Are you reading this asking yourself what the difference is between a retention pond and a detention pond?
Two different kinds of ponds are often used for flood control and storm water runoff treatment: retention ponds and detention ponds. Both systems function to settle suspended sediments and other solids typically present in storm water runoff. Retention ponds are also called wet ponds and they hold back water similar to water behind a dam. They are typically found in neighborhoods and on farm land. The retention pond has a permanent pool of water that fluctuates in response to precipitation and runoff from the contributing areas. Maintaining a pool discourages re suspension and keeps deposited sediments at the bottom of the holding area. Detention ponds- also called dry ponds are more common around commercial land and serve as important flood control features. They are usually dry except during or after rain. Their purpose is to slow down water flow and hold it for a short period of time such as 24 hours. Urban areas rely on these structures to reduce peak runoff rates associated with storms, decreasing flood damage. Detention ponds can be designed for a variety of storm events and purposes. The land area available for construction, slope of the site and contributing area are all factors to be considered. Also, an emergency spillway is usually required to allow for safety during flood events. Although detention ponds can vary in size and shape, they all function to settle storm water particles and reduce peak flows. All of the ponds are designed to be separate from local groundwater supplies to prevent movement of dissolved pollutants from surface water to groundwater sources. Both types of ponds assist with flood management and can improve water quality. Sediment and associated pathogens, nutrients and metals settle out of storm water runoff in the ponds. If pollutants enter streams or lakes during storm events, ponds interrupt the transport process. While both types of ponds provide a water quality benefit, retention ponds allow for additional biological interactions that assist in improving water quality for nutrients. Detention ponds usually hold storm water long enough to settle sand and larger silt particles. Fine silts and clay will not have a chance to settle and will continue down the water course. Retention ponds hold storm water for longer periods of time and allow even the fine sediments to settle to the bottom of the pond. Contact All Tex Service Comany to determine the needs for your next commercial or residential pond.