Retention & Detention Pond Management
The requirement for water diversion grows as towns develop. Stormwater runoff clogs municipal sewers and causes erosion in surrounding streams and rivers. Stormwater management at the source can save millions of dollars in costly repairs that would otherwise be used to remedy erosion or prevent floods. The construction of a basin is a popular method of stormwater management. Basins are designed to gather water and release it slowly enough to avoid floods and erosion.
The Difference Between Detention and Retention Ponds
The presence or absence of a permanent pool of water, or pond, is the major distinction between a detention basin and a retention basin. A low flow orifice regulates the water level. The orifice is usually part of a riser, which is a metal or concrete structure. A detention pond, also known as a dry pond, has an orifice level at the bottom of the basin but no permanent pool of water. Between storms, all of the water evaporates, and the area is normally dry. A riser and orifice at a higher point are used to keep a persistent pool of water in a retention basin or pond. A retention pond resembles a conventional pond, yet it serves a crucial function in stormwater runoff control.
The basins are crucial for holding and reducing stormwater runoff from neighboring regions, particularly in locations where asphalt or concrete construction has taken place. Stormwater runoff flows significantly quicker from these surfaces than it does from naturally occurring regions, thus it must be channeled to achieve the appropriate rate of discharge. The amount of water that can be cleaned and treated is restricted. Only flood flows are controlled by dry basins, also known as detention basins. By minimizing pollutants and sediments, a retention pond can help to improve water quality.
Dry Detention Basins
Dry detention ponds are most effective in places with 10 acres or more of land. Water quality is harder to manage on smaller locations, therefore alternative choices may be more suited.
To redirect water, dry detention ponds usually have a very tiny slope. To guarantee the proper quantity of water flow through the system, the intake must be no more than 15% higher than the outflow. The technique works by providing for a huge water gathering area, or basin. The water then gently drains out the bottom of the building into the outlet. Concrete blocks and other structures can be used as a deterrent to impede the flow of water and collect debris.
Wet Retention Basins
Wet retention ponds are a type of stormwater management structure that collects and treats polluted stormwater runoff. Wet retention ponds regulate stormwater quantity and quality by catching and holding stormwater runoff. Pollutants are subsequently removed by the pond's natural processes. To promote bank stability and aesthetic advantages, retention ponds should be surrounded by natural vegetation.
A network of buried pipes connects storm drains to a wet retention pond. The system permits enormous volumes of water to enter the pond, while the outlet releases little amounts of water as needed to keep the water level at the appropriate level.
Standing water is always a source of worry from a health aspect. This is a potential drowning hazard, especially for youngsters. Mosquitoes are attracted to ponds, which may contribute to disease transmission.
The orifice must not get blocked or clogged, which is one of the most critical maintenance tasks for any of these basins. The ponds and basins will work correctly if the pipelines are kept clean of debris. Keeping up with maintenance will save you money in the long run.
Typical routine retention and detention pond maintenance tasks include:
- Check for gullies and other disturbances on the bank a few times a year and after significant storms to identify and fix areas of erosion.
- removing silt and debris - Clearing debris from pipes and removing sediment ensures that they work properly. To avoid difficulties, remove debris from around and in ponds before it reaches the outlets.
- Vegetation care varies depending on the type of vegetation that surrounds the basin. Some grasses require weekly mowing, while others can be mowed just a few times a year.
If you are planning a new project, Smith Creek Fish Farm can help you design the proper sized structure to comply with DEC SPEDES regulations.
We can also handle compliance on an existing structure. Compliance inspections and maintenance would include inspection and cleaning of incoming and outgoing pipes and weirs, sediment depth monitoring for estimating volume, budgeting for a full clean-out situation, and weed and algae management.
We also offer suction dredging and geo-textile bag containment of the sediment. This is often an affordable option compared to complete mechanical dredging.
Fountains can often turn a retention pond into a focal point of the property rather than a cattail choked swamp, and stocking fish will help with mosquito control.
For all your retention and detention pond BMP's in the New York Area, please contact us at Smith Creek Fish Farm here.