- Background to the Study
Throughout history, every act of human development has a price, which is increasingly an important problem within social sustainability scientific research. For example the two world wars WW1 and WW2 were the price for growth in political interactions and interests, militarism and territorial integrity among the world powers (Lyon, 2009). As cities grow and more people migrate, the needs for housing units and improved urban utilities arise, leading to increased impervious surfaces. In developing countries, some complex human activities; indiscriminate disposal of waste, blockage of drainage systems, construction on drains and failure to heed warning, all which seem to increase the occurrence and impacts of flooding in urban areas which are implicated (Aderogba, 2012). In recent times in Nigeria, flood has displaced more than two million people as the flood gates on dams were opened to release rising waters along the Niger River. Flooding has also affected at least 300,000 people, submerging hundreds of communities. Some 1.3 million Nigerians have been displaced and 431 died in what the authorities say is the worst flooding in over 40 years, with 30 of the country‟s 36 states affected since July 2012, according to the National Emergency Management Agency, NEMA (2013). In the year 2012, flooding started in plateau state in central Nigeria in July, spread through Borno, Cross River, Ebonyi, Nassarawa, Bauchi, Gombe, Katsina and Kebbi States in August, hit Taraba, Benue, Niger, Kaduna and Kano in September, before affecting Delta
and Bayelsa states in September and October (National Emergency Management Agency, 2012).
1.2 Research Problem
Flooding and flood risk management are issues of grave significance in Lagos (Aderogba, 2012 a, b). It is clear from previous studies (for example, Ajibade et al. 2013, 2014; Adelakan, 2013), that flooding in Lagos can be devastating, affecting hundreds of thousands of people and causing considerable economic damage. A typical example is the July 2011 flooding event, which affected approximately 5 thousand people and resulted in about 25 deaths. The direct economic losses resulting from the event total about 50 billion Nigerian naira (i.e. USD 250 million). Public utilities including road networks, bridges, and schools were destroyed. In addition, houses collapsed, private homes were submerged, and several cars were swept away by flood water. From historical perspective, Lagos has always been susceptible to various types of flooding which are well documented since 1960s (Odunuga, 2008; Oyebande, 1974; Etuonovbe, 2011). However, in recent years fluvial flooding events (rainfall related), have arguably been wide spread (Olajuyigbe et al, 2012). Flooding has been identified as one of the major factors that prevents Africa‟s growing population of city dwellers from escaping poverty and stands in the way of the United Nations 2020 goal of achieving significant improvement in the lives of urban slum dwellers (Action Aid, 2006). This is because many African cities lack the infrastructure to withstand extreme weather conditions.
The rapid growth of the third world urbanization is consistent, thus urban population remains in crowded areas with so many people residing in low lying areas and fragile housing systems. Lagos has about 65% of Nigeria‟s commercial activities and about 5% of the Nigeria‟s population reside in “Greater Lagos” which includes; Bariga,
Oshodi, Mushin, Ikeja, Agege, Ketu, Maryland and Oworonshoki. With this, there is need to look at urbanization resulting to flooding in Nigeria, threat of urban flooding in Lagos should focus more in Ikeja Local Government which is the second most industrialized local government area in Lagos state. Therefore there is need to embark on this study in order to provide answers to the following questions;
- What are the factors responsible for flooding in Ikeja Local Government?
- What are the effects of urban flooding on the residents of Ikeja Local Government?
- What could be the possible measures to improve the Flooding situation and mitigate occurrence of this hazard in Ikeja Local Government?
- Aim and Objectives
The aim of this study is to evaluate the urban drainage structure and its efficiency in flood control in Ikeja Local Government Area of Lagos state. In other to achieve this, the study has the following as its specific objectives, to:
- identify the factors responsible for flooding in Ikeja Local Government;
- examine the effect of urban flooding on the residents of Ikeja Local Government;and
- assess adaptive measures put in place to mitigate the impacts of urban flooding.
Water will always find its way if not well channelized. Its choice route often poses problems to man by tampering with his physical environment, health and products of agriculture, urbanization and industrialization. This has created a lot of social and economic cost on the environment and the citizenry. Most areas in Ikeja Local Government are prone to flooding incidence which is due to bad drainage structures. Flooding occurs in this area whenever there is heavy rainfall. Some of the communities which experiences flooding in Ikeja include: Oregun, Ikeja GRA, Obafemi Awolowo
Way, Computer Village and it‟s environ, and Olusosun areas. This research work is aimed at calling the attention of the Ministries of Environment, Education, Health and Information as well as various Agencies, Organizations, Firms and Bodies to the menace of urban flooding in Ikeja Local Government. It will be beneficial for the ministries, Agencies, Firms, Organization and Bodies in the area of policy formation, most especially in the area of educating the public in schools and out-of-school. It will assist them when formulating laws that will promote human health and protect the environment. The citizenry will also benefit greatly from this study, as it will reveal how a person‟s carefree attitude about the environment can be costly not only to himself but others.
1.7 Scope of the Study
This research is focused on the analysis of urban drainage structure and its efficiency on flood control in Ikeja Local Government area of Lagos State. Attempts would be made to
identify the factors responsible for this natural hazard, its effect on the residents and adaptive measures put in place to mitigate the impacts of urban flooding. This study is limited to selected areas in Ikeja Local Government that are mostly affected by flood.
1.6 The Study Area
1.6.1 Location and Size
Ikeja is the capital of Lagos state, it is the area chosen for this study. Ikeja lies on the geographical coordinates between Latitude 6o33`0 and 6o39`0 North of the Equator and between Longitude 3o18`0 and 3o24`0 East of the Greenwich Meridian. Ikeja became the Capital of Lagos State in 1976 after the creation of 19 states in the country. The total land area of Ikeja is 49.92 km2 (19.27 sqmi).
Notable communities in Ikeja include, Oregun, Opebi, Akiode, Alausa, Olusosun and Government Residence Area (GRA), Ikeja. Ikeja local government has Onigbongbo as its Local Council Development Area (LCDA). It is a highly urbanized area as far as the level of urbanization rate is concerned, with a teeming population of about 317, 614, which represents 3.82% of the state‟s population. 171,782 of the total population are male while the remaining 145,832 are female (National Population Commission, 2006).