It usually takes a pretty hefty threat to get a Louisiana native nervous, but nowadays, all it takes is a few days worth of a steady hard rain in order raise anxiety levels due to flood risk.
While most residents are looking to invest in water pumps, sandbags, and flood insurance, there is a much more effective avenue for helping to reduce flooding: Retention and Detention Ponds!
What are Retention Ponds?
Retention ponds are basins constructed for holding water. Typically this is water that is runoff from higher elevation.
Often they are built near areas of development such as larger buildings or parking lots.
You’ve probably seen retention ponds without knowing what their real purpose is or why developers or contractors placed them there.
You have probably seen them at local places such as the Stine's in Broussard or next to the Academy on Ambassador Caffery. They can also be found near some residential areas and subdivisions (at least ones built after the mid-1980s).
Retention ponds are built to control water runoff and to help limit flooding. So, why are they needed around new large construction areas?
Simple: the larger the square footage, the larger the surface area of runoff. When rain hits the dirt, it can soak into the soil. When it hits a large parking lot, it will usually take the path of least resistance... which isn't slithering through concrete.
Without ample retention ponds, rain water would likely pour into local sewer systems, potentially filling them up and overflowing them.(Sound familiar...?)
Instead of flooding, with a retention pond near by, the water can flow into the lower elevation and spare local residential areas the pain of rising water.
There’s another version called a “detention pond” or “detention basin”. Detention ponds are slightly different in that they simply "detain" water for a short period of time. They can remain dry most of the time and simply hold water overflow during rainy periods. (FYI, sometimes retention ponds are called wet detention ponds, although the difference is sometimes subtle.)
Often times retention and detention ponds are built close to one another. The detention pond will hold the water up first and help prevent flooding. If necessary, water will then slowly drain out into the retention pond where it is held.
These ponds also can assist with pollution removal. When heavy rains hit, and the water becomes stagnant, the heavier solids and metals sink to the bottom. The clean water can drain out into nearby fields, rivers, or marsh.
While detention/retention ponds can clean outgoing water, the water in them isn’t always the safest, especially when they’re in a residential area. They are not recommended for swimming because of the contaminants that fall to the pond floor.
Another avenue, shown below, for decreasing flooding is simply adding in some underground drainage pipe that functions as "retention pipe" to hold water as well when your site doesn't have enough space to dig a retention/detention pond.
You can see small green pipes that let water out after the box is filled with water from the large pipes. This means that the large pipes hold water until as a retention pond would only it's spread out under your parking lot or other location on your site.
All in all, aside from making sure that drainage systems are engineered and built to spec, as well as remain free from trash and sediment, retention and detention ponds are a great avenue for controlling local flood risk.
Keep an open eye the next time you drive around your local mall or shopping center and you’re likely to spot one.
Who Are We?
Chase Group was founded by Chase Landry in Lafayette, Louisiana after growing up and working in the construction industry for fifteen years in South Louisiana. Whether renovating, building new, or developing, Chase Group raises the bar on client experience.
Understanding that business owners want a full service company, we ventured into acquiring a real estate brokers license and started participating in land development to better serve our clients. Our knowledge in the building process helps us identify pieces of land with costly issues so we steer our clients to construction friendly parcels.
Our process is simple:
- We understand your needs
- Show you previous projects and design to spark ideas for your project
- Undertake design for your project
- Form a contract with a full budget
At Chase Group, we offer a range of services. Click on one of the services below to find out more!