What is a Retention Pond and Why Do Cities Need Them?
Tom PerkinsMay 24, 2018Ponds & Lakes
Retention ponds are becoming increasingly required when it comes to city planning and development. A wet pond, or retention pond, is simply a basin that catches the water runoff from higher elevation surfaces. They are established to help limit flooding during torrential rainfall, and to help remove the pollutants from the surrounding environment. Retention ponds are becoming very important to city development and construction sites because the overflow from a city’s storm drain system needs an appropriate place to go instead of flooding into buildings, parking lots, and houses.
Retention ponds are established where new buildings, roads, and parking lots are being built. The waste and pollutants from rainfall often enter from sewers that are in areas with significant construction (such as cities and towns) and where there are a lot of impermeable surfaces such as buildings, streets, highways, and parking lots that cause a fair amount of runoff. These ponds are designed to handle the fast influx of water from thunderstorms and rain showers. Retention ponds are excellent for removing the trash and pollutants from the runoff.
Because it is a controlled body of water, the retention pond captures the trash and debris, and pollutants have a chance to settle out of the water. Because a wet pond is like a living organism, harmful substances such as petroleum products, fertilizers, sediments, bacteria, and metals can safely be separated from the potable water. The algae, bacteria, and other biological processes in the retention pond can safely consume the pollutants and purify the water to a large degree.
Cities, towns, and other municipalities increasingly need a way to manage the runoff at construction sites and retention ponds perform that job. Because of all the impenetrable surfaces in a city, all the rainfall cannot soak in during thunderstorms. If it doesn’t soak in, it must go somewhere, usually heading toward areas of lower elevation. This affects cities and towns because the more buildings and pavement in an area, the more chances of flooding because the rainwater cannot soak into the ground fast enough. Good city planning can prevent flooding completely by requiring retention ponds.
Containment is the key to a successful retention pond, and companies such as Western Liner can provide a suitable retention pond liner for the pond used by cities or construction sites. Geomembrane pond liners can be used in retention ponds to prevent pollutants and chemicals from seeping into the groundwater, thus helping protect the environment and the drinking water supply. Most pond liners are made from reinforced polyethylene (RPE) and it is becoming more popular for such containment applications because of its high chemical-resistant, tear-resistant, and puncture-resistant properties.
Cities and towns are starting to use retention ponds as they move forward with construction and building, so more and more retention ponds are popping up. As long as they are correctly designed and installed, use a proper liner, and drain accordingly, retention ponds can be a great asset to any city or town.