Adequate land management can reduce flood risks – Builders

The Building Collapse Prevention Guild has called for sustainable land management practices to reduce flood risks.

This was disclosed in a statement tagged, “Erosion and Flooding Control: A Surveyors Perspective.”

It stated, “Sustainable land management practices can help to reduce flood risks in Nigeria. These practices include soil conservation, terracing, contour farming, and crop diversification. Sustainable land management can help to reduce soil erosion, increase soil water holding capacity, and improve crop productivity. These practices can also help to reduce the impact of floods on agricultural lands and improve the resilience of farming communities.

“Lagos is dominated by its system of islands, sandbars, and lagoons. The islands are connected by bridges and the land is low-lying. According to LagosGeoinfo, Lagos lies on a coastal plain with an average elevation of less than 15m above sea level. The land slopes gently from the interior to the sea. Water bodies and wetlands cover over 40 per cent of the total land area of the State with lagoons and creeks consisting 22 per cent of its area. An additional 12 per cent is subject to seasonal flooding.”

The guild pointed out that perennial flooding in Lagos has left many homeless and destroyed lives and property in millions of dollars which is a dent to the ultra-modern city concept of Lagos.

It noted that according to the National Emergency Management Agency data, more than two million people were directly affected by flooding nationwide in 2020.

“Beyond Lagos’ vulnerability to climate change, poor drainage systems and clogged street gutters in large swathes of the city are believed to have escalated its flooding challenges,” the statement added.

It noted that regular bathymetric survey is the study of the depths and shapes of underwater terrain, such as the ocean floor. Hydrographic surveys are deployed for this.

It added, “Hydrographic survey is the science of measurement and description of features which affect maritime navigation, marine construction, dredging and offshore operations. This gives us the predictive advantage through data to determine and accommodate for any potential disaster that might occur through flooding by ensuring our Rivers and lagoons can handle such volumes generated through floods.

“Also, reforestation and afforestation can be effective nature-based solutions for flood risk management. Planting trees and restoring forest cover can help to reduce runoff and soil erosion, regulate water flow, and improve soil structure. Reforestation can also provide other benefits such as carbon sequestration, biodiversity conservation, and livelihood improvement.”

The statement further noted that green infrastructure can be an effective nature-based solution for flood risk management.

It noted, “Green infrastructure includes natural or engineered features such as green roofs, rain gardens, and permeable pavements. These features can help to reduce runoff, increase infiltration, and improve water quality. Green infrastructure can also provide other benefits such as improving urban aesthetics, enhancing biodiversity, and reducing the urban heat island effect.

“Wetland restoration can help to mitigate flood risks in Pakistan. Wetlands act as natural buffers against flooding by absorbing and storing water, reducing peak flows, and filtering pollutants. Restoring degraded wetlands can provide multiple benefits such as improving water quality, enhancing biodiversity, and providing recreational opportunities.

“Establishment of a partnership with the public and private sector that will be focused on erosion and flooding control by the Lagos State Government. This relationship already exists with other parastatals of Lagos as regards building collapse, waste management, etc, therefore, erosion and flooding should not be left out.”