4 Road – water management issues and solutions

Based on the survey (household and physical) findings and outcomes of FGDs and KIIs, a catalog of issues and solutions related to road - water interactions is discussed below. Issues and solutions are presented in an order that reﬂects local priorities emerging during the Focus Group Discussions.

5.4.1 Discussion on Polder 26

5.4.1.1 Rethink number and capacity of water crossings

Internal roads change natural drainage patterns and direction of water and waterways. Roads thus shape how water is distributed and lead to differentiated water availability and waterlogging conditions within the polder. During the construction of the polder, the population density of the polder was very low. But with the time, people started living in the flood protected polder area. And for those people’s communication UP & LGED started constructing internal polder road in an unplanned way. They didn’t consider the drainage system while constructing the roads. As a result natural drainage patterns and direction of water and waterways changed a lot. This caused a massive waterlogging problem in this polder area (Photo 5.14).

Photo 5.14: Waterlogged household in a polder area

Fieldwork also highlighted that there are insufficient water crossings (culverts and bridges) along internal roads to ensure the connectivity of both the khal system and communication ways for people living in the polder. The Union Road crosses two large khals (one was previously a river) flowing from East to West. Along this road there are two single vent culverts allowing the water to flow from East to West, but these structures are of inadequate size to convey the huge water flow generated in the eastern part during monsoon. One is located at the intersection between Shaka Bai khal and the Union Road, the other one is situated where the road intersects Kata khal (Photo: 5.15). As a consequence of few water crossings, large areas of farmland on the East side of the main road are waterlogged.

Photo 5.15: Inadequate culvert on Kata Khal

Waterlogging impacts severely on farming and reduce its potential. Household surveys reported direct crop damage and delay in farming activities leading to reduced yields and harvest losses. Crops are particularly vulnerable at the flowering stage, approaching maturity, and at the seed and seedling stages because water would wash the seeds away. Waterlogging also limits crop choices to few crops which tolerate better waterlogged conditions, and restricts vegetable farming. Around 65% of the respondents to household surveys reported to face recurrent crop failures (almost every year) and to have abandoned some portions of their cultivable land, in some cases up to 85 percent, because of flooding. In areas that are irrigated with khal or river water, which was reported to be somewhat saline especially during the dry season when flows are smaller, a secondary effect of waterlogging i.e. salinization of soil occurs. For a number of farmers this is a major cause of loss of land productivity. Aquaculture activities are also affected as fish is flooded away out of ponds during high water.

Roads are not only developed by LGED and UP. Earthen pathways are also constructed by local people to restore communication across khals, often to be able to transport agricultural products from their fields to the nearest road. This unplanned construction of roads, however, encroaches on the connectivity of the khal system and creates additional barriers to drainage flows. Besides insufficient numbers of water crossings, the capacity of several existing ones is not enough to convey the large flows of water generated within the polder catchment during the rainy season. This is an even more important aspect in view of BG/BWDB plan to re-excavate several khals in the polder.

Photo 5.16: Village road disrupting canal connectivity

As mentioned in the physical survey summary, 3 bridges and 6 culverts were found on the internal polder roads. Two of the bridges are in good condition but old. The third one is blocked and too old to function and it needs to be replaced by a new one. Among the 6 culverts 2 are functioning well, 3 of them are inadequate in size and the 6th one doesn’t have any connection with any khals.

In the North side of the polder, where settlements are concentrated and density of khals is lower, drainage is poor both along roads and around homesteads and waterlogging is a problem. According to respondents, in certain areas, water would stay for 2-3 months. Several families reported about extremely intense rains that would cause water entering into their homes and other public buildings such as schools. Some families cope with this situation by laying down pipes and excavate ditches around their homes to help drain the excess water towards safer areas such as farm fields.

Waterlogging affects several areas in the polder. Thus, adding a certain number of water crossings is found as a top priority by the local community as it will have large impacts in terms of reducing waterlogging, increasing agricultural productivity, creating opportunities to diversify crops, improving communication and local livelihoods, improving overall socio-economic

83 development. Overall, at least 6 additional culverts are needed and the size of 3 other culverts needs to be increased. Problematic locations where additional culverts or bridges are needed have been identified through physical survey and focus group discussions with UP and WMG members.

Photo 5.17: A LGED road without water crossing structure

According to the current design specifications for roads adopted by LGED, there must be at least a total 6-10 m (For plane area) opening for each kilometer of roads for facilitating drainage even if there is no water crossing and if there is any water crossing found then LGED must provide an adequate size of water crossing structure for easy passing of water. LGED should perform simple hydrologic analysis for culvert design. In turn, improved drainage will increase the durability of roads and related structures and reduce maintenance and repair costs significantly.

5.4.1.2 Re-excavate and reconnect khals

The re-excavation of khals to increase both drainage and storage capacity of fresh water for multiple purposes is reported as very important by the local community and should go hand in hand with the provision of adequate water crossings. A number of khals have lost their original carrying capacity due to siltation (Photo: 5.18) and the overall connectivity of the khal system has decreased because of land reclamation to create space for settlements, farming, fishing, and road construction (often unplanned) without providing enough cross drainage. Implementing

84 organizations (i.e. BWDB and BG) indicated that re-excavating khals is a challenge as several khals have been leased out by the government to landless, and others have been encroached by powerful individuals, fishing and settlements.

Photo 5.18: A silted canal in Polder 26

Because of the complex socio-political nature of the issue, it was suggested during the FGDs that the re-excavation of khals should be a joint effort of governmental agencies, UP, WMGs, and BWDB. UP members can play major role in creating awareness about the benefits that reconnecting the khal system would yield for the whole community. WMG members expressed their interest in being involved in khal maintenance by mobilizing the local community to carry out excavation and maintenance works. It is also suggested that extend participation in WMG committees to UP members to improve and accelerate the implementation of water management related activities.

BWDB has undertaken a comprehensive plan to re-excavate a number of khals in Polder 26. However, from the present study, it was observed that more khals are needed to be re-excavated other than the BWDB list, such as Kaliduharkhal, Bujtolakhal, Zilerkhal, Kurirbeelerkhal, Hoglabuniakhal, ChingraKodalkatakhal etc.

5.4.1.3 Gated water crossings to retain and control water

When they were first developed in the 1960s, polders were designed with the main objective to protect lands from flooding and with a focus on drainage of flood and runoff water, allowing the safe settlement of people and their socio-economic development. Water control for farming and other productive uses was not integrated in the original design. Today, the need to improve water control and water distribution within the polder becomes increasingly manifest. Higher elevated lands are difficult to irrigate because there are no water regulators built into the khal system to retain water in specific areas of the polder at needed times. Water tends to flow toward and concentrates in lowlands, causing drainage congestion and waterlogging here. In high lands, pump lifting of water from the khals to the field is needed in several cases.

Photo 5.19: A model Gated Culvert

Roads represent an opportunity and should be turned into instruments of polder water management by providing regulation structures at water crossings. The gains are multiple:

(a) Retain water in high lands and control water levels in different compartments of the polder (b) Reduce drainage congestion in low lands (c) Increase fresh water storage for multiple purposes (d) Diversify crop production (e) Increase number of crops per year (f) Obtain higher yields (g) Grant more flexibility to farmers to plan their cropping patterns and farming activities

Once gated water crossings are implemented, there should be a body responsible for their

86 operation and maintenance. WMGs expressed their willingness in being involved in internal polder water management. Fieldwork and FGDs have indicated a potential location for gated water crossings on Chingra- KodalkataKhal in Polder 26 (Figure 5.3).

