Assessment Of Poor Drainage System In Nigeria

This study aims to assess the effect of poor drainage network on flash flooding in Jiddari Polo, Maiduguri city, Borno State. The study is a survey research in that data was generated on the field through physical observation, oral interview, structured interview schedules and photographs. The sample size for this study was 221 respondents which is 05% of the population of the study area. The data collected from the field and extant literatures were used to achieve the outlined objectives which are; to examine the intensity and frequency of floods, to evaluate the spatial distribution and intensity of drainage networks in the area, examine the effect on poor drainage system on the residents of the studied area, assess the drainage system and determines the attitudes of the residents towards poor drainage systems and flooding. The results of this study indicate that high drainage width correlated positively with runoff volume in Bulunkutu and new GRA. In view of these, the study put forward some recommendations which when implemented will help in mitigating flood incidence in Maidugu.

Introduction
1.1 Background to the Study
Poor drainage systems form part of major threats to urban environments in Nigeria. Most of streets within the urban and rural settlement are faced with the challenges such as lack of drainages or properly designed drainages to evacuate storm water from the surface-course of our roads. Cities the world over are the dominating forces in the organization of human population. As the world most crowded places, cities continue to show increase in urban population. This increase leads to a growing urbanization trend. Duru and Nnaji (2008) defined urbanization as the increase in the population of cities in proportion to the region's rural population. Urbanization is the outcome of social, economic and political developments that lead to concentration and growth of large cities, changes in land use and transformation from rural to metropolitan pattern of organization and governance. Rapid growth of towns and cities has been common feature of the developing world (Aderamo, 2008). Although urbanization is the driving force for modernization, economic growth and development, there is increasing concern about the effects of expanding cities, principally on human health, livelihoods and the environment.

Drainage systems are constructed to ensure that waste water and sewage is transported neatly to disposal points, thereby keeping the environment well drained and free of waste. Examples of components that make up a good drainage system includes; closed ditches having pipe drains, drainage pipes, channels and conduits (Folorunsho, & Awosika, 2001). Sustainable Drainage Systems are approaches put in place to manage the water quantity (flooding), water quality (pollution) and amenity issues in the environment. Sustainable drainage is a concept that includes long term environmental and social factors in decisions about drainage. Sustainable Drainage Systems are intended to regulate surface water runoff close to where it falls and simulate natural drainage as closely as possible. They provide opportunities to reduce the causes and impacts of flooding, remove pollutants from urban runoff at source, and combine water management with recreation and wildlife. They also help to enhance water quality while protecting natural flow regimes in watercourses (Dipanjan & Mukherjee 2014).

In many parts of Nigeria today, there is a great need for properly managed sustainable drainage systems in order to help manage surface water runoff. Neighborhoods keep springing up without proper planning, which also involves planning for drainage and sewage or waste disposal. Residents regularly dump their waste in gutters, and this clogs the gutters and prevents the flow of water, causing the gutters to overflow (Enger & Smith, 2006). It is common to see flooded streets with litter floating everywhere after a short period of rainfall. Such situations create very unsanitary conditions for residents of the neighborhoods and contribute to the degradation of the environment. In the year 2012, 363 people were feared dead while 2.1 million citizens were displaced across Nigeria as a result of floods. According to the National Emergency Management Agency (NEMA), 30 states out of 36 in Nigeria were affected by that flood experience and it was concluded as the worst that has ever happened in the past 40 years, causing damages of an estimated value of N2.6 trillion Naira (Jimoh, 2008). These floods also gave rise to environmental pollution problems which affected the health of Nigerians across the various affected areas. Nigeria is currently experiencing its annual rainy season, and in order to avoid lethal floods it is important to have very effective drainage systems and strive towards ensuring free flow of water during and after heavy downpours. Poorly maintained drainage systems and poor waste management habits can adversely affect our environment (Okupe, 2002).

