BMP and Bioswales: Keeping Pollutants from Rivers

Rivers are the most important inland body of water. It serves as the source of life of plants, animals, and even humans. The first civilizations had thrived alongside rivers and getting their food, water, and even transportation from it. They took advantage of the river for their agriculture and sanitation. This is the reason most developed cities today are located near riverbanks.



One of the most important functions of rivers is to transport rainwater or melted snow from elevated regions back to the sea and lakes. This way, water will not flood areas occupied by plants, animals and people. Unfortunately, today, rainwater coming from cities contains pollutants, which eventually pollutes natural rivers and bodies of water.



Water pollution has been a serious problem since places alongside rivers were urbanized. Rainwater falls in large volumes during storms, mixing with chemicals in roads, buildings and factories, and then flowing into a river through storm drains. The rivers carry the pollutants to the river banks, killing the local ecosystem, including people living nearby.



Keeping the rivers free of pollutants is almost impossible because of the huge amount of polluted runoff. The government has begun implementing stormwater management BMP to reduce the level of contamination in rivers. Among the BMPs widely used today are commercial storm water chambers embedded beneath the ground for water storage during storms and biorentention systems for filtering storm water before being released into rivers.



Engineers have designed a new device for BMP called "bioswales". This is a form of BMP system made of landscape elements designed to filter runoff before going to the drains and eventually to the rivers. This is one of the stormwater solutions that are both organic and sustainable. Bioswales remove as much as 50 percent of all pollutants, and in some cases, they can reduce storm water runoff by more than half.



Stormwater solutions such as this can arrest several types of water pollutants including inorganic and organic chemicals, pathogens and silt. Inorganic compounds like lead, chromium and other heavy metals can cause terrible damage to natural ecosystems. These compounds are usually found in fertilizers and pesticides used in agricultural and urban landscaping.