5.4.1.4 Improve quality of roads

The quality of both internal and embankment roads is a challenge in Polder 26 and household surveys highlighted that the majority of the polder population is affected to some extent by poor road conditions, particularly during the rainy season. Many village roads are earthen or paved with bricks. During the rains, earthen roads become extremely muddy, slippery, and uneven under the pressure exercised by the wheels of motorized vehicles (Photo: 5.20). Brick roads are frequently damaged with bricks being displaced and leaving behind large potholes, ruts, and portions of muddy soil. Tarmac roads also deteriorate due to the corrosive effect of water. Portions of the tarmac carpet detach from the subgrade leaving large holes and unpaved portions. Current road conditions affect people’s lives and livelihoods in a number of ways: the use of motorized vehicles is limited during the rainy season, riding bicycles causes waist pain because of the ruts and potholes, transport of goods, products, and household supplies to and from the market is hampered, general communication and mobility is reduced and time consuming, school attendance is a challenge, and so is the transport of sick people to the hospital, the risk of accidents is also reported to be higher.

Photo 5.20: A muddy earthen road after rain

The main causes of poor quality roads are:

- Poor quality of soil used as subgrade. Sourcing of good soil is challenging in some locations and it cannot be found within cost-effective transportation distance.

- Construction is often delayed in the rainy season, which hampers the whole construction process. Compaction of the road becomes a challenge as the soil is imbued with water. This reduces the stability and sustainability of the structure. A contributing cause to the late execution of works is the disbursement of funds to LGED in July (financial year is July-June) so that by the time plans are approved, field surveys done, and works are ready to be started, it is already the inception of the rainy season.

- Quality checks on contractors are challenging. Roads are not provided with adequate drainage facilities and water erodes and damages carpeting and road sides.

- No regular maintenance is done, only periodic interventions to fill major damages or for carpeting and widening of roads. Moreover, premature erosion of embankment roads and internal roads occurs often in correspondence of pipe culverts and pipe inlets/outlets. Two are the reasons: i) the length of pipe inlets/outlets is smaller than the width of (embankment) roads so that water scours the shoulders of roads and road embankments, ii) Collar joints are not field adequately when laying down pipe culverts so that water leaks out of the joint and erodes the road above.

Photo 5.21: A broken road in Polder 26

The quality and sustainability of roads can be improved by addressing the issues highlighted above. For instance, during FGDs it was proposed to form community-based committees responsible to check the quality of road construction works and when needed demand relevant authority to deliver higher quality work. Moreover, design modifications to pipe culverts and pipe inlets and outlets shall be done and appropriate length should be chosen to match future widening and carpeting of (embankment) roads.

5.4.1.5 Repair of Sluices and Re-excavation of surrounding rivers

Initially Polder 26 had 6 drainage sluices (Two 3 vent and four 1vent) all around the polder and those were sufficient enough to drain out water from the polder. But with time going, the surrounded rivers got silted and now there is river only in the western side of the polder (Teliganga River). Among the 6 initial sluices, all the four 1 vent sluices are already damaged, a 3 vent sluice is still active and the other 3 vent sluice is in good condition but that has no connection with the active river. In the meantime, the local people constructed two 1vent outlets (One made by concrete and another made by wood) and each of those outlets can drain out water only from a single khal. Recently, BG started some development work in this polder. BG already constructed two 1vent outlets and another two outlet (One 1vent and one 2vent) is under construction.

Repair and reactivation of those sluices with river re-excavation can reduce waterlogging problem from most of the waterlogged areas. It can bring a massive positive change in farming and fishing activities within the polder. But repair of sluices and river re-excavation needs huge investment which is tough to manage for any organization from their regular budget.

5.4.2 Discussion on Polder 43/2F

5.4.2.1 Gated water crossings and regulator structures to retain and control water

Due to the irregular relief and the absence of water control structures on the khals, farmers face challenges to access canal water to irrigate higher elevated fields, particularly during the dry season in Polder 43/2F. This problem occurs especially in the middle of the polder in Dalachhara Catchment. Here, farmers have to pump water from the khals to their Boro paddy fields. Retaining water on highlands and controlling water levels in canals would enable farmers to grow a second paddy rice crop in the year and in general increases their farming flexibility and crop options. In Polder 26, farmers have access to groundwater and can thus attain two paddy harvests per year.

To improve the distribution and management of water in the khal system, there is a need to segregate different parts of the polder and to control the water flow and water levels in the khals. There are many internal structures, culverts (box and pipes) and bridges. These could be used as

89 regulator structures to distribute and retain water where and when most needed. Road crossings can be turned into instruments for improved water management. There is only one gated culvert with missing gate (Photo: 5.22) found in Polder 43/2F which was constructed by Bangladesh Agricultural Development Corporation (BADC). Many more of these should be implemented to achieve a win-win situation of decreased drainage congestion and waterlogging in lowlands while improving water retention in highlands. Box culverts should be provided at specific locations at transition points between high and low lands.

Photo 5.22: Only gated culvert with missing gate in Polder 43/2F

Moreover, to improve overall polder water management, embankment regulators (sluice gates, inlets, and outlets) should be repaired and regularly maintained to improve water control and water retention in the polder. Defective structures (Photo: 5.23) that do not close hermetically lead to water losses out of the system or entering of unwanted river water creating flooding risks. Of the 19 surveyed sluice gates, 12 had some defects and do not allow for full water control. Moreover, inlets and outlets should be provided with gates and maintenance should be done routinely.

Photo 5.23: A defective sluice which can’t control water properly

In 2016, BG repaired 25 inlets/outlets, yet the provision of gates is responsibility of the Mechanical Engineering Department of BWDB. BG has plans to construct 4 new outlets in 2018. Out of 28 surveyed gated inlets/outlets along the embankments, 20 were found to be lacking the gate. Of the total 28 surveyed inlets and outlets, 23 were silted up or blocked by farmers with earth or bricks to control the water flow because still devoid of metal gates. Inlets and outlets are designed to pass water in one direction only, yet farmers usually use inlets also to drain out water, which damages the structure.

5.4.2.2 Re-excavate khals and increase water storage

Many khals have silted up in the years after the development of the polder (Photo 5.24). Siltation has occurred partly as a natural process because the bottom of sluice gates has been positioned higher than the bottom of khals, partly as because of human encroachment. Thus, a re-excavation of khals is needed and has emerged as a major improvement to increase the drainage and water retention capacity of the khal system. This would reduce waterlogging and increase water availability for different uses. According to farmers, increasing the capacity of khals to store freshwater would enable them to grow a rabi paddy crop during the dry season. This intervention goes hand in hand with the previous solution, the provision of regulation gates to water – crossings. The order of intervention should be the re-excavation of khals fist and the intervention

91 on the water -crossing after that. BG is planning to re-excavate 10 khals in Polder 43/2F. WMA and WMGs are involved in the selection of khals needing re-shaping. The idea is that after khals are being rehabilitated; regular maintenance will be taken over by the local community.

Photo 5.24: A silted canal in Polder 43/2F

In addition to those already planned by BG, a list of khals that need to be re-excavated has been suggested in FGDs such as Zintola khal, Angarpora khal, Rishikata khal, Madartola (South) khal, North Gojhkhali (North) khal, Bahannowkura khal, Gunachonda khal, Dalachara khal, Chandra khal, Patabuniya khal, Shoilabunia khal and Dhupaihuta khal.

However, the designs of khals re-excavation should be done by considering the capacity of sluice gates and internal structures. BG is planning to construct a new sluice gate in 2018 and to replace the Khekuani sluice gate by a new one. BG has already repaired structures of 15 sluices in 2016, but the metal gates of those sluices are yet to be replaced by the Mechanical Engineering Division of BWDB. The reparation of the gates is fundamental in order to maximize water control and flood protection. Another challenge is connected to the financing. Just as it happens for roads, the budget for the re-excavation of khals is disbursed in the rainy season, making the dredging and re-shaping very hard and unsustainable and affecting the overall quality of works. This type of works should be done during the dry season (October- December).

