Why Are Some Buildings Built on Floodplains?

Published Categorized as Construction
Floodplain Construction

It can be concerning to watch new construction begin in a floodplain, especially after seeing other seasons of high rains. That’s counter-intuitive even to the layman. So, why do professionals construct some buildings on floodplains?

Building on a floodplain has certain perks. They are flat and usually inexpensive to buy while being near cities. However, there are long-term drawbacks to building on floodplains, including higher insurance costs and potential damage in the future.

Keep reading for more information about why certain things are built on floodplains.

What Is a Floodplain?

A floodplain is a flat stretch of land adjacent to a river or stream. These areas are prone to flooding and can stretch from the river’s edge to the furthest reaches of a river valley. Some floodplains can be massive, and others can be very small or seasonal.

A floodplain can shift and change as a river evolves. A sandy bank on the edge of the river may eventually be in the center of the river itself, and the river can bend in all new directions. More stable rivers may have had the same floodplain for over a hundred years but could change in a couple of years.

Rivers can also be seasonal and not flow constantly. For example, the Todd River in Australia can be dry for months before the river flows again. This can create dangerous conditions with the risk of flash flooding.

Since floodplains can be so unpredictable, there are a lot of rules about what can and cannot be built on them. FEMA risk levels also rate floodplains and help determine how strict the regulations are.

What Can Be Built on Floodplains?

You can build many things on floodplains, such as agricultural, residential, or business construction. However, there’s also a very long list of what is not permitted to be built on a floodplain, and regulations vary all over the United States.

The things built in a floodplain vary by the local area and how active the river is. Some communities also allow certain buildings despite river activity, so you should also check and research the weather patterns and river behavior.

Most commonly, you can build residential communities or agricultural infrastructure on floodplains. Certain types of business and industrial construction are also permitted. They have to meet different standards for environmental reasons, and some are outright prohibited, such as mining or drilling work.

Every county has different building permits and regulations about building on floodplains. What is permitted by Los Angeles County in California may not be allowed by Baltimore County in Maryland.

If you’re going to build in a floodplain zone, you need to study the benefits and risks before seeking regulatory approval. The pros and cons can dramatically impact the longevity of your build.

Pros and Cons of Floodplain Building

There are many pros and cons to floodplain building, but every construction needs to analyze if the pros outweigh the cons. Homeowners also need to consider how they feel about buying in a floodplain seriously.


There are quite a few pros to building on a floodplain:

  • The land is flat. It’s much easier and less expensive to construct buildings on flat land, which can be a big incentive for construction companies.
  • Floodplains tend to be closer to cities. Many cities worldwide are built on the banks of a river, making them ideal for commuter communities.
  • Floodplain housing can be much cheaper than non-floodplain housing. Homes built in floodplains can be more affordable to buyers because they are less expensive to produce.

Building on floodplains is less expensive for contractors and businesses. The land is flat, which means there is less terraforming you have to do. This lowered cost means that housing communities in floodplains can also be less expensive.

More affordable housing is great, especially if the housing is closer to the cities where people are commuting to. Many floodplain communities also have mass transportation into cities, such as trains.

Floodplain construction can be very beneficial and lucrative, but there are also some serious cons.


While all these pros might sound fantastic, there are some cons to consider seriously:

  • Flooding causes damage. If the river does overflow, there can be catastrophic consequences.
  • Floodplain flooding can be hazardous to human life. This is the exact reason Hurricane Katrina was so deadly; many people who died lived in floodplains, and their homes couldn’t handle the flooding.
  • Insurance can be prohibitively expensive. Over time, and since flooding does occur, insurance companies may not cover the building or damage claims.
  • There are environmental dangers. Construction on floodplains can contaminate local waterways with untold consequences down the road.

All of these reasons mean that you need to think seriously before building on floodplains. Climate change, in particular, has made construction on floodplains an even harder decision to make.

With our changing climate, we see a rise in massive storms and unpredictable weather. One terrible flood could cause enormous property damage and put countless people in danger. The people who live in floodplain communities are also the ones who will be affected the most.

On top of that, floodplain construction can also create a cycle of poverty. Insurance companies are less likely to cover flood damage to homes built in floodplains, and that means homeowners and businesses have to accept the repair costs in full. This can drive these businesses and individuals into massive debt.

Not only that, but construction in floodplains can cause massive environmental issues. Contamination from construction sites and higher traffic next to rivers can poison the water and ruin their ecosystems.

Floodplains are also critical environments for many endangered and local species. These ranges continue to shrink, and floodplain construction makes it difficult for these animals and plants to continue to survive.

Final Thoughts

Floodplains can help expand cityscapes, but they can also come with drawbacks. They can be harmful to the environment or dangerous to human life. It is vital to research the floodplain you are looking to buy in so you can make the best, most educated decision for your future.


By Giovanni Valle

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

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