The implications of rapid urbanization and demographic trends for employment, food security, water supply, shelter and sanitation, especially the disposal of wastes (solid and liquid) that the cities produce are staggering (Oduwaiye, 2009). The process of urbanization is believed to be connected with levels of development and some assert that, for a country to develop there is the need for an increased level of industrialization as it is generally accepted that there cannot be urbanization without rapid economic growth (Tettey, 2005). The pattern of urbanization in developing countries, particularly Africa, however, is creating some concern that it may be generating a lot of development problems in the process of its growth. One of the daunting challenges facing African countries in the wake of unprecedented urbanization during the last few decades is the planning and management of physical infrastructure and the urban environment (Kwasi, 2011).

As urbanization gathered pace in most developing countries, the problem of inadequacy of infrastructure services and deteriorating urban environment became enormous (Sule, 2009). These problems range from poor housing conditions, inadequate infrastructure, to squatter settlements (Arimah, 2002). Spurred by the oil boom prosperity of the 1970s and the massive improvements in roads and the availability of vehicles, Nigeria since independence has become an increasingly urbanized and urban-oriented society. During the 1970s, Nigeria had possibly the fastest urbanization growth rate in the world (Sule, 2009). Because of the great influx of people into urban areas, the growth rate of urban population in Nigeria in 1986 was estimated to be close to 6 percent per year, more than twice that of the rural population. Specifically, while only 7% of Nigerians lived in urban centers in the 1930s, and 10% in 1950, by 1970, 1980 and 1990, 20%, 27% and 35% respectively lived in the cities (Okupe, 2002). Over 40% of Nigerians now live in urban centers of varying sizes. Like other developing countries, the rapid growth in urban areas in Nigeria is a ""sword of two edges‟ (Sule, 2009). While increasing human capital increased the economic status of the country, the growths of large centers had outpaced government capacity to meet the increasing demand for the provision of basic infrastructural facilities and services. These are manifested in poor investment in roads, housing, water supply, electricity, waste disposal mechanisms, adequate drainage systems etc. (Sule, 2007; Aderamo, 2008; Jimoh, 2008). These problems have continued to persist and made worst due to non-compliance to planning ordinances (Sule, 2010). Appropriate management of drainage systems requires knowledge relating to the system boundary, system resources, interactions between adjacent systems and allowable limits, or thresholds, for each resource. Each of these elements will be unique to the particular system under consideration, and each system must be assessed on its own merits (Offiong, et" al, 2008).

Drainage quality is an important parameter which affects the highway pavement performance. The excessive water content in the pavement base, sub-base, and sub-grade soils can cause early distress and lead to a structural or functional failure of pavement. Drainage is the most important aspect of road design. Proper design of drainage is necessary for the satisfactory and prolonged performance of the pavement. In designing drainage, the primary objective is to properly accommodate water flow along and across the road and conveniently transport and deposit the water o the downstream without any obstruction in the flow (Rokade, Agarwal & Shrivastava, 2012). A typical road construction is multi-layered in form, comprising of unbound materials. Essentially, the lower indigenous subgrade layer is covered by a bound or unbound sub base, providing drainage and frost protection for the subgrade, and the road base layer upon which the asphalt layers are laid as a final surface coating. Poor drainage in pavement can lead to early pavement distresses lead to driving problems and structural failures of the road. The primary source of water in pavements is atmospheric precipitation. This water can enter the pavement through several ways (e.g., cracks, infiltration, through shoulders and ditches, high groundwater) and is moved by an energy gradient, such as gravity, capillary forces, osmotic forces, and temperature or pressure differences (Henderson, 2004).
Flooding in urban areas is not just related to heavy rainfall and extreme climatic events; it is also related to changes in the built-up areas themselves. In the case of Maiduguri, the problems of street flooding began when some socio economic and anthropogenic activities gained momentum as a means of face lifting the city as State Capital. The influx of people from both rural and adjoining states led to increased demand for housing. Houses were hurriedly built to meet the burgeoning demand for shelter as a result of insurgency. This alters the aesthetic image of the city as buildings were erected anyhow and anywhere (Sule, 2004).
1.2 Statement of the Problem
Worldwide, there has been a rapid growth in the number of people killed or seriously impacted by storms and floods and also in the amount of economic damage caused; a large and growing proportion of these impacts are in urban areas in low- and middle-income nations. For instance, in Nigeria, flooding affected more than three million people in selected urban areas between 1983 and 2009 (Folorunsho & Awosika, 2001). Poor urban infrastructural development and planning is likely to have been a factor in much of this, but even if it was not, it is proof of the vulnerability of urban populations to floods and storms whose frequency and intensity is likely to increase in most places. Maiduguri is one of the cities that are growing at a high rate in terms of infrastructural development, which involves construction and concretization of the city land surface. This, as a result of poor drainage systems, leads to flooding and other environmental problems such as roadway pavement failure (Giwa, 2007).