As mentioned previously, land acquisition for the re-excavation of khals is also a challenge. During the validation workshop it was suggested to leave out from re-excavation those khals which have been allocated by the government to landless people, to consider their needs and priorities. The feasibility of re-shaping khals should thus be discussed closely with the local community. Members of both UP and WMGs are willing to support in this process and WMGs showed interest in being more actively involved in the execution of excavation and maintenance works, if given the authority to do so by BWDB. Again, many lessons can be drawn from LGED’s PSSWRS project.

5.4.2.3 Improve the design of inlets and outlets

The length of the pipe barrel of inlets and outlets along the embankment is a design characteristic that has a huge impact on the durability and stability of the portion of embankment or embankment roads above the structure. It has been observed that in several cases, the length of the inlet or outlet is smaller than the width of the embankment as often, the design length is not chosen in view of future widening of the embankment that accompanies the carpeting of an embankment road. Water entering or leaving the polder through the pipe gets in contact with the sides of the embankment and erodes them (Photo: 5.25). This reduces the stability and height of the embankment and reduces flood protection. This relatively easy to find that design detail has so much impact on the sustainability and flood protection function of embankments and on the sustainability of embankment roads. Thus, design of inlets and outlets should consider future widening of embankments in view of a potential development of an embankment road.

Photo 2.25: Road collapse near inlet structure

5.4.2.4 Improve shelter function of (embankment) roads

Embankments, embankment roads and also higher elevated internal roads are used as shelters during floods and high water. Around 20% of the respondents seek shelter on high sections of internal roads and on embankments (Photo 5.26) when river flooding occurs (or there is risk thereof) and when intense rains and insufficient drainage cause internal flooding in the polder. They took shelter on embankments for 2/3 days to 2 weeks. And that time they faced a lot of challenges like drinking water problem, food, disease etc.

Photo 5.26: People using embankment as flood shelter

The shelter function of internal roads and embankment roads has to be enhanced, not neglected, as it is an important safety haven for polder inhabitants. An option would be to make levees along targeted roads where people (and livestock) could find shelter. As for embankments, current design manuals for the construction of embankments by both LGED and BWDB prohibit the use of embankments for afforestation and for flood shelters (from stability considerations). However, special additions could be made to existing design to allow the provision of berms at specific embankment sections to shelter people and livestock during flood (risk) and high water.

5.4.2.5 Improve Collaboration between LGED and BWDB for embankment road carpeting

The risk of river flooding is higher in Polder 43/2F than in Polder 26 because the polder is surrounded by rivers, the large Payra river is very close to its embankment. The perception among the majority of household respondents is that the embankments do not protect them sufficiently from river surges. It was observed in several cases that the carpeting of an embankment affects the height of the embankment and reduces thus flood protection. In 4 of the 5 carpeted embankment sections surveyed, the height of the embankment was found to be lower than the other embankment sections.

Photo 5.27: LGED cut down embankment road to achieve their design top width There is a lack of coordination and cooperation between BWDB and LGED. BWDB takes long time to approve LGED’s plans for developing an embankment road. As a result, sometimes LGED start working without NOC and they cut down the embankment height to meet their design top width. This under dimensional embankment can easily overtop during big floods or cyclones. Moreover, the quality of carpeting of embankment roads is not good enough for reasons similar to those already mentioned for internal roads. This results in rapid degradation of the road, which, in turns, also leads to the deterioration of the embankment.

This needs to be changed. The process to approve embankment carpeting plans shall be streamlined, design heights for embankments and embankment roads adopted by LGED and BWDB should be harmonized and better monitoring is needed by BWDB of embankment roads implemented by LGED. Quality carpeting respects safety height standards for embankments and implies. Moreover, it implies the use of good materials and a close monitoring of the construction process, which altogether lead to durable embankment roads and stable, flood-proof embankments.

5.4.2.6 Additional culverts to reduce waterlogging

Despite the large number of water-crossing structures, sluice gates, and the extensive khal system, a large number of respondents are affected by waterlogging. Waterlogging occurs in patchwork manner in low lying lands and around homesteads. A large number of respondents reported to have abandoned some land because of waterlogging. A vast majority of respondents reported regular damages to crops and crop failures because of waterlogging. Excess water washes seeds and seedlings away, is cause of rot, delays farming activities and marketing of crops. Altogether this reduces yields, crop quality, and the price farmers can get

96 from their products. Flooding and waterlogging on farmland can be largely reduces by re- excavating and re-shaping khals to increase their water storage and drainage capacity, and by repairing sluice gates and providing outlets and inlets with gates. Waterlogging around homesteads and settlements can be improved by simply adding some additional culverts and pipes to safely divert excess water to ditches and khals or beels. In addition to damaging property and goods (e.g. furniture, food storage, livestock and small animals), hampering communication and mobility, waterlogging around homes is also source of water- borne diseases. People would dig drainage ditches around their homestead and lay down rudimental pipes to drain water from around their house to safer areas such as farm fields.

A number of additional culverts and pipe drains should be implemented at different locations, particularly in and around villages, to drain water toward drainage khals and beels.

Chapter 6

DESIGN OF WATER CROSSING STRUCTURES

6.1 Introduction

Among the two selected polder, severe waterlogging problem was observed in Polder 26. The main reasons behind these are insufficient and inadequate water crossing structures along the internal polder road. Most of the polder roads were constructed by blocking Khals/Rivers which causes a massive waterlogging problem within the polder. As a part of the study, some simple hydrograph is conducted to calculate the proper culvert size for all the possible culvert location (Both existing and missing). This Chapter presents the summary of findings from simple hydraulic designs of culverts.

6.2 Data Collection and Processing

For hydraulic designs on very small watersheds, a complete hydrograph of runoff is not always required. The maximum, or peak, of the hydrograph is sufficient for design of the structure in question (Thompson, 2006). Therefore, a number of methods for estimating a design discharge, that is, the maximum value of the flood runoff hydrograph, have been developed. The rational method is a simple technique for estimating a design discharge from a small watershed. It was developed by Kuichling (1889) for small drainage basins in urban areas.

The rational method is the basis for design of many small structures. In particular, the size of the drainage basin is limited to a few tens of acres.

Application of the rational method is based on a simple formula that relates run off producing potential of the watershed, the average intensity of rainfall for a particular length of time (the time of concentration), and the watershed drainage area. The formula is

Q = 0.0028CiA Where, Q = Peak discharge (m3/s), C = runoff coefficient (dimensionless), i = design rainfall intensity (mm/hr), and A = watershed drainage area (ha)

6.2.1 Rainfall Intensity

The study site selected for this study is Polder 26. Since no rain gauge station is located in Polder 26, the data from nearest rain gauge station is considered for this analysis. Therefore, daily rainfall data of Khulna Station (nearest to Polder 26) over a period of 20 years (1995-2014) was collected from Bangladesh Metrological Department (BMD). From the available rainfall data, rainfall series for different durations (e.g. 1day, 2 days, 3 days, 4 days, 5days, 6days and 7days) are developed. For each selected durations, the annual maximum rainfall depths are calculated. It has been found from the previous studies that among the rainfall distribution methods, Log Pearson Type III distribution gives more accurate result; hence the present study adopted Log Pearson Type III distribution method for determination of rainfall intensity. Table 6.1 and Figure 6.1 show the rainfall intensity of stated return period using Log Pearson Type III distribution.

