1. Increased Surface Runoff: Concrete surfaces such as roads, pavements, and buildings in a municipal township area create impervious surfaces. This means that rainwater cannot penetrate the ground and instead forms surface runoff. As a result, the volume of water entering the drainage system increases significantly during rainfall events.

2. Reduced Infiltration: With concrete covering the ground, the natural process of infiltration is hindered. Infiltration refers to the ability of water to seep into the soil. Concrete prevents water from being absorbed, leading to a decrease in groundwater recharge and an increase in runoff.

3. Overloading of Drainage System: The increased surface runoff places a higher demand on the capacity of the drainage system. The existing drainage infrastructure, such as pipes, drains, and culverts, may not be designed to handle such high volumes of water. This can lead to flooding, especially during heavy rainfall or prolonged periods of precipitation.

4. Decreased Natural Drainage Areas: Concrete jungle development often involves filling and leveling of low-lying areas, wetlands, or natural drainage channels. This eliminates natural water storage and flow paths, further exacerbating the drainage problems. The loss of these natural drainage areas reduces the system’s ability to manage water effectively.

5. Limited Absorption and Water Filtration: Concrete surfaces prevent rainwater from being naturally filtered by the soil, leading to poor water quality. The runoff can pick up pollutants such as oil, chemicals, and debris, which then enter the drainage system and may eventually reach nearby water bodies, causing environmental damage.

6. Lack of Green Spaces: Concrete-dominated urban areas often have limited green spaces, such as parks and gardens. These green spaces can act as infiltration areas and temporary water storage during rainfall events. Their absence reduces the natural absorption capacity and further contributes to increased runoff.

7. Need for Infrastructure Upgrades: To mitigate the negative impact on the drainage system, municipal authorities may need to invest in infrastructure upgrades. This can include increasing the capacity of existing drainage systems, constructing additional retention ponds or green spaces, implementing rainwater harvesting techniques, and installing permeable pavements or rain gardens.

By Harsevak, Jia Laroia