Flood Protection


In St. John the Baptist Parish flooding can occur during any season of the year. And because so much of the land here is low, your property may be in a Special Flood Hazard Area as determined by the Federal Emergency Management Agency (FEMA).

The principal source of floodwater in St. John the Baptist Parish is rain and Lakes Pontchartrain and Maurepas.

Floodwater collects in a saucer of land prone to subsidence or sinking. The low, flat ground provides little gravity drainage.

The Parish drainage system does a remarkable job. But when the ground is saturated and heavy rain falls quickly, the system can be overwhelmed and flooding can result.

FEMA publishes maps showing flood hazard areas and the degree of risk in those areas. These maps are on file at your local library or the Parish Administrative Offices, 1801 W. Airline Highway in LaPlace. Check with the Parish Planning & Zoning Department (985) 651-5565, to see if your property is in a flood hazard zone.

Did you know that your property may be located in a flood prone area? You're not alone. Over 87% of St. John the Baptist Parish has been designated by the Federal Emergency Management Agency (FEMA) as a special flood hazard area. Special Flood Hazard Areas are designated as Zones "A" and "V". Zone "A" is referred to as the "100 year floodplain" meaning that this is an area that will be flooded on the average of once every 100 years, with a 1% chance of being flooded in any given year. Put another way, there is a 30% chance of your property being flooded over the life of a 30-year mortgage. Flood zone "V" is an area where wave action is likely to occur over and above the flooding. The areas along the shore of Lakes Maurepas and Pontchartrain are designated as "V" zones. Almost all of the rest of the Parish designated as "B" zone, or the area of the 500 year floodplain. In other words, flooding would likely occur once every 500 years. We all know, however, that localized flooding can occur anywhere in the Parish when isolated rainstorms drop large amounts of rain in relatively short periods of time.

Flood Warning

In a flood-prone area like St. John the Baptist Parish, you'll often hear these two terms: Watch and Warning. A Flood Watch means flooding is possible. A Flash Flood Watch means a flash flood, which can happen very fast with little warning, is possible. A Flood Warning means a flood is occurring or will occur soon; the flood may take several hours to develop. A Flash Flood Warning means a flash flood is occurring or will happen very soon; you should find safety immediately.

Watches and warnings will be broadcast on radio and television. Listen to local stations for news, information, and instructions.

One radio station, the National Oceanic and Atmospheric Administration (NOAA) Weather Radio, broadcasts weather information at 162.55 MHz 24 hours a day from National Weather Service Offices in Louisiana. To receive the NOAA broadcasts, you must have a weather radio or conventional AM/FM radio with a weather band.

  • Tune to WWL 870 AM radio.

  • If you have cable TV, bulletins will be broadcast on all cable channels

  • If you do not have cable TV, tune to WWL Channel 4, WDSU Channel 6, WVUE Channel 8, or WGNO Channel 38 to obtain timely civil defense reports or National Weather Service bulletins


Natural / Beneficial Functions

Floodplains are lowland areas adjacent to lakes, wetlands and rivers that are covered by water during a flood. The most easily seen function of a floodplain is its ability to carry and store floodwaters. Undeveloped floodplain also provides many other natural and economic resource benefits. They have high biological diversity and productivity. Floodplain vegetation and soils serve as water filters, intercepting surface water runoff before it reaches nearby lakes. This process aids in the removal of excess nutrients, pollutants and sediments from the water and helps reduce the need for costly clean-ups and sediment removal. The floodplain also serves as a natural reservoir, temporarily holding flood waters and slowly releasing them, reducing the extent and frequency of flooding.

Flood Safety 

Keep alert to rapidly changing weather and to news bulletins.

Learn the safest route from your home or business to higher, safer ground, but stay tuned to reports of changing flood conditions.

If emergency officials tell you to evacuate or leave your home, go immediately to a safe shelter, hotel, or relative's or friend's home. Turn off all utilities at the main switch - BUT ONLY IF TIME PERMITS. Do not touch any electrical equipment unless it is in a dry area. Every source of electricity can be dangerous during and after flooding.

If you are caught in a building by suddenly rising water, move to the second floor or the roof (you may need a tool on hand to break through to the roof. Take drinking water, a flashlight and a portable radio with you. Wait for help.

If your car stalls in a flooded area, abandon it as soon as possible. Floodwater can sweep a car away.

Swimming or playing in or near floodwater is life threatening. Drainage ditches and canals carry fast-moving floodwater and are extremely dangerous. Explain this to your children.

