subject: Learning About The Common Stormwater Best Management Practices [print this page] The first common best management practice is the utilization of dry ponds. Dry ponds store water in a limited period of time after a strong rainfall and it is usually within 48 hours. Water is retained in a temporary manner so that various sediments and pollutants can settle down. When the substances have adequately settled down, the water is then discharged through the outlet that can provide release for prolonged periods.
Implementation of this particular BMP is necessary especially when the stored water is inappropriately visible even 72 hours after a strong rainfall. Another sign that theres a need for maintenance is when insects and odor have increasingly caused problems. The presence of wetland vegetation emerges unless it is designed with marsh or wetland vegetation also prompts maintenance as well as the visibility of damage to the embankment and mechanical components. Animal burrows or tree roots on embankment and low flow orifice also requires maintenance.
Another common BMP involves wet ponds. This form of storing water is designed to accommodate permanent pool of water while having a room for stormwater runoff above the pool of water. The runoff is released in a controlled rate, which is regulated by a similar outlet as in the dry pond. The wet pond is more advantageous than the dry pond with regards to the higher margins of removing pollution and the lower chance of re-suspension of pollutants.
All stormwater best management practices are very much alike regardless of how the water is stored but wet ponds need to be maintained when there are visible signs of accumulation of sediments, blooming of algae, damage, seeps on the dam face, woody vegetation and the presence of beavers on the plunge pool. Regular inspection of the integrity of the wet pond is necessary especially when it is protected with perimeter fencing.
Another form of stormwater BMPs is the infiltration trenches that are actually gravel filled excavation that can temporarily store stormwater runoff so that it can seep through to the underlying soil. This practice is classified into two ways namely dispersed input facility and concentrated input facility. Dispersed input facility directs runoff into sloping grass areas before reaching the facility so that large particles are removed.
On the other hand, concentrated input facility directs runoff water into curb inlets, gutters and pipes. As part of maintenance of stormwater best management practices such as infiltration trenches, it includes observation of standing water 48 hours after the rainfall event. When there is a presence of wetland vegetation, damage, debris on gravel surface and deviation of water runoff, maintenance is hereby required.