Table 6.1: Rainfall Intensity for different Duration and Return Period Duration Return Period (in Years) (in Days) 2 5 10 20 50 100 200 500 1 4.859632 6.667923 8.016236 9.375371 11.18952 12.56538 13.93236 15.70673 2 3.644986 4.773962 5.510521 6.203516 7.076814 7.710467 8.321204 9.091375 3 2.842462 3.713377 4.30453 4.872592 5.601449 6.137802 6.659845 7.324391 4 2.396931 3.081627 3.534244 3.963116 4.506862 4.903286 5.286648 5.771644 5 2.049545 2.634067 3.028656 3.40674 3.890663 4.246098 4.591597 5.030856 6 1.81832 2.319644 2.646901 2.954897 3.34313 3.624885 3.896491 4.239048 7 1.645718 2.087291 2.374979 2.645449 2.986071 3.233095 3.471101 3.771135

90 80 500 Years

70 60 200 Years 50 100 Years 40 50 Years 30 20 Years Intensity (mm/hr) 20 10 Years 10 5 Years 0 2 Years 1 2 3 4 5 6 7 Duration (Days)

Figure 6.1: IDF curve for 20 years (1995-2014) rainfall in Polder 26

Using the plotted (Figure 6.1) IDF curve, the required rainfall intensity was calculated.

6.2.2 Catchment Area

Google Earth Pro software was used to calculate the catchment area of the culvert points. The catchments (like polygon) were plotted in the software manually using polyline and the software itself calculated the area of the catchments. Figure 6.2 shows an example of the catchment area calculation.

Figure 6.2: Catchment area calculation in Google Earth Pro

6.2.3 Runoff coefficient (C)

It is measured by determining the soil type, gradient, permeability and land use. The values are taken from the table below (Table 7.2). The larger values correspond to higher runoff and lower infiltration. The value of runoff coefficient for agricultural land is 0.15 to 0.4. In this study, a runoff coefficient 0.4 was considered to calculate the discharge as most of the study area is agricultural land.

Table 6.2: Runoff Coefficients for Rational Formula (From Michigan State Administrative Rules R 280.9) Type of Drainage Area Runoff Coefficient (C) Concrete or Asphalt Pavement 0.8 – 0.9 Commercial and Industrial 0.7 – 0.9 Gravel Roadways and Shoulders 0.5 – 0.7

100

Residential – Urban 0.5 – 0.7 Residential – Suburban 0.3 – 0.5 Undeveloped 0.1 – 0.3 Berms 0.1 – 0.3 Agricultural – Cultivated Fields 0.15 – 0.4 Agricultural – Pastures 0.1 – 0.4 Agricultural – Forested Areas 0.1 – 0.4

6.2.4 Culvert Dimension Calculation

FHWA Design chart (Figure 6.3) was used to calculate the required culvert dimension.

Figure 6.3: FHWA Design chart for culvert design

101

6.3 Sample Calculation

During physical survey several locations were found where road goes along a khal/river without providing any structure. Besides, several inadequate sizes of culverts also found which are disrupting the drainage system. Culvert location 1 (C1) (Figure 6.4) is also such a location where the main UP road crossed a river but LGED didn’t provide any culvert. From the survey and FGD outcomes, it has also been observed that local people want a culvert on those locations as the road impede the passes of water and causes waterlogging. The following calculation was done to recommend a design dimension for a culvert in Culvert location 1 (C1).

Figure 6.4: Location of culverts for Hydraulic design analysis

102

For Culvert location 1 (C1)

From IDF curve, Rainfall intensity i = 4.872592 mm/hr (For 20 years return Period and 3 Days Rainfall) Runoff coefficient C = 0.4 (For agricultural land) and Watershed drainage area A =5.70 sq. km (from Google Earth Pro)

Peak discharge Q = 0.0028CiA = 3.0605 m3/s

Headwater Depth, Hw= 0.84 m

Using FHWA Design chart (Figure 6.3),

For 3.0605 m3/s peak discharge and 0.84 m Headwater Depth,

Culvert Diameter = 4.2 m Cross Sectional area = 13.85 m2 Recommended equivalent culvert dimension for C1= 2.5m x 6m

103

6.4 Recommended Design Dimensions of Culverts

The design of existing culverts in Polder 26 has been reviewed and recommended design of these culverts has been carried out following the sample design stated in section 6.3. Hydraulic Design Analysis of culverts in polder 26 was performed considering two different rainfall intensity. First one was for 20 years Return Period and 3 Days Rainfall and another one was for 20 years Return Period and 1 Days Rainfall. Outcome of these two analysis is compared with the existing condition of culverts in Table 6.3.

Table 6.3: Recommended Design Dimensions of Culverts for Polder 26

Culv Recommended Recommended Number of Existing Culvert ert Design (For 20 Design (For 20 Vents (For Culvert Locations No years Return years Return 20 years Dimension Period and 3 Period and 1 Return (Height x Days Rainfall) Days Rainfall) Period and 3 Width) (Height x Width) (Height x Width) Days Rainfall) C1 2.5mx6.0m 2.5m x 6.5m 3 No Culvert ShakhaBai Khal C2 2.5m x 1.0m 2.5m x 1.0m 1 0.5 x 0.5 Boro Biller Khal C3 2.5m x 4.0m 2.5m x 5.5m 2 No Culvert Chingra Kodalkata Khal C4 2.5m x 5.0m 2.5m x 6.5m 2 No Culvert GhugumariKhal C5 2.5m x 3.5m 2.5m x 1.0m 2 0.5 x 0.5 Boyarsin Khal C6 2.5m x 2.5m 2.5m x 5.0m 1 No Culvert Baluijhaki Khal C7 2.5m x 1.5m 2.5m x 2.0m 1 0.3 x 0.3 Dangar Khal C8 2.5m x 2.0m 2.5m x 2.5m 1 No Culvert Kata Khal C9 2.5m x 1.0m 2.5m x 1.0m 1 No Culvert Branch Khal of DangarKhal C10 2.5m x 2.5m 2.5m x 3.5m 1 2.5m x 3 m Kata Khal C11 2.5m x 2.0m 2.5m x 3.5m 1 2.5m x 4 m Chingra Kodalkata Khal

It has been found from Table 6.3 that three existing culverts (C2, C5, and C7) are of inadequate sizes. To facilitate proper drainage in those locations, at least the recommended size (for 20 years return period and 3 days rainfall) should be provided. Moreover, the Polder needs at least 6 more culverts in stated locations to reduce waterlogging.

104

6.5 Financial Benefits of Recommended Culvert Implementations

The entire polder area is under medium highland (F1) which is normally flooded between 0-90 cm depths of water continuously for more than two weeks to few months during the monsoon season. Table 6.4: Land Use of Polder 26 (Blue Gold Program, 2016)

Land Use Area (ha) % of Gross Area Net Cultivable Area 1993 75 Settlement 560 20 Road 15 1 Water Bodies 100 4 Gross Area 2664 100

105

Figure 6.5: Land Use Map of Polder 26 (Blue Gold Program, 2016)

During the rainy season, groundwater stands within 1 meter depth and 94% of the NCA is poorly drained (Blue Gold Program, 2016). The soil remains under water for 15 days to few months. Water is drained from the soil slowly. The soil of the polder area indicates that the timely removal of water in rainy/monsoon season is crucial for growing rabi / dry land crops in the polder area.