Remember, FLOODS ARE DECEPTIVE. Try to avoid flooded areas, and don't attempt to walk through floodwater that is more than knee deep.

Flood Insurance 

Purchase flood insurance! Most standard homeowner's insurance policies do not cover losses from flooding. Renters can also buy policies to protect their personal property.

You are eligible for flood insurance because St. John the Baptist Parish participates in the National Flood Insurance Program, administered by FEMA. If the FEMA flood maps show that a property is in a Special Flood Hazard Area, which includes all A and V Zones, flood insurance is required by law in order to get federally secured financing to buy, build, or improve structures on that property.

Your insurance agent will help you decide how much coverage you need. For more information, talk to your insurance agent or call FEMA at 1-800-638-6620.

Once you've purchased flood insurance, keep your policy and an itemized list of your furnishings, clothing, and valuables in a safe place, such as a safe deposit box. Remember, or carry in your wallet, the name and address of the agent or broker who wrote your policy. Call your agent or broker immediately if you suffer flood damage.

Property Protection 

There are many things you can do to an existing building to minimize or eliminate the potential for flood damage.

Sandbags, plywood, plastic sheeting, and lumber can be used to protect property temporarily.

(Remember, sandbags should not be stacked directly against the outer walls of a building since wet bags may create added pressure on the foundation).

Permanent floodproofing measures for flood prone structures are preferable to temporary ones. These permanent retrofitting methods include elevating the structure, building floodwalls and closures, and protecting utilities.

A booklet called Flood Proofing Techniques, Programs, and References (1991, 23pp) is free from the US. Corps of Engineers, National Flood Proofing Committee, Attn.: CECW-PF, 20 Massachusetts Avenue, Washington DC 20314-1000. You can also get information on retrofitting from the main parish public library. In addition to retrofitting booklets, the main library has publications on flood insurance, flood protection, and floodplain management.

Permit Requirements

Before proceeding with retrofitting measures, or any construction and development, check with the Parish Planning and Zoning Department at 651-5565 for applicable building codes, permit requirements, and zoning restrictions.

Additionally, if any citizen observes any illegal development in the floodplain, it should be reported immediately to the Community Rating System Coordinator in St. John Parish at 651-5565.

  • Before you do anything - including prepare construction plans, finalize financing, and/or purchase one 2" x 4", call the St. John Parish Inspection Department to find out what regulations apply to you.
  • Explain, precisely, where your property is located and the entirety of your plans for construction. Find out the cost of the permit application fee.
  • Don't hesitate to ask for certain requirements in writing; This protects you and the building official from miscommunication.

  • If you are not sure about a regulation, ask for clarification; and

  • Above all, don't believe for one second that you won't get caught violating the building permit requirement. It may take a while before you are discovered, but, it will happen. Remember - 'tis better to be safe than sorry.

Substantial Improvements / Damage Requirements

Additions, reconstruction or rehabilitation of your property is subject to National Flood Insurance Policy (NFIP) requirements. Check with the Parish Engineer before proceeding.

The NFIP requires that when the cost of reconstruction, rehabilitation, addition or other improvements to a building equals or exceeds 50% of the fair market value, then the building must meet the same construction requirements as a new building. Substantially damaged buildings must also be brought up to the same standards. A residence or building damaged so that the cost of repair equals or exceeds 50% of the structure's fair market value must also be elevated above the Base Flood Elevation (BFE) in flood zones where BFE's exist. Questions about these requirements may be directed to the Planning & Zoning Dept. at 651-5565.

Drainage System Maintenance

To be habitable, our parish needs to have a drainage system. And keeping the system in tiptop shape is important too. The Public Works Department has a regular program of drainage system maintenance. You can help by clearing the catch basins in front of your property. Also, per section 26:150 of the St. John Parish ordinance, dumping debris in catch basins or in drainage ditches and canals is prohibited and is punishable by a fine. Call the Public Works Department at 652-4815 if you have questions about the parish's drainage system.

FEMA Elevation Certificates 

These certificates are required to determine Base Flood Elevation (BFE) when building a structure or mitigation of a structure which has been repetitively flooded or substantially damaged. A licensed surveyor must provide this form. Completed certificates are on file in the Planning & Zoning Dept for structures built after 2000. Copies of these certificates can be obtained by calling the department at 651-5565.

For inquiries about the National Flood Insurance Program write:

Federal Emergency Management Agency
Federal Insurance Administration
500 C. Street, S. W.
Washington, DC 20472