Henderson (2004) revealed that the level of risk and vulnerability in urban areas of developing countries is attributable to socio-economic stress, aging and inadequate physical infrastructure. Indeed, according to Satterthwaite, et" al, (2007), hundreds of millions of urban dwellers have no all-weather roads, no piped water supplies, no drains and no electricity supplies; they live in poor quality homes on illegally occupied or sub-divided land, which inhibits any investment in more resilient buildings and often prevents infrastructure and service provision.

A high proportion of this are tenants, with very limited capacities to pay for quality housing and their landlords have no incentive to invest in better-quality buildings. Most low-income urban dwellers face serious constraints in any possibility of moving to less dangerous sites, because of their need to be close to income-earning opportunities and because of the lack of alternative, well-located, safer sites. Douglas et al (2008) also report that many of the urban poor in Africa face growing problems of severe flooding; they further buttressed the fact that increased storm frequency and intensity related to climate change are exacerbated by such local factors as the growing occupation of flood plains, increased runoff from hard surfaces, inadequate waste management and silted up drainage. Askew (1999) reiterated that floods cause about one third of all deaths, one third of all injuries and one third of all damage from natural disasters globally. Generally, flood events are attributed to global warming, climate change, ocean swell/surge and torrential rains. Although flood hazards are natural phenomena, damage and lose from floods are mostly the consequences of urbanization without corresponding infrastructural restructuring (Brooks, 2003).

Flooding is the most common environmental hazard in Nigeria (Etuonovbe, 2011). The intensity of flood problems over time and space in Nigeria urban centers is closely related to the rapid rate of urban expansion especially where the simultaneous provision of adequate run-off disposal systems is lacking as is the case of most Nigerian cities and Maiduguri in particular (Abaje and Giwa, 2008). The implications of recent flooding in Nigerian cities include, among others, loss of life and properties, spread of diseases, deformed livelihoods, assets and infrastructure using both questionnaire and secondary data in the analysis of the history and causes of flood incidence in the city of Maiduguri opined that no year passes without flooding in the city destroying houses and blockage of road; on the average four lives were lost yearly to flooding.

Recently Maiduguri especially Jiddari Polo is facing extensive water logging during the rainy season (July to September) as result of a serious problem of poor drainage. Inadequate drainage problems become one of the most common sources of compliant from the residents in the study area and this problem becoming worse in this year. Poor existing drains and their improper operation and management mainly cause severe flooding which creates damages and problems to the road pavement and road users. In addition, deceases are spread and give problems to the population such as malaria and diarrhea. This critical situation was severely aggravated because the natural drainage system, which conveys storm runoff from the areas to the river were not fully operated and the existing drains blocked with huge amount of garbage, solid waste, silt sand accumulation and vegetation.
It is against this background that this research intends to assess the effect of poor drainage system on flash flooding in Jiddari Polo, Maiduguri city, Borno State.
1.3 Aim and Objectives of the Study
The main aim of this study is to assess the effect of poor drainage network on flash flooding in Jiddari Polo, Maiduguri.

The specific objectives of the study are to:

• Examines the intensity and frequency of floods in Jiddari Polo, Maiduguri;
• Assess and evaluate the spatial distribution of drainage networks in the area;
• Examine the effect of poor drainage system on the residents of the study area and
• Assess the attitudes of the residents towards drainage system and flooding in the study area.

1.4 Research Questions
The study answered the following research questions toward achieving the research objectives:

• What is the frequency and intensity of floods in Jiddari Polo, Maiduguri?
• What is the spatial distribution of drainage networks in the area?
• What is the effect of drainage width and depth on flood in the study area?
• What is the attitudes of the residents towards drainage system and flooding in the study area?