106

Figure 6.6: Inundation Map of Polder 26 (Blue Gold Program, 2016)

107

Table 6.5: Benefits of Culvert Implementation

Culvert Culvert Benefited Average Average Average Total Crop S/N Locations Agricultural Dry Wet Yield Loss per Land Area (A) Season Season (Ton) per Year in Ton Acre Loss Loss Acre/ Season

C1 ShakhaBai Khal 1181 432 C2 Boro Biller Khal 79 29

C3 Chingra 803 294 Kodalkata Khal

C4 GhugumariKhal 1312 480 C5 Boyarsin Khal 49 18

C6 Baluijhaki Khal 770 50% 33.33% 0.88 282 C7 Dangar Khal 128 47 C8 Kata Khal 202 74 C9 Branch Khal of 84 31 DangarKhal

C10 Kata Khal 793 290 C11 Chingra 227 83 Kodalkata Khal

Total 5628 Acre 2060 Tons

If the recommended culverts can decrease 50% of this cop loss by improving drainage. Then total benefit in taka will be as follows,

Total increase in yield per year = 2060/2 tons = 1030 tons Now, 1 ton paddy = 24,000 taka So, total benefit in taka = (1030 x 24000) taka = 24, 720, 000 taka = 290, 823 USD

108

Chapter 7

CONCLUSION

7.1 Conclusions

The present study observes that in the studied polders, intensive rainfall, and not river surges, is the major cause of waterlogging and flooding. This is aggravated by infrastructures mainly roads and settlements that creates obstacles to the natural drainage in the polders. It has been found from the study that the siting of the culverts are not in appropriate locations, the size of the drainage control structures is not adequate for proper drainage, canals are silted up or encroached by the influential people, sluices are not working properly and there is no coordination of LGED, UP and BWDB to integrate the road construction with water management. The major conclusions drawn from this research are as follows:

 The study findings show that the overall scenario of road condition and water management within the two selected polders is not good. Most of the roads are earthen or broken. Both polders have waterlogging problem but it has become severe in polder 26. In polder 26, Farmers facing crop failures (almost every year) and to have abandoned some portions of their cultivable land, in some cases up to 85 percent, because of waterlogging.  Fieldwork in polder 26 highlighted that there are insufficient water crossings structures (culverts and bridges) along internal roads to ensure the connectivity of both the canal system and communication ways for people living in the polder. There are several locations found in Polder 26 where roads were constructed blocking canals or providing an inadequate culvert. This claims later supported by FGDs. Polder 43/2F also needs some additional culvert to improve canal connectivity and drainage system.  A hydraulic design analysis of culverts was performed considering 20 years Return Period with two different rainfall intensity (3 Days Rainfall and 1 Days Rainfall). For 3 Days Rainfall, among 11 culvert locations only 2 locations have adequate size culvert. In 3 locations, the culverts are inadequate and in other 6 locations there is no culvert (Table 6.3 and Figure 6.4). And for 1 Days Rainfall, among 11 culvert locations only 1 locations have adequate size culvert. In 4 locations, the culverts are inadequate and in other 6 locations there is no culvert (Table 6.3).  Implementations of those recommended culverts will improve drainage in 5628 acre agricultural land. And if the improved drainage system can decrease 50% of the current cop loss then the total financial benefit will be USD 290, 823.

109

 The re-excavation of khals to increase both drainage and storage capacity of fresh water is seen as very important by the local community and should go hand in hand with the provision of adequate water crossings. A number of khals have lost their original carrying capacity due to siltation and the overall connectivity of the khal system has decreased because of land reclamation.  Due to the irregular relief and the absence of water control structures on the khals, farmers face challenges to access canal water to irrigate higher elevated fields, particularly during the dry season. Retaining water on highlands and controlling water levels in canals would enable farmers to grow a second paddy rice crop in the year and in general increases their farming flexibility and crop options. In Polder 26, farmers have access to groundwater and can thus attain two paddy harvests per year.  This study found a lack of coordination and cooperation between BWDB and LGED. BWDB takes long time to approve LGED’s plans for developing an embankment road. As a result, sometimes LGED start working without NOC and they cut down the embankment height to meet their design top width. This under dimensional embankment can easily overtop during big floods or cyclones.  Embankments, embankment roads and also higher elevated internal roads are used as shelters during floods and high water. Around 1/3 of the respondents seek shelter on high sections of internal roads and on embankments when river flooding occurs and when intense rains and insufficient drainage cause internal flooding in the polder. But BWDB don’t consider this issue while designing the embankment. According to law, it’s illegal to take shelter on embankment but it’s happening regularly.  It has been observed that in several cases, the length of the inlet or outlet is smaller than the width of the embankment as often, the design length is not chosen in view of future widening of the embankment that accompanies the carpeting of an embankment road. Water entering or leaving the polder through the pipe gets in contact with the sides of the embankment and erodes them. This reduces the stability and height of the embankment and reduces flood protection.

7.2 Recommendations

Based on the research findings and discussion, following recommendations are made.

 LGED should perform simple hydraulic analysis like rational method for culvert design. In this study, simple hydraulic design of culverts (only for polder 26) was performed using rational method and proper dimensions of the culverts were recommended for further implementation (Table 6.3).

110

 The re-excavation of khals is must to increase both drainage and storage capacity of fresh water for multiple purposes. UP members should play major role in creating awareness about the benefits that reconnecting the khal system would yield for the whole community.

 More gated culvert should be installed to control the water flow and store the water for dry season irrigation. It will decrease the farming cost and at the same time, it will increase the yield.

 Collaboration between LGED and BWDB should improve as soon as possible. The process to approve embankment carpeting plans shall be streamlined, design heights for embankments and embankment roads adopted by LGED and BWDB should be harmonized and better monitoring is needed by BWDB of embankment roads implemented by LGED. Additionally, LGED and BWDB should consult with the locals (UP, WMA, WMGs etc.) before any kind of development within the polder. And this two department should also involve the locals in maintenance of roads/embankments and structures upon roads/embankments.

 As for embankments, current design manuals for the construction of embankments by both LGED and BWDB prohibit the use of embankments for afforestation and for flood shelters (from stability considerations). However, special additions could be made to existing design to allow the provision of berms at specific embankment sections to shelter people and livestock during flood (risk) and high water.

 LGED/LGIs should check soil property and compaction during construction of a road. And they should avoid rainy season for road construction. Additionally, regular minor maintenance work is the key to reduce future repair cost. And turfing by local vegetation can protect the road from erosion.

If the above mentioned recommendations can be implemented, the researcher believes that a huge area will be free from waterlogging. As a result there will be huge change in farming activities. With the increased farmland there will be an increase amount of yields, and with a better communication system the marketing of those yields will be easier and more profitable.

111

REFERENCES

Ali M. L. (2002), An Integrated Approach for the Improvement of Flood Control and Drainage Schemes in the Coastal Belt of Bangladesh, PhD dissertation, Wageningen University, International Institute for Infrastructural, Hydraulic and Environmental Engineering, The Netherlands.

Angrish R, Toky OP, Datta KS (2006), Biological water management: biodrainage. Curr Sci. 90(7): p. 897.

AASHTO (1975), ”Guidelines for Hydraulic Design of Culverts” Task Force on Hydrology and Hydraulics, Sub-Committee on Design, American Association of State Highways and Transport Officials, 341 National Press building, Washington, D.C-20045, USA.

Bangladesh Bureau of Statistics (2010), Census of agriculture 2008

Bangladesh Water Development Board (1998), Annual Flood Report, Flood Forecasting and Warning Centre, Dhaka, Bangladesh.

Bangladesh Water Development Board (1998), Guidelines for People‟s Participation (revised draft), System Rehabilitation Project, Ministry of Water Resources, Dhaka, Bangladesh.

Bangladesh Water Development Board (1998), Water Management Planning Methodology for Flood Control and Drainage Systems, A Handbook System Rehabilitation Project, Technical Report No. 52, Dhaka, Bangladesh.

Barrett-Lennard, EG (2002), Restoration of saline land through revegetation. The Role of Agroforestry and Perennial Pasture in Mitigating waterlogging and Secondary Salinity. Agric. Water Manage. 53(1–3): pp. 213–226.

