Retention Pond vs. Detention Pond

In Louisiana, we are no stranger to the dangers of excessive rain and flooding. Over the past few years, we have experienced tumultuous storms and many families have lost homes because of it. For this reason, it is important to understand what stormwater basins are as well as how they affect your community. As a builder, we are constantly looking for new areas to build communities in but as communities grow the need for diverting water becomes urgent. Developers do so by adding basins. These basins are meant to collect stormwater and release it at a rate that prevents flooding and erosion. This safety measure is to not only to protect the subdivision you're developing from flooding but also to protect nearby and adjacent existing communities. There are two types of basins, dry detention ponds and wet detention ponds, also known as retention ponds. The biggest difference between the two is that a detention pond will remain dry until a storm occurs, and a retention pond will have a constant pool of water. Both dry detention and wet detention can be planned in a good way to provide an added amenity to your community so that they are not just a protection to flooding. For instance, dry detention can act as a grassed soccer park that kids play in under normal conditions and only during heavy rain events will it hold water. In both cases using a 3 to 1 or 4 to 1 slope will impede erosion on the embankments of both and allow the banks to easily be maintained long term by mechanical mowing.

Detention ponds are best used in areas with plenty of land and usually use a very small slope to divert the water. Water is accumulated in a large collection area and then slowly drains through the outlet. In some cases, concrete blocks are put in place to slow water flow and collect debris. Dry detention basins are great for the surrounding areas because they have a vegetative buffer that can deal with dry or wet conditions. These basins are usually more cost-effective but they also require a large amount of space that could take away property value and attract mosquitoes.

Retention ponds are stormwater control structures that help retain the water and treat contaminated storm runoff. Retention ponds remove pollutants and should be surrounded by natural vegetation to improve stability and essentially improve the overall look of the basin. Water is sent to the pool using an underground network of pipes and released through outlets to maintain the desired water level. The biggest advantages to using a retention pond are that they are simple to put in, the water quality is improved, and new habitats are created. On the other hand, these pools can be a drowning hazard and if not designed properly can have a negative effect on the water quality. Regardless of the basin type, the systems should be maintained and should never become blocked or clogged. Both ponds have their positive and negative attributes but with these helpful hints, you should be a retention/detention pro in no time!

- Written by our Marketing Director, Krista Toussant