1.5 Scope of the Study
This study was restricted to selected area of Maiduguri Metropolis that is prone to flood occurrence. It assessed the capability of drainage networks to effectively handle run off volume in the area. The study was conducted in Jiddari Polo, Maiduguri. This location was selected because it has a history of frequent floods especially during the rainy seasons. In addition, flood prone areas are largely characterized by poor planning as compared to the control.
1.6 Significance of the Study
This study will be of great benefit to various sectors both governmental and Non-governmental organization. The study will be significant to National Emergency Management Agency (NEMA) as it revealed the various areas of poor sanitation in Maiduguri. It will be of benefit to environmentalist and town planners as the study revealed the various areas of poor town planning which resulted to lack of drainage because no good street for drainages to be constructed. The study will also help the health sectors in identifying the various diseases bedeviling the community of the study area due to excessive flooding which breaded some bacterial and diseases. NGOs who are concern with WASH activities will also find this study very useful as it revealed the sanitary conditions of the environment. Finally, the study will be of great benefit to students and researchers who may need information on the subject matter under study.

Summary, Conclusion and Recommendations
5.1 Summary
This study sought to assess the Effect of Poor Drainage Network in Relation to Flooding in Jiddari Polo and Maiduguri in General. The study formalized five objectives which are; to examine the intensity and frequency of floods, to evaluate the spatial distribution and intensity of drainage networks, examine the effect of poor drainage system on the residents of the study area, assess the drainage system and determines the attitudes of the residents towards poor drainage system. The frequency of floods episode in the city of Maiduguri is not unconnected to the problem of inadequate drainage networks as the study has revealed. The study indicates that a significant number of the respondent said flood occurs every year in the city of Maiduguri while others were of the view that they do experience flood most parts of the year. However, only few of the sampled residents claimed they have never experience flood. This response is likely to have come from those who live Satellite Town which is highbrow residential area with relatively adequate drainages. On the frequency of flood, majority of the sampled population supported the view that flood events are often very high while others said flood episode is fairly high and only few claimed flood intensity is low in the city. The also observed that drainage dimension in the study areasvary but generally the depth and width of the drainages are not adequate for the runoff volume flowing through them hence the incessant overflowing of the banks. A total of 4 channels were studied. This area has little or no flood as rainstorm water flow freely without any impediments. The study also indicates that heavy rainfall was the main factor responsible for flood occurrence in Maiduguri. It is imperative to note that different views were expressed as the perceived cause of inadequate drainage in Maiduguri. On the bases of this, many of the sampled population blamed it on non-conformity to land use zoning, poor monitoring and government negligence.
5.2 Conclusion
Flood remains a very serious environmental problem in Maiduguri. Recurrent flood events in the city of Maiduguri have been traced to in inadequate drainage channels. Many properties have been destroyed, lives lost and this has subjected the people to unquantifiable trauma. More so, the menaces of flood have been on the increase as a result of incipient and prolong weather conditions. The findings of this study was to assess drainage network and floods occurrence in Maiduguri Metropolis. The data collected from the field and extant literatures were used to achieve the outlined objectives. The result revealed that flood occurs every year and most parts of the season while the flood intensity ranges from very high and fairly high. On the dimension of the drainages across the sampled areas, only two areas hard consistent patterns of drainage width and runoff. That is, high drainage width correlated positively with runoff volume in Bulunkutu and new GRA. However, other areas showed irregular patterns in drainage width and runoff volume. The presence of waste and other household items like furniture in the gutters might have been responsible for the storm water over flowing it bounds. Many factors were identified as being responsible for flood occurrence. Some of them include building on storm water drainages, poor physical planning, inadequate drainage channels, heavy rainfall, dumping of waste on drainage networks and nature of the terrain. This flood causing factors have created series of environmental and socioeconomic problems in Maiduguri. Some of which include flooding of streets, lost of life, pollution of domestic water sources, distortion of the beauty of the environment, prevented from going out among others.