Bender, H. (2009), Pistes rurales et mesures antierosives. Recommandations techniques, Wiesendangen: bender Partner GmbH, engineering Umwelt.

Bernier, Q., Sultana, P., Bell, A.R., Ringler, C., (2016), Water management and livelihood choices in southern Bangladesh. J. Rural Stud. 45, 134–145.

Blue Gold Program (2016), Final Report on Environmental Impact Assessment (EIA) on Rehabilitation of Polder 26. Ministry of Water Resources, Bangladesh Water Development Board, Dhaka, Bangladesh.

112

Blue Gold Program (2016), Revised Final Report on Environmental Impact Assessment (EIA) on Rehabilitation of Polder 43/2F. Ministry of Water Resources, Bangladesh Water Development Board, Dhaka, Bangladesh.

Borgia, C (2017), Coastal Bangladesh: Roads to the Rescue? The water blog. Retrieved from http://www.thewaterchannel.tv/thewaterblog/454-costal-bangladesh-roads-to-the-rescue. [accessed 23 July 2018].

Brammer, H., (2013), Bangladesh‟s dynamic coastal regions and sea-level rise. Clime Risk Manage. 1, 51–62.

Chandio AS, Lee TS, Mirjat MS (2012), The extent of waterlogging in the lower Indus Basin (Pakistan) – a modeling study of groundwater levels. J. Hydrol. 426–427: pp. 103–111.

Dulac, J. (2013), Global land transport infrastructure requirements: Estimating road and railway infrastructure capacity and costs to 2050. International Energy Agency. France.

East Pakistan Water and Power Development Authority (1964), Master Plan, Volume I, International Engineering Company Inc., San Francisco, USA.

East Pakistan Water and Power Development Authority (1968), Coastal Engineering Project, Engineering and Economic Evaluation, Volume 1, Leedshill-de-Leuw Engineers, Dacca, East Pakistan.

Garcia-Landarte Puertas, D., Woldearegay, K., Mehta, L., Beusekom, M., Agujetas, M. and van Steenbergen, F. (2014), Roads for water: the unused potential. Waterlines, 33, 120-138.

Hatton TJ, Bartle GA, Silberstein R, Salama RB, Hodgson G, Ward PR, et al. (2002), Predicting and controlling water logging and groundwater flow in sloping duplex soils in western Australia. Agric. Water Manage. 53(1–3): pp. 57–81.

Hofwegen, P.J.M. van and M. Svendsen, (2000), A Vision of Water for Food and Rural Development, The Hague, The Netherlands.

Hoque, S.A.K.M. (1997), Drainage and Flood Problems in Bangladesh: Environmental Challenges and Options, 7th ICID International Drainage Workshop, „Drainage for the 21st Century‟, Malaysian National Committee on Irrigation and Drainage, Penang, Malaysia.

Hsu MH, Chen SH, Chang TJ (2000), Inundation simulation for urban drainage basin with storm sewer system. J. Hydrol. 234(1–2): pp. 21–37.

113

Ibisch, P. L., Hoffmann, M. T., Kreft, S., Pe‟er, G., Kati, V., & Biber‐Freudenberger, L. (2016). A global map of roadless areas and their conservation status. Nature , 1423 ‐ 1427.

International Commission on Irrigation and Drainage, (1996), Multilingual Technical Directory on Irrigation and Drainage, New Delhi, India.

IRC:SP-42 (1994), “Guidelines on Road Drainage”, Published by Indian Roads Congress, R.K.Puram, New Delhi.

IRC:SP-13 ((2004), “Guidelines for the Design of Small Bridges and Culverts”, Published by Indian Roads Congress, New Delhi.

Jansen, T.G.H., (1997), Farmers‟ Capacity in the Financing and Management of Irrigation in Asian Countries In: Proceedings of the 3rd Netherlands National ICID day, Delft, The Netherlands.

Japanese National Committee of ICID, (2000), Proceedings Asian Regional Workshop on Sustainable Development of Irrigation and Drainage for Rice Paddy Fields, Tokyo, Japan.

Kapoor AS (2001), Biodrainage: A biological option for controlling waterlogging and salinity. New Delhi: Tata McGraw Hill Pub. Co. pp. 1–332. ISBN: 978-0070402317.

Khan, A (2013), Bangladesh – The Most Climate Vulnerable Country. World Bank Blog. Retrieved from http://blogs.worldbank.org/endpovertyinsouthasia/bangladesh-most-climate-vulnerable-country. [accessed 23 July 2018].

King, H.W. & E.F.Brater (1976), “Handbook of Hydraulics”, Sixth Edition, McGraw-Hill Book Co.

Konukcu F, Gowing JW, Rose DA (2006), Dry drainage: a sustainable solution to waterlogging and salinity problems in irrigation areas? Agric. Water Manage. 83(1–2): pp. 1–12.

Kubbinga, B. (2012), Road Runoff Harvesting in the Drylands of Sub-Saharan Africa: Its Potential for Assisting Smallholder Farmers in Coping with Water Scarcity and Climate Change, Based on Case Studies in Eastern Province, Kenya, MSc thesis, Amsterdam: Vrije university.

Lázár, A.N., Clarke, D., Adams, H., Akanda, A.R., Szabo, S., Nicholls, R.J., Matthews, Z., Begum, D., Saleh, A.F.M., Abedin, M.A., Payo, A., Streatfield, P.K., Hutton, C., Mondal, M.S., Moslehuddin, A.Z.M., (2015), Agricultural livelihoods in coastal Bangladesh under climate and environmental change - a model framework. Env. Sci. Process. Impact. 17, 1018–1031.

114

Li C (2012), Ecohydrology and good urban design for urban storm water-logging in Beijing, China. Ecohydrol. Hydrobiol. 12(4): pp. 287–300.

Local Government Engineering Department (2005), Road Design standards- Rural Road. Government of People‟s Republic of Bangladesh, Japan International Co-operation Agency, Dhaka, Bangladesh.

Mancuso S, Shabala S (ed.) (2010), Waterlogging Signalling and Tolerance in Plants. Heidelberg, Berlin: Springer Berlin Heidelberg. ISBN 978-3-642-10304-9.

MOWR (2004), ”Silting of Rivers and Solutions” Proc. Of Seminar org. by Min. of Water Res., Central Water Commission and Central Water &Power Research Station, Govt. of India. New Delhi.

Nissen-Petersen, E. (2006), Water from Roads: A Handbook for Technicians and Farmers on Harvesting Rain Water from Roads, Nairobi: ASAL consultants ltd.

Onneshan U. (2006), The development disaster: waterlogging in the southwest region of Bangladesh. IFI Watch Bangladesh 3(2): pp. 1–9. Retrieved from: http://www.unnayan.org/documents/International_Economic_Relations/IFIv3n2.pdf.

Qureshi AS, McCornick PG, Qadir M, Aslam Z (2008), Managing salinity and waterlogging in the Indus Basin of Pakistan. Agric. Water Manage.95(1): pp. 1–10.

Ragunath, H.M. (1985), “Hydrology” pub. by Wiley Eastern Ltd. Delhi, Bangalore, Mumbai, Kolkata, Madras, Hyderabad.

Rahman S. and Rahman M.A. (2015), Climate extremes and challenges to infrastructure development in coastal cities in Bangladesh. Weather and Climate Extremes, Volume 7, Pages 96-108.

Rahman, A. (1995), Beel Dakatia: The Environmental Consequences of a Development Disaster. Dhaka University Press, Dhaka, Bangladesh.

Ram J, Garg VK, Toky OP, Minhas PS, Tomar OS, Dagar JC, et al. (2007), Biodrainage potential of Eucalyptus tereticornis for reclamation of shallow water table areas in north-west India. Agrofor. Sys. 69(2): pp. 147–165. doi: 10.1007/s10457-006-9026-5.

