Stormwater Management and its importance
The rain that falls on the roof and land and whatever it carries with it qualifies as Stormwater. The rain that falls on the roofs is usually cleaner and referred to as rainwater. Whereas, stormwater is usually rich in soil, organic matter, litter and oil residues and it can pollute downstream waterways. However, if utilised wisely and efficiently, this stormwater can be a valuable resource. Utilising stormwater can save potable water and reduce the load on other potable water sources.
Stormwater can not only be utilised for our day to day purposes but if left untreated it can end up causing pollution downstream in the water body it ends up in, cause erosion, even flooding and various health and environmental issues. A high percentage of water pollution is due to the land pollution that ends up in water due to runoff. Therefore, stormwater treatment is one of the key practices of stormwater management.
The amount and type of pollutants in stormwater are usually affected by the location of the region. Urban setups can usually have high amounts of litter and gross pollutants, whereas in agricultural areas the nutrient levels in stormwater can be very high due to the contact of stormwater runoff with the pesticides and fertilizer laden fields. In industrial areas the stormwater can be rich in heavy metals.
Therefore, utilising best stormwater management practices is very important to reduce the load on potable sources of water as well as reduce the pollution downstream. The easiest way to prevent the litter and coarse pollutants from entering the water bodies is by installing gross pollutant traps (GPTs). GPTs are simple devices with basic designs to prevent litter and gross pollutants from entering the stormwater.
Agricultural areas and industrial areas should utilise the tertiary treatment devices to ensure the removal of nutrients (like phosphorus and nitrogen) and metals (like copper, zinc) respectively from the stormwater. Tertiary treatment devices are utilised for removal of nutrients and heavy metals from stormwater.
Biofilters are one of the most commonly used tertiary filters. They utilise the plants for removal of the nutrients and heavy metals and can be utilised by plants for their growth, thereby making them really good interdependent systems. However, they do require large area for installation and are replaced with complex filters that are designed to remove these heavy metals or nutrients via adsorption or chemical coagulation.
Thus, utilising stormwater wisely and using best management practices can be very vital for our ecosystems. Understanding the importance of stormwater and making the best use of it can help reduce the load on potable water sources and curb the water pollution.