In view of these, the study put forward some recommendations which when implemented will help in mitigating flood incidence in Maiduguri. Some of the recommendations are; the government should award contract to a competent company for the construction of underground drainages covering the entire city of Maiduguri, as surface drainages have created many problems to the resident including the loss of lives, the present drainage systems should be cleared with shove is on regular basis to allow for the free flow of storm water and the government and NGOs should carry out massive awareness campaigns on the need for the people to stop dumping waste in the drainage channels. In addition, government should put in place flood early warning signal system with the capability to deliver reliable timely and effective flood information at an appropriate response time. This will help to reduce the loss of lives and properties in the city.
5.3 Recommendations
In view of these, the study put forward some recommendations which when implemented will help in mitigating flood incidence in Maiduguri.

The government of Borno state should take proactive measure to mitigating the storm waters by clearing the drainage channel on regular basis.

The government contract should be awarded to a competent company for the construction of under drainages covering the entire city of Maiduguri, as surface drainages have created many problems to the resident including the loss of lives.

The government and NGOs should carry out massive awareness campaigns on the need for the people to stop dumping waste in the drainage channels.

The Borno State government should re-enact the monthly sanitation exercise which will help in the total removal or reduction of waste in the drainage channels.

Abstract

Chapter One
Introduction
1.1 Background to the Study
1.2 Statement of the Problem
1.3 Aim and Objectives of the Study
1.4 Research Questions
1.5 Scope of the Study
1.6 Significance of the Study

Chapter Two
Literature Review
2.1 Conceptual Framework
2.1.1 Concept of Drainage
2.1.2 Concept of Flooding
2.1.2 Concept of Sustainable City Development
2.2 Literature Review
2.2.1 Problems Associated with Drainage
2.2.1.1 Poor Design and Construction
2.2.1.2 Poor Maintenance Culture
2.2.2 Requirements of Highway Drainage System
2.2.3 Types of Drainage Systems
2.2.4 Effects of Bad Drainage System
2.2.5 Methods for Improving Drainage
2.3 Causes of Flooding
2.4 Effects of Flooding

Chapter Three
Study Area and Methodology
3.1 The Study Area
3.1.1 Location and Extent
3.1.2 Relief and Drainage
3.1.3 Vegetation and Soils
3.1.4 Climate
3.1.5 Socio-Economic Activities
3.1.6 People and Population
3.2 Methodology
3.2.1 Nature of Data Required
3.2.2 Sources of Data
3.2.3 Method of Data Collection
3.2.4 Sampling Size and Sampling Techniques
3.5 Methods of Data Analysis

Chapter Four
Results and Discussion
4.1 Data Presentation
4.2 Frequency and Intensity of Flooding in Jiddari Polo, Maiduguri
4.2.1 The Frequency of Flooding in Jiddari Polo, Maiduguri
4.2.2 Flood Intensity in Jiddari Polo of Maiduguri
4.2.3 The Month that Flood Disaster often Occur in Maiduguri
4.2.4 The Volume of Flood in Jiddari Polo
4.3 The Spatial Distribution of Drainage Networks in Some Areas
4.3.1 Drainage Width, Depth, and Flood (Runoff) in Some Areas in Maiduguri
4.3.2 Environmental States of Drainage Systems in Maiduguri
4.3.2.1 Factors of Flood Occurrence
4.3.2.2 Perceived Causes of Inadequate Drainage Networks in Maiduguri
4.3.3 Quality of Drainage Networks
4.4 The Effect of Poor Drainage System on the Residents of the Study Area
4.4.1 Effects of Poor Drainage Network on the Environment/Infrastructure of the Study Area
4.4.2 The Poor Drainage of the Area Gives Room for Excessive Flooding
4.4.3 The Poor Drainage of the Area Paves Ways for Breeds of Mosquitoes and Other Bacteria
4.4.4 Excess Sediments and Garbage
4.4.5 Outbreaks of Cholera as a Result of Poor Drainage System in Jiddari Polo
4.5 Effect of Poor Maintenance Culture
4.6 Lack of Community Participation
4.7 Discussion of the Findings

Chapter Five
Summary, Conclusion and Recommendations
5.1 Summary
5.2 Conclusion
5.3 Recommendations
References
Questionnaire

• Challenges Of Poor Drainage Systems And Floods Control
• Impact Of Poor Drainage System And Flood Control

• Urban and Regional Planning Project Topics and Materials