RDSO (1990), “Flood Estimation Methods for Catchments Less than 25 km2 in Area” pub. by Min. of Railways, Bridges and Floods Wing, Report No.RBF-16.

115

Rice knowledge Bank (2018), „How to manage water‟. Retrieved from: http://www.knowledgebank.irri.org/step-by-step-production/growth/water-management [accessed 23 July 2018].

Ritzema HP, Satyanarayana TV, Raman S, Boonstra J (2008), Subsurface drainage to combat waterlogging and salinity in irrigated lands in India: lessons learned in farmers‟ fields. Agric. Water Manage. 95(3): pp. 179–189.

Roberts, P., KC, S., & Rastogi, C. (2006), Rural Access Index : A Key Development Indicator. World Bank, Washington, DC: Transport paper series; no. TP‐10.

Sarker S.S.B.B. (2012), Why water logging in southwestern region of Bangladesh? Physical Geography-a web based academic blog. Retrieved from http://www.pg-du.com/why-water-logging-in- southwestern-region-of-bangladesh/.

Segeren, W.A., 1983, Final Report, Polders of the World, International Symposium, Lelystad, The Netherlands.

Singh A (2011), Estimating long-term regional groundwater recharge for the evaluation of potential solution alternatives to waterlogging and salinisation. J. Hydrol. 406(3–4): pp. 245– 255.

Steenbergen, F.V., Lawrence, P., Mehari Haile, A., Faures, J.M. and Salman, M. (2010), „Guidelines for spate irrigation‟, Irrigation and Drainage Paper 46, Rome: FAO.

Steenbergen, F.V. and Mondal, M. (2015), Managing the polder patchwork: Lessons from Bangladesh to East Africa; Water, Land and Ecosystem. Retrieved from https://wle.cgiar.org/thrive/2015/12/21/managing-polder-patchwork-lessons-bangladesh-east-africa. [accessed 23 July 2018].

Talukder, B.M.A. (1991), “Current status of land reclamation and polder development in coastal lowlands of Bangladesh” in Polders in Asia: Atlas of Urban Geology, Vol. 6. Economic and Social Commission for Asia and the Pacific (ESCAP), United Nations, New York.

Thompson, D. B. (20 September 2006), “The Rational Method”, Civil Engineering Department, Texas Tech University.

Toky OP, Angrish R, Datta KS, Arora V, Rani C, Vasudevan P, et al. (2011), Biodrainge for preventing water logging and concomitant wood yields in arid agro-ecosystems in North- Western India. J. Sci. Indus. Res. 70(8): pp. 639–644.

116

United Nations, (1957), Water and Power Development in East Pakistan, Report of a United Nations Technical Assistance Mission (Krug Mission Report), Vol. 1, New York, USA

Volker, A., (1982), Lessons from the History of Impoldering in the World, Key Notes, Polders of the World, International Symposium, Lelystad, The Netherlands.

World Population Review (2018), Retrieved from: http://worldpopulationreview.com/countries/bangladesh-population/ [accessed 23 July 2018].

World Bank (2006), Ethiopia: Managing Water Resources to Maximize Sustainable Growth, World Bank Water Resources Assistance Strategy for Ethiopia, Washington, DC: World Bank.

WSDT (1997), “Hydraulics Mannual” Pub.by Wasington State Deptt. of Tarnsportation, Environmental and Engineering Service Center, Hydraulics Branch, January.

Zeedyk, B. (2006), A Good Road Lies Easy on the Land. Water Harvesting from Low-Standard Rural Roads [pdf] Santa Fe: The Quivira coalition, Zeedyk ecological consulting, LLC, the Rio Puerco Management Committee – Watershed initiative, and the New Mexico environment department – Surface Water Quality bureau [accessed 23 July 2018].

117

ANNEX A

Questionnaire (Physical Inventory)

118

1 Internal Roads

S/N Road (numbering system Road type Start point (take End point (take Union Parishad/Ward of the road/road section you picture and note down picture and note down are observing, must be number of picture) number of picture) preceded by letter R for Road and followed by a number e.g. R1; R2; R3; …) • Village R • Union R • Upazila R Who constructed it? Type of use (multiple Traffic type Seasonality of use (information to be obtained on options possible) the field or from UP/LGED/BG/BWDB/WMGs) • Access • Pedestrian • All year • Transport of goods • Light vehicles • Seasonal • Flood shelter • Heavy vehicles When? …………. • Post-flood shelter

Paving State of the road (describe Pictures related to state Frequency and Pictures of low-lying briefly the physical state of of the road (take picture intensity of flooding of sections of the road (to the road e.g. and note down number road be able geo-localise breaches/erosion/low lying of picture to geo-localise points and cross with and subject to flooding) points that deserve DEM maps) attention) • Asphalt • Every year • Earth • Once every • Bricks …….years

119

• Other: ………………… During which months is the road usually flooded by high waters?......

For how long is the road usually inaccessible because of flooding?......

Who is responsible for What type of maintenance How frequent is regular Who is responsible for When was the last time maintenance? work is done? maintenance done? major repairs? major repairs were When was this done done? last time?

Challenges for drainage congestion and waterlogging and causes (describe briefly the main challenges that the road poses to drainage congestion and waterlogging and causes of these challenges e.g. insufficient water-crossings, underdimensioned or damaged/obstructed)

120

2 Embankments

S/N Embankment Start point (take picture End point (take picture Union Parishad/Ward (numbering system for and note down number of and note down number embankment/embankment picture) of picture) section you are observing, must be preceded by letter E for Embankment and followed by a number e.g. E1; E2; E3; …)

Who constructed it? Type of use (multiple Traffic type Seasonality of use (information to be obtained on options possible) the field or from UP/LGED/BG/BWDB/WMGs) • Flood/Tidal protection • Pedestrian • All year • Flood shelter • Light vehicles • Seasonal • Post-flood shelter • Heavy vehicles When? …………. • Transport of goods • Small roadside business (shops, selling of bricks…)

Paving State of the Pictures related to Frequency and Pictures of low-lying embankment (describe state of the intensity of flooding of sections of the briefly the physical state embankment (take embankment embankment (to be of the embankment e.g. picture and note down able geo-localise points breaches/erosion/low number of picture to and cross with DEM lying and subject to geo-localise points that maps) flooding) deserve attention) • Asphalt • Every year

121

• Earth • Once every • Other: ………………… …….years

During which months is the embankment usually overtopped by river surges?......

Who is responsible for What type of How frequent is Who is responsible for When was the last time maintenance? maintenance work is maintenance done? major repairs? major repairs were done? When was this done done? last time?

Challenges for flood protection and causes (explain briefly the main challenges related to flood protection and the causes e.g. embankment or road is too low, has been lowered and does no longer protect against floods, embankments are not robust and susceptible to erosion and breaching) Challenges for shelter function and causes (e.g. road/embankment is too narrow and does not accommodate shelter function and post-shelter function)

122

3 Sluice gates

S/N Sluice gates S/N Road or Picture/s Union Who constructed it? Who is responsible (numbering system embankment Parishad/Ward for maintenance? for sluice gates you along which it is are observing, must located be preceded by letter S for Sluice gate and followed by a number e.g. S1; S2; S3; …)

Design specifications (Such as design discharge, vertical gates and/or flap gates, number of gates, bottom elevation) State, functioning, and operation of the sluice gate (describe briefly the physical state of the sluice gate, how does it function i.e. inlet function and/or outfall function, how it is operated i.e.

