Tag Archives: #stormwatereducation

Examples of sustainable storm water management practices in urban areas

By John Cee Onwualu (FNSE, FNICE, FNIWE, P.E., R.ENG)

Sustainable Stormwater Management Practices in Urban Areas

Urbanization and development often result in changes to natural land surfaces, leading to increased impervious surfaces and reduced vegetation.

This alteration leads to higher volumes of rainwater runoff, which can overwhelm urban drainage systems and lead to flooding, erosion, and pollution.

To manage these impacts, sustainable stormwater management practices that mimic natural processes are necessary. Here are three examples of such practices:

Green Roofs

Green roofs are designed to replicate natural ecosystems by adding vegetation to rooftops. They help to regulate stormwater runoff by absorbing and retaining rainwater, thereby reducing the volume and velocity of stormwater runoff that enters the drainage system.

Green roofs also provide other benefits, such as reducing urban heat island effects, improving air quality, and enhancing biodiversity.


Bioretention cells

Bioretention cells are gardens or plant beds that are designed to capture, store and filter stormwater runoff. They use soil, plants, and microbes to slow down and treat runoff before the water enters the drainage system.

Bioretention cells are effective in removing pollutants from stormwater, such as nitrogen, phosphorus, and particulate matter


Permeable Pavement

Permeable pavement is designed to allow stormwater to infiltrate into the soil, mimicking the natural water cycle.

Permeable pavement is made of porous materials that allow rainfall to pass through, thereby reducing the volume and rate of runoff. It helps to prevent flooding and erosion by storing and slowly releasing stormwater back into the environment.


Works Cited

Alshammari, E. et al., 2023. The Impacts of Land Use Changes in Urban Hydrology, Runoff and Flooding: A Review. In: E. Alshammari, et al. eds. Current Urban Studies. Malaysia: Scientific Research Publishing Inc., pp. 120-141.
Bibi & Sambeto, T., 2022. Modeling Urban Stormwater Management in the Town of Dodola based on Land-use and Climate Change using SWMM 5.1. Journal of Hydrology: Regional Studies, Volume 44.
Hale, R. L., 2016. Spatial and Temporal Variations in Local Stormwater Infrastructure Use and Stormwater Management Paradigms over the 20th Century. Urban Drainage and Urban Stormwater Management, 8(7).
Li, L. et al., 2021. The Effect of Urban Land-Use Change on Runoof Water Quality: A Case Study in Hangzhou City, Hangzhou City: Environmental Research and Public Health.
Wu, J. et al., 2013. Using the Storm Water Management Model to predict Urban Headwater Stream Hydrological response to Climate and Land cover change. Hydrology and Earth System Sciences, 17(12), pp. 4743-4758.

Flooding: A Global Warming Aftermath by Engr. John Cee Onwualu

Climate change which is a direct effect of global warming has brought extreme weather changes to our environment, such as sea-level rise, more frequent rainfall with its associated flooding. The effects of these extreme changes have brought more flooding in our Cities, especially Asaba, Warri, Effurun, and Environs since they lie within the Niger Delta region of Southern Nigeria.

Despite these extreme weather changes from global warming, less attention is being given to the management, and control of stormwater by the government. The excess stormwater leads to the loss of agricultural farmlands, contamination of groundwater and rivers, and loss of lives and property of immeasurable values.

Today, due to the global climate change, Asaba, Warri, Effurun, and its environs are experiencing more months and frequent rainfall rather than the old known pattern of six months dry and six months rainy seasons. The effect on these cities and environs has defied the efficacy of existing drainage systems put in place by government and corporate bodies over the years. Hence, there was an urgent need by the government of Delta State to study and construct sustainable drainage systems for the management and control of Stormwater in Asaba, Warri, Effurun, and Environs.

This desire led to the Engineering Study and Design conducted in Asaba, Warri, Effurun, and Environs. Using interviews of locals, participatory meetings, and engineering surveys more in-depth knowledge of the flooding and causes was gathered.

The study looked at how overland drainages can be incorporated into nature-based gifts, such as Valleys, Waterways, and Rivers for the safe evacuation of the excess runoff generated from the environment.

Results obtained showed that improving the efficiency of these Natural Watercourses and Rivers would bring better management and control of the outfalls of both existing and new drainages into these Natural Watercourses. For this to be successful, the inhabitants must be aware of the environmental hazards associated with blocking of Valleys and Waterways with structures and dumping of waste materials into Storm Sewers and Drains, which would create blockages for the efficient evacuation of the Stormwater generated from the Environment.