Image source; guardian.ng
Incessant flooding is one of the most obvious and terrible impacts of global warming; more and more coastal towns and cities, such as Lagos, Nigeria, are suffering the precarious effects of increasing sea water levels, which are caused by the melting of our planet's polar ice caps. Lagos, in fact, is undergoing such catastrophic flooding that experts believe the continent's most populous metropolis could soon become uninhabitable. This is an alarming concern among residents in Lagos.
Urban Flooding
When water overflow from lakes, rivers, or ocean, it escapes boundaries, and when it saturates the ground due to heavy rainfall, flooding is bound to occur. Urban flooding is the inundation of land or property in a built environment caused by rainfall surpassing the capacity of drainage systems such as storm sewers, particularly in densely populated areas. This phenomenon can occur despite the location of impacted towns and cities, whether or not inside designated floodplains or near any body of water. Urban flooding is defined by its recurrent and systemic impacts on communities. It is typically caused by occurrences such as flash floods or snowmelt. In addition to potential river and lake overflows, snowmelt, rainfall, or water released from damaged water mains may gather around properties, penetrate building walls and floors, or enter structures through sewage pipes, toilets, and sinks.
Effects of Urban Flooding
Floods can cause severe damage to houses and businesses. Other losses include loss of lives and damage to structures and infrastructure, including bridges, sewage systems, roads, and canals. Due to this infrastructural devastation, it can result to long-term relocation of inhabitants and an increase in the spread of waterborne illnesses and vector-borne diseases. Floods interrupt electricity transmission and, in certain circumstances, power generation, causing a chain reaction of negative repercussions. This includes the loss of drinking water treatment and supply, which might result in a water shortage or severe contamination. Sewage treatment plants may be forced to close as a result. Depending on the circumstances, there is increased risk of waterborne diseases like cholera, typhoid, giardia etc. when drinking water gets mixed up with human waste in flood water.
The Lagos Scenario
Nigeria is prone to flood from March to November each year and have experienced several flood cases but the July - September 2021 floods were among the worst on record. The worst of it is felt in Lagos, a low-lying coastal metropolis with a current metro area population of 14,862,000 which is a 3.44 percent increase from 2020. According to All Africa, floods have killed people and forcefully displaced them from their homes, while structures in low-income communities constructed on reclaimed land are sinking. There are a number of factors responsible for perennial flooding in Lagos State. The factors ranges from anthropogenic (human) factors to policy inconsistencies.
Factors contributing to Lagos flooding
Erosion: According to the Pulitzer Centre, the city is coping with a constantly deteriorating shoreline in addition to increasing sea levels and climate change resulting in severe weather conditions (aka heavy rain). Lagos mines sand for building, and because it is constructed on a series of islands, erosion makes staying stable and sheltered from increasing sea levels more difficult.
Overpopulation: With increased urbanization and influx of people to towns, overcrowding is a common phenomenon in Lagos. According to Population Matters, floods affect more people in congested cities due to increased pressure on sewage systems. It also encourages growth to high-risk areas of the country, which are typically underprivileged populations that will surely feel the consequences of climate change first. The ever increasing population of Lagos resulting in land cover modifications (indiscriminate removal of vegetative cover) and depletion of ecosystems in the name of development is another factor.
Inadequate Town Planning: Increased population in metropolitan areas have been connected to urban floods. With expanding urbanization, a greater proportion of ground surfaces are concreted, preventing water from percolating and resulting in insufficient drains to adequately discharge surface runoff. This necessitates the construction of drainage systems to fight flooding. The size of the flood danger is mostly determined by the state of existing infrastructure. Proper urban planning is a challenge and in the instances government managed to plan, implementation is always a challenge. In urban planning, collaborative effort amongst all the stakeholders; government agencies and citizens is a critical success factor, but what is operational in Lagos is opposite, government agencies work independently of one and other and vis-à-vis the citizens. This makes proper implementation and coordination unachievable.
Poor waste management system: Poor garbage disposal frequently causing clogs in drains and watercourses, effectively reducing their storage and conveyance capacity, and resulting in floods. During a flood, trash and other material gathered by floodwaters can cause more property damage and result in larger flood losses. After a flood, waste deposition can impede access and serve as a source of toxins and disease breeding grounds. Floods can also disrupt waste management systems, resulting in the release of contaminants into the groundwater. Poor waste management structure within the state is another contributing factor coupled with the inconsistencies of Government policies. The current waste management structure is not inclusive, it excludes the informal sector; the cart pushers and waste scavengers, despite their exclusion they are still very much around. People still largely patronize them because of the ineffectiveness of the current structure. Government should integrate them into the existing waste management structure, what is required is to get them properly organized and regulate their operations and use them for neighborhood operations and areas inaccessible to waste trucks. For the current structure to work and cater for the growing need of the citizens, the state must adapt the adopted structure to our realties here, copying directly from the west will not yield the desired results because our realities and culture are different from theirs.
Inadequate Law Enforcements: Enforcement of law against the violators of the environmental laws is weak and most times it is politicized – this is not just a Lagos State thing but a national challenge. Environmental legal framework is weak in Nigeria; there are institutional bottlenecks; multi-duplicity of functions among agencies of government saddled with the enforcement of the law, penalties and fines against the offenders are unimaginably very low. Because of this loophole, people contravene environmental law at will. Government needs to review, update and strength these laws as soon as possible and make them relevant to our present day realities. Corrupt practices among government/enforcement officials is a related setback; they compromise on established standards and overlook wrong doings at the altar of gratification. This set wrong precedence for people to evade the law at will.
Land Use: Incessant and unregulated sand filling going on in the state is another key contributor, coupled with poor drainage systems within the state. Allocation of floodplains and wetlands for development is another trigger to this problem of perennial flooding in the state. Floodplains and wetlands are meant to be preserved, they serve as buffer in the event of flash floods but in Lagos practically all the wetlands have been destroyed in the name of development and economic gains.
Bad human behavioral pattern: This is another leg to this perennial flooding problem – indiscriminate littering and dumping of wastes and debris into the drains, construction on drainage pathways; blockage of drains, violation of building codes and regulations.
Lagos is a coastal city and coupled with the problem of Climate Change with attendant heavy torrential rains, Lagos State Government needs to act fast in tackling the problem of incessant flooding in the state by encouraging planting of more trees and vegetative covers in the state, create more awareness among the citizens through the Community Based Organizations, Faith based Organizations, Neighborhood Watch, Landlord and Residence Associations, Traditional Rulers etc. about the danger of persistent flooding to our city, activate processes to review and update our obsolete environment laws, incorporate the informal sector into the existing waste management structure. Also, Government should not play lip service to the Environmental Impact Assessment (EIA) process before signing-on on development projects, reclaim our wetlands and floodplains and preserve the same and prohibits illegal sand filling and mining in the state with immediate effect.
Above all, an effective and all-encompassing urban planning should be the bedrock of an effective intervention and preservation of the same to tackle the problem of perennial flooding in the state.
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