123 when are vertical gates opened and closed, if the sluice functions the way it is expected to function) Outfall function (does the sluice gate allow to drain excess water out of the polder during monsoon season?) Challenges for flood protection (inlet function) and drainage congestion (outfall function)

4 Internal water crossings – bridges and culverts

S/N Internal water S/N Road along Picture/s Union Parishad/ward Who constructed it? Who is responsible crossings which it is for maintenance? (must be preceded by located letter B for bridges or C for culvert followed by a number e.g. B1; B2; B3; or C1; C2; C3…)

Design specifications (Such as design

124 discharge, dimensions) State and functioning (describe briefly the physical state of the water crossing and if it functions the way it is expected) Challenges for drainage congestion and waterlogging

5 Impacts-Issues

S/N Impact S/N road or Picture(s) Damage type code (see embankment along below) which the impact was observed

Description of issue (and seasonality) and causes

125

Damage Damage Type Damage type code Damage Type type code WA Waterlogged area PF Damage to property and facilities CL Damage to B Damage to public cultivated land buildings R Damage to road E Damage to embankment

126

ANNEX B Questionnaire (House Hold Semi-Structured Interview)

127

A. Questionnaire information

No. questionnaire Polder Union Parishad Ward

Road S/N Embankment S/N

No of Picture(s)

B. General HH Information

Name respondent Gender Age Type of Relation to Household Head of Household

F   20-30  Female  Head of Headed household M   30-40  Male -  Spouse  40-60 Headed  Sister  above  Daughter  Mother  Mother –in law  Sister – in law  Other

Source of Income Nr of Number Number of Nr of hh children of HH School going members with members members disabilities

Farming Fishing Business Labour Other

128

Number of home

C. Water-roads problems

What are the main problems related to water? Open response

What are the causes of these problems?

What are the main problems related to roads? Open response

What are the causes of these problems?

What is the drainage situation?

When in the year do you have problems with waterlogging? Every year? Causes of waterlogging?

Is there any need of new culverts?

Are you affected by flooding from the river (river surges)? This question applies to HH located near the embankment facing the river

When in the year are you affected by river flooding? Every year?

129

Causes of flooding?

D. Impacts on farming (take pictures if possible) – jump this section if HH has no farming activity What crops do you grow? (wet season and dry season)

How is your farming activity affected by waterlogging?

Open response

Which crops are most severely affected? At what growing stage?

Do you experience regular crop failures because of waterlogging?

If yes, can you estimate how much losses do you experience? Did you abandon cultivable land because of waterlogging?

If yes, how much land is being abandoned/lost?

Do you experience delays/constraints in carrying out farming activities because of waterlogging?

Do you experience delays/constraints in marketing your farming products because of waterlogging?

How do you cope with the impacts of waterlogging?

Do you take any action to improve drainage? (e.g. maintenance/clearing of culverts)

Which water source you use for irrigation in the dry season?

Is there any canals you can draw water from for irrigation?

130

What is the condition of water in canals during the dry season?

Is there any need of canal improvement?

If yes, what improvement is needed?

Do you experience water scarcity that impacts on your farming activity? Every year? Causes of water scarcity?

How do you cope with water scarcity?

Do you have access to and use ponded water (water that is being preserved within the polder area for dry season uses or shrimp farming)?

What do you use this water for?

E. Use of roads and mobility Which roads do you use most? Indicate on map, or sketch map, indicate if village, union or upazila roads

What do you use the roads for? (e.g. transport of people/goods)

What means of transport do you use? (e.g. bicycle, rickshaw, van, motorcycle, three wheeler, heavy vehicle)

What is the current condition of roads?

131

What is the reason behind the bad condition?

Is there any need of new roads?

Is there any need for road repairing?

If yes, what type of repairing? (e.g. width, height, smoothness, material change, change design, repair damage)

How does the bad road condition affect your mobility?

How does this affect your daily life?

F. Flood protection (take pictures if possible) – This section applies to HH located near the embankment facing the river Is the embankment capable of controlling river flood water?

If no, why?

Is the elevation of the embankment adequate to control floods?

If no, what elevation is needed for flood control?

Are there sluice gates for flood control?

Are they effective?

If no, why?

Has your life being endangered by floods?

How do you perceive the risk of

132 accidents because of floods?

Do you use roads/embankments as shelter during floods?

Which ones?

How frequent?

For how long?

What are the challenges?

G. Impact on property and facilities (take pictures if possible) Did you experience damages to or loss of your house because of floods? If yes, when, how frequent, extent of damage Did you experience damages to or loss of equipment and goods?

If yes, what equipment, when did it happen, how frequently Did you experience damages to your food storage facilities?

If yes, how does this affect your food security, how frequent does this happen, how much losses What do you do to protect your house and property?

Do you use roads/embankments as post-flood shelters?

Which ones?

For what use?

133

Permanently?

What are the challenges?

134

ANNEX C

Questionnaire (Focus Group Discussions – UP/WMGs)

135

General questions about roles and responsibilities related to water and roads:

1. What are the roles and responsibilities of the WMG? 2. Are WMGs also responsible for constructing/maintaining lower level khals? 3. Are WMGs responsible for maintenance of internal structures (culverts and bridges) and field outlets within the polder? 4. What are roles and responsibilities of UP in relation to water management and drainage? 5. What are roles and responsibilities of UP in constructing and maintaining village roads? 6. Is the UP responsible of constructing/maintaining drainage structures along village roads?

Present to the group the various options to solve waterlogging based on first findings of physical inventory, HH surveys, KII indicate options and potential drainage pattern on a map to visualize better

Social – political feasibility of the various options:

136

ANNEX D

Questionnaire (Key Informant Interview- BWDB/BG)

137

Key Informant Interview – Bangladesh Water Development Board/BG

1. What is the responsibility of BWDB in digging and O&M and rehabilitation of khals in polder 26 and 43/2F? 2. What are the different khal levels and who has responsibility (construction/M&M) of lower levels? 3. What are the khals that BG/BWDB is planning to improved? Where? What type of intervention (e.g. enlargement, reshaping) 4. Capacity of current drainage network (larger khals) and after enlargement? 5. What governmental level is responsible for leasing khals to individuals) 6. Role of BWDB in construction and maintenance/rehabilitation of field outlets? 7. Design approach and specifications for field outlets (only for drainage or also for intake from irrigation khal?) 8. Role of BWDB in construction and maintenance/rehabilitation of embankments? 9. Design approach and specifications for embankments? Any reinforcement of river-facing side of embankment? Carpeting of crest? 10. Any challenges created by road constructed on embankments? Where? 11. Plans to improve/repair/rehabilitate any embankment? What type of intervention? 12. Role of BWDB in construction and maintenance/rehabilitation of intake/outfall structures? 13. Design approach and specifications for sluice gates? 14. How are they operated? Do all the sluices function both ways (intake and outfall?) If not which ones only one way and which way? 15. Do sluices work to drain water out of the polder area during monsoon? 16. Do they have data on water levels in the river during monsoon (low and high tide) and water level in the khal approaching the sluice? 17. What is the status of the sluices? Which work and which not and why not? 18. Plans to improve/repair/rehabilitate any intake/outfall structure? Which ones? What type of intervention? 19. DEM maps of polder and catchment area, rainfall data

138

ANNEX E

Questionnaire (Key Informant Interview- LGED)

139

Key Informant Interview – Local Government Engineering Department

1. Role of LGED in construction and maintenance/rehabilitation of internal roads? Which roads? Which are constructed by UP/community? 2. Design approach and specifications of road construction 3. Role of LGED in construction and maintenance/rehabilitation of cross-drainage structures (i.e. culverts and bridges)? 4. Design approach and specifications of cross-drainage structures? 5. Definition of culvert and bridge? 6. Plans to improve/repair existing roads? 7. Plans to construct new roads? Where? 8. Plans to repair/improve/rehabilitate internal structures? 9. Plans to construct additional cross-drainage structures? Where?

140