Run-off water from rain contains a lot of debris, sediments, oil and waste. At this stage, the water is unfit for any usage. Through a proper stormwater management system, this water can be cleaned and put to better usage. There’re two basic systems of stormwater management. One is above-ground stormwater management, where the run-off is collected above-ground in open ponds and sewers. The other is under-ground stormwater management where the run-off is collected sub-surface in tanks and chambers.
Even though the above-ground system has its merits, there’re certain limitations that cannot be overlooked. The biggest concern is of maintaining the quality of run-off which could be put to more usage. Let’s see why this is an issue -
The run-off is collected in open ponds/sewers. Water stays in the open ponds for as long as the sediments take time to settle to the bottom of the pond. The debris and other bigger particles float on the top, which are later removed by filtration.
The unclean water remains in open space for months. Open stagnant water becomes a breeding ground for mosquitoes. The mosquitoes, in tun, spread several diseases, some of which are too dreaded like the West Nile Virus. According to Pennsylvania Department of Environmental Protection, stormwater in open catch basins are significant production areas for mosquitoes, typically those that cause the west Nile virus. Such is the intensity of the disease that till now there’re no vaccines to prevent or medicines to cure the disease caused by West Nile Virus.
In that report, it is mentioned that mosquitoes need at least four days of larval development to reach adulthood. This means that storm water retention basins that contain water for more than a week following a rain event can pose a serious health concern by being a perfect ground for growth of these mosquitoes.
Water in open space are also open liabilities. Often it gets difficult to pave a very large periphery. Unfenced waterbody, steep slopes of ponds are accident prone areas. They might lead to drowning accidents if people are not cautious enough while roaming near pond area.
On the other hand, under-ground stormwater system stores water sub-surface after filtering out pollutants and oil from the run-off. An early treatment of water ensures the water remains safe and fit for usage other than drinking. This system has got tanks for storing water that are built below the surface of land while the surface above the ground can be used for commercial purpose like development of athletic grounds, parking area or pavement. Under-ground stormwater management system ensures quality of water by treating water early and then storing those in sub-surface tanks. These tanks are closed containers with lots of open spaces for huge storage.
If you want to learn more about underground stormwater solutions, click here